Chapter No. 03 Automatic Transfer Switch (ATS) 3.1 Introduction: This section describes the basic introduction of the automatic transfer switch. 3.1.1 Periodic Switching Problem: The problem with this arrangement is the switching of energy between the local utility and the proprietary generator. Whenever the local utility is turned off, the generator must be turned on, and vice versa, for economical operation. is the requirement that the generator must be turned off when utility power is restored again. This periodic switching scheme between the utility and the generator can be operated manually on a small scale, but in cases where there is more than one generator or in a harsh industrial environment, switching is not a quick and economical procedure. Uneconomical in the sense that staff will be needed to handle this manual operation. 3.1.2 Solution to the problem: The only answer to the problem is to make the switching system automatic. The circuit breaker will shift the load from the utility to the generator (turning it on) every time the utility is turned off and, conversely, will turn off the generator and shift the load to the utility when the utility power is restored.3.1.3 Automatic Transfer Switch (ATS): A transfer switch is an electrical switch that reconnects the electrical power source from the primary source to a backup source. The switches can be operated manually or automatically. An automatic transfer switch (ATS) is often installed where a standby generator is located, so that the generator can provide temporary electrical power in the event of a power source failure. For example, in a home equipped with a backup generator and an ATS, when an electrical breaker experiences a utility outage, the ATS tells the backup generator to start. Once the ATS sees that the generator is r...... center of the card ......on.3.4.2 When WAPDA power is restored again (generator shutdown)1. But the power supply of the wapda is continuously monitored, whenever it reaches >180 volts, its circuit is turned on and the generator circuit is turned off.2. This turns the generator off.3.5 REAL TIME SIMULATIONS:2 The simulations are shown below:3.5.1 The WAPDA circuit is on.1- First with the wapda power on, i.e. the generator circuit is off.2 - The yellow LED on indicates that the Wapda circuit is onFigure 3.8: Simulation 13.5.2 The WAPDA circuit is off.1. According to when Wapda power is turned off .2. Note the green LED, which lights up, indicating that the generator is on. Figure 3.9: Simulation 23.6 Hardware work: Figure 3.10: Hardware image