| DC generator system which consists of a permanent magnet synchronous generator(PMSG)and a PWM rectifier,hence called PMSG system,has the merits of high power density,high efficiency and bidirectional power flow.It has been widely used in many applications,such as mobile power supplies and renewable energy.The current regulation strategy is studied for the wide-speed-range PMSG system in this thesis.The m aximum torque per ampere(MTPA)control strategy is employed at low speed,whilst at high speed the flux weakening control upon the voltage closed-loop is implemented with an appropriate d-axis current.Therefore,the d-q axis currents are properly regulated under different speed and load conditions.In this thesis,voltage regulation control for the wide-speed-range PMSG system with PWM rectifier is also studied.The model of control system suitable for a variety of common loads is firstly established,then influence of the control parameters and generator rotating speed on the voltage regulation performance is analyzed theoretically,and finally,the optimization method of the control parameters is presented.Simulation and experimental results show that the PMSG system can timely adjust the d-q axis currents according to a variation of rotating speed and load within a wide speed range of 200rpm-2000rpm(nmi:nmax=1:10),and the current response is fast.Additionally,due to application of the optimized control parameters,the system has a good voltage following performance and anti-load-disturbance ability in the case of step or pulse load,and high-performance voltage regulation of the PMSG system is realized. |
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