Influence of Negative Excitation on Loss and Temperature Field of Dual-Excited Synchronous Condenser

The traditional synchronous condenser (TSC) has the maximum consumption of the reactive power when the field current is zero. However, the dual-excited synchronous condenser (DESC) can operate with the negative excitation mode to absorb more reactive power, thus it has better advantage in improving the voltage stability of the power system than the TSC. In order to obtain the reactive power consumption limit of the DESC, the stator and rotor losses and temperature fields are calculated under the different negative excitations by coupling the electromagnetic field, loss and temperature field models. The effect of the negative excitation on the loss and temperature rise of the DESC is studied. The stator and rotor regions where the highest temperatures appear are found, and the variation laws of the stator and rotor highest temperatures along with the increase of the reactive power consumption are revealed. According to the maximum permissible temperatures of the stator and rotor material, the reactive power consumption limit of the DESC is obtained. This study can provide the theoretical basis for the improvement of the reactive power consumption ability of the DESC.