Abstract：Maximum torque per ampere（MTPA）control can effectively improve system efficiency through

reducing copper loss，which is suitable for air conditioning permanent magnet compressor system. However，due to the inverter non-ideal characteristics，the tracking accuracy of the optimal current vector angle decreases. The

negative influence of inverter non-ideal characteristics on virtual direct signal injection based MTPA control and the

compensation method were studied. Aiming at the digital delay issue of the control system，the voltage information

in the process of current vector angle tracking was corrected according to the system sampling time. In addition，the saturation function based dead-time compensation method was utilized to reduce the voltage error caused by the inverter nonlinearity. Experimental results show that the compensation method of inverter non-ideal characteristics improves the tracking accuracy of the optimal current vector angle.

      Key words：interior permanent magnet synchronous motor（IPMSM）；maximum torque per ampere（MTPA）

control；virtual signal injection；inverter non-ideal characteristics