LCL filtering based voltage type active rectifier steady control system and method

Abstract

The utility model relates to a voltage type source rectifier stable control system and method based on LCL filter wave, belonging to the source rectifying technical range of electronic technology. The system comprises a DC voltage control cell, a current control cell, an active damp control cell and a voltage space vector generating cell. the utility model produces six PWM signals to gain the current signal of the filter wave capacitor branch directly or indirectly, outputs the reference value of the damp voltage and achieves the stable control on the system. The method provides an adjustable sine control on the DC voltage output and input current through the active damp vector control of the voltage type source rectifier stable control system, the damp voltage reference value outputted by the active damp vector control cell, and the network voltage to execute summation operation. The utility model has the advantages of controllable DC voltage, low aberrance rate of the network input current, high power factor, satisfying the requirement of energy double-redirection flowing, and achieving the stability of the system without increasing the quantity of hardware damp resistance.

Description

technical field [0001] The invention belongs to the technical scope of active rectification in power electronic technology, and in particular relates to a voltage-type active rectifier stability control system and method based on LCL filtering. More specifically, the present invention relates to a voltage space vector control method with an active damping unit that can be applied to an inductor-capacitor-inductor (LCL) filtered voltage-type active rectifier. The active damping unit realizes the stability of the unstable system stability control. Background technique [0002] Active rectification technology is an important field in the development of power electronics technology. Voltage source active rectifier (Voltage Source active Rectifier) ​​has the advantages of controllable DC voltage, low input current distortion rate at the grid side, high power factor and bidirectional energy flow, etc. It is used in renewable energy grid-connected power generation, hybrid parallel...

AI Technical Summary

Problems solved by technology

These high-frequency components may adversely affect equipment connected in the line that is particularly sensitive to electromagnetic interference

[0004] In order to reduce the harmonic component of the grid-side current near the switching frequency to avoid harmonic pollution, the traditional voltage-type active rectifier using inductive filtering, as shown in Figure 1, has to choose a larger inductance parameter

Using a large inductance as an input filter brings two problems: one is that a large inductance means an increase in manufacturing cost and volume; the other is that a large inductance reduces the dynamic performance of the system

This method is simple and reliable, and does not need to change the controller structure and parameters, but it also has some shortcomings: the efficiency of the system is reduced due to the loss of the damping resistor; the ability to attenuate harmonics is limited due to the increase of the impedance of the capacitor branch due to the damping resistor Weaken, the content of harmonic current in grid side current increases

This method has the following disadvantages: it does not consider the delay problem of the actual digital controller. In the case of delay, the transformation of the system transfer function is very difficult; the differential component of the filter capacitor current is introduced, and the digital controller is easy to introduce high frequency Component interference

[0015] (2) V. Blasko in the literature "V Blasko, V Kaura. A novel control to actively dampen resonance in input LC filter of a three phase voltage source converter [J]. IEEE Transactions on Industry Applications, 1997, 33 (2): 542- 550". An active damping method based on the lead-lag module (Lead-Lag) filter capacitor voltage feedback is proposed. This method needs to collect the filter capacitor voltage, which is not conducive to the integration of the filter. At the same time, the selection of the parameters of the Lead-Lag module is very troublesome. Need to repeat the calibration calculation

[0016] (3) Macro Liserre in the literature "M Liserre, A Dell'Aquila, F Blaabjerg. Genetic algorithm-based design of the active damping for an LCL-filterthree-phase active rectifier[J]. IEEE Transactions on Power Electronics, 2004, 19 (1): 76-86." proposed an active damping method based on a genetic algorithm without adding a voltage / current sensor, but obviously due to the complexity of the genetic algorithm, it cannot be applied in industry

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