Study Of Asynchronous Extra-High Synchronous Generator And Its Excitation System

Asynchronous extra-high voltage synchronous generator is a new type of generator based on asynchronous synchronous generator and extra-high voltage generator. It obtains the advantages of asynchronous synchronous generator and extra-high voltage generator at the same time. The generator can be connected to the grid directly without transformer. Besides decoupling control of active power,reactive power and speed can be realized. Asynchronous extra-high synchronous generator and its excitation system was studied and analyzed in this paper.Firstly, considering characteristic of asynchronous synchronous generator and extra-high voltage generator, asynchronous extra-high synchronous generator was designed and analyzed based on rating data, stator core and winding, rotor core and winding. The magnetic circuit and generator parameters were calculated while working performance was analyzed.Secondly, finite element method was adopted to analyze electromagnetic of the asynchronous extra-high synchronous generator. Magnetic flux density and magnetic field lines distribution inside the generator was verified under the condition of slip at-0.04, 0 and 0.08 respectively. Harmonic analysis was carried out when slip was 0.08.Open loop field-circuit coupling model of asynchronous extra-high synchronous generator was simulated in Simploer and Ansoft. It shows that the frequency of excitation current is matched with slip.Finally, the mathematical model of asynchronous extra-high synchronous generator was built. The decoupling model of active power and reactive power was also built in able to realize decoupling control of active power, reactive power and speed under different operating states. The mathematical model of excitation control system was built based on the models above. Simulation platform was utilized to establish the simulation model of asynchronous extra-high synchronous generatorsystem, verify the mathematical model and realize decoupling control of active power, reactive power and speed of asynchronous extra-high synchronous generator.