Research Of Compound Control Scheme For Two-stage Matrix Converter Based On Fuzzy PI Control And Repetitive Control

Due to the two-stage matrix converter (TSMC) is a device of direct frequency convert, every disturbance of input voltage interferes with the output waveform, as well as voltage drop of output filter inner resistance and load disturbance. In addition, harmonic components are brought to TSMC output voltage for element characteristic, computation error and random disturbance. Therefore, it is very significant to study on TSMC closed-loop control.This paper introduces the topology of TSMC, harmonize control strategy of double space vector of rectifier stage & inverter stage and zero-current commutation scheme. In order to improve the robustness of TSMC under voltage source's sudden change and load disturbance, a closed-loop control method for TSMC based on adaptive fuzzy proportional integral (PI) control is proposed. The line voltage is transformed into DC value in dq rotating coordinate by abc-dq transformation. The adaptive fuzzy PI controller is used to track the d, q components of reference voltage. On the basis of which, in order to get very nice static characteristic and enhance TSMC system ability of harmonic suppression, a novel control scheme of integrating adaptive fuzzy PI controller & repetitive controller for TSMC is proposed. The adaptive fuzzy PI controller is used to improve TSMC system robustness and dynamic performance; the repetitive controller is used to improve its stable performance. Adaptive fuzzy PI controller, of which input is error e and error variety ratio ec, adjusts PI parameters itself in line according to e and ec in different time, and can overcome system performance reducing caused by variety of controlled object parameters and various non-linear uncertain disturbances, so it possesses better robustness and dynamic performance. Repetitive controller correct voltage cycle by cycle using disturbances repetitive characteristic, therefore high quality output voltage waveform is obtained, as well as well stable output and definite robustness. This paper build simulation model by means of MATLAB to test the control scheme validity. TSMC experimental sample device is trial-manufactured, of which result verifies its modulation strategy validity.