Saturated iron core type superconducting current limiter with direct current control system and method for controlling same

Abstract

The invention relates to a saturated iron core type superconducting fault current limiter with a direct current control system, which comprises a superconducting magnet, a reactance system, namely an iron core and an alternating current winding, a refrigeration system and a monitoring system and also comprises a direct current control system which is connected with two ends of the superconducting magnet and connected with the monitoring system by a data wire; the direct current control system comprises a direct current power module, a magnetic energy absorption module and a control module. The invention also provides a method for controlling the current limiter; when an electric net has normal operation, the control module of the direct current control system automatically adjusts the size of the direct current excitation current in the superconducting magnet according to the size of load in the electric net; when the electric net has short-circuit fault, the control module actively cuts off a direct current loop, simultaneously releases the magnetic energy of the superconducting magnet and clamps the overvoltage; the total iron core of the current limiter participates in the current limiting; and after the fault of the electric net is removed or cut, the control module improves the output voltage of the power supply and forces the superconducting magnet to rapidly magnetize through a power electronic switch so that the current limiter can be rapidly restored to a low resistance state.

Description

Technical field [0001] The invention relates to a superconducting current limiter, in particular a saturated iron core type superconducting fault current limiter with a direct current control system and a control method thereof. In addition to superconducting magnets, reactance systems, cryogenic systems, and monitoring systems, it also Including DC control system. The DC control system includes a DC power supply module, a magnetic energy absorption module and a control module. The present invention can automatically adjust the size of the current in the superconducting magnet when the protected power grid line is operating in a steady state, so the operation of the current limiter has higher economical efficiency; and can occur when a short-circuit fault occurs at the protected power grid location , Automatically identify faults. By cutting off the current in the superconducting magnet, all cores of the current limiter participate in limiting the fault current in the power grid. ...

AI Technical Summary

Problems solved by technology

If the grid is running under a small load, the DC loss on the current limiter will affect the overall operating efficiency of the current limiter

Therefore, the application of the saturated core type current limiter in the past has great limitations.

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