Based On The Research Of Feedback Linearization Control Of PWM Rectifier

The traditional PWM converter is mainly used in diode or thyristor to implement the phase-controlled or non-controlled rectifier technology. This circuit is a relatively simple structure, control technology is matured, so it has been in a dominant position in the PWM inverter circuit. With the advances of the science and technologies nowadays, there are a lot of countries start to pursue the development of green energy technologies, but the traditional converter technology is also increasingly obvious shortcomings, the low energy utilization will bring a lot of power harmonic current, and it will be the advantage of the two-way transmission circuit. Therefore, the use of full-controlled power electronic switching devices will achieve results from the PWM converter technology. By controlling the PWM pulse signal to the switching device operation, this method can achieve sinusoidal line current, power factor and energy. It can be a two-way adjustable flow characteristic to achieve a green energy transformation and to take the advantage of the new energy. On the current control strategy, the indirect control current from the early to the current direct control and current nonlinear control method, it can be said that control technology has been in constant development. In this paper, the nonlinear control method is now more advanced as a research strategy for voltage-type PWM converter for comprehensive studies.Firstly, detailed in-depth analysis of the operating characteristics of PWM converter and works, then PWM converter operates in the state rectifier and inverter status, the role of the switch-mode current loop to do a detailed explanation, the establishment of a mathematical model of the system in three coordinates.Then, in-depth analysis of the linear control theory and control method of nonlinear control system input and output feedback, and were the two feedback linearization control method theoretical derivation. By combining the feedbacks, linearization control method gives multiple inputs and outputs to block the diagram of the control system. Next, based on the control theory in the zero-pole configuration method, it is to derive control tracking feedback.Finally in Matlab Simulink simulation environment is established based on input-output feedback on the PWM inverter control system structure model linearization method and the conventional PI control method. Comparison of the respective grid system voltage and current waveforms, the DC bus voltage waveform is active and reactive current waveforms in both control methods, this system results in the input-output linearization control method and there are some advantages in the traditional PI control method.