DESIGN AND DEVELOPMENT OF PLC AND SCADA BASED CONTROL PANEL FOR CONTINUOUS MONITORING OF 3-PHASE INDUCTION MOTOR

DESIGN AND DEVELOPMENT OF PLC AND SCADA BASED CONTROL PANEL FOR CONTINUOUS MONITORING OF 3-PHASE INDUCTION MOTOR

  Electrical and Electronics Project by Ravi Devani

ABSTRACT

Three phase squirrel cage induction motors are widely used motors in industry because of its rugged construction and negligible maintenance. To operate this kind of this motor star-delta starters are used .But ,because of its constant speed characteristics, many a times it is driven with the help of variable frequency drives. To have reliable operation its performance must be monitored continuously. The implementation of monitoring and control system for the induction motor based on programmable logic controller technology is described. Also the implementation of a hardware and software for speed control and protection with the result obtained from the test on induction motor performance is provided. Other performance parameters of three phase induction motors can also be monitored by the other control devices. Variable Frequency Drives (VFD) can also used to control the motor rotation direction and rotation speed of the three phase induction motor. All the required control and motor performance data will be taken to a personal computer via PLC for further analysis. Speed control from control side and protection from performance side will be priority.

Index Terms—Computer-controlled systems, computerized monitoring, electric drives, induction motors, programmable logic controllers (PLCs), variable frequency drives, voltage control, SCADA (Citect Software)

INTRODUCTION

Since technology for motion control of electric drives became available, the use of programmable logic controllers (PLCs) with power electronics in electric machines applications has been introduced in the manufacturing automation. AC induction motors (IMs) are used as actuators in many industrial processes. Although IMs are reliable, they are subjected to some undesirable stresses, causing faults resulting in failure. Monitoring of an IM is a fast emerging technology for the detection of initial faults. It avoids unexpected failure of an industrial process. Monitoring techniques can be classified as the conventional and the digital techniques. Classical monitoring techniques for three-phase IMs are generally provided by some combination of mechanical and electrical monitoring equipment. Mechanical forms of motor sensing are also limited in ability to detect electrical faults, such as stator insulation failures. In addition, the mechanical parts of the equipment can cause problems in the course of operation and can reduce the life and efficiency of a system.

In study, a computer based protection system has been introduced. Measurements of the voltages, currents, temperatures, and speed were achieved and transferred to the computer for final protection decision. In this paper, although all the variables of the motor were considered, usage of an analog-to-digital conversion (ADC) card increases the cost and the size of the system. A programmable integrated circuit (PIC) based protection system has been introduced in. The solutions of various faults of the phase currents, the phase voltages, the speed, and the winding temperatures of an IM occurring in operation have been achieved with the help of the microcontroller, but these electrical parameters have not been displayed on a screen.

Nowadays, the most widely used area of programmable logic controller (PLC) is the control circuits of industrial automation systems. In this method, all contactors, timers, relays, and the conversion card are eliminated. Moreover, the voltages, the currents, the speed, and the temperature values of the motor, and the problems occurred in the system, are monitored and warning messages are shown on the computer screen. PLC provides higher accuracy as well as safe and visual environment compared with the classical, the computer, and the PIC-based protection system. This use offers many advantages such as

1) Lower voltage drop when turned on and the ability to control motors and other equipment with a virtually unity power factor.

2) Many factories use PLCs in automation processes to diminish production cost and to increase quality and reliability.

3) Fault or error detection and correction is easy.

4) It has very less amount of component.

5) Maintenance is easy. Other applications include machine tools with improved precision computerized numerical control (CNC) due to the use of PLCs.

To obtain accurate industrial electric drive systems, it is necessary to use PLCs interfaced with power converters, personal computers, and other electric equipment. Disadvantage of this method is that this makes the equipment more sophisticated, complex, and expensive.

Other performance parameters of three phase induction motors can also be monitored by the other control devices. Variable Frequency Drives (VFD) can also use to control the motor rotation direction and rotation speed of the three phase induction motor. Many applications of induction motors require besides the motor control functionality, the handling of several specific analog and digital I/O signals, home signals, trip signals, on/off/reverse commands. In such cases, a control unit involving a PLC must be added to the system structure. In this paper presents a PLC-based monitoring and control system for a three-phase induction motor. It describes the design and implementation of the configured hardware and software. This configuration is interfaced on SCADA through PLC via RS232. Thus, the PLC correlates and controls the operational parameters to the speed set point requested by the user and monitors the induction motor system during normal operation and under trip conditions.

CONTROL SYSTEM OF INDUCTION MOTOR

In Fig. 1, the block diagram of the experimental system is illustrated. The following configurations can be obtained from this setup.

1) A closed-loop control system for constant speed operation, configured with speed feedback and load current feedback. The induction motor drives a variable load, is fed by an inverter, and the PLC controls the inverter V/f output.

2) An open-loop control system for variable speed operation. The induction motor drives a variable load and is fed by an inverter in constant V/f control mode. The PLC is inactivated.

3).The standard variable speed operation. The induction motor drives a variable load and is fed by a constant voltage-constant frequency standard three-phase supply.

The open-loop configuration can be obtained from the closed-loop configuration by removing the speed and load feedback. On the other hand, operation results if the entire control system is bypassed

   Electrical and Electronics Project by Ravi Devani

HARDWARE DESCRIPTION

The control system is implemented and tested for a Squirrel cage induction motor, having the technical specifications given in Table I. The three-phase power supply is connected to a three-phase main switch and then to 3 pole MCB which provides protection against current overloads. Then it is connected to variable frequency drives (VFD) which control speed of motor and we change direction of motor through PLC and this is interface on SCADA. Its technical specifications are summarized in Table II. Due to its versatility and compact dimensions the FR-E 500 EC is a frequency inverter (VFD) solving most effectively your individual drive tasks. Its extensive functions allow flexible applications.

