Power device temperature detection system

Abstract

A power device temperature detection system disclosed by the present invention comprises a sampling resistor RS1, a phase voltage detection circuit and an MCU, the phase voltage detection circuit comprises a U-phase detection circuit, a V-phase detection circuit and a W-phase detection circuit, and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit are respectively connected with a power device. The MCU is connected with the sampling resistor RS1, the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit, and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit respectively collect UAD, VAD and WAD signals of a power device and transmit the UAD, VAD and WAD signals to the MCU; and the MCU reads the variation of the UAD, VAD and WAD signals and compares the variation with the variation of the sampling signal of the sampling resistor RS1 to detect the temperature change of the corresponding U-phase / V-phase / W-phase lower bridge arm power device.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a temperature detection system for a power device. Background Art

[0002] In motor control applications, in order to prevent power devices from being damaged by overheating, many applications require temperature detection of power devices. In the application circuit, a temperature sensor is usually set near the power device to detect the temperature, so that the power device always operates within a safe temperature range; in high-voltage IPM module applications, modules with temperature detection or over-temperature protection are preferred.

[0003] There are two main types of existing technologies. The first is the application of separate power devices, which mainly uses temperature sensors to detect the temperature near the heat source. The second is the application of IPM module devices, which mainly uses the real-time voltage value output by the temperature sensor inside the IPM module to identify the temperature of the power device or the IPM module with over-temperature protection to stop running directly after the over-temperature is triggered. The first temperature detection method will increase the cost of the temperature sensor. The second IPM module with temperature detection is relatively expensive on the market, and the competitive advantage is not obvious. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] Therefore, the purpose of the present invention is to provide a power device temperature detection system, which collects the internal resistance or voltage drop of the power device when it is turned on, compares it with the signal at the sampling resistor end, and calculates the real-time temperature of the power device through software processing.

[0006] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0007] A power device temperature detection system, comprising:

[0008] Sampling resistor RS1;

[0009] A phase voltage detection circuit, comprising a U-phase detection circuit, a V-phase detection circuit and a W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit are respectively connected to the power device;

[0010] MCU is connected to the sampling resistor RS1 and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit respectively collect U_AD, V_AD, W_AD signals of the power device and transmit them to the MCU, and the MCU reads the changes of the U_AD, V_AD, W_AD signals and compares them with the changes of the sampling signal of the sampling resistor RS1 to detect the corresponding temperature changes of the U-phase / V-phase / W-phase lower bridge arm power device.

[0011] As a preferred solution of the power device temperature detection system described in the present invention, the U-phase detection circuit includes a resistor R13, a resistor R16, a diode D1 and a capacitor C3.

[0012] As a preferred solution of the power device temperature detection system described in the present invention, the V-phase detection circuit is composed of a resistor R14, a resistor R17, a diode D2 and a capacitor C4.

[0013] As a preferred solution of the power device temperature detection system described in the present invention, the W-phase detection circuit is composed of a resistor R15, a resistor R18, a diode D3 and a capacitor C5.

[0014] As a preferred solution of the power device temperature detection system described in the present invention, the power device is a separation power device, a half-bridge IPM module or a full-bridge IPM module.

[0015] As a preferred solution of the power device temperature detection system described in the present invention, the separation power device realizes temperature detection by identifying the temperature of the lower bridge arm power device.

[0016] As a preferred solution of a power device temperature detection system described in the present invention, a half-bridge IPM module is encapsulated in a plastic package with upper and lower bridge arms consisting of two power devices, and the temperature of the lower bridge arm power device is equivalent to the temperature of the entire half-bridge IPM.

[0017] As a preferred solution of a power device temperature detection system described in the present invention, the full-bridge IPM module integrates three bridge arms and contains six power devices inside a plastic package. The temperature of any lower bridge arm power device is equivalent to the temperature of the three-phase full-bridge IPM.

[0018] Compared with the prior art, the present invention has the following beneficial effects: by collecting the internal resistance or voltage drop of the power device when it is turned on, and then comparing it with the signal at the sampling resistor end, the real-time temperature of the power device is calculated by software processing. The present invention detects the real-time junction temperature of the power device, and the detected temperature change will be more accurate and has nothing to do with the layout and placement of the power device. The NTC detects the ambient temperature and is related to the detected ambient temperature radiation field. The detection error is large, and compared with the half-bridge / full-bridge IPM with temperature detection, the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0020] Figure 1 A circuit diagram for performing temperature detection on a single resistor of a separation power device provided in Embodiment 1 of the present invention;

[0021] Figure 2 A circuit diagram for performing temperature detection on a half-bridge IPM single resistor module provided in Example 1 of the present invention;

