| To solve the problem that the output voltage of permanent magnet synchronous generator (PMSG) is not easy to control, a coordinate structure hybrid excitation synchronous generator (HESG) with AC excitation is proposed and the AC excitation field orientation vector control is mainly studied in this thesis.Firstly, a coordinate structure HESG with AC excitation is proposed and there is no electrical excitation rotor in the electrical excitation part. The structure, operation principle, electromagnetic relation and the steady-state equivalent circuit of the HESG are analyzed and summarized. Then the mathematical model and simulation model are built considering that the d,q-axis reactance of armature windings are not unequal.In order to achieve the stable output voltage of the generator, the control strategy that the magnetic field produced by field current is oriented to the d-axis is studied. The control strategy ensures that the system can achieve the optimal voltage adjustment with minimum excitation electromotive force. Two field orientation control methods, voltage-space-vector and forced orientation, are proposed in this thesis. The two HESG’s excitation control systems are built and simulated with MATLAB/Simulink respectively. The theory analysis and simulation results are all shown that the output voltage adjustment only depends on the q-axis component of field voltage. Basing on the conclusion, the excitation working point of HESG is discussed. Moreover, the starting process of generator is considered in the simulation process.The simulation results show that the two systems all have good dynamic and steady-state performance, and the output voltage can keep constant when the load of HESG changes.The effect of the magnetic field orientation is good in forced field orientation control system.Finally, excitation current driver module and signal detection module included in the hardware circuit of AC excitation control system are designed and improved. |
PDF Full Text Request