Research On Control Strategy Of IAMC With Input Unbalance

Isolated AC-DC matrix converter(IAMC)has the advantages of traditional PWM rectifier three-phase sinusoidal current input and adjustable power factor.In addition,no large DC-side capacitor was required,the system was small,the cost was low,and the reliability was high.It has been widely used in V2 G systems,DC microgrid systems and other fields.Because of these applications,the system needs the ability to run stably for a long time.However,during the actual operation of the IAMC,the working environment was relatively complicated,and the voltage unbalance on the grid side will directly affect the waveform quality of the output side.Therefore,corresponding measures need to be taken to control the system.The main research contents of this article are as follows:This article first introduces the research background and significance of the subject,and expounds the research status of matrix converter topology and control strategy under input unbalance.then introduces the IAMC topology and its commonly used bipolar current space vector modulation strategy,and the working mode of its circuit was analyzed,which provides a theoretical basis for the control strategy research in the following part.Then,the mathematical model of IAMC was established,the IAMC based on the conventional fixed frequency direct power control method(DPC-SVM)was analyzed.Secondly,the power model based on a novel instantaneous power analysis method under input unbalance was established,and a deadbeat direct power control method based on active damping was proposed.Combining active damping control and deadbeat direct power control strategy,the proposed control method was simple in principle,does not require rotation coordinate transformation,and eliminates the traditional active damping capacitor voltage sensor.A simulation model based on the proposed control method was built.The simulation results verify that the proposed control method can effectively suppress the resonance of the LC filter on the input side,and can ensure that the input and output waveform quality of the system was better under the input unbalance.Finally,an experimental prototype was built to introduce the design of the hardware circuit in detail.a control system with DSP and CPLD as the control core was designed to realize the IAMC modulation strategy and a deadbeat direct power control method based on active damping.the experimental results verify the correctness of the proposed control method.