Wind Power Plant Controller Voltage Mode Switching
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Solution Overview
Problem
Wind power plants face challenges in maintaining stable voltage levels, as the highest wind turbine voltage level may exceed safe limits due to impedance variations, leading to potential damage from overvoltage or undervoltage conditions, which can cause disconnection from the grid.
Innovation Solution
A method for controlling wind power plants involves determining voltage levels and switching operational modes of the power plant controller between power factor, voltage, and reactive power control to maintain voltage within safe ranges, using a hysteresis control algorithm and ramping to ensure smooth transitions and prevent disconnection.
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 voltage compensation is improved, but the risk of overvoltage damage to the internal grid increases
Solution Approach 1:
The control system continuously monitors the voltage level at the point of common coupling and adjusts the wind turbine voltage output dynamically. When voltage drops are detected, the system increases voltage compensation; when voltage levels approach unsafe thresholds, the system reduces compensation. This closed-loop feedback mechanism resolves the contradiction by adapting voltage output to actual grid conditions rather than using fixed high compensation levels.
Solution Approach 2:
The patent implements dynamic voltage control that adjusts the voltage level of wind turbines based on real-time measurements of the internal power grid's impedance and voltage conditions. Instead of maintaining a static high voltage level for compensation, the system dynamically modulates voltage output to provide necessary compensation while staying within safe operational limits, thus resolving the contradiction between compensation effectiveness and overvoltage risk.
2Productivity
If the wind turbine operates at high impedance locations, then power generation capability is maintained, but voltage levels may exceed safe limits
Solution Approach 1:
The control system changes the voltage parameter dynamically based on the measured impedance characteristics of the internal power grid. At high impedance locations where voltage drops are more severe, the system increases voltage output to maintain power generation capability. However, it simultaneously adjusts the voltage parameter downward when approaching safe limits, thus maintaining productivity while ensuring voltage safety through parameter adaptation.
Solution Approach 2:
The patent applies localized voltage control tailored to each wind turbine's specific position and impedance characteristics within the internal power grid. Each turbine's voltage output is independently adjusted according to its local grid conditions, allowing turbines at high impedance locations to generate power while maintaining voltage safety, and turbines at low impedance locations to operate with standard voltage levels.
3Reliability
If the power plant controller switches operational modes frequently to maintain voltage levels, then voltage stability is improved, but control system complexity increases
Solution Approach 1:
The control system implements periodic measurement and evaluation of voltage levels at the point of common coupling, switching between operational modes (voltage control, active power control, reactive power control) based on predetermined voltage thresholds. This periodic monitoring and conditional switching provides voltage stability through systematic mode changes while managing complexity through structured, rule-based control logic rather than continuous complex calculations.
Data Source
AI summary
The present invention relates to a method for controlling a wind power plant, comprising one or more wind turbine generator(s) connected to an electrical grid, and a power plant controller having an operational mode, controlling electrical parameters, wherein the method comprises, determining a first voltage level of one or more wind turbine generator(s), determining if the first voltage level of one or more wind turbine generator(s) is outside a first predetermined range, in case the first voltage level of one or more wind turbine generator(s) is outside a first predetermined range then, changing the operational mode of the power plant controller between first and second operational modes, the first operational mode controlling a first electrical parameter, the second operational mode controlling a second electrical parameter, the first and second parameters being different. The present invention also relates to a power plant controller and a wind power plant operated according to the method.