Abstract:
Voltage source three-phase pulse width modulation (PWM) power converters are used in many industrial applications. Since the converters are inherently nonlinear, nonlinear control techniques have to be applied. This thesis proposes a Lyapunov-based direct-power-control (DPC) strategy for the converters. In the proposed control technique, the instantaneous active and reactive powers are controlled directly to achieve fast transient responses. The controllers for both power loops are designed using Lyapunov-based technique to guarantee stability over a wide operating range. The DC output voltage is controlled by using a conventional PI controller. Simulation and experimental results are in good agreement. The results show that, the system can operate with the desired control performance when the operating range of the DC voltage varies from 300V to 400V without changing the tuning parameters, fast transient response due to load change is evident, and near unity power factor is obtained.