Research And Design Of Three-phase Voltage Type SVPWM Rectifier

Due to the massive applications of nonlinear loads in power systems, the traditional diode and the controllable silicon rectifier can cause distortions of the terminal voltage and current when commutation, during which some "pollution" is occurred in power systems caused by harmonic, especially in the interfaces and networks between all kinds of electronic equipment. As a result, plenty of harmonic pollution leads to a low power factor. PWM rectifier can make itself have the advantages of sinusoidal input current by applying appropriate controls on the AC side. Meanwhile, having the same phase with the input voltage, PWM rectifier can realize the normal operation under a unity power factor. The two sides together can promote the maximum improvement of economic benefits, besides, they can help to reduce the electromagnetic pollution on the environment nearby made by power systems.In this paper, the topology structure、working principle and control strategy of PWM rectifier are studied intensively. Based on the topology structure of three-phase two-level voltage, PWM rectifiers’ mathematical models are established respectively under the three-phase static coordinate and the two-phase rotational coordinate. According to the established rectifier models, the double closed-loop control strategy which consists of outer voltage and inner current loop is made. Adjust the PI parameters of the regulator, and analyze the PWM control style of the voltage vector space.In order to verify the effectiveness of this control method, we should do as follows. First of all, set up the system model by using Simulink of MATLAB. Secondly, start the hardware design of rectifiers, including designs of the main circuit、control circuit、A/D sampling buffer and protection circuit、IGBT driving circuit、absorbing circuit、analog signal transformation circuit、PWM output logic control circuit、the output relay control circuit design and so on. Thirdly, we still need software design. In terms of software design, we adopt TMS320F28335 chip made by TI company as the core, and use CCS as a platform to write relevant programs. Finally, the experimental results verified the effectiveness of the control method.