Circuit control method and device, computer equipment and readable storage medium

Abstract

The invention relates to a circuit control method and device, computer equipment and a readable storage medium, and the method comprises the steps: determining the number of first sub-modules of a bridge arm circuit according to the tracking relation between the AC side current of an MMC bridge wall circuit and the AC side reference current of the bridge arm circuit, and driving the corresponding number of sub-modules to enter a use state; then adjusting the number of the first sub-modules according to the error voltage of the bridge wall circuit; and finally, determining the number of the sub-modules put into use on the upper bridge wall and the number of the sub-modules put into use on the lower bridge arm in the bridge wall circuit according to the voltage-sharing value of the sub-modules, the error voltage and the adjusted number of the sub-modules. According to the method provided by the invention, the optimal control of a plurality of control targets is realized through the step-by-step optimization control of the target function, the control process does not need to consider a weight factor, the optimal control of the plurality of control targets can be realized at the same time, and the purpose of reducing the unbalanced voltage of the bridge wall circuit to suppress the circulating current can be achieved.

Description

technical field [0001] The present application relates to the field of electric power technology, in particular to a circuit control method, device, computer equipment and readable storage medium. Background technique [0002] A modular multilevel converter (Modular Multilevel Converter, MMC) is generally formed by cascading multiple sub-modules with the same structure. Due to the advantages of MMC's modular redundant design, high waveform quality, increased voltage level and strong fault handling capability, it has been widely used in the field of flexible DC transmission technology and has become the preferred converter topology for flexible current transmission systems. And it has developed rapidly from the initial low-voltage and small-capacity demonstration project to high-voltage and large-capacity, showing a good development prospect. [0003] At present, MMC has many technical advantages, but due to the particularity of its topology, it leads to phase current contro...

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Problems solved by technology

[0003] At present, MMC has many technical advantages, but due to the particularity of its topology, it leads to phase current control on the AC side, sub-module capacitor voltage equalization control, and circulation suppression between each phase bridge arm, and the capacitor voltage of each independent sub-module The existence of unbalance and interphase circulation suppression will affect the stability and safety of the system operation. At present, the research on this problem is mainly to control multiple objective functions in the model through the method of model predictive control, so as to achieve the optimal control of multiple control objectives. However, the traditional control design needs to consider the selection of weight factors, and it is difficult to achieve the optimal control of multiple control objectives at the same time.

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