Electric pump and method for protecting an electric pump

Abstract

The application relates to an electric pump and a protection method of the electric pump, wherein the electric pump comprises a PCB board and an MCU arranged on the PCB board; the MCU acquires a temperature value of the PCB board; in the case that the temperature value is greater than or equal to a first preset temperature value, the MCU configures a first preset power as an electric pump protection power; in the case that the temperature value is less than the first preset temperature value, the MCU configures a second preset power as the electric pump protection power, wherein the first preset power is less than the second preset power, the problem that the service life of the electric pump is shortened due to long-time high-power operation is solved, and the service life of the electric pump is maintained.

Description

Technical Field

[0001] This application relates to the field of electric drive technology, and in particular to an electric pump and a method for protecting the electric pump. Background Technology

[0002] When an electric pump operates at high power for an extended period, the temperature of the pump's PCB board will rise. The lifespan of each electronic component on the PCB board is related to temperature. Prolonged high-power operation of the electric pump will affect the lifespan of these electronic components, thereby shortening the lifespan of the electric pump.

[0003] There is still no effective solution to the problem of shortened lifespan of electric pumps caused by prolonged high-power operation in related technologies. Summary of the Invention

[0004] The purpose of this invention is to provide an electric pump and a method for protecting the electric pump, which helps to maintain the lifespan of the electric pump.

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

[0006] An electric pump, the electric pump including a PCB board and an MCU disposed on the PCB board;

[0007] The MCU acquires the temperature value of the PCB board;

[0008] When the temperature value is greater than or equal to the first preset temperature value, the MCU configures the first preset power as the electric pump protection power;

[0009] When the temperature value is less than the first preset temperature value, the MCU configures a second preset power as the electric pump protection power, wherein the first preset power is less than the second preset power.

[0010] This invention also discloses a protection method for an electric pump, the method comprising:

[0011] Obtain the temperature value of the PCB board located inside the electric pump;

[0012] When the temperature value is greater than or equal to the first preset temperature value, the first preset power is configured as the electric pump protection power;

[0013] When the temperature value is less than the first preset temperature value, a second preset power is configured as the protection power of the electric pump, wherein the first preset power is less than the second preset power.

[0014] This invention obtains the temperature value of the PCB board through an MCU; when the temperature value is greater than or equal to a first preset temperature value, the MCU configures a first preset power as the electric pump protection power; when the temperature value is less than the first preset temperature value, the MCU configures a second preset power as the electric pump protection power. The first preset power is less than the second preset power, which solves the problem of shortened electric pump life caused by long-term high-power operation and helps to maintain the electric pump life. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 This is a schematic diagram of the internal structure of an electric pump according to an embodiment of this application;

[0017] Figure 2 It is a schematic diagram of the control principle of an electric pump based on relevant technologies;

[0018] Figure 3 This is a flowchart of a protection method for an electric pump according to an embodiment of this application;

[0019] Figure 4 This is a schematic diagram illustrating the relationship between ambient temperature and the protection power of the sampling resistor according to an embodiment of this application;

[0020] Figure 5 This is a schematic diagram showing the relationship between the temperature of the PCB board and the protection current of the sampling resistor according to an embodiment of this application;

[0021] Figure 6 This is a schematic diagram illustrating the relationship between the temperature of the PCB board and the protection current of the sampling resistor according to an embodiment of this application.

[0022] Figure 7 This is a flowchart of a protection method for an electric pump according to another embodiment of this application;

[0023] Figure 8 This is a schematic diagram of the control principle of an electric pump according to an embodiment of this application;

[0024] Figure 9 This is a system operation block diagram of the protection module according to an embodiment of this application;

[0025] Figure 10 This is a system operation block diagram of the power comparison module according to an embodiment of this application;

[0026] Figure 11 This is a flowchart illustrating the operation of the protection module according to an embodiment of this application;

[0027] Figure 12 This is a structural block diagram of the electric pump and host computer interaction system according to an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0029] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0031] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "a," "an," "an," "the," and similar words used in this application do not indicate quantity limitation and may represent singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms "connected," "linked," "coupled," and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "And / or" describes the relationship between related objects, indicating that three relationships may exist; for example, "A and / or B" can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. The terms “first,” “second,” “third,” etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0032] This application provides an electric pump that can be applied to products such as vehicle air conditioning systems and cooling systems that use water or oil as the circulating medium. Figure 1 This is a schematic diagram of the internal structure of the electric pump according to an embodiment of this application, as shown below. Figure 1 As shown, the electric pump 10 includes a PCB board 11, an MCU 12 disposed on the PCB board 11, and a motor 13 electrically connected to the MCU 12. The MCU 12 acquires the temperature value of the PCB board 11. When the temperature value is greater than or equal to a first preset temperature value, the MCU 12 configures a first preset power as the electric pump protection power. When the temperature value is less than the first preset temperature value, the MCU 12 configures a second preset power as the electric pump protection power, wherein the first preset power is less than the second preset power. By comparing the actual power of the electric pump with the electric pump protection power, when the actual power of the electric pump is greater than the electric pump protection power, the MCU 12 determines a first target speed and instructs the motor 13 to be set to the first target speed.