Table I

INDUCTION MOTOR SPECIFICATION

Table II

VARIABLE FREQUENCY DRIVE SPECIFICATION

Fig. 1. Electrical diagram of experiment system

PLC AS SYSTEM CONTROLLER

A PLC is a microprocessor-based control system, designed for automation processes in industrial environments. It uses a programmable memory for the internal storage of user-orientated instructions for implementing specific functions such as arithmetic, counting, logic, sequencing, and timing. A PLC can be programmed to sense, activate, and control industrial equipment and, therefore, incorporates a number of I/O points, which allow electrical signals to be interfaced. Input devices and output devices of the process are connected to the PLC and the control program is entered into the PLC memory.

(fig.2)

Fig. 2. Control action of a PLC

In our application, it controls through analog and digital inputs and outputs the varying load-constant speed operation of an induction motor. Also, the PLC continuously monitors the inputs and activates the outputs according to the control program. This PLC system is of modular type composed of specific hardware building blocks (modules), which plug directly into a proprietary bus: a central processor unit (CPU), a power supply unit, input-output modules I/O, and a program terminal. Such a modular approach has the advantage that the initial configuration can be expanded for other future applications such as multimachine systems or computer linking. PLC configuration is shown in table III

SOFTWARE DESCRIPTION

PLC’s programming is based on the logic demands of input devices and the programs implemented are predominantly logical rather than numerical computational algorithms. Most of the programmed operations work on a straightforward two-state “on or off” basis and these alternate possibilities correspond to “true or false” (logical form) and “1 or 0” (binary form), respectively. Thus, PLCs offer a flexible programmable alternative to electrical circuit relay-based control systems built using analog devices.

The programming method used is to ladder diagram method.

The PLC program uses a cyclic scan in the main program loop such that periodic checks are made to the input variables .The program loop starts by scanning the inputs to the system and storing their states in fixed memory locations (input image memory I). The ladder program is then executed rung-by-rung. Scanning the program and solving the logic of the various ladder rungs determine the output states. The updated output states are stored in fixed memory locations (output image memory Q). The output values held in memory are then used to set and reset the physical outputs of the PLC simultaneously at the end of the program scan. For the given PLC, the time taken to complete one cycle or the scan time is 0, 18 ms/K (for 1000 steps) and with a maximum program capacity of 1000 steps.

TABLE III

PLC configuration

A.PLC Speed Control Mode

In Fig. 4, the flowchart of the speed control software is illustrated.The software

Read inputs Forward / reverse signal Start signal Speed set point signal nsp Speed feedback signal Stop signal Compute speed error signal If error =0 Correct V/f Update inverter Y N regulates the speed and monitors the constant speed control regardless of load variation. The inverter being the power supply for the motor executes this while, at the same time, it is controlled by PLC’s software. The inverter alone cannot keep the speed constant without the control loop with feedback and PLC.

 

Fig. 3. Flowchart of speed control software.

  Electrical and Electronics Project by Ravi Devani

From the SCADA, the operator selects the speed setpoint and the forward/backward direction of rotation. Then, by pressing the start button, the motor begins the rotation.

If the stop button is pushed, then the rotation stops. The corresponding input signals are interfaced to the DI and the output signals to the DO. The AIM receives the speed feedback signal from the tachogenerator, and the signal from the control panel. In this way, the PLC reads the requested speed and the actual speed of the motor. The difference between the requested speed by the operator and the actual speed of the motor gives the error signal. If the error signal is not zero, but positive or negative, then the PLC according to the computations carried out by the CPU decreases or increases the of the inverter and, as a result, the speed of the motor is corrected The implemented control is of proportional and integral (PI) type (i.e., the error signal is multiplied by gain Kp , integrated, and added to the requested speed). As a result, the control signal is sent to the DOM and connected to the digital input of the inverter to control V/f variations. At the beginning, the operator selects the gain Kp by using SCADA programming and the AIM receives its voltage drop as controller gain signal (0–10 V). The requested speed is selected using SCADA programming and the AIM reads this signal. Its value is sent to the AOM and displayed at the control panel (speed set point display). Another display of the control panel shows the actual speed computed from the speed feedback signal.

SCADA

The computer interface program has been written using package SCADA software known as Citect. The communication is achieved according to “SIMPPI” protocol between the PLC and a computer. This protocol is defined as follows.

Configuration: SIMPPI

Port: COMEX

Baud rate: 9600

Stop bit: 1

Data bit: 8

SCADA configuration is given in Table IV

TABLE IV

SCADA configuration

RESULTS

The system is tested during operation with varying loads including tests on induction motor speed control performance. The PLC monitors the motor operation and correlates the parameters according to the software. At the beginning, for reference purposes, the performance of Induction motor supplied from a standard 415 V, 50- Hz network is measured. Then, the experimental control system is operated during load condition in the two different modes.

a) Induction motor fed by the inverter and with PLC control;

b) Induction motor fed by the inverter.

a) Induction motor fed by the inverter

Generator voltage =230 V

Rated current=2.1 A

Speed set point=900 rpm

Fig .4.Experimental speed–%load of motor characteristics with inverter at speed set point 900rpm

b) Induction motor fed by the inverter and PLC

Generator voltage =230 V

Rated current=2.1 A

Speed set point=900 rpm

Fig .5.Experimental speed–%load of motor characteristics with PLC and inverter at speed set point 900rpm

Fig 6.Experimental speed–torque characteristics with PLC and Inverter

RESULT ON SCADA

 Speed set point=900 rpm

 

Fig .7.Experimental result on SCADA

The speed versus torque characteristics were studied in the range 500–1500 r/min and are illustrated in Fig. 6. The results show that configuration b) operates with varying speed-varying load torque characteristics for different speed set points .Configuration a) operates with constant-speed-varying load torque characteristics in the speed range 0–1400 r/min and 0–100% loads. However, in the range of speeds higher than 1400 r/min and loads higher than 70%, the system operates with varying-speed-varying-load and the constant speed was not possible to be kept. Thus, for nsp>=1400 r/min both configurations a) and b) have a similar torque-speed response. This fact shows that PI control for constant speed as implemented by the software with PLC is effective at speeds lower than 93% of the synchronous.

