KR-102963391-B1 - METHOD AND APPARATUS FOR ESTIMATING JUNCTION TEMPERATURE OF POWER SEMICONDUCTOR DEVICE IN POWER MODULE

KR102963391B1KR 102963391 B1KR102963391 B1KR 102963391B1KR-102963391-B1

Abstract

A method for estimating the junction temperature of a power semiconductor device in a power module is disclosed, comprising a first power semiconductor device disposed adjacent to a heat sink for cooling and having a temperature sensor, and a second power semiconductor device disposed adjacent to the first power semiconductor device and not having a temperature sensor. The method for estimating the junction temperature of a power semiconductor device in the power module comprises: a step of calculating a predicted junction temperature value of the first power semiconductor device based on the power loss and thermal resistance of the first power semiconductor device; a step of calculating a predicted junction temperature value of the second power semiconductor device based on the power loss and thermal resistance of the second power semiconductor device; a step of calculating a predicted temperature value of the heat sink by subtracting the predicted junction temperature value of the first power semiconductor device from the sensing temperature sensed by the temperature sensor; and a step of finally determining the junction temperature of the second power semiconductor device by adding the predicted junction temperature value of the second power semiconductor device to the predicted junction temperature value of the second power semiconductor device.

Inventors

이제환

Assignees

현대자동차주식회사
기아 주식회사

Dates

Publication Date: 20260511
Application Date: 20200428

Claims (12)

A method for estimating the temperature of a power semiconductor device junction of a power module comprising a first power semiconductor device disposed adjacent to a heat sink for cooling and having a temperature sensor, and a second power semiconductor device disposed adjacent to the first power semiconductor device and not having a temperature sensor, wherein A step of calculating a predicted junction temperature value of the first power semiconductor device based on the power loss and thermal resistance of the first power semiconductor device; A step of calculating a predicted junction temperature value of the second power semiconductor device based on the power loss and thermal resistance of the second power semiconductor device; A step of calculating a predicted temperature value of the heat sink by subtracting a predicted junction temperature value of the first power semiconductor device from a sensed temperature sensed by a temperature sensor provided in the first power semiconductor device; and A step of finally determining the junction temperature of the second power semiconductor device by adding the predicted temperature value of the heat sink to the predicted junction temperature value of the second power semiconductor device; A method for estimating the junction temperature of a power semiconductor device of a power module including
In claim 1, The step of calculating the predicted junction temperature value of the first power semiconductor device is: A step of calculating the power loss of the first power semiconductor device; and A method for estimating the junction temperature of a power semiconductor device of a power module, characterized by including the step of calculating a predicted junction temperature value of the first power semiconductor device by multiplying the power loss of the first power semiconductor device by a preset thermal resistance of the first power semiconductor device.
In claim 2, The step of calculating the power loss of the first power semiconductor device is, A method for estimating the junction temperature of a power semiconductor device of a power module, characterized by calculating the power loss of the first power semiconductor device using a predetermined power loss calculation formula in which a plurality of parameters related to the operation of the power module are variables.
In claim 2, A method for estimating the junction temperature of a power semiconductor device of a power module, characterized in that the thermal resistance of the first power semiconductor device is determined in advance by measuring the temperature change of the first power semiconductor device according to the flow rate of cooling water flowing through the heat sink.
In claim 1, The step of calculating the predicted junction temperature value of the second power semiconductor device is: A step of calculating the power loss of the second power semiconductor device; and A method for estimating the junction temperature of a power semiconductor device of a power module, characterized by including the step of calculating a predicted junction temperature value of the second power semiconductor device by multiplying the power loss of the second power semiconductor device by a preset thermal resistance of the second power semiconductor device.
In claim 5, The step of calculating the power loss of the second power semiconductor device is: A method for estimating the junction temperature of a power semiconductor device of a power module, characterized by calculating the power loss of the second power semiconductor device using a predetermined power loss calculation formula in which a plurality of parameters related to the operation of the power module are variables.
In claim 5, A method for estimating the junction temperature of a power semiconductor device of a power module, characterized in that the thermal resistance of the second power semiconductor device is determined in advance by pre-measuring the temperature change of the second power semiconductor device according to the flow rate of cooling water flowing through the heat sink.
In claim 1, A method for estimating the junction temperature of a power semiconductor device of a power module, characterized by further including the step of derating the operation of the power module or stopping the operation of the power module when the junction temperature of the second power semiconductor device finally determined above is greater than a preset reference value.
In claim 1, A method for estimating the junction temperature of a power semiconductor device of a power module, characterized in that the first power semiconductor device is an IGBT and the second power semiconductor device is a diode.
A power semiconductor element junction temperature estimation device of a power module comprising a first power semiconductor element disposed adjacent to a heat sink for cooling and having a temperature sensor, and a second power semiconductor element disposed adjacent to the first power semiconductor element and not having a temperature sensor, wherein A memory storing the thermal resistance of the first and second power semiconductor devices, each predetermined by measuring the temperature change of the first and second power semiconductor devices according to the flow rate of cooling water flowing through the heat sink, and a plurality of parameters related to the operation of the power module as variables in a predetermined power loss calculation formula for each of the first and second power semiconductor devices; and It includes a processor that determines the junction temperature of the second power semiconductor device based on information stored in the memory and the temperature sensed by the temperature sensor, and The above processor is, Parameters related to the operation of the power module are input to calculate the power loss of the first power semiconductor device, and a predicted junction temperature value of the first power semiconductor device is calculated based on the power loss and thermal resistance of the first power semiconductor device. Parameters related to the operation of the power module are input to calculate the power loss of the second power semiconductor device, and a predicted junction temperature value of the second power semiconductor device is calculated based on the power loss and thermal resistance of the first power semiconductor device. Calculate the predicted temperature value of the heat sink by subtracting the predicted junction temperature value of the first power semiconductor device from the sensed temperature sensed by the temperature sensor provided in the first power semiconductor device, and A power semiconductor device junction temperature estimation device of a power module, characterized by adding the predicted temperature value of the heat sink to the predicted temperature value of the second power semiconductor device to finally determine the junction temperature of the second power semiconductor device.
In claim 10, The above memory stores a preset reference value for comparison with the second power semiconductor device, and A power module power semiconductor device junction temperature estimation device, characterized in that the processor derates the operation of the power module or stops the operation of the power module when the finally determined junction temperature of the second power semiconductor device is greater than the reference value.
In claim 10, A power semiconductor device junction temperature estimation device of a power module, characterized in that the first power semiconductor device is an IGBT and the second power semiconductor device is a diode.

