The Design And Application Of High-Voltage Inverter With Overlying Series Units

With the development of new power electronic component and computer technology, high performance variable-speed system for induction motor has been applied extensively. The variable-frequency variable-speed system for high voltage induction motor is a burgeoning technology, which has just been applied in recent years. It has wide applying prospect and capacious developing space for it not only has solved the problems of soft jump-start and variable speed on high-power fan or water pump but also can save energy remarkably. In the paper, the problems that high voltage inverter has electromagnetism pollution on electric network, motors and other electric equipments in the high voltage variable-frequency variable-speed system were analyzed. To solve the problem that high voltage inverter has pollution on the electric network and electric equipments, a method of series power units was adopted to design an inverter which has a new topological structure and can be applied in common fan or water pump for variable-speed driving, according to the principle that the harmonics of its output alternating current may be ignored by increasing category of output voltage vector because of series unites. And the test results show that the output voltage waves of the new type inverter are satisfying with the engineering requirement, and it has solved the problems of electromagnetism pollution induced by the harmonics in the high voltage variable-frequency variable-speed system. Having complex topological structure, the design for the main controller of the inverter is difficult because of the complex calculating, numerous transferring dada and controlling difficulty. To gain excellent control performance, the main controller with double DSP has been designed and the control configurations of total system are introduced in the paper. At the same time, the software flow charts of control system are also given. At last, in order to demonstrate the economy benefits and social benefits of the high voltage variable-frequency variable-speed system, we make an example that inverter with overlying series units have been applied in fan and get conclusion that it has wide prospect.