Power conversion equipment

摘要

In a multilevel conversion equipment, although a capacitor series circuit is used in a direct current portion, parts such as semiconductor switches and a reactor are added to the exterior in order to balance the voltages, but this leads to an increase in size, and an increase in cost, of an equipment.

<Paragraphs id="pa02" num="0002" xmlns:base="http://www.sipo.gov.cn/XMLSchema/base">A power conversion equipment, a capacitor series circuit Cp, Cn being connected in parallel with a direct current power supply Ed, outputs an alternating current voltage having three or more potentials in a half-cycle period with the capacitor series circuit as a direct current input, wherein a neutral point of an alternating current load M and an intermediate connection point of the capacitor series circuit are directly connected, the voltage of each of the capacitors Cp, Cn is detected, and a zero voltage vector obtained by making each alternating current output of the same potential is adjusted in accordance with the difference between the voltages.