Converter Generator-Side Voltage Control for DC Utilization
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Solution Overview
Problem
Existing converter technologies face issues of low DC voltage utilization, overmodulation, and reduced efficiency in electric transmission due to a constant control target value for the generator-side terminal voltage.
Innovation Solution
A method and device for dynamically controlling the generator-side terminal voltage of a converter by determining a target value upper limit based on the current DC bus voltage and minimizing the generator-side current, thereby optimizing the target voltage setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a constant control target value for field weakening voltage is used, then the control system is simple to implement, but the DC voltage utilization rate decreases and overmodulation occurs in certain working conditions
Solution Approach 1:
The patent applies dynamics by transforming the constant control target value into a dynamic variable that changes with operating conditions. The control target value is calculated based on real-time parameters including DC voltage, generator speed, and current, allowing the system to adapt to different working conditions and avoid overmodulation while maximizing DC voltage utilization.
Solution Approach 2:
The patent changes the control parameter from a fixed constant to a dynamically calculated value that varies with system state. By continuously adjusting the control target value based on measured parameters (DC voltage, generator speed, current), the system optimizes performance across different operating points while preventing overmodulation issues.
2Device complexity
If a constant control target value is used, then the control algorithm is simple, but the efficiency of the electric transmission chain decreases
Solution Approach 1:
The control algorithm dynamically adjusts the target value based on real-time system state, enabling optimal operation across different working conditions. This dynamic approach reduces energy losses by ensuring the converter operates at peak efficiency points rather than being constrained by a fixed target value.
Solution Approach 2:
The patent implements feedback by continuously measuring system parameters (DC voltage, generator speed, current) and using these measurements to calculate and adjust the control target value. This closed-loop approach ensures the system adapts to changing conditions and maintains optimal efficiency.
3Loss of energy
If the control target value is optimized for minimum generator current, then the transmission efficiency improves, but the control system complexity increases
Solution Approach 1:
The control target value is transformed into a calculated parameter that varies with system state to minimize generator current. By using mathematical relationships between system parameters, the patent achieves current minimization without requiring complex control structures, balancing performance optimization with implementation feasibility.
Data Source
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AI summary
The present application provides a method and device for controlling a generator-side terminal voltage of a converter, and a controller of the converter. The method includes: determining (S10) a target value upper limit of the generator-side terminal voltage based on a current voltage value of a direct-current (DC) bus of the converter, wherein the generator-side terminal voltage is a terminal voltage of a generator whose output terminal is connected to the converter; determining (S20) a target value of the generator-side terminal voltage that is able to minimize a generator-side current at present, and using the determined target value of the generator-side terminal voltage as an optimal target value of the generator-side terminal voltage, wherein the generator-side current is an output current of the generator; setting (S30) the target value of the generator-side terminal voltage based on the determined target value upper limit of the generator-side terminal voltage and the optimal target value of the generator-side terminal voltage.