Research On Constant Frequency Hysteresis Control Of Active Power Filter Based On Space Vector

The subject is the Ministry of Education doctoral fund project "grid harmonic suppression technology research"(20101402120004)follow-up research content,is to solve the harmonic pollution problems in the power grid.With the large amount of nonlinear load and rectifier,the harmonic pollution in the power grid is becoming more and more serious,which reduces the power quality and can cause the fault accident.The design of the active filter provides a better way for the harmonic control.Compared with the traditional LC filter,active filter as a new harmonic compensation device,high precision detection,dynamic characteristics,the compensation effect is obvious,has now become the main equipment to solve the harmonic pollution.In this paper,the active space filter of voltage space vector control is improved,and the APF of fixed frequency hysteresis and space vector is designed.The whole system is designed from the purpose of design,theoretical research,simulation verification and experimental verification.The three-phase three-wire structure is designed.The unit power factor method is used as the harmonic detection method and the fixed-frequency hysteresis space vector as the control method Type APF.The specific research contents are as follows:The causes and hazards of harmonics are introduced,and the requirements of harmonic control are described from the power quality standard.The research hotspots and directions of APF are briefly described.The circuit structure and mathematical model of APF are studied and studied,and the harmonic detection method and current tracking control method used in this paper are analyzed and analyzed in detail.Harmonic detection using unit power factor method,and the introduction of phase-locked loop,to ensure the accuracy of the command current detection.Reasonable debugging PI regulator,so that the DC side of the voltage quickly reach the specified value and stable operation.The control method uses fixed-frequency hysteresis space vector,which is different from the traditional SVPWM.This method eliminates a large number of mathematical operations.It chooses the optimal voltage vector by logic judgment,saves the time and constant frequency so that the ring width satisfies the frequency demand.In MATLAB / Simulink to build simulation model,according to the circuit requirements,the first APF capacity,AC side of the inductor,DC side of the capacitor and voltage parameters of the calculation,build part of the simulation module,integrated simulation circuit.In different load and power conditions,the system simulation,the results.The results show that the APF can meet the requirements based on the fixed-frequency hysteresis space vector.Learning to improve the experimental hardware and software platform,the preparation of hardware corresponding software program.The program part includes the main program and the interrupt service routine,which focuses on the design of the control part of the specific process of detailed analysis.At the same time,other design deficiencies were optimized.In the experimental platform to build experiments,debugging optimization hardware and software configuration.The experimental data were analyzed and the experimental waveforms were observed.The results show that the harmonic current distortion is obviously suppressed,and the effect of the low-order harmonic suppression is obvious,and the feasibility and effectiveness of the fixed-frequency hysteresis space vector APF are verified.