This paper presents a new power converter, which uses 9 bidirectional switches with turn-off capability to connect directly the three-phase source to the three-phase load. Each bidirectional switch is composed of two power MOSFET transistors working in the switching mode. The converter works with a high switching frequency and for this reason the harmonics in the load and in the source currents can be easily removed by using small filters. A novel strategy based on spatial vectors is used to control the load currents. A drastic reduction of the input harmonics is obtained by controlling the reactive component of the input currents. The converter acts as a controlled three-phase current source and the frequency of the fundamental component of the load current can be higher than the source frequency (50 Hz) without affecting the harmonic distortion. The input currents of the converter are practically sinusoidial and they remain in phase with the source voltage independently of the amplitude and frequency of the output currents. The converter presents no restriction to the direction of power flow between the source and the load and for this reason it is well suited to be used in the four-quadrant speed control of ac machines.
|Title of host publication||Unknown Host Publication Title|
|Publisher||Koninklijke Vlaamse Ingenieursvereniging|
|Publication status||Published - 1985|
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