DRIVING DEVICE FOR SYNCHRONOUS MOTOR, AND DRIVING METHOD FOR SYNCHRONOUS MOTOR

To provide a highly reliable driving device for a synchronous motor capable of highly accurately estimating and limiting a DC current without requiring an additional configuration such as a dedicated sensor for current detection.SOLUTION: A driving device for a synchronous motor comprises: a first DC current calculation unit for calculating a first DC current based on a first voltage command value, a current value of a coil of the synchronous motor and a battery voltage; a second DC current calculation unit for calculating a second DC current based on the current value of the coil of the synchronous motor, a rotation speed of the synchronous motor and predetermined motor characteristics of the synchronous motor; a model error extraction unit for calculating inverter efficiency based on the first DC current and the second DC current; a DC current correction unit for calculating an estimate DC current based on the first DC current, the second DC current and the inverter efficiency; and a DC current limitation unit for correcting a current command value of the coil based on the estimate DC current and a predetermined DC current limit value.SELECTED DRAWING: Figure 2 【課題】専用の電流検出用センサなどの追加構成を必要とせず、高精度な直流電流の推定と制限が可能な信頼性の高い同期電動機の駆動装置を提供する。【解決手段】第１電圧指令値と同期電動機の巻線の電流値とバッテリ電圧とに基づいて第１の直流電流を演算する第１の直流電流演算部と、前記同期電動機の巻線の電流値と前記同期電動機の回転数と前記同期電動機の所定のモータ特性に基づいて第２の直流電流を演算する第２の直流電流演算部と、前記第１の直流電流および前記第２の直流電流に基づいてインバータ効率を演算するモデル誤差抽出部と、前記第１の直流電流と前記第２の直流電流と前記インバータ効率とに基づいて推定直流電流を演算する直流電流補正部と、前記推定直流電流と予め定められた直流電流制限値とに基づいて前記巻線の電流指令値を補正する直流電流制限部と、を備えることを特徴とする。【選択図】 図２