Patent ID: 8488344
Filing Date: 2013-07-16
Classification: B60L,H02M

Abstract:
1. An electrical power conversion apparatus for an electric railroad car, comprising: a converter for converting AC power produced between a line and a rail into DC power; a capacitor connected in parallel with the converter on the DC side thereof; a DC voltage measurement unit for measuring a voltage across the capacitor; an inverter including switching elements, connected in parallel with the capacitor, for converting DC power into AC power of an arbitrary frequency; and a control microprocessor into which DC voltage values each measured by the DC voltage measurement unit are inputted in a predetermined sampling period, for controlling the inverter, wherein the control microprocessor includes the DC voltage-value estimation unit obtains a predetermined-order polynomial that approximates the DC voltage values stored in the DC voltage-value memory unit, and, using the polynomial, predicts a DC voltage estimate value at a predetermined time after the latest sampling time-point, and the beat suppression unit operates on the frequency control unit so that the frequency becomes smaller when the DC voltage estimate value predicted by the DC voltage-value estimation unit becomes larger, and the frequency becomes larger when the DC voltage estimate value becomes smaller.