Convertor

Abstract

The invention relates to a convertor with switching element temperature protection function. The convertor comprises converting circuit, a radiator, a temperature detecting circuit, a controlling circuit, a radiator allowable temperature computing device, an overheat processing device, a current detecting circuit, a pulse-width modulation (PWM) controlling device, a carrier frequency setting device and a reference value setting device, wherein the radiator allowable temperature computing device comprises a first computing device and a second computing device. The convertor is characterized in that the computing relationship of the first computing device meets the condition. The convertor is capable of easily, accurately and reliably computing the allowable temperature, can realize the overheat protection of the switching elements of a transducer without sacrificing the design redundancy and has small volume and low cost.

Description

technical field [0001] The invention relates to a converter device, in particular to a converter device with temperature protection for switching elements. Background technique [0002] Converters have been successfully used in many fields, such as motor speed regulation, solar power generation, backup power supply, etc. [0003] At present, power devices such as IGBT (Insulated Gate Field Effect Transistor) are often used as the main switching element of the converter. These elements have switching loss (loss when turning on / off) and on-state loss. Since this loss increases the temperature inside the element, the maximum allowable temperature inside the element is generally 150°C. The usual practice is to detect the temperature of the radiator to indirectly reflect the temperature inside the switch element. By comparing the detected temperature of the radiator with the preset maximum allowable temperature of the radiator, when the set value is reached or exceeded, Protect...

AI Technical Summary

Problems solved by technology

The main difference between this method and the usual method lies in the acquisition of the maximum allowable temperature of the radiator. The usual method to obtain this value is a fixed value. This method obtains a value obtained by real-time calculation, but when calculating this value, it only uses the Several physical quantities that affect the temperature of the switching element are attributed to a proportional and inverse proportional relationship. Although this can be effectively protected to a certain extent, it is much better than the usual method, but due to the consideration of many nonlinearities in the characteristics of the switching element relationship, rather than a simple proportional and inverse proportional relationship can be accurately described, so this method cannot completely solve the above problems

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