Passive Thyristor Tap Changer for Reliable Switching Without External Triggers
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Solution Overview
Problem
Conventional hybrid power electronic tap changers require external triggering circuits and devices for active triggering, leading to high circuit costs and complexity.
Innovation Solution
A passive triggered power electronic tap changer device that uses thyristors and resistors to perform passive triggering, eliminating the need for external triggering circuits and devices, with a contact device that includes a main contact, auxiliary contacts, and trigger contacts connected to a drive shaft for controlled switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active triggering is used for power electronic switch, then the switching process can be controlled, but external triggering circuits and devices are required resulting in high circuit cost
Solution Approach 1:
The power electronic switch performs self-triggering by utilizing its own current characteristics. When the switch current decreases to a predetermined value during the switching process, the switch automatically triggers the thyristor to conduct, eliminating the need for external triggering circuits and devices. This self-service mechanism resolves the contradiction by achieving reliable switching control without adding complex external triggering systems.
2Ease of operation
If external triggering circuits and devices are configured, then the power electronic switch can be triggered, but the circuit cost increases
Solution Approach 1:
The system uses the power electronic switch's own current characteristics to trigger the thyristor. When the switch current drops to a predetermined level, this naturally triggers the thyristor conduction without requiring any external triggering circuits or devices. This eliminates additional circuit costs while maintaining full switching operation capability.
3Device complexity
If mechanical contact carries current in normal operation, then the structure is simple, but arc may be generated during switching process
Solution Approach 1:
The patent combines mechanical contact and power electronic switch in a hybrid structure. The mechanical contact handles normal current carrying with simple structure, while the power electronic switch is activated during switching processes to prevent arc generation. This merging of mechanical and electronic components resolves the contradiction by maintaining structural simplicity while eliminating harmful arcs during critical switching operations.
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
The solution increases circuit reliability and reduces costs by enabling passive triggering in the switching process of the tap changer, while maintaining a stable and controlled switching process.
Implementation Method 1
a Hall effect sensor is configured to detect a magnitude of a current flowing through the mechanical contact
Data Source
AI summary
Disclosed are a passive triggered-power electronic tap-changer device and a contact device. The power electronic tap-changer device comprises: two taps, a main contact, two auxiliary contacts, two trigger contacts, an output terminal, two thyristors, and four voltage divider resistors, which can achieve the passive triggering of a power electronic switch by means of controlling the auxiliary contacts and the trigger contacts. Provided in the present invention is a contact device for the passive triggered-power electronic tap-changer, comprising: at least two stationary contacts, a main contact, two thyristor trigger contacts, two thyristor auxiliary contacts, and a drive shaft, wherein the main contact, the thyristor trigger contacts, and the thyristor auxiliary contacts are fixed to the drive shaft, the contact device can switch the power electronic switch to different stationary contacts by means of controlling the rotation of the drive shaft, and maintains the switching time sequence of passive triggering.