JP2517930B

PURPOSE:To make an inverter with large capacity and high precision, by connecting two sets of inverter of the same class in series, deciding the switching of one of the inverters in accordance with the variation rate of the current set value and operating the other one with the output of a hysteresis comparator. CONSTITUTION:For a DC power source E1 switching elements S1 and S3 are connected in series, while switching elements S2 and S4 are also connected in series, so that the first switching circuit INV1 is formed along with regenerating diodes D1-D4. To the other DC power source E2 the second switching circuit INV2 of the same structure is formed. Between the points of contact of these switching elements S1 and S3 and S6 and S8 a load 1 is connected through a current limiting reactor L0. The current value detected by a detector 2 is compared 3 with the set value, the output of which is connected to a hysteresis comparator 4 and a band comparator 8. Each switching circuit INV's are controlled in corresponding with the rate of change of set value along with use of a polarity discriminator 7, a variation rate detector 6, etc., of the load current.