Converter Reactive Current Control for Grid Fault Voltage Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power supply systems experience instability and low security due to converters repeatedly adjusting reactive currents in response to power grid faults, leading to circuit oscillation and increased resistance, especially in high-resistance power grids.
Innovation Solution
A power supply system with a converter circuit and drive control circuit that adjusts reactive currents to maintain voltage stability by increasing or decreasing output currents based on predefined trigger and recovery voltage values, ensuring stable operation during grid faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the converter increases reactive current output to maintain voltage during power grid faults, then the voltage stability is improved, but the converter repeatedly adjusts current causing circuit oscillation and reducing system stability
Solution Approach 1:
The control method predicts future voltage trends based on historical voltage data before faults fully develop. By performing preliminary voltage prediction and taking preventive action, the system avoids the need for repeated reactive current adjustments, thereby maintaining voltage stability while preventing circuit oscillation and preserving system stability.
2Reliability
If the converter continuously adjusts reactive current in response to voltage changes, then the voltage ride-through capability is improved, but the control complexity and response time increase
Solution Approach 1:
The system performs preliminary voltage prediction using historical data and trend analysis before actual voltage deviations occur. This advance preparation enables the converter to respond more quickly and accurately to voltage changes, improving ride-through capability while reducing the effective response time by avoiding delayed reactive adjustments.
3Adaptability or versatility
If the power grid has high resistance, then the grid can accommodate more distributed power generation, but increasing reactive current significantly increases the voltage drop across the grid
Solution Approach 1:
The control method predicts voltage drops caused by high grid resistance before they become problematic by analyzing historical voltage patterns and power generation data. This preliminary prediction allows the system to proactively adjust operating parameters and coordinate reactive current output, thereby accommodating distributed power generation in high-resistance grids while minimizing excessive voltage drops and energy losses.
Data Source
AI summary
A converter circuit is configured to output a first reactive current to a power grid when a voltage value of an output port of the converter circuit decreases from a first working voltage value to a second working voltage value. The drive control circuit is configured to: in a process in which the converter circuit outputs the first reactive current to the power grid, when it is detected that the voltage value of the output port of the converter circuit increases to a third working voltage value and the third working voltage value is greater than or equal to a first recovery voltage value, control the converter circuit to output a second reactive current to the power grid, to recover the voltage value of the output port of the converter circuit to the first working voltage value.