Online Load Power Factor Angle Estimation and Its Application in a Current Sensor-Less Dead-Time Distortion Compensation Technique in Single-Phase PWM VSI With Lagging Load

Dead-time distortion is a major issue in PWM VSI, which results in a deviation in the profile of the inverter output voltage and reduction in the amplitude of its fundamental component. Intensive research works have been carried out to develop different techniques for correcting dead-time distortion with or without using current sensors. This paper proposes an online load power factor angle estimation technique and its utilization in a current sensor-less dead-time distortion compensation method, which is applicable for single-phase two-level PWM VSI, feeding a lagging type load. This power function-based technique uses instantaneous power theory (IPT) in its modified form. This method does not involve any additional hardware or sensor for power factor angle estimation and its application in the compensation process and reduces the cost and complexity of the set-up. The software-based technique is simple, can be implemented in a low-cost digital controller. This technique is verified through experiments in the laboratory.