Fault diagnosis method and device for converter filter circuit, and storage medium

Abstract

The invention discloses a fault diagnosis method and device for a converter filter circuit, and a storage medium. The fault diagnosis method for the converter filter circuit comprises the steps: detecting the grid-side multi-phase voltage of the filter circuit; obtaining the current of each phase of capacitor branch according to the network side multi-phase voltage and the actual capacitance valueof each phase of capacitor branch in the filter circuit; respectively comparing the current of each phase capacitor branch with an instantaneous current threshold, and judging the state of the filtercircuit according to the comparison result; wherein the actual capacitance value of the capacitor is determined by the corresponding phase input current of the filter circuit and the grid-side voltage when the grid-side power supply is disconnected. By adopting the embodiment of the invention, fault diagnosis can be carried out on the converter filter circuit in advance, and faults of the capacitor branch caused by abnormal current are avoided.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a fault diagnosis method, device and storage medium for a filter circuit of a converter. Background technique [0002] The wind power converter is the core component of the grid-connected electric energy of the wind power generating set, and the grid side of the wind power converter includes a filter circuit. During operation, the filter circuit on the grid side is easily affected by the grid or converter, and phenomena such as overcurrent and high harmonic content occur, resulting in failure of the capacitor branch in the filter circuit, such as burnout of switches or capacitors. [0003] At present, in order to avoid the capacitor branch fault caused by the abnormal current, the main method is to add a fuse in the filter circuit, and then implement the protection strategy according to the fusing curve. [0004] However, the inventors of the present application fo...

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Problems solved by technology

[0004] However, the inventors of the present application found that even if the current in the filter circuit continues to be lower than the protection value, the heat will always accumulate, causing the temperature in the filter circuit and devices to rise. If the heat dissipation effect is poor, it will still cause the switch or capacitor to burnt out

In addition, the fuse needs to be replaced after triggering the fault, and the replacement requires downtime, which not only leads to increased cost, but also poor maintainability

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