Parallel Matrix Converter Control for Dynamic Reactive Power Compensation
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Solution Overview
Problem
Existing high-power multi-functional efficient charging systems based on unidirectional topology can only charge batteries and cannot feed energy back to the grid, and high frequency link matrix converters with LC filters at the AC side suffer from phase deviation between voltage and current, limiting reactive power compensation to fixed values and sometimes causing over or undercompensation.
Innovation Solution
A power compensation control method and apparatus that utilizes a topology structure of at least two parallel high frequency link matrix converters, calculating phase differences between input voltage and ideal reference current phases, rotating space current vectors to achieve zero total instantaneous reactive power, and generating control pulse signals to act on the converters for dynamic power compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single high frequency link matrix converter is used, then the system structure is simple, but the reactive power compensation is fixed and cannot adapt to changing power grid conditions
Solution Approach 1:
The system divides the single converter function into multiple parallel converters, where odd-numbered converters maintain original operation and even-numbered converters perform space vector rotation. This segmentation allows the system to maintain structural simplicity while achieving adaptive reactive power compensation through coordinated operation of multiple units.
Solution Approach 2:
The patent introduces dynamic space vector rotation for even-numbered converters based on real-time phase difference calculations. This dynamic adjustment enables the system to adapt to changing power grid conditions by continuously modifying the operating state of converters, transforming fixed compensation into flexible, real-time adaptive compensation.
2Object-affected harmful factors
If LC filter is added to reduce harmonics, then power quality improves, but phase deviation between voltage and current increases causing fixed reactive power compensation
Solution Approach 1:
The system continuously monitors the phase difference between input voltage and reference current, and uses this feedback to dynamically calculate the required space vector rotation angle for even-numbered converters. This closed-loop feedback mechanism compensates for the phase deviation introduced by LC filters, maintaining adaptive compensation capability despite the presence of filters for harmonic reduction.
Solution Approach 2:
The patent changes the operating parameters of even-numbered converters by rotating their space vectors based on calculated phase differences. This parameter adjustment compensates for the fixed phase shift caused by LC filters, enabling the system to maintain flexible reactive power compensation while benefiting from the harmonic filtering provided by the LC circuits.
3Power
If multiple parallel converters are used, then system capacity and adaptability increase, but control complexity and coordination difficulty increase
Solution Approach 1:
The control system is segmented into simple, repeating units where each converter follows a clear rule: odd-numbered converters operate normally while even-numbered converters apply space vector rotation. This segmentation reduces control complexity by providing a systematic, easily implementable control strategy that scales with the number of converters.
Solution Approach 2:
The system pre-establishes the control pattern where odd and even converters have different operating modes. This preliminary arrangement simplifies real-time control by eliminating the need for complex coordination algorithms, as each converter's behavior is predetermined based on its position in the parallel configuration.
4Adaptability or versatility
If space vector rotation is applied to even-numbered converters, then dynamic reactive power compensation is achieved, but control algorithm complexity increases
Solution Approach 1:
The patent applies dynamic space vector rotation to even-numbered converters based on real-time phase difference calculations. This dynamic approach achieves adaptive reactive power compensation by continuously adjusting converter operation to match changing grid conditions, transforming the control algorithm from static to dynamic while maintaining implementability through systematic rules.
Data Source
AI summary
A power compensation control method and apparatus for a high-power multi-functional efficient charging system. A topology structure of the charging system includes at least two parallel high frequency link matrix converters. The power compensation control method includes: calculating a difference between an input voltage phase of an ith converter and an ideal reference input current phase under a dq two-phase synchronous rotating coordinate system, where i is an odd number; calculating, according to the above difference, a required rotating phase angle of a space current vector of an (i+1)th converter, where by total instantaneous reactive power at input sides of the ith converter and the (i+1)th converter is zero; correspondingly rotating the vector, and judging a sector to which the rotated vector belongs; and generating a corresponding control pulse signal based on the corresponding sector and modulation ratio, so as to act on the (i+1)th converter to realize power compensation.