CONCLUSION

The monitoring control system of the induction motor driven by VFD and controlled by PLC proves its high accuracy in speed regulation at constant-speed-variable-load operation. The PLC proved to be a versatile and efficient control tool in industrial electric drives applications. The effectiveness of the PLC-based control software is satisfactory up to 96% of the synchronous speed

Despite the simplicity of the speed control method used, this system presents:

• Constant speed for changes in load,

• Full torque available over a wider speed range;

• Very good accuracy in closed-loop speed control scheme;

• overload protection.

Thus, the PLC proved to be a versatile and efficient control tool in industrial electric drives applications

REFERENCES

[1]Maria G. Ioannides (S’85–M’86–SM’90) graduated from the Electrical Engineering Department of the National Technical University of Athens (NTUA), Athens, Greece. Currently, she is Professor of Electric Drives at NTUA. Her research interests include control of electric machines, renewable energy systems, small and special electric motors, new materials

[2] G. Kaplan, “Technology 1992. Industrial electronics,” IEEE Spectr., vol. 29, pp. 47–48, Jan. 1992.

[3] , “Technology 1993. Industrial electronics,” IEEE Spectr., vol. 30, pp. 58–60, Jan. 1993.

[4] A. R. Al-Ali, M. M. Negm, and M. Kassas, “A PLC based power factor controller for a 3-phase induction motor,” in Proc. Conf. Rec. IEEE Industry  Applications, vol. 2, 2000, pp. 1065–1072.

[5] A. Hossain and S. M. Suyut, “Monitoring and controlling of a real time  industrial process using dynamic model control technology,” in Proc. IEEE Ind. Applicat. Soc. Workshop on Dynamic Modeling Control Applications  for Industry, 1997, pp. 20–25.

  Electrical and Electronics Project by Ravi Devani

GSM BASED AUTOMATED EMBEDDED SYSTEM FOR MONITORING AND CONTROLLING OF SMART GRID

GSM BASED AUTOMATED EMBEDDED SYSTEM FORMONITORING AND CONTROLLING OF SMART GRID

 Electrical and Electronics Project by Ravi Devani

ABSTRACT

The purpose of this paper is to acquire the remote electrical parameters like Voltage, Current, and Frequency from Smart grid and send these real time values over GSM network using GSM Modem/phone along with temperature at power station. This project is also designed to protect the electrical circuitry by operating an Electromagnetic Relay. The Relay can be used to operate a Circuit Breaker to switch off the main electrical supply. User can send commands in the form of SMS messages to read the remote electrical parameters. This system also can automatically send the real time electrical parameters periodically (based on time settings) in the form of SMS. This system also send SMS alerts whenever the Circuit Breaker trips or whenever the Voltage or Current exceeds the predefined limits.

Keywords—GSM Modem, Initialization of ADC module of microcontroller, PIC-C compiler for Embedded C programming, PIC kit 2 programmer for dumping code into Micro controller, Express SCH for Circuit design, Proteus for hardware simulation.

INTRODUCTION

The time complicated interlocking and operation controlling requirements usually noticed in the Smartgrid working, which lead to necessity of automation of the undergoing process. In this respect, Smartgrid automation, which is the creation of a highly reliable, self-healing power system that rapidly responds to real time events with appropriate actions, ensures to maintain uninterrupted power services to the end users.

PROPOSED METHOD

This research paper aims at continuously monitor the load conditions of the Smartgrid. It also monitors the temperature of the devices present in the Smartgrid. If the load increases beyond the Smartgrid’s rated capacity, the microcontroller will automatically shut down the Smartgrid and intimates the same to the operator by sending a message through a GSM modem. A modem provides the communication interface. It transports device protocols transparently over the network through a serial interface. A GSM modem is a wireless modem that works with a GSM wireless network. A wireless modem behaves like a dial-up modem. The main difference between them is that a dial-up modem sends and receives data through a fixed telephone line while a wireless modem sends and receives data through radio waves. If the temperature of the Smartgrid increases, then the microcontroller will automatically starts the cooling system for the Smart grid. At any point, if the operator wants to know the loads conditions and the temperature, he has to send a predefined message to the modem which is interfaced with the microcontroller and the controller acknowledges the operator with the required information.

1. Sensing different electrical parameters (voltage, current, temperature).

2. Forwarding the electrical parameters over GSM network.

3. Producing buzzer alerts (if necessary).

4. Automatic circuit breaking operation.

An embedded system is a combination of software and hardware to perform a dedicated task. Some of the main devices used in embedded products are Microprocessors and Microcontrollers. Microprocessors are commonly referred to as general purpose processors as they simply accept the inputs, process it and give the output. In contrast, a microcontroller not only accepts the data as inputs but also manipulates it, interfaces the data with various devices, controls the data and thus finally gives the result.

The research paper GSM Based Embedded System for Smartgrid Monitoring and Control System using according to the instructions given by the above said microcontroller. Distributed transformers are prone to damages due to the rise in oil temperature when there is an overload or huge current flows through the internal winding of the transformer. When the oil temperature rises, it increases the probability of getting damages in the transformers. The transformers are to be monitored very cautiously during these situations. The proposed system consists of a monitoring unit that is connected with the distribution transformer for the purpose of monitoring the same. Hence, we introduce a simulation model which details the operation of the system to rectify the mentioned problem. The monitoring system is constituted by three major units, namely,

1. Data processing and transmitter unit

2. Load and Measurement Systems

3. Receiver and PC display unit

We have designed a system based on microcontroller that monitors and controls the voltage, current and oil temperature of a distribution transformer present in a Smartgrid. The monitored output will be displayed on a PC at the main station that is at a remote place, through RF communication. The parameters monitored at the distribution transformer are compared with the rated values of the transformer. Additionally the breakdowns caused due to the overload and high voltage are sensed and the signals are transmitted to the main station using RF communication. The software in the PC compares the received values with the rated measurements of the distribution transformer and shuts down the transformer so that it can be prevented from damages and performances can be enhanced quiet to a remarkable level. The controller consists of a sensing unit which collects the essential parameters such as current, voltage and the oil temperature within the distribution transformer. The digital display connected to the processing unit displays corresponding parameter values at the Smartgrid for any technical operations. The controller also senses the overload and high current flow conditions in the internal windings that may lead to breakdown of the corresponding unit. The microcontroller is programmed in such a manner so as to continuously scan the transformer and update the parameters at a particular Time interval. The parameter values sensed by the microcontroller are transmitted through the RF transmitter connected to the microcontroller unit. The transmitted signals are received at the main station using the RF receiver. The received signals are then passed to the PC. The software loaded in the PC is used to monitor the changes in the parameters that are measured from the distribution transformer. When a remarkable change is noticed in the measured values it controls the unit by ending it from any serious damages. The values of voltage, current and temperature of the transformer is directly applied to Port A (one of the input ports of the microcontroller). Along with this, a display is connected in the Port B (another input port of the microcontroller). The RF transmitting section and the load variation control are connected to the Port C (one of the output ports in the microcontroller).

