A Multiple Loops-Based Control Strategy of Current Source Rectifier for Low-Voltage DC Distribution Systems

Controlling three-phase current source rectifiers presents intricate challenges due to the input LC filters and DC bus capacitors. This paper proposes a multiple-loop-based control strategy for current source PWM rectifiers for low-voltage DC distribution systems to address these challenges. Firstly, the independent control of the active and reactive power is achieved based on the adjustment of the d-axis and q-axis currents on the grid side. Subsequently, a compensation scheme of capacitance current using the phasor method is proposed. Next, as an alternative damping method, the capacitor-voltage feedback is used to suppress the LC resonance, and the influence of the feedback gains on the system's stability is discussed. Furthermore, the dynamic performance is further improved by adopting DC-side inductor-current feedback and a damping factor. Ultimately, the feasibility and efficacy of the proposed approach are confirmed through experiments.