Distribution Network Monitor Inverter Power Design

This dissertation introduces a design of distribution network monitor inverter power. This inverter power is an independent module, installed in the distribution network monitor product. When the external AC power is cut off, the inverter will supply the steady AC power for the distribution network monitor system by transforming the internal 12VDC storage battery.Based on the different structures of inverter power supply, this dissertation studys DC (12V) /AC (220V) inverter to get a high efficiency and output waveform quality inverter. In the main circuit, this system uses a new type of push-pull forward DC/DC circuit which transforms the 12V low DC to 320V high DC, and adopts SG3524 chip to generate a PWM modulated signal. This DC/AC system adopts full bridge inverter, and uses IGBT as switching tube, and utilizes the special chip TLP250 as a driver to generate a SPWM modulated signal by SG3524. The design method of PID controller based on pole-assignment is proposed in this dissertation. In the design process of the inverter, the dissertation introduces the DC/DC push-pull forward circuit; DC/AC full bridge inverter; PWM modulation circuit; SPWM signal generation circuit; MOSFET and IGBT driver circuits; DC/DC and DC/AC output filters. The dissertation also introduces some protective circuits such as over voltage protective circuit; over thermal protective circuit; storage battery protective circuit; MOSFET protective circuit and PID controller circuit.The trail shows that with decreasing the break-over loss, switching loss, driver loss of switching components, and the coordinative controlling, the efficiency will be imported effectively. The inverter system which is made up of a new type of DC/DC step up transformer and DC/AC full bridge transformer has some excellent features, it can achieve high transform efficiency.