Research On Simulative Device Of Typical Non-linear-load

The continuous development and application of power electronics technology brings a lot of convenience to people's life.However,the non-linear-load of power electronic devices inject a lot of harmonics into the power grid,which seriously threatens the safe operation of the power grid.A set of test devices to verify the impact of non-linear-load on power performance is the main purpose of this study.Test equipment in traditional laboratories is typically composed of measured power supplies and common loads.Due to the individuality of the load,and in order to test the performance of different load conditions as much as possible,the traditional test equipment usually takes up a lot of space,and the load switch is very inconvenient.Single-phase transmission of energy in the traditional test brings a lot of energy loss,contrary to the economic principles.In this paper,the typical non-linear-load simulation device designed by using the current cutoff performance of electronic technology can completely replace the traditional load.The advantages of one-load multi-purpose can greatly save the laboratory space resources.The characteristics of energy bi-directional transmission can save the energy loss in the experiment.In this paper,a typical non-linear-load simulator topology of three-phase back-to-back structure is proposed,two converters connect with DC,and the construction method of mathematical model is introduced in detail.Using the whole device IGBT as the basic unit,from the voltage,current,heat dissipation and switching frequency introduced IGBT selection.According to the ripple range to select the appropriate storage capacitor,which is the key to achieve analog output,through the analog output filter performance analysis and comparison,select the LCL filter to improve the output waveform quality.The correct control strategy directly determines the output current accuracy.This paper analyzes the control strategies that may be needed for a typical non-linear-load simulator from a macro perspective.The control principle and parameter design of PI control,dead-zone compensation,repetitive control and SVPWM are introduced in detail.The functions of the feed side and the load side are different,and the control of the specific control is different.The feed side maintains the system power balance under the control of PI control,dead-zone compensation and SVPWM.The load side simulates the current waveform required by the experimental personnel under the control of the multiple control and SVPWM.In the Matlab/Simulink simulation environment,the validity and practicability of the designed control strategy are verified.This paper chooses DSP and FPGA as the main controller,to achieve data sampling,control the calculation and communication transmission function.Use well-designed hardware module to component typical non-linear-load simulator that verifies the machine function when the power is turned on.Experiments show that the design of this paper is reasonable,the normal operation of the machine can maintain the power balance,and accurately simulate the required linear-load and non-linear-load.