CONTROLLER FOR PWM CURRENT-CONTROLLED TYPE INVERTER

摘要

PROBLEM TO BE SOLVED: To provide a controller for a PWM current-controlled type inverter, which can always obtain good load current, as commanded without being affected by the magnitude of instantaneous value of the load current. ;SOLUTION: An inverter is provided with a voltage compensation function 11, for compensating output voltage deviation generated by dead time forming functions 9up, 9un, 9vp, 9vn, 9wp and 9wn, which set short circuit preventing periods of power switching function elements 2up, 2un, 2vp, 2vn, 2wp and 2wn for an inverter. Compensation signals ΔVue, ΔVve, ΔVwe are formed, which increase according to a prescribed characteristic increasing function in pulse or minus corresponding to a current value detected by current detection functions or polarity of a current command signal, when a current value detected by the current detection functions 3u, 3w, or an amplitude value of the current command signals ius, ivs and iws ranges from zero to a prescribed value, and become a constant prescribed value respectively, when a current value detected by the current detection functions, or an amplitude value of the current command signals reaches a prescribed value. The compensation signals are added to voltage reference values Vus, Vvs and Vws.;COPYRIGHT: (C)1998,JPO