Description

Method and apparatus for estimating junction temperature of power semiconductor device in power module The present invention relates to a method and apparatus for estimating the junction temperature of a power semiconductor device in a power module, and more specifically, to a method and apparatus for estimating the junction temperature of a power semiconductor device in a power module that can appropriately estimate the junction temperature of a power semiconductor device without an internal temperature sensor even when a malfunction occurs in the cooling system supplying cooling water to the power module. Generally, an inverter is required to convert DC power into three-phase AC power for motor driving. The inverter is equipped with a power module containing power semiconductor devices that perform switching operations, such as insulated gate bipolar mode transistors (IGBTs) and diodes. The power semiconductor devices in the power module must be maintained within a preset maximum allowable temperature to prevent burnout and ensure their durability. Conventionally, temperature management for power modules was performed by applying a thermal model that estimates the junction temperature of a power semiconductor device based on the switching frequency, current, voltage, etc., of the power semiconductor device within the power module. Korean Published Patent No. 10-2018-0069954, previously filed by the applicant of the present application, discloses a technology for measuring the junction temperature of a power semiconductor device by applying such a thermal model. In conventional junction temperature estimation techniques for power semiconductor devices using such thermal models, the temperature of the cooling water supplied to cool the power semiconductor device is applied to the junction temperature estimation. Since the temperature of the cooling water is mainly measured by a cooling water temperature sensor installed at the inlet of the cooling water passage where the cooling water is supplied, a problem arises in that the junction temperature estimate fails to properly reflect the temperature rise even when the temperature of the power module rises because the actual cooling water is not properly supplied to the location where the power module is installed. In particular, among recently commercialized power semiconductor devices, IGBTs are equipped with built-in temperature sensors that can easily detect temperature rises caused by abnormal cooling water supply; however, diodes, another power semiconductor device, cannot incorporate temperature sensors. Consequently, even when a temperature rise occurs due to abnormal cooling water supply, the junction temperature is still predicted to be low, leading to problems such as burnout and reduced lifespan of the power module. The matters described above as background technology are intended only to enhance understanding of the background of the present invention and should not be construed as an acknowledgment that they constitute prior art already known to those skilled in the art. FIG. 1 is a plan view illustrating a part of a power module to which various embodiments of the present invention are applied. FIG. 2 is a cross-sectional view illustrating an example of a part of a power module to which various embodiments of the present invention are applied. FIG. 3 is a simplified diagram illustrating a power module cooling system to which various embodiments of the present invention are applied. FIG. 4 is a block diagram illustrating a power semiconductor device junction temperature estimation device according to one embodiment of the present invention. FIG. 5 is a flowchart illustrating a method for estimating the junction temperature of a power semiconductor device according to one embodiment of the present invention. Hereinafter, a method and apparatus for estimating the junction temperature of a power semiconductor device of a power module according to various embodiments of the present invention will be described in detail with reference to the attached drawings. First, we will briefly describe the structure of a power module to which various embodiments of the present invention are applied. FIG. 1 is a plan view illustrating a part of a power module to which various embodiments of the present invention are applied, and FIG. 2 is a cross-sectional view illustrating an example of a part of a power module to which various embodiments of the present invention are applied. Referring to FIGS. 1 and 2, the power module (10) may include a plurality of IGBTs (11) and diodes (12) disposed on a substrate (13). Although not shown in FIGS. 1 and 2, the IGBTs (11) and diodes (12) may be electrically connected to each other by power lines implemented by conductive patterns formed on the substrate (13), and these power lines may exchange power with other external electrical components through power leads (14) such as those shown in FIG. 2. Additionally, although not sho