PLC based load managment
- 1. PLC Based Load Management Guidance By: Dinesh Saini Asst. Professor, Electrical Department, BKBIET Presented By: Manish Kumar 11EBKEX028 Divya Saini 11EBKEX016 Aishwarya 11EBKEX002
- 2. Content Introduction about Load management Block diagram of Load Management About PLC Programming in PLC(Ladder logic) Advantage and short-comings
- 3. What is Load Management ? Load Management is the "proper management of load“ which means balancing the electrical power supply with the variations in the load and its behavior. As we all know that there are generation stations connected in parallel to each other to ensure continuous supply of power to the load. In the LOAD Management, there are contactors and the closing / opening of these Contactors maintain the Load management.
- 4. How to do Load Management ? Since electric power can not be stored and used later , so Electricity is produced, distributed and consumed by the Load simultaneously and this is the place where Load Management comes into Action. Also as the Load demand is not fixed so we have to design the system keeping in mind the Maximum Load Condition. As for example when the Induction Hardening Machine is started then there is a sudden increase in the load by 400 - 600 % , so we have to keep in mind all these behavior of loads. There are many ways for Load Management but here we will focus on PLC based Load Management.
- 5. PLC Programming for Load Management ? To do Load Management using DG Sets, we will need an overcurrent relay that will tell us all the data regarding current and it will help us to determine the load value. The overcurrent relay output will be connected with PLC input MODBUS. We have made this PLC program for Load Management and using ALLEN BRADLEY PLC. There are two sections in PLC program , one is for reading data from overcurrent Relay and other is for PLC logic. PLC logic will provide required output to ensure regular load management by connecting with busbars through contactors.
- 6. Block diagram of load management
- 7. What is PLC ? A Programmable Logic Controller (PLC) is an industrial computer that accepts inputs from switches and sensors, evaluates these in accordance with a stored program, and generates outputs to control machines and processes. PB1 LS1 INPUTS M1 M2R LOGIC OUTPUTS M1 SOL Block Diagram of a Control System
- 8. Major Components of a Common PLC PROCESSOR POWER SUPPLY I M N O P D U U T L E O M U O T D P U U L T E PROGRAMMING DEVICE From SENSORS Pushbuttons, contacts, limit switches, etc. To OUTPUT Solenoids, contactors, alarms etc.
- 9. Major Components of a Common PLC POWER SUPPLY Provides the voltage needed to run the primary PLC components I/O MODULES Provides signal conversion and isolation between the internal logic-level signals inside the PLC and the field’s high level signal. PROCESSOR Provides intelligence to command and govern the activities of the entire PLC systems. PROGRAMMING DEVICE used to enter the desired program that will determine the sequence of operation and control of process equipment or driven machine.
- 10. What' happens in an operating cycle Based on the data in the output image file the PLC energises or de-energises it’s output circuits,controlling external devices. 1.Input Scan 2. Program Scan 3. Output Scan START - - - - PLC OPERATING CYCLE TYPICALLY 1 to 25 ms. During the input scan PLC examines the external input devices -On or Off. The status of the inputs is temporarily stored in an input image memory file. The PLC scans the instructions in the ladder logic program,uses the input status from the input image file & determines if an output will be energised.The resulting status of the outputs is written to the output image memory file.
- 11. Inputs and outputs of PLC INPUTS Pushbuttons Selector Switches Limit Switches Level/Pressure/Temperature Sensors Photoelectric Sensors Motor Starter Contacts Relay Contacts Transducers/Transmitters Encoder OUTPUTS Relay Motor Starters Solenoids Valves Control Relays Alarms Lights Fans
- 12. Programming in PLC Ladder Logic Structured Text Sequential functional chart Functional Block Diagram Instruction List
- 13. Programming in PLC Ladder Logic Structured Text Sequential functional chart Functional Block Diagram Instruction List
- 14. Ladder logic Ladder Logic is a graphical system of symbols and terms. Those who are not familiar with relay wiring. Diagram, can easily learn it. In ladder logic, we have to translate all of the items we're using into symbols the PLC understands
- 15. Advantages Simple wiring Flexibility in programming and reprogramming in the Plant. Low space Wider functions like high speed counters, etc. Faster Scan Time. Simpler installation. Economic in cost. Minimum maintenance. Ability to communicate with HMI/MMI Programmable troubleshooting aids which reduce downtime
- 16. Short-comings Difficulty with changes or replacements. Difficult to find error hence require skillful workforce. When problem occurs, hold up time is indefinite.
- 17. References http://en.wikipedia.org/wiki/Load_management http://ab.rockwellautomation.com/Programmable-Controllers/MicroLogix-1100 https://www.energyvortex.com/files/PLCCaseStudy.pdf http://www.plcedge.com/plc-architecture.html Automating Manufacturing Systems with PLC by Hugh Jack. http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Ladder_logic.html
- 18. Thank You