Embedded-friendly online dead-time compensation using PWM timer

An applicative and embedded-friendly improved dead-time compensation method has been developed. Basic concepts of the proposed method are based on the error time between phase voltage commands and each phase actual output voltage. The error time can be obtained by applying an external pulse width measuring timer which is synchronized with a PWM timer of a micro-controller unit (MCU). This means that key components for the proposed method have already been implemented into most controllers. Also, because of the high frequency of the MCU base clock, the proposed method precisely compensated for dead time errors even in the tricky time period caused by switching ripple zero-crossing. Various experimental results show that the proposed method is effective and robust. Moreover, curious results are investigated in which the compensation time for the error time has transition periods through the current zero-crossing. Finally, the relationships between the current zero-crossing period and the voltage compensation values are experimentally verified.