Method for determining maximum reactive capacity of MMC type direct-current ice melting device

Abstract

The invention discloses a method for determining the maximum reactive capacity of an MMC type direct-current ice melting device, and the method comprises the following steps of calculating equivalent ice melting resistance according to a direct-current resistance value, and calculating the required active capacity and direct-current ice melting voltage according to the direct-current ice melting current of a line; calculating the number of required bridge arm modules according to the alternating-current side line voltage and fluctuation range of the ice melting device, the direct-current ice melting voltage, the module direct-current operation voltage and the module maximum modulation ratio; calculating a bridge arm current AC component, a bridge arm current DC component and a bridge arm current effective value according to the AC side line voltage; calculating the capacitance of a single module according to the number of the bridge arm modules and the active power; according to the effective current of the bridge arm, regarding the MMC device as two sets of parallel reactive power compensation devices to calculate reactive capacity in a reactive power operation mode; determining module capacity corresponding to the reactive capacity and carrying out accounting to obtain module capacitance; and finally determining the maximum reactive capacitance. The technical problem that the maximum reactive capacity under the ice melting working condition cannot be calculated is solved.

Description

technical field [0001] The invention belongs to the field of high-power electric electronic equipment, and in particular relates to a method for determining the maximum reactive capacity of an MMC-type DC ice-melting device. Background technique [0002] With the development of DC ice melting and power electronics technology in recent years, new DC ice melting devices based on new topology have emerged, which have greatly improved in terms of power density, control performance, and power quality. Among them, MMC type DC ice melting The ice device is particularly prominent. Because of its topological structure, which naturally has the functions of ice melting and reactive power compensation, the availability of daily operation of the equipment has been greatly improved. Therefore, it has been widely used in recent years and has become a mainstream new solution. For a new type of device, how to make full use of its performance characteristics, maximize the power device capabil...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a method for determining the maximum reactive capacity of the MMC-type DC ice-melting device, so as to solve the problem that the MMC-type ice-melting device has many parameters in the prior art and does not satisfy the internal and external parameters reasonably and effectively. The coupling relationship of the MMC type DC ice-melting device is not fully utilized. The characteristics of the decoupling control of active power and reactive power of the MMC type DC ice-melting device are not fully utilized, so technical problems such as the maximum reactive power capacity under the conditions of ice-melting conditions cannot be calculated.

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