The monitoring PC is connected to the main station. The microcontroller at the Smartgrid monitors and captures the current, voltage and temperature values for a particular period of time interval. The captured values are stored in the data register and displayed using the LCD display. The monitored voltage, current and temperature values of the transformer are transmitted using the RF transmitter for each and every time interval. Any antenna tuned for the selected RF frequency can be utilized for the transmission of the RF signal but the antenna has to exhibit a unidirectional radiation pattern. In the receiver side of the proposed system, the receiver antenna converts the RF signal into electrical signal and acquires the information which has been transmitted by the transmitter. Based on the received information, controlling operation is performed. If the receiver receives the transformer parameters which is greater than the fixed threshold level, then immediately the units is shutdown so as to protect the same. The voltage level is reduced using transformers and power is transferred to customers through electric power distribution systems. Power starts from the transmission grid at distribution Smartgrid where the voltage is stepped-down (typically to less than 10kV) and carried by smaller distribution lines to supply commercial, residential, and industrial users. Novel electric power systems encompassing of power transmission and distribution grids consist of copious number of distributed, autonomously managed, capital-intensive assets.

Electrical and Electronics Project by Ravi Devani

A. Real Time System Design

Real time systems have to respond to external interactions in a predetermined amount of time. Successful completion of an operation depends upon the correct and timely operation of the system. Design the hardware and the software in the system to meet the Real time requirements. Designing real time systems is a challenging task. Most of the challenge comes from the fact that Realtime systems have to interact with real world entities. These interactions can get fairly complex. A typical Realtime system might be interacting with thousands of such entities at the same time. Real time Response, Recovering from Failures, Working with Distributed Architectures, Asynchronous Communication, Race Conditions and Timing

B. Architecture and Working of GSM Networks

A GSM network consists of several functional entities whose functions and interfaces are defined. The GSM network can be divided into following broad parts. The Mobile Station (MS), The Base Station Subsystem (BSS), The Network

Switching Subsystem (NSS), The Operation Support Subsystem (OSS). The added components of the GSM architecture include the functions of the databases and messaging systems: Home Location Register (HLR), Visitor Location Register (VLR), Equipment Identity Register (EIR), Authentication Center (AuC), SMS Serving Center (SMS SC), Gateway MSC (GMSC), Chargeback Center (CBC), Transcoder and Adaptation Unit (TRAU) The MS and the BSS communicate across the Um interface, also known as the air interface or radio link. The BSS communicates with the Network Service Switching center across the A interface. In a GSM network, the following areas are defined:

Cell: Cell is the basic service area: one BTS covers one cell. Each cell is given a Cell Global Identity (CGI), a number that uniquely identifies the cell.

Location Area: A group of cells form a Location Area. This is the area that is paged when a subscriber gets an incoming call. Each Location Area is assigned a Location Area Identity (LAI). Each Location Area is served by one or more BSCs.

MSC/VLR Service Area: The area covered by one MSC is called the MSC/VLR service area.

PLMN: The area covered by one network operator is called PLMN. A PLMN can contain one or more MSCs.

C.Debugging Tolls

Embedded debugging may be performed at different levels, depending on the facilities available. From simplest to most sophisticate they can be roughly grouped into the following areas [1], [2]:

1. Interactive resident debugging, using the simple shell provided by the embedded operating system (e.g. Forth and Basic)

2. External debugging using logging or serial port output to trace operation using either a monitor in flash or using a debug server like the Remedy Debugger which even works for heterogeneous multi core systems.

3. An in-circuit debugger (ICD), a hardware device that connects to the microprocessor via a JTAG or Nexus interface. This allows the operation of the microprocessor to be controlled externally, but is typically restricted to specific debugging capabilities in the processor.

4. An in-circuit emulator replaces the microprocessor with a simulated equivalent, providing full control over all aspects of the microprocessor.

5. A complete emulator provides a simulation of all aspects of the hardware, allowing all of it to be controlled and modified and allowing debugging on a normal PC.

6. Unless restricted to external debugging, the programmer can typically load and run software through the tools, view the code running in the processor, and start or stop its operation. The view of the code may be as assembly code or source-code.

Because an embedded system is often composed of a wide variety of elements, the debugging strategy may vary. For instance, debugging a software (microprocessor) centric embedded system is different from debugging an embedded system where most of the processing is performed by peripherals (DSP, FPGA, and co-processor). An increasing number of embedded systems today use more than one single processor core. Embedded development makes up a small fraction of total programming. There are also a large number of embedded architectures, unlike the PC world where 1 instruction set rules, and the UNIX world. Where there are only 3 or 4 major ones. This means that the tools are more expensive. It also means that they're lowering featured, and less developed. On a major embedded project, at some point you will almost always find a compiler bug of some sort. Debugging tools are another issue. Since you can't always run General programs on your embedded processor, you can't always run a debugger on it. This makes fixing your program difficult. Special hardware such as JTAG ports can overcome this issue in part. However, if you stop on a breakpoint when your system is controlling real world hardware, permanent equipment damage can occur. As a result, people doing embedded programming quickly become masters at using serial IO channels and error message style debugging.

