变频调速原理及变频方案可靠性的分析

Principle of frequency-changing speed control and reliability of its scheme

从效率角度分析了变频调速原理，论述了一种能够实现高效率交流电机调速的P理论及相应的变频调速的功率控制原理。指出了变压器、绝缘栅极型功率管（IGBT）直接串联、多电平串联3种高压变频方案的优缺点，分析了高压变频调速方案的可靠性。经对变频调速中击穿IGBT的解剖研究，得出基于IGBT变流器件变频调速不适宜（6～10kV）高压大功率异步机。对于高压的交流调速，基于转子的低压控制应该引起充分的重视。

This paper analyses the principle of frequency-changing speed control of AC-motor. A power control theory in realizing high-efficiency in speed control of AC-motor and the corresponding principle of frequency-changing speed control are elaborated. High voltage frequency changing scheme including transformer,direct series of IGBT and series of multi-electric level are reviewed. The reliability of the scheme is also analszed and the punctured IGBT is dissected. It is concluded that frequency-changing speed control with IGBT is not applicable to high voltage （6 - 10 kV）AC-motor. Consequently low voltage control of rotor calls for adequate attention for high voltage speed control of AC-motor.