[0033] Figure 2 It is based on the control principle diagram of the electric pump in related technologies, such as Figure 2The entire control system shown includes a speed PI controller and a current PI controller. The speed PI controller, as the outer loop of the control system, controls the target current of the output bus by controlling the difference between the actual speed fed back by the motor 13 and the target speed given by the host computer. The current PI controller, as the inner loop of the control system, controls the torque of the output motor 13 by controlling the difference between the feedback current of the bus and the target current of the bus given by the host computer. When the target speed given by the host computer in the entire system input is too large and the load is large, the torque of the output motor 13 of the entire system is very large, causing the electric pump 10 to operate at high power (i.e., overload), thereby shortening the service life of the electric pump 10.

[0034] This embodiment also provides a protection method for the electric pump 10, which is used to implement the above embodiment. Figure 3 This is a flowchart of a protection method for an electric pump according to an embodiment of this application, as shown below. Figure 3 As shown, the process includes the following steps:

[0035] Step S301: Obtain the temperature value of the PCB board 11 set inside the electric pump 10;

[0036] Step S302: If the temperature value is greater than or equal to the first preset temperature value, configure the first preset power as the electric pump protection power.

[0037] When the temperature value is lower than the first preset temperature value, a second preset power is configured as the electric pump protection power, wherein the first preset power is lower than the second preset power.

[0038] For example, the above method is used with an electric pump 10 with a rated power of 50W. Table 1 shows the protection current parameters of each component in the 50W electric pump 10 under different ambient temperatures:

[0039] Table 1

[0040]

[0041] As shown in Table 1, within the junction temperature range of each component in Table 1, a comprehensive consideration is made between a lower ambient temperature of -40℃ and a higher ambient temperature of 125℃. When the ambient temperature is -40℃, the minimum protection current of each component in Table 1 is 8A. When the ambient temperature is 125℃, the minimum protection current of each component in Table 1 is 6.6A. The protection current is the maximum allowable current of the component at that ambient temperature. Therefore, the sampling resistor corresponding to the 6.6A protection current is selected as the limiting component. Since the protection current of this sampling resistor is the minimum, the service life of other components will not be affected if the service life of this sampling resistor is not affected. Thus, the magnitude of the protection current of the electric pump 10 can be defined by analyzing the protection current of this sampling resistor at different ambient temperatures.

[0042] It should be noted that Table 1 only lists 3 components for illustrative purposes and is not restrictive. In actual operation, all components of the electric pump 10 need to be considered.

[0043] Figure 4 This is a schematic diagram illustrating the relationship between ambient temperature and the protection power of the sampling resistor according to an embodiment of this application. Pe represents the rated power of the sampling resistor, and the protection power is the maximum allowable power of the sampling resistor at that ambient temperature. The ambient temperature can be the temperature of the PCB board 11 where the sampling resistor is located. It is known that the square of the protection current value of the sampling resistor is proportional to the protection power value of the sampling resistor. Figure 4 The relationship curve between ambient temperature and the protection power of the sampling resistor can be obtained as follows: Figure 5 The relationship curve shown, Figure 5 This is a schematic diagram illustrating the relationship between the temperature of the PCB board and the protection current of the sampling resistor according to an embodiment of this application, as shown below. Figure 5 As shown, when the temperature of PCB board 11 (PCB Temperature, abbreviated as TPCB) is 70℃, the performance of the sampling resistor begins to decline significantly. Therefore, 70℃ is selected as the first preset temperature value. When TPCB is greater than or equal to 70℃, the first preset power is configured as the electric pump protection power; when TPCB is less than 70℃, the second preset power is configured as the electric pump protection power, wherein the first preset power is less than the second preset power.

[0044] In this embodiment, the selection of the first preset power value can be made by referring to the following method: according to Figure 5 As shown by the curve, after the TPCB value reaches 70℃, the protection current value of the sampling resistor decreases as the TPCB value increases. Furthermore, it is known that if the TPCB value of the electric pump 10 exceeds 137℃, the over-temperature protection of the PCB board 11 will be triggered. Therefore… Figure 6This is a schematic diagram illustrating the relationship between the temperature of the PCB board and the protection current of the sampling resistor according to an embodiment of this application. Figure 6 As shown, the TPCB value for triggering the over-temperature protection of PCB board 11 is defined as T0, and the corresponding protection current value I0 is defined as I0. The values ​​can be selected as follows: Figure 6 The current value I1, slightly lower than I0, is used as the protection current value corresponding to the first preset power in this method. This ensures that before triggering the over-temperature protection of the PCB board 11, the protection current value I1 is less than the protection current value corresponding to any temperature value within the entire temperature range of the TPCB, thereby providing stable protection for the electric pump 10. Figure 6 It can be seen that I1 is 5.5A; when the power supply voltage of the electric pump 10 is 12V, since the protection current of the sampling resistor is equal to the protection current of the electric pump 10, and the first preset power of the electric pump 10 is the product of the protection current of the electric pump 10 and the power supply voltage, the first preset power of the electric pump 10 is 66W. It is known that the operating point power of a 50W electric pump in the related technology is 63W. Therefore, the first preset power setting of 66W is sufficient to meet the normal operation of the 50W electric pump.