 Electrical and Electronics Project by Ravi Devani

BLOCK DIAGRAM OF THE PROPOSED RESEARCH PAPER

The circuit was designed using electronic workbench software. This software was used to design a sample for the power supply which was incorporated on the receiver system. The receiver sections were designed by this computer aid. In designing the power supply, the software has a menu that contains the various components of the circuit. One has to identify which menu contains the component for the power supplies were selected. The components that were selected are: diodes (1n4001) capacitor (220μF and 10μF) and regulator 7805. A step down transformer of 240/12V AC Was also selected was also selected. These components were laid out and their pins were joined appropriately with lines. These lines are similar to the conductors on the printed circuit board (PCB). The same procedure was followed in the design of the receiver circuit. The receiver was constructed on printed circuit board (PCB) of 30mm x 14mm x 1.5mm dimensions. The PCB was etched in accordance with the receiver circuit shown below with various integrated circuit (IC) pin hole drilled. The microcontroller chip PIC16F877A, circuit breakers and the relays were all inserted on the board to form a complete receiver unit. The implementation of the system involves two steps which are: Setting up the system and inter facing with graphic user interface (i.e. application software). The application software for the system has been developed by using a high lever language C-programming debugger. The debugger contains a high speed simulator and a target debugger that let you simulate an entire PIC16F877A system including on chip peripherals.

The SI unit for magnetic field strength H is A/m. However, if you wish to use units of T, either refers to magnetic flux density B or magnetic field strength symbolized as μ0H. Use the center dot to separate compound units, e.g., “A·m2.”

 

Fig1. Schematic diagram

 

Fig2. Communication system

WORKING PRINCIPLE

The system was tested by connecting a GPRS modem and RS232 cable to the PC. The RS232 cable is connected to microcontroller PIC16F877A is connected to the circuit breaker through a relay. When the circuit is powered by connecting it to 240V AC supply, the incoming AC voltage is rectifier by bridge rectifier. The voltage s than reduce to 5V by a regulator which serves as an input to the microcontroller. The system was tested manually by pressing a knob on the software to activate the circuit breaker. Secondary, the system was tested remotely by sending a sms message to the GPRS or modem through the PC to RS232 cable to the micro controller PIC16F877A and it also worked. Below is the screen shot of the system control panel with circuit breakers turned ON. Thus the automation of electrical power smartgrid is designed and implemented using GSM technology. This brings out the efficient way of power transmission and distribution in electrical Smartgrid though it is carried out using wireless mobile communication the GSM modem and the microcontroller. Cellular phones enable people to communicate over a wide area by using a network of radio antennas and transmitters arranged in small geographical area called cells. By using a rooming facility provided by cellular phone providers, communication could be effective wherever you are on a globe. Technology can explore more benefit on the utilization of cellular phones. The GPRS was able to read the data sent by cell phone at a frequency of 900MH. The GPRS uses packet switching method to transfer data. This means that data is sent over the time, which has less traffic. The microcontroller PIC16F877A is a low power, high performance CMOS 8-bit computer. It provides high-flexible and cost effective solution to the control application. The above schematic diagram GSM based Embedded system for Smatrgrid monitoring and control system explains the interfacing section of each component with micro controller and GSM module. 

The crystal oscillator connected to 13^th and 14^th pins of micro controller and regulated power supply is also connected to microcontroller and LED’s also connected to microcontroller through resistors and motor driver connected to microcontroller. 

 

Fig. 3 Screen shot of control Panel with circuit breakers turned ON

SCOPE OF THE RESEARCH

Our research paper “GSM Based Embedded System for Smartgrid Monitoring and Control System” is mainly intended to operate the devices like fans, lights, motors etc.., through a GSM based mobile phone. The system has a GSM modem, temperature, current, voltage sensors and the devices to be operated through the switches like Relay which are interfaced to the microcontroller. The micro controller is programmed in such a way that if a particular fixed format of SMS is sent to GSM modem from mobile phone, which is fed as input to the microcontroller which operates the appropriate devices. A return feedback message will be sent to the mobile from GSM modem. The temperature at the place where devices are being operated can be known. In future we can use this research paper in several applications by adding additional components to this research paper. This research paper can be extended by using GPRS technology, which helps in sending the monitored and controlled data to any place in the world. The temperature controlling systems like coolant can also use in places where temperature level should be maintained. By connecting wireless camera in industries, factories etc. we can see the entire equipment from our personal computer only by using GPRS and GPS technology. The monitoring and controlling of the devices can be done from the personal computer and we can use to handle so many situations. By connecting temperature Sensor, we can get the temperature of dangerous zones in industries and we can use personal Computer itself instead of sending human to there and facing problems at the field. The temperature sensor will detect the temperature and it gives information to the micro controller and micro controller gives the information to the mobile phone from that we can get the data at pc side.

RESULT

The research paper designed such that the devices can be monitored and also controlled from anywhere in the world using GSM modem connected to mobile phone. The proposed system which has been designed to monitor the transformers essential parameters continuously monitors the parameters throughout its operation. If the microcontroller recognizes any increase in the level of voltage, current or temperature values the unit has been made shutdown in order to prevent it from further damages. The system not only controls the distribution transformer in the Smartgrid by shutting it down, but also displays the values throughout the process for user’s reference. This claims that the proposed design of the system makes the distribution transformer more robust against some key power quality issues which makes the voltage, current or temperature to peak. Hence the distribution is made more secure, reliable and efficient by means of the proposed system.

REFERENCES

[1] www.silicontechnolabs.in

[2] Embedded Automobile Engine Locking System, Using GSM Technology, Jayanta Kumar Pany1 & R. N.Das Choudhury2 International Journal of Instrumentation, Control and Automation (IJICA) ISSN : 2231-1890 Volume-1, Issue-2, 2011.

[3] PIC Microcontroller Manual, Microchip Technology Inc. (2003), Page no 3-41-49.

[4] PIC Microcontroller and Embedded Systems, Mazidi, Muhammad Ali; Mckinaly, Rolin D; Causey, Page no 99-112.

[5] www.allaboutcircuits.com.

[6] Microcontrollers Architecture, Programming, Interfacing and System Design, Raj kamal, (2011), Page no 34-52[10] PCB Designe Tutorial. Page no 17-25, David.L.Jones (2004)

[7] GSM based Automated Embedded System for Monitoring and Controlling of Substation, Amit Sachan, M.Tech. Thesis, Page no 7-9 June 2012.

