Improvement of Reactive Power Consumption Ability for Dual-Excited Synchronous Condenser

The traditional synchronous condenser (TSC) has the strong ability of the reactive power delivery; however, the reactive power consumption ability is limited by the minimum field current of zero, which is detrimental for suppressing the overvoltage. The dual-excited synchronous condenser (DESC) with two sets of field windings on the rotor can absorb more reactive power through the negative excitation and improve the stability of the power system. In this paper, it is proposed a wide range reactive power control (WRRPC) strategy which realizes the d-axis negative excitation through the feedback of the terminal voltage and keeps the rotor speed stable through the feedback of the rotor speed. With the sudden rise of the system voltage as an example, the dynamic process of the DESC is calculated and compared with that of the TSC. The reactive power consumption ability of the DESC is revealed by increasing the sudden rise level of the system voltage. The influence of excitation resistance and rotor damping effect on the reactive power consumption ability of the DESC are studied. The results can provide technical support for suppressing the system transient overvoltage.