An electric heat pump compressor controller over-temperature diagnosis method, medium and device

Abstract

This invention discloses an over-temperature diagnostic strategy, medium, and device for an electric heat pump compressor controller. The diagnostic strategy includes the following steps: controlling the temperature sampling unit to collect the initial temperature temp0 when the compressor starts; setting a temperature protection threshold based on the initial temperature temp0 and a preset temperature threshold: if temp0 < the preset temperature threshold, the temperature protection threshold is set to temp3; otherwise, the temperature protection threshold is set to temp2, where temp2 > temp3; controlling the temperature sampling unit to collect the power module operating temperature temp in real time; and executing a protection action based on the power module operating temperature temp and the temperature protection threshold: if temp ≥ the temperature protection threshold, controlling the shutdown to protect the power module; otherwise, controlling the compressor to operate normally.

Description

Technical Field

[0001] This invention relates to a method, medium, and equipment for diagnosing over-temperature in an electric heat pump compressor controller, belonging to the field of compressor technology. Background Technology

[0002] With the development of the automotive industry, new energy vehicles have occupied a certain market share. Heat pump compressors, as a major component of air conditioning systems, are widely used in summer cooling and vehicle charging cooling. Power modules, as a key component of the controller, affect the normal operation of the compressor and air conditioning system; damage to the power module can result in anything from the air conditioning failing to cool in summer to serious safety accidents.

[0003] Data statistics show that the main cause of power module failure is temperature. Most existing over-temperature diagnostic methods set a fixed protection threshold. While these methods may provide normal protection in most cases, they can trigger over-protection when the compressor is under abnormal operating conditions, such as high temperature (120℃). Similarly, when the compressor is operating at low speed and high current, insufficient cooling capacity causes the temperature to rise continuously, resulting in an excessively high protection temperature, delayed protection, and controller over-temperature damage. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an over-temperature diagnosis method, medium, and device for an electric heat pump compressor controller, which solves the problem in existing technologies where the power module activates over-temperature protection or damages components before the over-temperature protection is activated, affecting the stability and reliability of the system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for diagnosing over-temperature in an electric heat pump compressor controller includes the following steps:

[0007] The temperature sampling unit is controlled to collect the initial temperature temp0 when the compressor starts running;

[0008] Based on the initial temperature temp0 and the preset temperature threshold, set the temperature protection threshold: if temp0 < the preset temperature threshold, then set the temperature protection threshold to temp3; otherwise, set the temperature protection threshold to temp2, where temp2 > temp3.

[0009] The temperature sampling unit controls the real-time acquisition of the power module's operating temperature (temp).

[0010] Based on the operating temperature temp of the power module and the temperature protection threshold, the protection action is executed: if temp is greater than or equal to the temperature protection threshold, the power module is stopped to protect it; otherwise, the compressor is kept running normally.

[0011] Furthermore, the aforementioned temp3 is the temperature value corresponding to the operating phase current I, according to the power module temperature-phase current relationship diagram.

[0012] Furthermore, as mentioned above, temp2 = temp0 + offset, where offset is the difference between the maximum allowable operating temperature of the controller and the ambient temperature at startup. The specific value of offset is obtained from the ambient temperature calibration experiment of the compressor operation.

[0013] Furthermore, as mentioned above, Tj > temp2 > temp3, where Tj is the junction temperature of the power module.

[0014] Furthermore, when the temperature protection threshold is set to temp2, the steps for executing the protection action based on the power module operating temperature temp and the temperature protection threshold include:

[0015] The enable timer tracks the compressor's running time T and sets the judgment time T1;

[0016] When T≥T1 and temp≥temp2, the system will shut down to protect the power module.

[0017] If T≥T1 and temp<temp2, then the temperature protection threshold is set from temp2 to temp3.

[0018] Furthermore, the aforementioned temperature protection threshold is set from temp2 to temp3 in the following way: with a fixed step size, smoothly transition from temp2 to temp3.

[0019] A computer-readable storage medium storing a computer program, which is read and executed by a processor to implement an over-temperature diagnosis method for an electric heat pump compressor controller.

[0020] A computer device includes a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement an over-temperature diagnosis method for an electric heat pump compressor controller.

[0021] The beneficial effects achieved by this invention are as follows:

[0022] 1. Based on the instantaneous temperature at which the compressor starts operating, the ambient temperature can be inferred to avoid frequent protection due to over-protection in high-temperature environments, which would affect the driving experience.

