DC/AC Converter Control via Adaptive Reference Correction
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Solution Overview
Problem
Existing DC/AC converters exhibit unacceptable deviations from desired electric behavior under varying operating conditions, such as changes in electric loads or power flow direction, leading to instability and poor dynamic response.
Innovation Solution
A method of controlling a DC/AC converter that involves setting a reference correction value based on the desired AC side reference value and actual AC side signal, calculating an AC side reference signal, and generating a converter control signal to iteratively converge the actual AC side signal to the desired behavior, establishing a feedback control loop and a higher control level to mitigate deviations and ensure stable operation across a wider range of conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional control methods are used for DC/AC converters, then the system can operate under basic conditions, but the converter exhibits unacceptable deviations from desired electric behavior when operating conditions change (varying loads, power flow direction changes)
Solution Approach 1:
The patent implements a control method that continuously monitors the actual AC side signal and compares it with the desired AC side reference value. Based on the deviation detected, the controller adjusts the converter control signal to minimize the error, creating a closed-loop feedback system that maintains stable operation under varying conditions.
Solution Approach 2:
The control method dynamically adapts to changing operating conditions by iteratively adjusting the converter control signal based on real-time feedback. The system transitions from static conventional control to dynamic control that responds to varying loads and power flow directions, enabling the converter to maintain desired electric behavior across different operating states.
2Measurement precision
If the control system attempts to maintain high accuracy under all conditions, then precision is improved, but the system becomes overly sensitive to operating condition changes and fails to converge under certain conditions
Solution Approach 1:
The control method modifies the AC side reference signal based on the detected deviation between actual and desired values. By dynamically adjusting reference parameters rather than maintaining fixed high-accuracy targets, the system achieves both precision and adaptability, allowing convergence even when operating conditions change significantly.
Solution Approach 2:
The iterative feedback mechanism allows the system to detect when high accuracy targets become unachievable under certain conditions and automatically adjusts the control approach. The feedback loop continues to reduce deviation progressively, ensuring convergence to acceptable operating points rather than failing to converge entirely.
3Device complexity
If a simple control approach is used, then the device complexity is reduced, but the converter cannot maintain stable operation under varying operating conditions
Solution Approach 1:
The control method enables the DC/AC converter to self-regulate under varying operating conditions through autonomous feedback control. The system monitors its own performance and automatically adjusts control signals without external intervention, maintaining stable operation while avoiding the need for complex external control infrastructure.
Data Source
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AI summary
A method of controlling a DC/AC converter (2) comprises the steps of (a) providing a desired AC side reference value (VAmp); (b) setting a reference correction value (VAmp.corr.1); (c) calculating an AC side reference signal (VAc.set.1) as a function of the desired AC side reference value (VAmp) and the reference correction value (VAmp.corr.1); (d) obtaining an actual AC side signal (VAc.Act.1); and (e) calculating a converter control signal (MAc.1) as a function of the AC side reference signal (VAc.set.1) and the actual AC side signal (VAC,Act.1); wherein the setting of the reference correction value (VAmp.corr.1) is based on a relation of the desired AC side reference value (VAmp) and the actual AC side signal (VAc.Act.1).