A temperature protection method for indirect measurement of a charger

Abstract

The invention discloses a temperature protection method of indirect measurement of a charger. Analog temperature environment is established, and temperature rise data testing is carried out to acquire an experiment value, and then a power device is the worst device. A heat circuit model is established by adopting a thermoelectricity analogy method to acquire a heat circuit model expression, and the experiment value of the worst device is substituted into the heat energy model expression of the power device, and then the various parameters of the heat circuit model expression are calculated. The highest limiting temperature of the worst device is set, and is smaller than the highest value of an industrial level working temperature range, and the input power and the environmental temperature of the charger are acquired in a real-time manner, and according to the heat circuit model expression, the real-time steady-state temperature of the worst device is calculated, and then by comparing with the highest limiting temperature of the worst device, when the real-time steady-state temperature is higher than the highest limiting temperature, the input power of the charger is reduced, and the temperature rise of the worst device is limited, and therefore the temperature protection of the charger is realized.

Description

technical field [0001] The invention relates to the technical field of fast chargers, in particular to an indirect temperature protection method for chargers. Background technique [0002] With the rapid development of the electric vehicle industry, the demand for electric vehicle chargers is also increasing day by day. Fast chargers generally use high current or high voltage to directly charge the battery. Higher charging power can charge the battery to about 80% in a short time. . However, the internal temperature of electric vehicles is extremely high in high temperature and sunny weather, and the on-board charger works in a high-power and high-temperature environment for a long time, and the temperature of its internal power devices rises rapidly, which is likely to cause various failures and cause safety problems. There are some foreign countries. Scholars began to study the thermal protection method of power devices. This technology is mainly realized through active t...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the technical problem that the internal temperature of the electric vehicle is extremely high under high-temperature sunshine, and the on-board charger works in a high-power and high-temperature environment for a long time, and the temperature rise of its internal power devices is relatively fast, which easily causes various failures and faults. Overcome the technical defect that the current active thermal control method uses the temperature probe to directly test the temperature of the power device, and the probe is prone to misalignment or falling off when the on-board charger is in a violently vibrating environment

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