Single Phase Multiple Load Control
Single-Phase Multiple Load Control system is designed for labs which will monitors voltage, current and frequency and detects harmonics for different test tables. It has upper and lower thresholds and uses relays, which gives this system upper hand over circuit breakers and fuses wh
2025-06-28 16:35:02 - Adil Khan
Single Phase Multiple Load Control
Project Area of Specialization Electrical/Electronic EngineeringProject SummarySingle-Phase Multiple Load Control system is designed for labs which will monitors voltage, current and frequency and detects harmonics for different test tables. It has upper and lower thresholds and uses relays, which gives this system upper hand over circuit breakers and fuses which only have over current protection. This system uses fast processing of pic microcontroller to monitor the electrical parameters and uses solid state relays to trip load which kept pace with processing speed. Within 30ms, a test table could be trip over any kind of electrical parameter issue. The other tables will continue to get their supply. That faulty table is to be monitored and recloses to its normal position. If faults remain, the LCD will show error for that particular test table. There is a keypad that will provide flexibility in changing the thresholds in real time, if equipment gets changed. Every single table could have its own thresholds which provide more flexibility. The data catalog could be saved in computer for record. Auto-reclose of relays will eliminate the manual ON/OFFs of CBs. Whole system’s blackout will be prevented by separate relays for each channel which is not effectively handled by CBs. This whole project is very cost effective compared to the features it provides for an expensive system to ensure its protection.
In a broader concept, due to vast operability of current sensors and relays, this system could be deployed from industries to commercial and domestic and military sectors. This system could be updated to 3-phase supply system which could target big industries. It is capable to use Solid State Contactors for Industries, Solid state relays for commercial sector and TRIACs for domestic loads. This system could also be used by WAPDA to monitor every house’s load. The flexibility provided by keypad/SSR and current sensors could help make necessary changes in future.
Project ObjectivesTo design a system for University Lab, that will monitors the power supply and the load activity at each table. Each load (table) will have a separate set of lower and higher threshold values for electric variables (voltage, current, frequency) which will be monitored. The harmonic component will also be monitored in each table seperately to protect expensive equipment in lab. If any of parameter over/under shoots, the micro-controller will trip the the supply to that faulty table to protect it and will monitor its situation and then automatically recloses to its working position.
- Features
- Read values in 40ms.
- Trip load within 2 to 3ms.
- Auto-reclose after fault is removed.
- LCD is used to display all status in real time.
- Channels parameter for threshold could be changed using a keypad.
- For different channels, different rated ACS 712 current sensors are used..
- Industrial Commercial and Domestic Project.
In the first phase, simulation and coding of the project is done step by step.
- Power supply was designed that supplies 5V,12V constant DC voltage over the range of 180V-270V.
- Voltage was measured and displayed on LCD.
- Frequency is measured and displayed on LCD
- Current is measured using RMS value technique. for current measuring, we read papers to understand how to get accurate current values within 30ms, so that the whole process is quick enough to respond on a fault quickly.
- the upper and lower thresholds are set for V/I/Hz for each table.
- keypad is included to get the real time transitions..
In the second phase, hardware is prepared and testing is done.
- pcb is designed
- components purchased
- testing
- harmonic detection (coding)
- some more features
- Industrial Sector
- Commercial Sector
- Domestic Sector
- Military Applications
The main aim of this project was to make a system that protects the test tables in lab by monitoring all the parameters of electricity (current, voltage and frequency) that includes both upper and lower thresholds harmonics detection unlike the CB or fuse which has only the over current protection. The equipment in lab is sensitive and expensive and different equipment has different electrical ratings, so there needs to be a system that monitors the situation at run time and takes necessary actions for that particular table while the other tables continue their work. The range of relay/ current rating and keypad availability helps to change the parameters in real time which is quite handy if the equipment in lab is replaced with newer equipment which might have different ratings.
Now to think widely, this system has significance in almost every sector. This system is capable to use either Solid State Contactors for Industries, Solid state relays for commercial sector and could also use triacs for domestic loads. For example one device will monitor and control loads of a house (domestic). It also include a pump.1 relay could be used for pump in house. If there is overload or dry run of pumps, then based on those current settings it will trip the pump, while other house will have power depending on their channels.
This system could also be used by WAPDA to monitor every home’s load. If any house will exceeds its Load from a value told to wapda over which the transformer of that street is place, it will cut off that houses’ supply and could give a warning. This flexibility provided by keypad/ssr current sensors could help make changes in future.
The max time to determine current, freq and voltage is around 25ms and to trip it, it will not take more than 3ms. The minimum cut off time for best quality CB is 250ms; this system could trip within 40ms. And then will monitor the situation and will try to reclose the system after time stamps. This fast processing could help this system to be deployed where high sensitivity is required.
