Power Converter Impedance Estimation for Adaptive Control
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Solution Overview
Problem
Power converters face challenges in maintaining stable control due to varying system impedance, leading to increased component size and cost, as it is difficult to gauge impedance values in future installation environments.
Innovation Solution
A power converter with an impedance estimation unit that injects a disturbance signal into the load, measures the voltage response, and sets control parameters for impedance compensation, allowing for adaptive control based on actual load characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If control parameters are set with a margin built into the inductance value to account for maximum impedance, then control stability is improved, but component size and cost increase
Solution Approach 1:
The patent applies dynamics by making the control parameters adaptive rather than fixed. The control parameter setting unit dynamically adjusts control parameters based on real-time impedance detection results, allowing the system to optimize performance for the actual installation environment rather than relying on conservative fixed margins that increase component size.
Solution Approach 2:
The patent changes parameters by detecting actual impedance values and adjusting control parameters accordingly. The control parameter setting unit modifies control parameters based on detected impedance, enabling the system to adapt to different installation environments without requiring oversized components designed for worst-case scenarios.
2Reliability
If control parameters are set with a margin built into the inductance value to account for maximum impedance, then control stability is improved, but cost increases
Solution Approach 1:
The system dynamically adjusts control parameters based on detected impedance values, eliminating the need for conservative fixed margins that increase cost. This adaptive approach allows cost-effective component selection while maintaining control stability through real-time parameter optimization.
Solution Approach 2:
By changing control parameters based on actual impedance detection, the system avoids the cost penalty of designing for maximum impedance margins. The control parameter setting unit optimizes parameters for the specific installation environment, reducing overall system cost while maintaining reliability.
3Measurement precision
If impedance detection is performed to enable adaptive control, then control accuracy is improved, but device complexity increases
Solution Approach 1:
The patent implements feedback by detecting impedance values and using this information to adjust control parameters. The impedance detection unit provides feedback to the control parameter setting unit, creating a closed-loop system that improves control accuracy without requiring complex manual configuration or calibration procedures.
Solution Approach 2:
The system performs self-service by automatically detecting impedance and adjusting its own control parameters without external intervention. The control parameter setting unit autonomously optimizes parameters based on detected impedance, simplifying the overall system while improving measurement precision through built-in detection capabilities.
Data Source
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AI summary
A power converter (100) is provided with an inverter unit (3) for converting DC power from a DC power supply into AC power, and a control unit (10) that generates a control signal for controlling the inverter unit. The control unit (10) includes an impedance estimation unit (14) that injects a disturbance signal into a load (6) and derives an estimated value of an impedance of the load based on a voltage signal from the load into which the disturbance signal is injected, the impedance compensator unit (13) whose control parameters are set based on the estimated value of the impedance, and that corrects an output current signal in accordance with the control parameters, a command value unit (12) that outputs a command value indicating a control target value, and a control compensator unit (11) that generates a control signal, based on the command value and the current signal.