PLL Control for Wind Generator Zero-Voltage Ride-Through
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbine generators, particularly those with doubly fed induction generators, are susceptible to grid voltage fluctuations, including zero voltage transients, which can lead to system trips and damage semiconductor devices.
Innovation Solution
A phase-locked loop (PLL) regulator is integrated into the control system to facilitate zero voltage ride through (ZVRT), allowing the generator to remain connected to the grid during zero voltage transients by dynamically adjusting gain constants and clamps based on grid voltage characteristics, thereby mitigating the risk of trips and protecting components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the generator remains connected to the grid during voltage transients, then the reliability and continuous operation is improved, but the semiconductor devices are exposed to damaging voltage fluctuations
Solution Approach 1:
The patent introduces a PLL regulator as an intermediary control mechanism between the generator and the grid voltage fluctuations. The regulator dynamically adjusts gain constants and clamps based on detected grid voltage characteristics, acting as a buffer that protects semiconductor devices from direct exposure to damaging voltage transients while maintaining generator connection to the grid
Solution Approach 2:
The system dynamically changes control parameters (gain constants and clamps) of the PLL regulator based on real-time grid voltage conditions. During voltage transients, the regulator adjusts these parameters to mitigate the harmful effects of voltage fluctuations on semiconductor devices while allowing continuous operation
2Object-affected harmful factors
If the generator is disconnected during voltage transients, then the semiconductor devices are protected, but the system trips and loses continuous operation
Solution Approach 1:
The patent implements a feedback control system using the PLL regulator that continuously monitors grid voltage characteristics and dynamically adjusts control parameters. This feedback mechanism allows the system to protect semiconductor devices during transients while maintaining connection to the grid, preventing trips and ensuring continuous operation
3Reliability
If traditional control systems are used without PLL regulator, then the device complexity is lower, but the system cannot handle zero voltage transients effectively
Solution Approach 1:
The PLL regulator serves multiple functions: it enables zero voltage ride through capability, protects semiconductor devices from voltage transients, and maintains continuous operation. By integrating this multi-functional regulator, the system achieves enhanced reliability without requiring multiple separate protection systems
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A control system 200 for an electrical machine is provided. The electrical machine configured to be electrically coupled to an electric power system, wherein the electric power system is configured to transmit at least one phase of electric power to and from the electrical machine, the control system facilitates the electrical machine remaining electrically connected to the electric power system during and subsequent to at least one voltage amplitude of the electric power operating outside of a predetermined range for an undetermined period of time.