Research On Sensorless Control And Virtual Synchronous Generator Control Of Open Winding Generator System

The development and utilization of renewable energy is of great significance in solving the society's energy crisis and environmental pollution.Multi-input source generation system has become a central issue due to its full utilization of renewable energy.Compared with the traditional multi-input power generation system structure,the open-winding generator system has the advantages of less controllable components,low construction cost and high efficiency.After reviewing the research status of open-winding generator system,this thesis studies the system's sensorless operation,power control algorithm,system modeling and parameter design for the existing research deficiencies.In order to realize the sensorless operation of open-winding generator system,this thesis proposes a novel synchronous reference frame filter structure without filtering phase delay.This thesis establishes system's simplified sliding observation model,analyzes filtering phase delay which is caused by the low pass filter of conventional synchronous reference frame filter structure.The position angle with phase delay is used for coordinate transformation of synchronous reference filter,and the output of sliding mode observer is filtered directly.The back EMF without phase delay is obtained,which improves the accuracy of rotor position identification.In order to solve the power control error in traditional double closed-loop vector control,the feasibility of virtual synchronous generator control algorithm is verified by analyzing the power angle characteristics of open-winding generator system.Aiming at solving the power coupling of the system,this thesis proposes a power decoupling strategy which achieves the effective control of active and reactive power of the system.Aiming at the pulse suppression of open-winding generator system,this thesis builds a closed-loop small signal model of system based on the averge switching method.The impedance matching between source and load is analyzed using Middlebrook criterion.The ability of pulse suppression under different system parameters is studied.A simple parameter design method is proposed.the designed filter parameters can effectively take into account both the size of the filter and the pulse suppression.Finally,this thesis builds an experiment platform of open-winding generator system and designs the digital control system based on DSP.The program of sensorless control and power loop decoupling is compiled.The effectiveness of above algorithms is verified by experiments.