MOTOR CONTROL DEVICE AND ELECTRIC POWER STEERING DEVICE MOUNTING THE SAME

• Main Authors: KOGURE TERUYOSHI, SHIMAKAWA SHIGERU, SHINKAWA NAOTO, KUMAGAI SHIN, FUKINUKI SHIGERU
• Format: Patent
• Language: English; Japanese
• Published: 07.02.2019
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; MOTOR VEHICLES; PERFORMING OPERATIONS; TRAILERS; TRANSPORTING

To provide a motor control device and an electric power steering device mounting the same capable of protecting a motor opening switch configured by a semiconductor switching element with high reliability.SOLUTION: A control unit that turns OFF control of an inverter comprises: an energy calculation unit that calculates energy of motor counter electromotive voltage and regeneration current when the control of the inverter is in an OFF state; and a determination unit that compares the energy with a safe operation region of an FET, and when the energy becomes within the safe operation region, turns OFF the FET of a motor opening switch. The safe operation region is determined on the basis of relation between drain current of the FET and drain-source voltage of the FET and ON width of the FET, and temperature characteristics of the maximum allowable loss of the FET. The maximum allowable loss is calculated on the basis of temperature estimated from case temperature of the FET, and decreases with a rise in the case temperature.SELECTED DRAWING: Figure 6 【課題】半導体スイッチング素子で構成されたモータ開放スイッチの保護を信頼性高く行うことのできるモータ制御装置及びそれを搭載した電動パワーステアリング装置を提供する。【解決手段】インバータの制御をＯＦＦする制御部は、インバータの制御がＯＦＦのときに、モータ逆起電圧及び回生電流のエネルギーを演算するエネルギー演算部と、エネルギーをＦＥＴの安全動作領域と比較し、エネルギーが安全動作領域の領域内となったときにモータ開放スイッチのＦＥＴをＯＦＦする判定部と、を具備し、安全動作領域は、ＦＥＴのドレイン電流、ＦＥＴのドレイン−ソース電圧及びＦＥＴのオン幅との関係、及びＦＥＴの最大許容損失の温度特性に基づいて決まり、最大許容損失は、ＦＥＴのケース温度から推定された温度に基づいて算出され、ケース温度が上昇するにしたがい、低下する。【選択図】図６