PCS Power Allocation With Adaptive Weights for Line Impedance Gaps
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Solution Overview
Problem
Existing power conditioning systems (PCSs) face challenges in achieving even power allocation due to large line impedance differences, leading to unstable operation and reduced electric power quality.
Innovation Solution
A power allocation method and apparatus that dynamically adjusts weights for the reactive-voltage droop control module, micro grid controller, and reactive-voltage differential droop control module based on the output voltage and current of each PCS, ensuring accurate power allocation even with significant line impedance differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large virtual impedance is constructed to compensate for line impedance difference, then power allocation uniformity is improved, but system stability deteriorates and voltage drop increases
Solution Approach 1:
The patent applies dynamics by making the virtual impedance adaptive rather than fixed. The virtual impedance values are dynamically adjusted based on real-time line impedance measurements and system operating conditions. This allows the system to achieve uniform power allocation when needed while maintaining stability under normal operating conditions, resolving the contradiction between power allocation uniformity and system stability.
Solution Approach 2:
The patent changes the parameter of virtual impedance from a large fixed value to variable values that adapt to system conditions. By measuring actual line impedances and calculating appropriate virtual impedance values, the system achieves uniform power allocation without causing the excessive voltage drop and instability associated with large fixed virtual impedances.
2Manufacturing precision
If virtual construction of different line impedances is performed for each PCS, then power allocation uniformity is improved, but implementation complexity increases
Solution Approach 1:
The patent applies self-service by enabling each PCS to autonomously measure its own line impedance and calculate its own virtual impedance value. Each PCS independently determines its power allocation based on its measured parameters, eliminating the need for complex centralized control or manual configuration. This significantly reduces implementation complexity while achieving uniform power allocation.
Solution Approach 2:
The patent uses feedback mechanisms where each PCS continuously measures its output voltage and current, calculates its line impedance, and adjusts its virtual impedance accordingly. This closed-loop feedback approach automatically achieves uniform power allocation without requiring complex external control systems or manual intervention.
3Device complexity
If conventional reactive-voltage droop control is used, then system simplicity is maintained, but power allocation uniformity deteriorates when line impedance difference is large
Solution Approach 1:
The patent segments the control approach by combining conventional reactive-voltage droop control with an additional virtual impedance compensation component. The overall control is divided into the basic droop control part (maintaining simplicity) and the virtual impedance part (achieving uniformity). This segmentation allows the system to maintain the simplicity of conventional control while adding only the necessary elements for uniform power allocation.
Solution Approach 2:
The patent creates a composite control strategy by combining conventional droop control with virtual impedance control. This composite approach integrates the simplicity of traditional methods with the precision of impedance-based compensation, achieving both system simplicity and power allocation uniformity simultaneously.
Data Source
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AI summary
This application provides a power allocation method and apparatus. For any one of a plurality of power conditioning systems, a power conditioning system controller first respectively sends different weight values to a reactive-voltage droop control module, a micro grid controller, and a reactive-voltage differential droop control module based on an output voltage and an output current that are of the power conditioning system; and then, determines a value of a power of the power conditioning system based on a first reference value determined by the reactive-voltage droop control module based on a first weight, a second reference value determined by the micro grid controller based on a second weight, and a third reference value determined by the reactive-voltage differential droop control module based on a third weight, so that power allocation can be evenly performed on each power conditioning system when a large line impedance difference exists between the plurality of power conditioning systems.