Digital Realization And Studying On The Reliability Of Cascaded High Voltage Conveter

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 because 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.That cascaded multilevel converters are applied to high-voltage great power occasion, but the multilevel PWM technology is the main problem of cascaded multilevel converter. In the paper, analyzed several kinds triangle-carrier PWM and their characteristic first, having suggested pulse shifting switch frequency optimizing PWM method, and simulated PWM method scribed above. On the new modulated tactics, have built the simulate model of three level cascaded converter, and studied the progress of starting, running and regulation. To verify what be studied theory correctness and control algorithm feasibility further, carried out not only simulating, but also have developed an experiment platform of three level cascaded converter in this paper. DSP is used as the control core of the experiment platform, and PLD is used as the multi-path PWM generator. In this experiment platform introduces the signal sample and insulated circuit, and has carried out introduction on two kinds different "DSP + CPLD"designs in detail, as well as given the flow chart and experiment results. The experiment platform establishes a basis for further studies.The high-voltage great power system demands high reliability ,specially important occasion such as electric power , energy , metallurgy , mine, petroleum and chemical industry .Malfunction can bring about enormous loss of the peoples'life and property, therefore analysis the Fault-Tolerant technique and reliability in the last, and gave the method to raising system reliability in this paper.