带四线制整流桥负载同步发电机的等效电路模型与小信号模型

Equivalent Circuit Model and Small-Signal Model of Synchronous Generator With 4-Wire Rectifier Load

带四线制整流桥负载的发电机始终处于非对称运行状态。为了进行系统性能的解析分析,将发电机的d、q轴变量分解为低频和高频分量分别处理,忽略了转子回路对高频电流的电阻及阻尼绕组对低频分量的作用,并在假定交、直轴超瞬态电抗相等的基础上,建立了同步发电机的等效电路模型,通过在稳态运行点线性化处理得到了等效发电机的小信号模型。文中还给出了稳态等效发电机的Park方程、相量图及稳态量的计算方法。分别通过发电机整流桥硬件系统的试验及在PSCAD/EMTDC软件环境下详细模型的仿真验证了等效电路模型,也间接证明了小信号模型的正确性。文中的等效电路模型与小信号模型可分别应用于此类系统的性能分析与小扰动稳定性研究。

A synchronous generator with 4-wire rectifier load operates in an asymmetric mode all the time.In order to perform the analytical solution of performance,the d-and q-axis variables of generator are decomposed into low-and high-frequency components and treated separately.The effects of the rotor resistances on high-frequency currents and the damper windings on low-frequency components are neglected.The equivalent circuit model of synchronous generator with the d-axis sub-transient reactance equal to the q-axis one is developed.The small-signal model of equivalent generator is obtained with linearizing method at the steady-state operation point.The Park＇s equations,phasor diagram and calculation methods of steady-state variables of equivalent generator are also presented.The developed equivalent circuit model is validated against a generator-rectifier hardware system via experiment and against the detailed model via simulation in PSCAD/EMTDC environment,which proves the correctness of small-signal model too.The circuit model and small-signal model can be respectively used for performance analysis and stability assessment with small disturbance for such systems.