Control strategy for single-phase PWM ac/dc voltage-source converters based on Lyapunov's direct method

Several methods for dc voltage control of single-phase pulse width modulation ac/dc voltage-source converters are known. They differ in their performance and the complexity of the hardware and software they use. One of the basic requirements of the control method is a nearly sinusoidal input current with unity power factor. However, global stability of the converter is not guaranteed by the methods proposed so far. This paper describes a new control method based on Lyapunov's direct method. It is shown that the converter can be stabilized globally to handle large signal disturbances. The closed-loop system not only ensures stability, but also exhibits excellent transient response for abrupt changes in the load. More importantly, the proposed control method can keep the advantages and remove the disadvantages of the existing methods. Computer simulations and experiments are presented to show the effectiveness and applicability of the proposed control method for the converter.