DITC OF SRM DRIVE SYSTEM USING 4-LEVEL CONVERTER

摘要

A DITC(Direct Instantaneous Torque Control) system of an SRM(Switched Reluctance Motor) is provided to improve dynamic characteristic and efficiency through excitation and demagnetization using a four-level converter. A torque estimator(510) estimates the torque using a phase current and a rotator position. A hysteresis controller(520) produces a state signal of the outgoing phase and the incoming phase. A switching table unit(530) switches the state signal of the incoming phase and the output phase into a switching signal with four modes. A four-level converter(540) supplies a power terminal voltage to the SRM in a mode 1. The four-level converter returns the current of the coil to the power in the mode 0. The four-level converter supplies the power terminal voltage and the boost capacitor voltage to the SRM in the mode 2. The four-level converter collects the energy stored in the coil to the capacitor in the mode -2.