Thyristor Valve Testing Apparatus With Auxiliary Valve Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thyristor valves in high voltage direct current (HVDC) systems face challenges in testing due to excessive current and voltage stress, requiring a method to artificially apply rated current and voltage for performance verification without causing damage.
Innovation Solution
An apparatus comprising a current source circuit, a voltage source circuit, and an auxiliary valve to protect the current source from high voltage, using a chopper circuit to supply current when the thyristor is on and a resonant circuit to apply reverse or forward voltage when it's off, with configurations including DC source circuits, chopper and resonant circuits, and switches like IGBTs and IGCTs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high voltage and large current are applied to the thyristor valve to test performance, then the testing accuracy is improved, but the current source circuit may be damaged by high voltage
Solution Approach 1:
The patent introduces a first auxiliary valve as an intermediary component between the current source circuit and the voltage source circuit. This auxiliary valve acts as a mediator that protects the current source circuit from high voltage while allowing the voltage source circuit to function. The auxiliary valve is strategically positioned to block high voltage from reaching the current source circuit during voltage testing, thereby resolving the contradiction between testing accuracy and circuit safety.
2Adaptability or versatility
If separate circuits are used for current and voltage testing, then the testing capability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the current source circuit and voltage source circuit into a single integrated testing apparatus. Instead of using completely separate circuits, the invention combines both functions in one system with shared components. The first auxiliary valve serves dual purposes: protecting the current source circuit during voltage testing and enabling proper current flow during current testing. This merging approach maintains versatile testing capability while reducing overall device complexity.
3Device complexity
If the auxiliary valve is not provided, then the circuit simplicity is maintained, but the current source circuit is exposed to high voltage damage
Solution Approach 1:
The patent implements beforehand cushioning by pre-positioning the first auxiliary valve between the current source circuit and the voltage source circuit. This auxiliary valve is already in place before voltage testing begins, creating a protective barrier that prevents high voltage from reaching the current source circuit. The auxiliary valve is configured to block high voltage during voltage testing while allowing current flow during current testing, providing continuous protection without adding significant complexity to the circuit.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient testing of current and voltage stress on thyristor valves by selectively applying current and voltage, enhancing operational simplicity and economic efficiency while protecting the current source circuit from high voltage.
Implementation Method 1
a chopper circuit that steps down an output voltage from the first DC source circuit section
Implementation Method 2
a voltage source circuit that provides a reverse voltage or a forward voltage when the thyristor valve is turned off
Data Source
AI summary
An apparatus for testing a thyristor valve includes: a current source circuit that provides an electric current when a thyristor valve as a test target is turned on; a voltage source circuit that provides a reverse voltage or a forward voltage when the thyristor valve is turned off; and a first auxiliary valve provided between a connection point between the thyristor valve and the voltage source circuit and the current source circuit, and that insulates the current source circuit from the voltage source circuit to protect the current source circuit from a high voltage of the voltage source circuit.