[0023] 2. Set different temperature protection thresholds according to the phase current to prevent excessive current and untimely temperature protection from damaging the controller and causing the compressor to fail to operate. Attached Figure Description

[0024] Figure 1 This is a flowchart of the diagnostic method of the present invention;

[0025] Figure 2 This is a temperature-phase current relationship diagram of the power module of this invention. Detailed Implementation

[0026] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0027] Example 1

[0028] This embodiment discloses an over-temperature diagnosis method for electric heat pump compressor controllers, such as... Figure 1 As shown.

[0029] When the compressor receives the enable signal, the temperature sampling unit collects the initial temperature temp0 when the compressor starts running. The initial temperature temp0 is approximately the ambient temperature of the power module.

[0030] The initial temperature temp0 is compared with the preset temperature threshold, and the preset temperature threshold is determined by comprehensively considering the controller's operating temperature requirements and the current flowing through the power devices at startup:

[0031] If temp0 < the preset temperature threshold, the temperature protection threshold is set to temp3. Temp3 is the temperature value obtained by looking up a table based on the operating phase current I according to the power module temperature-phase current relationship diagram. The operating phase current I is collected by the current sampling unit. During compressor operation, the temperature sampling unit collects the power module operating temperature temp in real time. If temp ≥ temp3, the compressor is stopped to protect the power module; otherwise, the compressor is kept running normally.

[0032] If temp0 ≥ the preset temperature threshold, the temperature protection threshold is set to temp2, where temp2 = temp0 + offset. Offset refers to the difference between the maximum allowable operating temperature designed by the controller and the ambient temperature at startup. The specific value of offset is obtained from the ambient temperature calibration experiment of the compressor operation. Where Tj > temp2 > temp3, Tj is the junction temperature of the power module. Since the compressor has just started, the cooling capacity will not immediately act on the power module. During this stage, the temperature of the power module will rise. Therefore, the enable timer counts the compressor running time T and sets the judgment time T1. When T ≥ T1, the temperature sampling unit collects the operating temperature temp of the power module at that moment in real time. If temp ≥ temp2, the machine will stop for protection; if temp < temp2, the temperature protection threshold is not triggered, and the temperature protection threshold smoothly transitions from temp2 to temp3 in a fixed step.

[0033] Example 2

[0034] This embodiment proposes a computer device, which includes a computer-readable storage medium storing a computer program and a processor. The computer program is read and executed by the processor to implement the over-temperature diagnosis method for the electric heat pump compressor controller as described above.

[0035] Example 3

[0036] This embodiment proposes a computer-readable storage medium storing a computer program. When the computer program is read and executed by a processor, it implements the over-temperature diagnosis method for the electric heat pump compressor controller as described above.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electric heat pump compressor controller over-temperature diagnostic method, characterized by, Includes the following steps: The temperature sampling unit is controlled to collect the initial temperature temp0 when the compressor starts running; Based on the initial temperature temp0 and the preset temperature threshold, set the temperature protection threshold: if temp0 < the preset temperature threshold, then set the temperature protection threshold to temp3; otherwise, set the temperature protection threshold to temp2, where temp2 > temp3. The temperature sampling unit controls the real-time acquisition of the power module's operating temperature (temp). Based on the operating temperature temp of the power module and the temperature protection threshold, the protection action is executed: if temp ≥ temperature protection threshold, the power module is stopped to protect it; otherwise, the compressor is kept running normally. When the temperature protection threshold is set to temp2, the steps for executing the protection action based on the power module operating temperature temp and the temperature protection threshold include: The enable timer tracks the compressor's running time T and sets the judgment time T1; When T≥T1 and temp≥temp2, the system will shut down to protect the power module. If T≥T1 and temp<temp2, then the temperature protection threshold is set from temp2 to temp3.

2. A method of over-temperature diagnosis of an electric heat pump compressor controller according to claim 1, characterized in that, The temp3 is the temperature value corresponding to the operating phase current I, according to the power module temperature-phase current relationship diagram.

3. A method of over-temperature diagnosis for an electric heat pump compressor controller according to claim 1, characterized in that, temp2 = temp0 + offset, where offset is the difference between the maximum allowable operating temperature of the controller and the ambient temperature at startup. The specific value of offset is obtained from the ambient temperature calibration experiment of the compressor operation.

4. The method for over-temperature diagnosis of an electric heat pump compressor controller according to claim 1, characterized in that, Tj>temp2>temp3, where Tj is the junction temperature of the power module.

5. A method of over-temperature diagnosis for an electric heat pump compressor controller as defined in claim 1, wherein The temperature protection threshold is set from temp2 to temp3 by using a fixed step size to smoothly transition from temp2 to temp3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which is read and executed by a processor to implement the over-temperature diagnosis method for an electric heat pump compressor controller as described in any one of claims 1-5.

7. A computer device, comprising: The computer device includes a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the over-temperature diagnosis method for an electric heat pump compressor controller as described in any one of claims 1-5.

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