Analysis of Operating Characteristics of Variable Speed Pumped Storage Motor-Generator

Abstract

Large-scale variable-speed pumped storage motor-generator adopts rotor winding AC excitation technology, which can adapt to the regulation requirements of wide speed range and wide power variation. In order to adapt to the demand of dynamic change of multiple operating conditions of pumped storage motor-generator, combined with the characteristics of bi-directional energy flow of variable speed motor-generator, and considering the complex control strategy due to its two operating modes of power generation and electric power, it is the basis to realize the stable operation of the system to clarify the constraint law affecting the electrical quantity of motor-generator under different operating conditions. In this paper, the mathematical model of variable speed pumped storage motor is established by using the magnetic field positioning vector control technology, and the mathematical model of variable speed pumped storage motor is derived to analyze the operating characteristics of the motor. The model is used to calculate and analyze the electrical quantities during the speed regulation, active power regulation and reactive power regulation of the power motor, and to investigate the changes of electrical quantities such as stator and rotor current, rotor voltage, rotor active power, rotor reactive power and stator power angle during the change of working conditions. The accuracy of the mathematical model was verified by comparison using a 10MW prototype test. It is a necessary theoretical reference for the analysis of variable speed pumped storage motor-generator operating conditions.