[0022] Figure 3 A circuit diagram for performing temperature detection on a three-phase full-bridge single resistor module provided in Example 1 of the present invention;

[0023] Figure 4 A circuit diagram for performing temperature detection on a dual resistor of a separated power device provided in Embodiment 2 of the present invention;

[0024] Figure 5 A circuit diagram for performing temperature detection on a half-bridge IPM dual-resistance module provided in Embodiment 2 of the present invention;

[0025] Figure 6 A circuit diagram for performing temperature detection on a three-phase full-bridge dual-resistance module provided in Embodiment 2 of the present invention;

[0026] Figure 7 A circuit diagram for performing temperature detection on three resistors of a separation power device provided in Embodiment 3 of the present invention;

[0027] Figure 8 A circuit diagram for performing temperature detection on a half-bridge IPM three-resistance module provided in Embodiment 3 of the present invention;

[0028] Fig. 9 A circuit diagram for performing temperature detection on a three-phase full-bridge three-resistance module provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] The present invention provides a power device temperature detection system, which collects the internal resistance or voltage drop of the power device when it is turned on, compares it with the signal at the sampling resistor end, and calculates the real-time temperature of the power device through software processing.

[0033] A power device temperature detection system includes a sampling resistor RS1, a phase voltage detection circuit and an MCU, wherein the sampling resistor RS1 and the phase voltage detection circuit include a U-phase detection circuit, a V-phase detection circuit and a W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit are respectively connected to the power device, and the MCU is connected to the sampling resistor RS1 and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit respectively collect U_AD, V_AD and W_AD signals of the power device and transmit them to the MCU, and the MCU reads U_AD, V_AD and W_AD signals. The change in the AD signal is compared with the change in the sampling signal of the sampling resistor RS1 to detect the corresponding temperature change of the U-phase / V-phase / W-phase lower bridge arm power device. The MCU is connected to the sampling resistor RS1 and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit respectively collect the U_AD, V_AD, and W_AD signals of the power device and transmit them to the MCU. The MCU reads the change in the U_AD, V_AD, and W_AD signals and compares the change in the sampling signal of the sampling resistor RS1 to detect the corresponding temperature change of the U-phase / V-phase / W-phase lower bridge arm power device.

[0034] In this embodiment, the U-phase detection circuit includes a resistor R13, a resistor R16, a diode D1 and a capacitor C3, the V-phase detection circuit includes a resistor R14, a resistor R17, a diode D2 and a capacitor C4, and the W-phase detection circuit includes a resistor R15, a resistor R18, a diode D3 and a capacitor C5.

[0035] Among them, the power device is a separated power device, a half-bridge IPM module or a full-bridge IPM module, wherein the separated power device realizes temperature detection by identifying the temperature of the lower bridge arm power device, the half-bridge IPM module is composed of an upper and lower bridge arm consisting of two power devices, which are encapsulated in a plastic package, and the temperature of the lower bridge arm power device is equivalent to the temperature of the entire half-bridge IPM, and the full-bridge IPM module integrates three bridge arms and contains six power devices in a plastic package, and the temperature of any lower bridge arm power device is equivalent to the temperature of the three-phase full-bridge IPM.

[0036] In order to introduce the above scheme of a power device temperature detection system of the present invention in detail, the present invention provides the following embodiments 1-3.

[0037] Example 1

[0038] See also Figure 1-Figure 3 , which are the sampling methods of single resistors of discrete devices, half-bridge IPM, and full-bridge IPM respectively. When only any one of the lower bridge arms of U phase, V phase, and W phase is turned on, in this implementation mode, MCU has a processing method, specifically: MCU reads the corresponding sampling signals of U_AD, V_AD, and W_AD respectively, and the sampling signal of the sampling resistor RS1 is used as a reference. The ratio of the change amount of the U_AD, V_AD, and W_AD signals to the change amount of the sampling signal of the sampling resistor RS1 is used to identify the temperature change of the corresponding U phase / V phase / W phase lower bridge arm power device.