Electrical and Electronics Project by Ravi Devani

DRIVE-BY-WIRELESS FOR VEHICLE CONTROL AND MONITOR USING WIRELESS CONTROLLER AREA NETWORK (WCAN)

DRIVE-BY-WIRELESS FOR VEHICLE CONTROL ANDMONITOR USING WIRELESS CONTROLLER AREA NETWORK(WCAN)

 Electrical and Electronics Project by Ravi Devani

ABSTRACT

Wired systems are complex, heavy, less secure and expensive. Hence, in today’s 21st century wireless technology has been gradually adopted by automobile manufacturers. A vehicle has various control units which were connected using traditional point-to-point wiring architecture in olden days. These were replaced by a CAN bus later. This paper uses Wireless CAN (WCAN) to interconnect various control units. This has several important advantages such as system flexibility, message routing, filtering, multicast, together with data consistency. This paper proposes a drive-by wireless technique for vehicle control and monitor functions using Wireless Controller Area Network. Traditional hydraulic or mechanical methods of steering, braking and accelerating of a vehicle will be replaced by Drive by Wireless Technique. Also, traditional vehicle monitoring methods are done in a wireless manner. The algorithm includes Unique Identification Codes which is sent with all the transactions involving wireless communication packets to reduce interference from adjacent drive-by-wireless system.

Keywords- Drive-by-wireless; WCAN; Vehicle Control and Monitor; Unique Identification Codes

INTRODUCTION

Drive-by-wireless techniques replace the mechanical and hydraulic connections between the driver and the associated vehicle actuators with electronic communication systems. These systems transmit electronic messages to direct a vehicle component based on the action taken by the driver of the vehicle, e.g., turning a steering wheel, pressing a brake pedal, or pressing an accelerator pedal. In the past the vehicle bus communication used point to point communication wiring systems which causes complexity, bulkiness, is expensive with increasing electronics and controller deployed vehicles. The abundance of wiring required makes the whole circuit complicated. CAN solve this complexity by using twisted pair cables that is shared throughout the control. Not only does it reduce the wiring complexity but it also made it possible to interconnect several devices using only single pair of wires and allowing them to have simultaneous data exchange. WCAN has several important advantages such as system flexibility, message routing, filtering, multicast, together with data consistency [2].The new WCAN is proposed to exploit the advantages of CAN and still providing wireless access. The rest of the paper is organized as follows; section II outlines the related work and Drive-by wireless technique, section III describes the block diagram of the system, section IV briefs on the components used, section V presents the circuit diagram of the system, section VI discusses algorithm, section VII presents the hardware output and section VIII briefs the conclusion.

RELATED WORK AND DRIVE-BY-WIRELESS TECHNIQUE

Stähle et. Al investigated the so-called drive-bywireless, i.e., using a wireless network to control steering, braking, accelerating and other functions within an automobile. Mary et.al showed that WCAN is suited for real time control applications giving maximum throughput for minimal latency for an optimized number of nodes. Iturri et. Al showed that ZigBee is a viable technology for successfully deploying intra-car wireless sensor networks. Lin et. Al proposed an Intra-car Wireless Sensor Network (WSN) to eliminate the amount of wiring harness and simplify the wiring structure. Lin et. Al evaluated the performance of intra-vehicular wireless sensor networks (IVWSNs) under interference from WiFi and Bluetooth devices. Torbitt et. Al analyzed the surface wave hypothesis at different frequencies in intra-vehicular environments. Ahmed et. Al investigated the issues around replacing the current wired data links between electrical control units (ECU) and sensors/switches in a vehicle, with wireless links. Lin et. Al proposed a new wireless technology known as Bluetooth Low Energy (BLE) and outlined a new architecture for IVWSN. This paper proposes Drive-bywireless technique using WCAN.

 Electrical and Electronics Project by Ravi Devani

A. Drive-by-wire System

Drive-by-wire technology in the automotive industry is the use of electrical or electro-mechanical systems for performing vehicle functions traditionally achieved by mechanical linkages. This technology replaces the traditional mechanical control systems with electronic control systems using electromechanical actuators and human-machine interfaces such as pedal and steering feel emulators. The Drive-by-wire system used point to point communication wiring systems as shown in Figure 1. This causes complexity, heaviness and is expensive.

Figure1. Existing System

B. Drive-by-wireless System

The Drive-by-wireless system ensures less weight, safety and comfort. The position of the sensor, motor and the wheel for the proposed Drive-by-wireless system is shown in Figure 2.

 

Figure2. Drive-by-wireless System

BLOCK DIAGRAM OF THE PROPOSED SYSTEM

The block diagram of the system is presented in Figure 3. The system has four microcontroller units and ZigBee over 802.15.4 protocol is used for wireless communication.

 

Figure3. Block Diagram

The Steering, Brake, Accelerator sensors are associated with the Engine Control Unit. The Dashboard unit contains the LCD, the D.C. Motor unit contains a D.C. motor with a motor drive and a temperature sensor. Finally, the Servo Motor Unit contains a Servo Motor and a level sensor.

COMPONENTS DESCRIPTION

PIC18F45K22 is the microcontroller used in the project. Circular potentiometers are used for Brake- Acceleration and Steering. Servo Motor and a level sensor is used for the Servo Motor Unit and DC Motor unit contains a D.C. motor with a motor drive and a temperature sensor. LCD Display is used for displaying the engine temperature and fuel levels.

A. PIC18F45K22

PIC18(L)F45K22 has 32k program memory, 1536 bytes of SRAM and 256bytes of EEPROM. It has three 8-bit timers and four 16-bit timers.All of the devices in the PIC18(L)F2X/4XK22 family offer ten different oscillator options, allowing users a wide range of choices in developing application hardware. These include:

• Four Crystal modes, using crystals or ceramic resonators

• Two External Clock modes, offering the option of using two pins (oscillator input and a divide-by-4 clock output) or one pin (oscillator input, with the second pin reassigned as general I/O)

• Two External RC Oscillator modes with the same pin options as the External Clock modes

• An internal oscillator block which contains a 16 MHz HFINTOSC oscillator and a 31 kHz LFINTOSC oscillator, which together provide eight user selectable clock frequencies, from 31 kHz to 16 MHz. This option frees the two oscillator pins for use as additional general purpose I/O.

