One kind of IGBT temperature detection method
NTC thermistor is characterized by high precision, high reliability and high sensitivity. The NTC sensor can function as a temperature detector in an IGBT (Insulated Gate Bipolar Transistor) module. IGBT modules are a relatively expensive component, and over temperature is one of the main causes of damage. At present, many IGBT manufacturers package an NTC thermistor inside the IGBT module to measure the temperature of the module's housing. Specifically, the temperature is converted into an electrical signal, which is isolated by a device such as a linear optocoupler and transmitted to a processor to judge and protect the temperature. However, this method is not only expensive, but also susceptible to electromagnetic interference, and sometimes misjudgment may occur.
In response to the above problems existing in the prior art, a temperature detecting method for an IGBT is introduced today. The method has strong anti-electromagnetic interference capability, and is suitable for applications where electromagnetic interference is required, and can significantly reduce application cost.
This method of temperature detection of IGBTs. First, connect the NTC thermistor to the power supply through a three-terminal regulator, and use a series resistor to divide the voltage so that the current through the NTC thermistor is substantially 4 mA, and then collect the voltage signal on the NTC thermistor; Then by the V-F conversion unit with the conversion chip and the peripheral circuit, press 1V: a ratio of 1 KHz converts the voltage signal into a frequency signal; Then, the transmitting unit first converts the frequency signal into an optical signal, and then transmits the optical signal to the receiving unit through the optical fiber; Next, the receiving unit first restores the optical signal to a frequency signal, and then transmits the frequency signal to the control unit. The control unit includes a DSP chip having a CAP capture interface, and the CAP capture interface is communicatively coupled to the receiving unit; Finally, the control unit first detects the frequency of the frequency signal, and then calculates the IGBT temperature, and the detection ends.
The temperature detecting method of the IGBT adopts an optical fiber transmission signal and has strong anti-electromagnetic interference capability, and is suitable for applications where electromagnetic interference is required to be high; By collecting the voltage of the NTC thermistor to detect the IGBT temperature, it plays a real-time monitoring role to avoid overheating and burning of the IGBT; The entire method steps are streamlined and the hardware costs are lower, which can significantly reduce application costs.
In response to the above problems existing in the prior art, a temperature detecting method for an IGBT is introduced today. The method has strong anti-electromagnetic interference capability, and is suitable for applications where electromagnetic interference is required, and can significantly reduce application cost.
This method of temperature detection of IGBTs. First, connect the NTC thermistor to the power supply through a three-terminal regulator, and use a series resistor to divide the voltage so that the current through the NTC thermistor is substantially 4 mA, and then collect the voltage signal on the NTC thermistor; Then by the V-F conversion unit with the conversion chip and the peripheral circuit, press 1V: a ratio of 1 KHz converts the voltage signal into a frequency signal; Then, the transmitting unit first converts the frequency signal into an optical signal, and then transmits the optical signal to the receiving unit through the optical fiber; Next, the receiving unit first restores the optical signal to a frequency signal, and then transmits the frequency signal to the control unit. The control unit includes a DSP chip having a CAP capture interface, and the CAP capture interface is communicatively coupled to the receiving unit; Finally, the control unit first detects the frequency of the frequency signal, and then calculates the IGBT temperature, and the detection ends.
The temperature detecting method of the IGBT adopts an optical fiber transmission signal and has strong anti-electromagnetic interference capability, and is suitable for applications where electromagnetic interference is required to be high; By collecting the voltage of the NTC thermistor to detect the IGBT temperature, it plays a real-time monitoring role to avoid overheating and burning of the IGBT; The entire method steps are streamlined and the hardware costs are lower, which can significantly reduce application costs.