[0039] Example 2

[0040] See also Figure 4-Figure 6, which are separate devices, half-bridge IPM, and full-bridge IPM dual-resistance sampling methods. MCU has two processing methods. The first processing method is: when only any one of the lower bridge arms of U phase, V phase, and W phase is turned on, MCU reads the corresponding sampling signals of U_AD, V_AD, and W_AD respectively. The sampling signal of the bus sampling resistor RS1 is used as a reference, and the ratio of the change amount of the U_AD, V_AD, and W_AD signals to the change amount of the sampling signal of the sampling resistor RS1 is used to identify the temperature change of the corresponding U-phase / V-phase / W-phase lower bridge arm power device; the second processing method is: when only any one of the lower bridge arms of the U-phase, V-phase, and W-phase is turned on, the MCU reads the corresponding sampling signals of U_AD, V_AD, and W_AD respectively, and the U_AD signal uses the corresponding phase sampling resistor RS2 signal as a reference, and the ratio of the change amount of the U_AD signal to the change amount of the sampling signal of the sampling resistor RS2 is used to identify the temperature rise of the U-phase lower bridge arm power device; the V_AD signal uses the corresponding phase sampling resistor RS3 signal as a reference, and the ratio of the change amount of the V_AD signal to the change amount of the sampling signal of the sampling resistor RS3 is used to identify the temperature rise of the V-phase lower bridge arm power device; the W_AD signal uses the bus sampling resistor RS1 signal as a reference, and the ratio of the change amount of the W_AD signal to the change amount of the sampling signal of the sampling resistor RS1 is used to identify the temperature rise of the W-phase lower bridge arm power device.

[0041] Example 3

[0042] See also Figure 7-Figure 9 , which are the three-resistor sampling methods of separation device, half-bridge IPM and full-bridge IPM respectively. MCU has two processing methods. The first processing method is: when only any one of the lower bridge arms of U phase, V phase and W phase is turned on, MCU reads the corresponding sampling signals of U_AD, V_AD and W_AD respectively. The sampling signal of bus sampling resistor RS1 is used as a reference, and the change amount of U_AD, V_AD and W_AD signals is compared with the change amount of sampling signal of sampling resistor RS1 to identify the temperature change of the corresponding U phase / V phase / W phase lower bridge arm power device; the second processing method is: when only any one of the lower bridge arms of U phase, V phase and W phase is turned on, MCU reads the corresponding sampling signals of U_AD, V_AD and W_AD respectively. The U_AD signal uses the corresponding phase sampling resistor RS2 signal as a reference, and the ratio of the U_AD signal change to the sampling resistor RS2 sampling signal change is used to identify the temperature rise of the U-phase lower arm power device; the V_AD signal uses the corresponding phase sampling resistor RS3 signal as a reference, and the ratio of the V_AD signal change to the sampling resistor RS3 sampling signal change is used to identify the temperature rise of the V-phase lower arm power device; the W_AD signal uses the corresponding phase sampling resistor RS4 signal as a reference, and the ratio of the W_AD signal change to the sampling resistor RS4 sampling signal change is used to identify the temperature rise of the W-phase lower arm power device.

[0043] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A power device temperature detection system, characterized in that: include: Sampling resistor RS1; A phase voltage detection circuit, comprising a U-phase detection circuit, a V-phase detection circuit and a W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit are respectively connected to the power device; MCU is connected to the sampling resistor RS1 and the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit, wherein the U-phase detection circuit, the V-phase detection circuit and the W-phase detection circuit respectively collect U_AD, V_AD, W_AD signals of the power device and transmit them to the MCU, and the MCU reads the changes of the U_AD, V_AD, W_AD signals and compares them with the changes of the sampling signal of the sampling resistor RS1 to detect the corresponding temperature changes of the U-phase / V-phase / W-phase lower bridge arm power device.

2. A power device temperature detection system according to claim 1, characterized in that: The U-phase detection circuit comprises a resistor R13, a resistor R16, a diode D1 and a capacitor C3.

3. A power device temperature detection system according to claim 1, characterized in that: The V-phase detection circuit is composed of a resistor R14, a resistor R17, a diode D2 and a capacitor C4.

4. A power device temperature detection system according to claim 1, characterized in that: The W-phase detection circuit is composed of a resistor R15, a resistor R18, a diode D3 and a capacitor C5.

5. A power device temperature detection system according to claim 1, characterized in that: The power device is a discrete power device, a half-bridge IPM module or a full-bridge IPM module.

6. A power device temperature detection system according to claim 5, characterized in that: The separated power devices realize temperature detection by identifying the temperature of the lower arm power device.

7. A power device temperature detection system according to claim 5, characterized in that: The half-bridge IPM module consists of an upper and lower bridge arm consisting of two power devices encapsulated in a plastic package. The temperature of the lower bridge arm power device is equivalent to the temperature of the entire half-bridge IPM.

8. A power device temperature detection system according to claim 5, characterized in that: The full-bridge IPM module integrates three bridge arms and contains six power devices inside a plastic package. The temperature of any lower bridge arm power device is equivalent to the temperature of the three-phase full-bridge IPM.

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