LCL filtering based voltage type active rectifier steady control system and method
A stable control and rectifier technology, applied in electrical components, high-efficiency power electronic conversion, output power conversion devices, etc., can solve problems such as large inductance parameters, weakened ability to attenuate harmonics, and unfavorable filter integration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Publication Date
- 2008-03-12
- Estimated Expiration
- Not applicable · inactive patent
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Abstract
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...
Examples
Embodiment Construction
[0056] The principle of implementation of the present invention will now be described in detail.
[0057] Since the filter capacitor C of the LCL filter f is very small, according to the impedance formula Z c =1 / (jωC f ), it can be seen that the filter capacitor is approximately an open circuit for low-frequency currents and a short-circuit for high-frequency currents. For power frequency current, its ω=100π, so the impedance of the filter capacitor is much larger than the network side inductance L g Large, similar to an open circuit state.
[0058] Remember L ∑ =L g +L, ignoring the loop resistance, the DC bus capacitance is C d , whose voltage is U dc , the load current is i L , the grid three-phase voltage is uga / gb / gc , grid current i ga / gb / gc , and the three-phase current i of the converter side ia / ib / ic approximately equal. Write down the switching function of the rectifier bridge:
[0059]
[0060] According to the voltage / current balance equation:
[00...