Voltage Protection System

Introduction

Every device is designed to work in a fixed range but voltage supplied to houses and industries may fluctuate due to various reasons like a sudden interruption of heavy load, lightning, etc. 

Nowadays major problem in the industry, as well as households, is sudden over voltage or under voltage which results in damaging the equipment. Electronic and Electrical based load increases day by day in the household as well as in industrial applications and they are very sensitive to voltage variation. An overvoltage is an increase in the RMS value of ac voltage greater than 110 percent or 0.11pu at the power frequency for a duration longer than 1 min. overvoltages are usually the result of load switching (e.g., switching off a large load or energizing a capacitor bank). 

Similarly, an under-voltage is a decrease in the RMS value ac voltage to less than 90 percent or 0.90pu at the power frequency for a time period longer than 1 min. Under voltages are the result of switching events that are the opposite of the events that cause over voltage.

Objective

A voltage power protection system is designed to protect the device by comparing its normal working voltage range with that of supplied voltage and deciding whether to operate the device or not. The main target is to design and develop an Arduino-based smart overvoltage and under-voltage protection system to protect the appliance from damage and electrical hazards.

System Requirement

  Hardware requirement:

1. Transformer 
2.  Arduino UNO 
3.  16*2 LCD display 
4.  4 channel 5-volt relay kit 
5. Potentiometer 
6. Breadboard 
7. Diodes 
8. Capacitors 
9. Resistor 
10. LED 
11. Adapter 
12. Integrated Circuit (IC) 
13. Preset 
14. Holders 

 Software Requirement 

• Arduino Software (IDE)

Connection and Working Mechanism

• The given circuit is designed on PCB.

Fig 1: Circuit diagram 

(Source: VMK Technical Power)

• Other Components like Transformer, Arduino, LCD display, Breadboard, Relay, Adapter, and Potentiometer are fixed on the plyboard, and the circuit is connected as shown in fig-2.

Fig 9: Prototype

 (Source: VMK Technical Power)

• First of all, we connect jumper wires in 5v pin and GND pin in Arduino and connect those jumpers to the breadboard. 
• After this we also connect 10K preset to the breadboard. 
• LCD pins are connected to Arduino pins as:

▪ LCD 1st pin is connected to Arduino GND pin 

▪ 2nd pin to Arduino pin 5V 

▪ 3rd pin connects to preset upper pin 

▪ 4th to Arduino pin 12

▪5th to Arduino GND

▪ 6th to Arduino pin 11 

▪ 16th to Arduino GND

▪ LCD 15th pin to Arduino 5V pin.

• LCD points are connected to Arduino pins as:

▪ LCD D7- Arduino pin 2 

▪ D6- Arduino pin 3 

▪ D5- Arduino pin 4 

▪ D4- Arduino pin 5

• Left pin of preset is connected to Arduino GND
• Right pin of preset is connected to Arduino 5V pin 
• Relay kit is connected to Arduino as:

▪ Relay GND- Arduino GND 

▪ VCC pin- 5V pin 

▪ IN1 pin - pin 8 

▪ IN2 pin- pin 9 

▪ IN3 pin- pin 10

• Potentiometer is connected to Arduino as:

▪ Potentiometer 1st pin – Arduino GND pin 

▪ 2nd pin - A0 pin 

▪ 3rd pin – 5V pin

• After this the three bulb holders are taken and stabilized in a plyboard
• The holders are connected to the relay as:

▪ One wire of the first holder to NO pin of the first relay 

▪One wire of the second holder to NO pin of the second relay 

▪ One wire of the third holder to NO pin of the third relay

• The one wire which is left from all the three holders is connected together. 
• Common pins of all three relays are connected together 
• A 230V is connected to both the common pin of the relay and the common pin of all the three holders • Operating supply is connected to Arduino through an adaptor which will change the parameters of the operated supply to the value which is required by Arduino for its effective mechanism. 
• AC input is given to both the transformer and relay input 
• Now input voltage is altered by using a potentiometer 
• According to the controlled input voltage, we can classify whether it is under-voltage, over-voltage, or normal voltage and accordingly it will display on the LCD screen. Also, accordingly, Arduino will give a signal to the relay which in turn will control the flow of current to load (Bulb in this case). 
• In case of over and under-voltage circuit will be open and appliances (Bulb in this case) will be protected whereas in the case of accurate voltage it will work smoothly.

Result and Expected Outcomes

• In this particular case, we will be demonstrating our proposed protection system using an electric bulb over and under the supply of AC mains. As of which, the bulb is supposed to turn off under low(<180V) and high voltage(>200V) as specified in Arduino's program and operate under normal voltage(180-200V)
•  From this proposed project, we will be able to prevent the operating devices from electrical hazards due to over and under supply of AC voltage by detaching it from the main supply, which in turn not only protects our appliance but also save personnel from any potential threats/injury.
• It will also be able to provide protection to sensitive electronic and electrical devices like motors and pumps.

Further Recommendations

•  If we can control the tap changing transformer automatically then we can operate the load normally under an over-voltage condition. Hence, protecting as well as operating the load in abnormal voltage at the same time.
•  This system can be improved by integrating it with a GSM modem that alerts users by sending an SMS about the tripping that occurred.
•  The hardware implementation can also be done by applying 3 phase power supply (Three-phase motor relay).
•  The concept in the future can also be extended by integrating an alarm that sounds when voltage fluctuation occurs.

Conclusion

When the circuit is completed, then the users of electrical devices can control the voltage level according to the demand of their devices. Their devices can be protected from an excessive-high or low voltage as relay kit trips when there is a difference in rated voltage and supplied voltage.