Method and device for predicting service life of thin-film capacitor and computer equipment

Abstract

The invention discloses a method and device for predicting the service life of a thin-film capacitor and computer equipment. The method comprises the steps: counting the actual operation duration of the thin-film capacitor corresponding to a plurality of preset power intervals and a plurality of environment temperature intervals; obtaining core temperatures of the thin-film capacitor correspondingto the plurality of preset power intervals and the plurality of environment temperature intervals; obtaining actual operation duration of the thin-film capacitor corresponding to the plurality of preset core temperature intervals according to the actual operation duration of the thin-film capacitor corresponding to the plurality of preset power intervals and the plurality of preset environment temperature intervals and the core temperatures corresponding to the plurality of preset power intervals and the plurality of preset environment temperature intervals; and predicting the service life ofthe thin-film capacitor according to the actual operation duration of the thin-film capacitor corresponding to the plurality of preset core temperature intervals and the rated operation duration of the thin-film capacitor. By adopting the embodiment of the invention, the accuracy of predicting the service life of the thin-film capacitor can be improved in the design stage of a wind power converter.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a method, device and computer equipment for life prediction of thin film capacitors. Background technique [0002] Film capacitors are electrical energy storage devices in wind power converters. like figure 1 As shown, the film capacitor C is connected between the DC positive bus DC+ and the DC negative bus DC-, and is used to absorb the ripple current and maintain the stability of the DC bus voltage. The operating life of film capacitors mainly depends on the DC bus voltage and core temperature. High DC link voltage or core temperature will reduce the operating life of film capacitors. Usually, the manufacturer of film capacitors will give the rated operating life of film capacitors under various load voltages and core temperatures. [0003] At present, because the core temperature of the film capacitor changes greatly during the operation of the wind power con...

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Problems solved by technology

[0003] At present, because the core temperature of the film capacitor changes greatly during the operation of the wind power converter, the limit value of the core temperature of the film capacitor cannot be accurately given in the design stage, and there is no good method for predicting the life of the film capacitor. The selection and design of film capacitors based on empirical values ​​will not only lead to waste of cost, but also to avoid changes in the output characteristics of wind power converters caused by reduced capacitance values, such as increased harmonics and reduced power control accuracy. It is necessary to regularly check the capacitance value of the film capacitor during the operation stage of the converter, and replace the film capacitor in time once the capacitance value is greatly reduced

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