Wind Power Plant Output Voltage Control for Grid Protection
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Solution Overview
Problem
Wind turbine voltage levels within a wind power plant often approach or exceed predetermined safety levels due to impedance variations, risking damage from overvoltage or undervoltage conditions, as existing methods fail to maintain sufficient protection margins.
Innovation Solution
A method is implemented to determine the highest and lowest wind turbine voltage levels, adjusting the wind power plant's output voltage to maintain a safe margin by setting it within a predetermined range relative to the point of common coupling, using a variable transformer ratio and control signals to ensure overvoltage and undervoltage protection, thereby preventing equipment damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wind turbine voltage level is increased to compensate for voltage drops in the internal power grid, then the voltage compensation effect is improved, but the risk of overvoltage damage to the internal grid increases
Solution Approach 1:
The control system continuously monitors the voltage levels at multiple wind turbines and uses this feedback information to dynamically adjust the voltage setpoints. The controller calculates the actual voltage drops based on measured values and adjusts the voltage compensation accordingly, preventing overvoltage conditions while maintaining effective compensation.
Solution Approach 2:
The invention changes the voltage parameter dynamically by adjusting the voltage setpoints of individual wind turbines based on their specific impedance characteristics and real-time grid conditions. The controller modifies voltage levels within a range around the nominal voltage, optimizing compensation while preventing overvoltage damage.
2Object-affected harmful factors
If the wind turbine voltage level is decreased to maintain safety margins, then the overvoltage protection is improved, but the voltage compensation effectiveness deteriorates
Solution Approach 1:
The invention applies different voltage levels to different wind turbines based on their local impedance characteristics and distance from the point of common coupling. Each wind turbine receives a customized voltage setpoint that provides adequate compensation for its specific voltage drop while maintaining safety margins, rather than applying a uniform voltage level to all turbines.
3Adaptability or versatility
If the output voltage level is dynamically adjusted, then the adaptability to grid conditions is improved, but the control system complexity increases
Solution Approach 1:
The control system pre-calculates appropriate voltage setpoints for each wind turbine based on their impedance characteristics and the nominal operating conditions. These preliminary voltage references are then adjusted in real-time within a defined range around the nominal voltage, combining proactive planning with reactive adaptation without requiring overly complex real-time calculations.
Data Source
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AI summary
The present invention addresses the problem of avoiding that wind turbine voltage levels within a wind power plant do not exceed predetermined overvoltage and/or undervoltage protection levels. In particular, the present invention relates to shifting of an output voltage level of a wind power plant in order to protect an internal power plant grid against overvoltages.