Dynamic energy release device and equipment and DC power transmission system

Abstract

The invention provides a dynamic energy release device and equipment and a DC power supply system. The dynamic energy release device comprises at least two dynamic energy release modules which are connected in series between a DC power transmission line and a first ground wire. A first switch is arranged between the input end of the dynamic energy release modules and the DC power transmission lineand / or the first switch is arranged between the grounding end of the dynamic energy release modules and the first ground wire. A second ground wire is connected between the at least two series connected dynamic energy release modules. The first switch is disconnected in case of fault elimination of continuous phase change failure of the DC power transmission system so that the dynamic energy release device can be quickly cut off, the problem of slow system recovery caused by capacitance charging in the recovery process of the DC power supply system can be avoided, and the system is enabled toquickly recover normal operation. The second ground wire is arranged between the series connected dynamic energy release modules so that the system insulation level can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of direct current transmission, in particular to a dynamic energy discharge device, equipment and a direct current transmission system. Background technique [0002] With the gradual implementation of the "West-to-East Power Transmission" strategy, the UHV DC transmission project has been put into operation intensively, and my country has built the AC-DC hybrid power grid with the largest capacity and the most complex topology in the world. The continuous improvement of UHV DC single-circuit transmission capacity makes the characteristics of "strong DC and weak AC" appear, which are mainly reflected in: first, the receiving end power grid is mostly a load center, and multiple DC feed-in locations are concentrated, and the electrical distance between inverter stations is relatively short. Nearby, the failure of the AC system near the converter station may lead to multiple DC commutation failures at the same t...

AI Technical Summary

Problems solved by technology

The continuous improvement of UHV DC single-circuit transmission capacity makes the characteristics of "strong DC and weak AC" appear, which are mainly reflected in: first, the receiving end power grid is mostly a load center, and multiple DC feed-in locations are concentrated, and the electrical distance between inverter stations is relatively short. Nearby, the failure of the AC system near the converter station may lead to multiple DC commutation failures at the same time; the second is that the sending-end power grid is an energy-concentrated area, and the connection of the AC system is relatively weak. Interruption will cause some important sections of the power grid at the sending end to exceed the stability limit, some thermal power units will overspeed, and wind turbines will be disconnected from the grid due to low voltage or high voltage on a large scale, seriously threatening the safe and stable operation of the system

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