• A Phase Lock Loop (PLL) frequency multiplier, available to both external and internal oscillator modes, which allows clock speeds of up to 64 MHz. Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 64 MHz – all without using an external crystal or clock circuit.

 

Figure4. PIC18F45K22 Microcontroller

B. Potentiometers

A potentiometer is a three terminal resistor with a sliding contact forms an adjustable voltage divider and only two terminals are used one end and the wiper acts as a variable resistor or rheostat. Electric potential is measured by potentiometer device.

C. LCD Display

The HD44780U dot-matrix liquid crystal display controller and driver LSI displays alphanumerics, Japanese kana characters, and symbols. It can be configured to drive a dot-matrix liquid crystal display under the control of a 4- or 8-bit microprocessor. Since all the functions such as display RAM, character generator, and liquid crystal driver, required for driving a dot-matrix liquid crystal display are internally provided on one chip, a minimal system can be interfaced with this controller/driver. A single HD44780U can display up to one 8-character line or two 8-character lines. The HD44780U has pin function compatibility with the HD44780S which allows the user to easily replace an LCD-II with an HD44780U. The HD44780U character generator ROM is extended to generate 208 5x8 dot character fonts and 32 5 x10 dot character fonts for a total of 240 different character fonts. The low power supply (2.7V to 5.5V) of the HD44780U is suitable for any portable battery-driven product requiring low power dissipation.

D. DC Motor

A DC motor has a two wire connection. All drive power is supplied over these wires. Most DC motors are pretty fast of about 5000 rpm. The DC motor speed is controlled by a technique called pulse width modulation or PWM.

 

Figure5. D.C. Motor

Electrical and Electronics Project by Ravi Devani

E. Servo Motor

The function of the servo is to receive a control signal that represents a desired output position of the servo shaft, and apply power to its DC motor until the shaft turns to that position. It uses position sensing device to rotate the shaft. The shaft can turn a maximum of 200 degree so back and forth.

 

Figure6. Servo Motor

F. Pressure Sensor

The MPX5010/MPXV5010G series piezoresistive transducers are state-of the-art monolithic silicon pressure sensors designed for a wide range of applications, but particularly those employing a microcontroller or microprocessor with A/D inputs. This transducer combines advanced micromachining techniques, thin-film metallization, and bipolar processing to provide an accurate, high level analog output signal that is proportional to the applied pressure.

It’s features are 5.0% Maximum Error over 0° to 85°C. Ideally Suited for Microprocessor or Microcontroller- Based Systems. Durable Epoxy Unibody and Thermoplastic (PPS) Surface Mount Package. Temperature Compensated over .40° to +125°C

 

Figure 7. Pressure Sensor

G. Temperature Sensor

The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level. The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies. As it draws only 60 μA from its supply, it has very low self-heating, less than 0.1°C in still air. The LM35 is rated to operate over a −55° to +150°C temperature range, while the LM35C is rated for a −40° to +110°C range (−10° with improved accuracy). The LM35 series is available packaged in hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface mount small outline package and a plastic TO-220 package.

H. CAN MCP2515

It is a Stand-Alone CAN Controller with SPI Interface, 18 pin I.C.

• Implements CAN V2.0B at 1 Mb/s: 0 – 8 byte length in the data field, Standard and extended data and remote frames

• Receive Buffers, Masks and Filters: Two receive buffers with prioritized message Storage, Six 29-bit filters and Two 29-bit masks

• Data Byte Filtering on the First Two Data Bytes (applies to standard data frames)

• Three Transmit Buffers with Prioritization and Abort Features

• High-Speed SPI Interface (10 MHz): SPI modes 0,0 and 1,1

• One-Shot mode Ensures Message Transmission is Attempted Only One Time

• Clock Out Pin with Programmable Prescaler: Can be used as a clock source for other device(s)

• Start-of-Frame Signal is Available for Monitoring the SOF Signal: Can be used for time-slot-based protocols and/or bus diagnostics to detect early bus degradation

CIRCUIT DIAGRAM

The system comprises of four control units which communicate with each other using Zigbee over 802.15.4 protocol. The four modules are Engine Control Unit, D.C. Motor Unit, Servo Motor Unit and the Dashboard Unit. The input 220V A.C. power supply is converted to 12V D.C. by an adapter. Various units in the modules require only 5V D.C and 3.3 V D.C. power supply. Hence a regulator is used for this purpose. The PIC18F45K22 microcontroller is a 40 pin I.C. There are 5 ports. Port A, B, C and D have 8 pins each while Port E has 3 pins. The remaining 5 pins are used for MCLR, VDD and Ground. The ICSP (In Circuit Serial Programmer) is a 5 pin device which is used by PitKit 3 to dump the program from the computer to the microcontroller. Pin 1 of the ICSP is connected to a high voltage to erase any previous programs, Pin 2 is the clock, Pin 3 is the data, Pin 4 is connected to Ground while Pin 5 is connected to VDD. The Dashboard Module circuit diagram is shown in Figure 8. It consists of a 16x2 LCD display.

 

Figure8. The Dashboard Module

SP1 and SP2 of the PIC18F45K22 are pins A5, C3, C4, C5 and A6, C3, C4, C5 respectively. A5 and A6 are the Enable Pin, C3 is the clock, C4 is the Data Input and C5 is the Data Output. UART1 and UART2 are pins 25, 26 and 29, 30 respectively. 25 and 29 are for transmission while 26 and 30 are for reception. In CAN, CANL is for transmission and CANH is for reception. In Zigbee Pin 2 is for transmission and Pin 3 is for reception. As shown in Figure 9, Pin 1 of Port C is used for the motor drive circuit while Pin 1 of Port A is used for the pressure sensor.

Figure9. The D.C. Motor Module

As shown in Figure 10, Pin 1 of Port C is connected to the servo motor while Pin 1 of Port A is connected to the temperature sensor.

 

Figure10. The Servo Motor Module

In Figure 11, the first three pins of Port A are connected to the Accelerator Sensor, Brake Sensor and Steering Sensor respectively.

