In three-phase applications, the six-switch boost power factor correction rectifier is the most widely employed topology because of its good performance and cost effectiveness. A vast amount of literature that deals with this circuit is exclusively focused on various control schemes aimed at optimizing different aspects of its steady-state and/or transient performance. However, almost no literature is available on its startup procedure, which is an indispensable part of control design of any practical circuit. To fill this gap, in this paper, a detailed startup procedure is described. This three-step startup procedure ensures that the inrush currents stay below a specified level and that the output voltage increases monotonically to its reference value, i.e., it does not exhibit any overshoot. The proposed startup procedure is illustrated with MATLAB/Simulink simulation waveforms and also experimentally verified.

http://www.deltartp.com/dpel/dpeltechjournals/06883141.pdf

Startup Procedure for DSP-Controlled Three-Phase Six-Switch Boost PFC Rectifier

This paper presents an integrated control strategy to achieve fast start-up and enable wide input frequency operation in a three-phase six-switch power factor correction (PFC) converter. Limiting the inrush current with simultaneously minimizing the start-up time is achieved by implementing a nonlinear compensator in the voltage control loop. In addition, the concerning issues regarding unity PFC operation with an accurate reference tracking in a system with wide input frequency variation (typical for more-electric-aircraft) are resolved by a second-order compensator integrated with a state-feedback controller in the current loop. For a proof-of-concept verification, a hardware prototype of 6 kW, three-phase six-switch PFC is developed and tested with the proposed integrated control strategy in a wide source frequency range (360–800 Hz) ac input that shows perfect unity power factor operation throughout. Both the start-up time and inrush current are reduced to $ of their values in conventional PI compensation.

An Integrated Control Strategy for a Fast Start-Up and Wide Range Input Frequency Operation of a Three-Phase Boost-Type PFC Converter for More Electric Aircraft

When a PWM rectifier has a low DC-link voltage during startup, the output voltage vector cannot be high enough to regulate the input current. This lack of a PWM rectifier output voltage vector can cause an unregulated inrush current when the rectifier operation starts. This paper presents a PWM rectifier start-up current control algorithm for when it starts operation with a lower DC-link voltage than unloaded condition case. To avoid the unregulated inrush current caused by a lack of DC-link voltage, the proposed control scheme regulates the one phase current with one switch chopping and it generates the current command considering the uncontrolled current magnitude information, which is calculated in advance. Simulation and experiment results support the validity of the proposed method.

/pdf/start-up-current-control-method-for-three-phase-pwm-4uoq4qxdy0.pdf

Start-Up Current Control Method for Three-Phase PWM Rectifiers with a Low Initial DC-Link Voltage

In three-phase applications, the six-switch boost PFC rectifier is the most widely employed topology because of its good performance and cost effectiveness. A vast amount of literature that deals with this circuit is exclusively focused on various control schemes aimed at optimizing different aspects of its steady-state and/or transient performance. However, no literature is available on its start-up procedure which is an indispensable part of control design of any practical circuit. To fill this gap, in this paper, a detailed start-up procedure is described. This three-step start-up procedure ensures that the inrush currents stay below a specified level and that the output voltage increases monotonically to its reference value, i.e., it does not exhibit any overshoot. The proposed start-up procedure is illustrated with Matlab/Simulink simulation waveforms and also experimentally verified.

/pdf/start-up-procedure-for-three-phase-six-switch-boost-pfc-3xkikitg8a.pdf

Start-up procedure for three-phase six-switch boost PFC rectifier

Stationary frame deadbeat power control of three-phase PWM rectifiers under unbalanced grid voltages

Usually, the control method with voltage and current PI regulators in synchronous rotating frame is applied to three-phase voltage source PWM rectifier. It is easy to generate inrush current during startup period. A slow ramp reference current is commonly used to achieve the soft starting, but not quite effective. The paper first analyzed the cause of inrush current and obtained the shortcomings of traditional PI method and slow ramp reference method. Then a feedforward compensation was proposed to decrease the inrush current. After analysis and comparison, the feedforward compensation method has the best performance. Finally, an experimental prototype of a three-phase voltage source PWM rectifier controlled by a TMS320F2812 DSP was built and tested. The experimental results verified the validity of the analysis.

A study of startup inrush current of three-phase voltage source PWM rectifier with PI controller

Usually, the deadbeat control strategy is applied to three-phase voltage source PWM rectifiers. Often, deadbeat control uses a forward predictive algorithm of the reference current to compensate the control delay. Because of the uncertainty of reference variations, single predictive algorithm may cause large current overshoot or phase delay in different reference changes. The paper obtained the relationship among the prediction parameter, the current overshoot, and the phase delay after comparing and analyzing three commonly used predictive algorithms. Based on it, a new predictive algorithm was introduced using fuzzy control method. This algorithm chose appropriate prediction parameter according to different reference current changes, which was a tradeoff between current overshoot and phase delay. As a result, the maximum value of current overshoot was limited and the phase delay was optimized. Finally, an experimental prototype of a three-phase voltage source PWM rectifier controlled by a TMS320F2812 DSP was built and tested. The experimental results verified the validity of the proposed control approach.

Qu Bo

Papers

A study of startup inrush current of three-phase voltage source PWM rectifier with PI controller

An Optimized Deadbeat Control Scheme Using Fuzzy Control in Three-Phase Voltage Source PWM Rectifier