Control strategy for three-phase current-source inverters based on Lyapunov’s direct method

A new control strategy for three-phase current-source inverters is proposed based on a model of the converter in the rotating dq frame. The control equations are derived by making use of Lyapunovpsilas direct method. It is shown analytically that a globally stable operation is possible for the closed-loop system. The amplitude of the dc current is adjusted by employing a proportional-integral regulator in the output voltage control loop. The correct operation of the proposed strategy is verified through simulations. Results pertinent to a step load change indicate that reasonably fast responses of the output voltage without large distortion can be obtained.