전압형 인버터 스위칭 서지전압 측정

A Measurement of Switching Surge Voltage using Voltage Type Inverter

Most adjustable-speed drives(ASDs) designed to operate 220[V] induction motors incorporate voltage-source inverters (VSIs), which create motor voltages at high switching frequencies. The motor leads used to connect an ASD to a motor can behave like transmission lines for voltage pulses, which can be amplified (reflected) at the motor terminals. The resulting oscillatory transient, known as the long-lead effect, can stress and consequently degrade the statorinsulation system of a motor. This Brief describes the results of tests to 1) determine the correlation between peak motor voltage and the length of motor leads and 2) determine the correlation between peak motor voltage and the switching frequency of the ASD Insulation failures like this usually are caused by voltage surges. Voltage surges are often the result of switching power circuits, lightning strikes, capacitor discharges and solid-state power devices.