Full-control type energy consumption device

Abstract

The invention discloses a full-control energy consumption device which is used in a wind power flexible DC grid-connected system and comprises a full-control cascade module, a filter capacitor and anenergy consumption resistor. The full-control cascade module is used for slowing down the instantaneous current and voltage changes of an energy consumption device in operation after a fault occurs, and changing the absorption power of the energy consumption resistor through the output voltage of the full-control cascade module. The filter capacitor is used for inhibiting harmonic waves of the fault current feed in the energy consumption device. The dissipation resistor is used for absorbing transient energy in a system AC-DC fault period and protecting safe operation of the converter stationin the fault period. In one control period, the sum of the energy absorbed and released by the full-bridge cascade module is 0, and the transient energy is completely transferred to the energy consumption resistor. The invention relates to the configuration and structure of the energy consumption device, the voltage modulation method of the full-control cascade module, the parameter design of theenergy consumption device, the control strategy of the energy consumption device and the application of AC / DC fault transient energy dissipation. In addition, the energy consumption device does not increase the loss of normal operation of the system.

Description

technical field [0001] The invention belongs to the technical field of power transmission and distribution in electric power systems, and more specifically relates to a full-control energy consumption device. Background technique [0002] In order to solve the uneven power distribution and improve the utilization rate of renewable energy, the use of flexible direct current transmission technology (HVDC) for long-distance wind power transmission is a widely recognized solution. Compared with AC transmission, because the modular multilevel converter (Multiple multilevel converter, MMC) can realize the independent control of active and reactive power, improve the transient stability of the AC system, damp power oscillation and other advantages, MMC-HVDC It has now become an even more attractive way of delivering large-scale wind power. [0003] For the long-distance transmission of onshore wind power, the system is prone to AC and DC short-circuit faults. Some current researc...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to provide a fully-controlled energy consumption device, aiming to solve the problem that the dissipation resistor in the prior art cannot realize the energy dissipation during the DC fault and cause the excess energy to damage the commutation during the fault. station uptime issues

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