An Active Boost Power Converter for Improving the Performance of Switched Reluctance Generators in DC Generating Systems

In this article, an active boost power converter is proposed for switched reluctance generators (SRGs) that support low-voltage dc loads or dc microgrids. In the proposed converter, a front-end circuit is added to a conventional asymmetric half bridge power converter. With the front-end circuit, excitation voltage and demagnetization voltage can be regulated flexibly to improve the system efficiency and increase the maximum output power under constant phase current constraints. Then a multiloop control strategy is developed to control the power converter. The multiloop controller contains a power controller and a boost voltage controller. The power controller is designed to control SRG over the entire operating range. The boost voltage controller is designed to control the front-end circuit. Two strategies are compared for the boost voltage control: voltage hysteresis control strategy and power flow control strategy. Comparing with voltage hysteresis control, proposed power flow control shows improvements in minimizing output voltage ripple and is suggested for the proposed converter. In the end, simulation and experimental results are given to verify the feasibility of the proposed power converter and control strategy. Comparisons between the proposed converter and the conventional converter are also given for evaluation.