DC Ice Melting Switching Circuit Without Saturable Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing direct current ice melting devices for power transmission lines suffer from noise issues due to saturable reactors and require current interruption during short line ice melting, and current-through tests can only be done when the device is switched in the power transmission line, limiting normal operation and maintenance.
Innovation Solution
A multi-functional automatic switching circuit with a six-pulse converter and specific reactor configurations, including reactors L1a, L1b, and L1c, and reactors L2a, L2b, and L2c, along with knife switches and a control and protection system, allows for automatic switching among TCR, TSR, and ice melting modes without being switched in the power transmission line, reducing noise and enabling current-through tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If saturable reactors are used in direct current ice melting devices, then the device can operate in multiple modes (TCR, TSR, ice melting), but noise is generated during operation
Solution Approach 1:
The patent divides the reactor system into separate functional components: smoothing reactors (L1a, L1b, L1c) and commutation reactors (L2a, L2b, L2c). This segmentation allows the device to operate in multiple modes without requiring saturable reactors, thereby eliminating noise while maintaining adaptability across TCR, TSR, and ice melting modes.
2Measurement precision
If the device is switched in the power transmission line for current-through tests, then test data can be obtained, but normal power transmission is disrupted
Solution Approach 1:
The patent introduces an equivalent test circuit that serves as an intermediary for conducting current-through tests. This test circuit includes components that simulate the characteristics of the power transmission line, allowing tests to be performed without disrupting actual power transmission. The test circuit acts as a mediator between the testing requirements and the operational power line.
3Reliability
If current interruption is performed during short line ice melting, then ice melting can be achieved, but operational complexity increases
Solution Approach 1:
The patent designs a universal switching circuit that handles both normal ice melting operations and short line ice melting without requiring separate current interruption procedures. The switching circuit is configured to automatically adapt to different line conditions, providing a unified operation mode that simplifies the process while maintaining effectiveness for both standard and short line applications.
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 significantly reduces noise during operation, enables automatic switching among multiple modes, and allows for current-through tests without disrupting power transmission, enhancing daily operation and maintenance of direct current ice melting devices.
Implementation Method 1
alternating current electric power available from the power system is converted into direct current electric power by high-power rectifier devices
Implementation Method 2
reactors L1a, L1b, and L1c, reactors L2a, L2b, and L2c
Implementation Method 3
the direct current electric power is input to wires of lines to be subjected to ice melting, the wires are heated with the action of the direct current to ensure that the ice covered thereon is melted
Data Source
AI summary
A multi-functional automatic switching circuit for direct current ice melting and a switching method thereof are provided. The automatic switching circuit comprises at least one sub-switching circuit. The sub-switching circuit comprises a six-pulse current converter (R) with no saturable reactor, six reactors (L1a, L1b, L1c, L2a, L2b, and L2c), three three-phase knife switches (Sac1, Sac2, and Sac3), and five single-phase knife switches (SV1, SV2, SV3, SV4, and SV5). The sub-switching circuits in series connection or parallel connection, four direct current side switching knife switches (Sdc1, Sdc2, Sdc3, and Sdc4), an isolation knife switch (K), a breaker (QF) and a control and protection system (CP) may form an automatic switching circuit for six-pulse or twelve-pulse direct current ice melting. The automatic switching circuit with no saturable reactor reduces noise during operation, achieves mutually automatic switching among modes of reactor switching, ice melting and test, and may complete the through-flow test of the automatic switching circuit without switching in a power transmission line, thereby solving the problem of daily operation and maintenance.