 

Figure11. The Engine Control Module

Electrical and Electronics Project by Ravi Devani

ALGORITHM

Some of the pseudo-codes for various control units are shown below. MPLAB IDE is the development platform used for coding.

tostring(adcvalue1, dispstring);

cantx('A');

cantx(dispstring[0]);

cantx(dispstring[1]);

cantx(dispstring[2]);

cantx(dispstring[3]);

cantx(dispstring[4]);

In the above pseudo-code, the data obtained by various sensor units in the Engine Control Unit are converted into string and transmitted using CAN. Before transmission identification characteristics like ‘A’, ‘B’, etc are also transmitted.

if(adcvalue1 > adcvalue2)

{ accelerator = adcvalue1 - adcvalue2;

}

else

{

accelerator = 0

}

The above conditions are followed in the D.C. motor unit.

adcvalue1 = map(adcvalue1 , 0, 1023, 1, 150);

temp = adcvalue1;

angle1_act = temp;

angle11 = angle1_act/10;

datareceivedbit = 0;

The above condition is followed in the Servo motor unit. The ADC values obtained by the engine control module steering sensor is mapped as 1 for 0 and 150 for 1023 and the servo motor is driven.

HARDWARE OUTPUT

The Servo Motor Module is shown in Figure 12. It consists of a Servo Motor and a Level Sensor.

 

Figure12. The Servo Motor Module

The Engine Control Module is shown in Figure 13. It consists of three sensors namely the accelerator sensor, the brake sensor and the steering sensor.

 

Figure13. The Engine Control Module

The Dashboard Module is shown in Figure 14. It consists of a 16x2 LCD display.

 

Figure14. The Dashboard Module

The D.C. Motor Module is shown in Figure 15. It consists of a D.C. Motor and a Temperature Sensor.

 

Figure15. The D.C. Motor Module

CONCLUSION

With the above experiments, that the concept of driveby- wireless is feasible. Error detection is also made easier using this technique. Safety of the automobile system is also guaranteed. Complexity, bulkiness and heaviness of the system is reduced. The system is also made less expensive.

REFERENCES

[1] Hauke St¨ahle, Kai Huang, Alois Knoll, “Drive-by-Wireless with the eCar Demonstrator”, Proceedings of the 4th ACM SIGBED International Workshop on Design, Modeling, and Evaluation of Cyber-Physical Systems. ACM, pp. 1-4, 2014.

[2] Mary, Gerardine Immaculate, Zachariah C. Alex, and Lawrence Jenkins., "REAL TIME ANALYSIS OF WIRELESS CONTROLLER AREA NETWORK.", ICTACT JOURNAL ON COMMUNICATION TECHNOLOGY, Volume.05, Issue. 03, pp.951-958, September 2014.

[3] J.-R. Lin, T. Talty, and O. Tonguz, “Feasibility of safety applications based on intra-car wireless sensor networks: A case study”, in Vehicular Technology Conference (VTC Fall), 2011 IEEE, pp. 1–5, 2011.

[4] C. Buckl, A. Camek, G. Kainz, C. Simon, L. Mercep, H. Staehle, and A. Knoll, “The software car: Building ict architectures for future electric vehicles”, in Electric Vehicle Conference (IEVC), 2012 IEEE International, pp. 1–8, March 2012.

[5] M. Eder and A. Knoll, “Design of an experimental platform for an x-by-wire car with four-wheel steering”, in Automation Science and Engineering (CASE), 2010 IEEE Conference on, pp. 656–661, 2010.

[6] Lin, Jiun-Ren, Timothy Talty, and Ozan K. Tonguz, "An empirical performance study of Intra-vehicular Wireless Sensor Networks under WiFi and Bluetooth interference", In Global Communications Conference (GLOBECOM), 2013 IEEE, pp. 581- 586, 2013.

[7] Torbitt, C., Tomsic, K., Venkataraman, J., Tsouri, G. R.,Laifenfeld, M., & Dziatczak, M.,“Investigation of waveguide effects in intra-vehicular environments”, In Antennas and Propagation Society International Symposium (APSURSI), pp. 599-600, July,2014.

[8] Ahmed, Mohiuddin, Cem U. Saraydar, Tamer ElBatt, Jijun Yin, Timothy Talty, and Michael Ames, "Intra-vehicular wireless networks", In Globecom Workshops, 2007 IEEE, pp. 1-9, 2007.

[9] Lin, Jiun-Ren, Timothy Talty, and Ozan K. Tonguz. "On the potential of bluetooth low energy technology for vehicular applications." Communications Magazine, IEEE , Vol.53, Issue. 1, pp. 267-275, 2015.

[10] Iturri, Peio Lopez, Erik Aguirre, Leire Azpilicueta, Uxue Garate, and Francisco Falcone, "ZigBee Radio Channel Analysis in a Complex Vehicular Environment [Wireless Corner]", Antennas and Propagation Magazine, IEEE, Vol.56, no. 4, pp.232-245, 2014.

[11] Deng, Han, Jia Li, Liuqing Yang, and Timothy Talty, "Intravehicle UWB MIMO channel capacity", In Wireless Communications and Networking Conference Workshops (WCNCW), 2012 IEEE, pp. 393-397, 2012.

[12] Lu, Ning, Nan Cheng, Ning Zhang, X. S. Shen, and Jon W. Mark, "Connected Vehicles: Solutions and Challenges", pp. 1-1, 2014.

[13] Firmansyah, Eka, and Lafiona Grezelda, "RSSI based analysis of Bluetooth implementation for intra-car sensor monitoring", In Information Technology and Electrical Engineering (ICITEE), 2014 6th International Conference on, pp. 1-5, 2014.

[14] Salahuddin, Mohammad A., Ala Al-Fuqaha, and Mohsen Guizan, "Software Defined Networking for RSU Clouds in support of The Internet of Vehicles", 2012.

[15] Gerla, Mario, Eun-Kyu Lee, Giovanni Pau, and Uichin Lee, "Internet of vehicles: From intelligent grid to autonomous cars and vehicular clouds", InInternet of Things (WF-IoT), 2014 IEEE World Forum on, pp. 241-246. IEEE, 2014.

Electrical and Electronics Project by Ravi Devani