Research On Three Power Automatic Transfer Switch

With the rapid development of national economy, the reliability requirement of power supply is increasingly high in many industries. In this case, the automatic transfer switch began to popularize gradually, which has been used to satisfy the continuous power supply requirements of the power supply system. Under the condition of existing technology, the application of automatic power transfer switch is relatively common. Three-phase voltage can be accurately detected, and abnormal voltage frequency can be judged. But to hospitals, airports and telecommunications departments, two power supplies can’t meet the requirements. In order to meet the need for continuous power supply, three power supplies is adopted for transformation, which is used as the main power supply, the first back-up power and the second stand-by power supply.Three automatic power transfer switches is deeply studied in this article and a set of drive actuator is designed. A motor is used to control the three power supply lines separately in this device. And the machinery chain is realized among the three power supply lines, that is, only one power supply line is on-state at the same time and the other two power supplies are off- state. In addition, based on the original double power supply, PIC is as the core and switching power supply circuit, voltage acquisition circuit, frequency acquisition circuit, angular displacement circuit and other hardware circuit are designed. The anti-interference processing is also taken into account. Finally, the main programs of three power automatic transfer switch and function interface are designed.Three power automatic power transfer switch, has the features of simple actuator control principle. The voltage and frequency can be accurately detected. This device has the function of human-computer interaction and can be applied in the industrial field.