Voltage Source Converter Module Utilization Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Voltage source converters in HVDC power transmission networks face challenges in maintaining optimal module utilization, leading to reliability issues and impaired voltage source capabilities due to either under or over utilization of modules, which is not effectively addressed by existing control methods.
Innovation Solution
A method of controlling voltage source converters by establishing a utilization peak and target utilization, determining a control function to adjust the number of modules providing a voltage source, and modifying the operating cycle average module voltage through corrective current adjustments, ensuring optimal module utilization and voltage source management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of modules providing voltage source is increased, then the voltage source capability is improved, but the module utilization becomes overly high which impairs the ability to provide increased voltage source when necessary
Solution Approach 1:
The control method establishes a utilization peak based on the actual peak number of modules providing voltage source, compares it with a target utilization, and determines a control function based on the difference to drive the utilization peak towards the target utilization in subsequent operating cycles
Solution Approach 2:
The control function dynamically adjusts the operating cycle average module voltage of the modules within the chain-link converter, modifying the magnitude of voltage source provided by each module to optimize utilization while maintaining power capability
2Reliability
If the number of modules providing voltage source is decreased, then the module utilization becomes overly low which requires each module to provide higher individual voltage, but this adversely impacts the reliability of the modules
Solution Approach 1:
The control method continuously monitors the utilization peak and compares it with the target utilization, using the difference to generate a control function that adjusts the operating cycle average module voltage to maintain optimal utilization levels
Solution Approach 2:
The control function modifies the operating cycle average module voltage parameter, which directly impacts the number of modules needed to provide a given voltage source, thereby optimizing both reliability and power capability
Data Source
AI summary
A method of controlling a voltage source converter including at least one converter limb, each converter limb including limb portions, at least one limb portion including a chain-link converter having modules, each module including at least one switching element and at least one energy storage device, which combine to selectively provide a voltage source, comprising the steps of: establishing during an operating cycle of the chain-link converter a utilization peak based on the actual peak number of modules providing a voltage source; establishing a target utilization based on a desired number of modules providing a voltage source during the operating cycle; and determining a control function based on a difference between the established utilization peak and the target utilization which alters the peak number of modules providing a voltage source during a subsequent operating cycle of the chain-link converter so as to drive the utilization peak towards the target utilization.