INVERTERS PARALLELED WITH REACTOR

摘要

A plurality of polyphase inverters are connected in circuit to substantially common polyphase loads through a polyphase reactor. Windings from each phase of each inverter are provided on the reactor to cancel the component of flux of the fundamental frequency within the reactor and to have the reactor substantially absorb the NP+/-1 harmonics where N is the number of inverters and P is the number of phases. For two three-phase inverters this substantially cancels the fifth and seventh harmonic voltages within the reactor applying a true 12-step voltage wave to each of the two common three-phase loads with nothing smaller than the 11th harmonic voltage supplied to each load. The two inverters are phase displaced by 360 DEG /2NP which normally at a 30 DEG phase angle would be a voltage loss of 3 1/2 percent applied to the load yet this reactor connection applies 100 percent voltage to the loads and the load power factor is reflected directly to each inverter. The loads may be DC isolated, permitting series connection of the inputs of the inverters from a single high voltage DC supply.