This system can be made wireless using wireless module. It could be made three phase using 3 separate pic modules and then can monitors the situation of 3 phase. It could be used in industries by replacing the solid state relays with solid state contactors. It could also be used in domestic sector by replacing the solid state relays with triacs. This system could be deployed in military applications where fast switching is needed. Wapda could use this system to monitor the excessive use in local areas.
Wapda could also use this system for metering. A memory card will be required to save the reading.
Cost Effective System to protect expensive appliances anywhere it is used.
Technical Details of Final DeliverableTechnical Details:
- Hardware designed on PCB.
- 4 different(ratings) Bulbs used as to represent 4 different test table in Lab.
- 4 10A relays used at Load side (test tables).
- 1 40A relay used at Mains side.
- LCD used to displays values and Keypad used to make changes in feature.
- Current measured using RMS
| Item Name | Type | No. of Units | Per Unit Cost (in Rs) | Total (in Rs) |
|---|---|---|---|---|
| Total in (Rs) | 50000 | |||
| Main Board PCB Designing | Equipment | 1 | 10000 | 10000 |
| Power Supply PCB Designing | Equipment | 1 | 5000 | 5000 |
| PCB Board | Equipment | 1 | 650 | 650 |
| PCB Etching Solution | Equipment | 1 | 90 | 90 |
| Main Board Components(TB, Base, res,cap,headers,LED,Button) | Equipment | 1 | 320 | 320 |
| Transformer 12V,1A | Equipment | 1 | 200 | 200 |
| Transformer 12,3A | Equipment | 1 | 480 | 480 |
| Keypad 4x4 | Equipment | 0 | 350 | 0 |
| Relay Board 4 channel | Equipment | 1 | 1000 | 1000 |
| Power Supply boards Components(Regulators,Capacitors, Fuse ac connect) | Equipment | 1 | 180 | 180 |
| Boards and Bulbs | Equipment | 4 | 870 | 3480 |
| Load wire | Equipment | 1 | 200 | 200 |
| Acrylic Sheet | Equipment | 1 | 480 | 480 |
| 20x4 LCD | Equipment | 2 | 550 | 1100 |
| Hole to Hole Jumper | Equipment | 2 | 80 | 160 |
| Pin to Hole Jumper | Equipment | 3 | 80 | 240 |
| Fotek SSR 40A | Equipment | 1 | 450 | 450 |
| Heat Sink 2mm | Equipment | 3 | 20 | 60 |
| Heat Sink 4mm | Equipment | 3 | 20 | 60 |
| Heat Sink 8mm | Equipment | 1 | 30 | 30 |
| Heat Sink 9mm | Equipment | 1 | 30 | 30 |
| Heat Sink 5mm | Equipment | 5 | 20 | 100 |
| Heat Sink 3mm | Equipment | 3 | 20 | 60 |
| Heat Sink 7mm | Equipment | 1 | 30 | 30 |
| Heat Sink 6mm | Equipment | 1 | 30 | 30 |
| Heat Sink 10mm | Equipment | 1 | 30 | 30 |
| PIC18F4550 | Equipment | 2 | 650 | 1300 |
| Pin to Hole Jumper wire | Equipment | 3 | 90 | 270 |
| Pin to Pin Jumper Wire | Equipment | 2 | 90 | 180 |
| Zmct118F Current Transformer | Equipment | 3 | 155 | 465 |
| ZMCT103C Current Transformer | Equipment | 5 | 600 | 3000 |
| Soldering Iron | Equipment | 1 | 2000 | 2000 |
| Soldering wire | Equipment | 1 | 450 | 450 |
| PCB drill Machine | Equipment | 1 | 2100 | 2100 |
| Rs232 Module | Equipment | 1 | 900 | 900 |
| RS232 Cable | Equipment | 1 | 250 | 250 |
| Transformer 12V 3A | Equipment | 1 | 480 | 480 |
| Pickit Programmer | Equipment | 1 | 4000 | 4000 |
| 4 channel 8A Solid State Relay | Equipment | 2 | 2720 | 5440 |
| Glossy Paper for Progress Reports | Miscellaneous | 20 | 25 | 500 |
| A4 papers bundle | Miscellaneous | 1 | 650 | 650 |
| Printing | Miscellaneous | 1 | 1000 | 1000 |
| Charts | Miscellaneous | 2 | 30 | 60 |
| Flyer(design and Printing) | Miscellaneous | 10 | 100 | 1000 |
| Standy | Miscellaneous | 2 | 500 | 1000 |
| Stationery(pencils,pointers,markers etc)) | Miscellaneous | 1 | 495 | 495 |