Inverter Output Impedance Angle Detection Method
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Solution Overview
Problem
Current methods lack the ability to accurately and simply detect the output impedance angle of inverters, which is essential for efficient control, especially in low-voltage power grids where active and reactive power coupling is high, hindering effective droop control.
Innovation Solution
A detecting device and method that calculates the output impedance angle of an inverter by controlling it to output voltage and current signals, calculating active and reactive power, and using amplitude parameters to derive the impedance angle, allowing for efficient decoupling of active and reactive power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If droop control is used in low-voltage power grids, then the control method is simple, but the coupling between active power and reactive power is high
Solution Approach 1:
The patent changes the impedance angle parameter from the conventional 90 degrees to a detectable actual value, transforming the control approach to achieve power decoupling while maintaining droop control simplicity
Solution Approach 2:
The patent introduces automatic detection of the output impedance angle as feedback to the control system, enabling the system to adapt to actual grid conditions and achieve effective power decoupling
2Measurement precision
If the output impedance angle is accurately detected, then active and reactive power can be decoupled, but no simple and accurate detection method currently exists
Solution Approach 1:
The inverter detects its own output impedance angle using its own output voltage and current signals, eliminating the need for external detection equipment and simplifying the overall system
Solution Approach 2:
The control unit performs multiple functions including both control and self-detection of impedance angle, reducing system complexity by consolidating functions
Data Source
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AI summary
A detecting method for detecting an output impedance angle of an inverter includes controlling an inverter to output a second voltage signal and a current signal based on a first voltage signal; calculating an active power and reactive power based on the second voltage signal and the current signal; and calculating an output impedance angle of the inverter based on the product of the active power and a first amplitude parameter, the product of the active power and a second amplitude parameter, the product of the reactive power and the first amplitude parameter, and the product of the reactive power and the second amplitude parameter. The first amplitude parameter corresponds to a first amplitude of the first voltage signal, and the second amplitude parameter corresponds to the first amplitude of the first voltage signal and a second amplitude of an AC voltage.