Research On The Power Generation Control System Of Asynchronous Generator

With the development and utilization of renewable energy such as wind energy and tidal energy,as well as the development of some Stand-alone power systems,the research on asynchronous motor stand-alone power generation system has become a research hotspot at home and abroad.In this paper,two asynchronous power generation systems are proposed:cage asynchronous power generation system and brushless doubly-fed power generation system.Both of these systems are brushless,and the structure is simpler.It is more suitable for complex and variable stand-alone power generation control.The cage asynchronous power generation system is more suitable for DC power generation,and only one converter can realize DC voltage output;the brushless doubly-fed power generation system is more suitable for AC power generation,and the AC stabilized output can be realized by connecting two inverters of the slip power.How to efficiently control the voltage that makes its output stable in a stand-alone power generation control system becomes the research focus of the stand-alone power generation system.In the cage-type asynchronous generator power generation control system,the overall scheme of the power generation system is first designed,including the construction of the pre-charging link,the selection of the intermediate capacitance parameters,and the two schemes of the slip frequency control and the rotor field oriented vector control.The system performs DC voltage regulation control,and for the problem of slow dynamic response of the motor,the load estimation feed-forward control strategy is proposed for vector control system.Finally,the comparative analysis shows that the vector control strategy of rotor field orientation is more resistant to load disturbance.Strong,steady-state fluctuations are smaller,and cost is better than slip frequency control.Aiming at the volume and cost of AC-regulated output of cage asynchronous power generation system,a power generation control system for brushless doubly-fed generator is proposed.Aiming at the control strategy of controlling the winding side converter,the current source model of the brushless doubly-fed motor is designed.The scalar control strategy is used to simulate the variable speed and variable load operation of the generator.The stand-alone power generation system under scalar control is verified.Excellent steady-state performance,but its resistance to load disturbance is poor.Aiming at this defect,a super-twisting sliding mode control algorithm is proposed for power generation control system.For the chattering problem of sliding mode control,the hyperbolic tangent function is used to reduce the sliding mode chattering.The simulation results show that compared with the traditional scalar control strategy,the improved power generation control system has better dynamic performance,immunity and robustness.Both asynchronous generators have advantages in stand-alone power generation systems,but poor load capacity is a common problem.According to their respective characteristics,the vector control strategy and super-twisting sliding mode control strategy proposed by the paper have strong anti-interference ability and load capacity after simulation verification.