[0045] The selection of the second preset power value can be made by referring to the following method: Since the first preset power of the electric pump 10 is 66W, according to Figure 6 As shown by the curve, the protection current of the sampling resistor before the TPCB value at 70℃ is greater than the protection current after the TPCB value at 70℃. Therefore, the second preset power is set to be greater than the first preset power. At the same time, considering that when the coolant temperature of the electric pump 10 is low, the electric pump 10 needs to ensure a sufficiently large starting power to start normally, the protection current value I2 corresponding to the second preset power can be set to 6A. Since the protection current of the sampling resistor is equal to the protection current of the electric pump 10, and the second preset power of the electric pump 10 is the product of the protection current of the electric pump 10 and the power supply voltage, the second preset power of the electric pump 10 is 72W.

[0046] Through the above steps S301 to S302, compared to the prior art where the temperature of the PCB board 11 of the electric pump 10 increases during long-term high-power operation, and the lifespan of each electronic component on the PCB board 11 is related to temperature, excessively high temperature of the electric pump 10 will affect the lifespan of these electronic components, thus leading to a shortened lifespan of the electric pump 10. In this embodiment, the temperature value of the PCB board 11 set in the electric pump 10 is obtained; if the temperature value is greater than or equal to a first preset temperature value, a first preset power is configured as the electric pump protection power; if the temperature value is less than the first preset temperature value, a second preset power is configured as the electric pump protection power. The first preset power is less than the second preset power, which avoids the electric pump 10 from still operating at high power when the temperature is too high, solves the problem of shortened lifespan of the electric pump 10 due to long-term high-power operation, and helps to maintain the lifespan of the electric pump 10.

[0047] In some of these embodiments, Figure 7 This is a flowchart of a protection method for an electric pump according to another embodiment of this application, as shown below. Figure 7 As shown, it includes the following steps:

[0048] Step S701: Obtain the temperature value of the PCB board 11 set inside the electric pump 10. For example, the temperature value of the PCB board 11 set inside the electric pump 10 can be obtained by temperature acquisition using a negative temperature coefficient (NTC) material.

[0049] Step S702: If the temperature value is greater than or equal to the first preset temperature value, configure the first preset power as the electric pump protection power.

[0050] When the temperature value is less than or equal to the second preset temperature value, the second preset power is configured as the electric pump protection power;

[0051] When the temperature value is within the hysteresis region that is greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value rises from less than or equal to the second preset temperature value into the hysteresis region, the second preset power is configured as the electric pump protection power.

[0052] When the temperature value is within the hysteresis region that is greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value drops from being greater than or equal to the first preset temperature value to the hysteresis region, the first preset power is configured as the electric pump protection power, wherein the first preset temperature value is greater than the second preset temperature value.

[0053] Through the above steps S701 to S702, since the maximum error of NCT temperature acquisition is 4℃, in this embodiment, a hysteresis margin of 10℃ can be set. When the acquired temperature value is less than the first preset temperature value but is within the hysteresis region, and the temperature value drops from greater than or equal to the first preset temperature value to the hysteresis region, the first preset power is still configured as the electric pump protection power. This avoids the second preset power being mistakenly used as the electric pump protection power due to temperature acquisition error when the actual temperature value is greater than or equal to the first preset temperature value, causing the electric pump 10 to operate under overload. In other embodiments, a temperature range above 4℃ other than 10℃ can also be selected as the hysteresis margin. By setting the hysteresis, the stability of the protection is improved.

[0054] Figure 8 This is a schematic diagram of the control principle of the electric pump according to an embodiment of this application, such as... Figure 8 As shown, in Figure 2 Before the entire control system shown, a protection module was added. By adding the protection module, the operating status of the electric pump 10 can be detected in a timely manner, and a safe first target speed can be provided for the electric pump 10 when the electric pump 10 is operating at high power. This avoids the electric pump 10 from operating at high power for a long time, which will shorten its lifespan and help maintain the lifespan of the electric pump 10.

[0055] Figure 9 This is a system operation block diagram of the protection module according to an embodiment of this application, such as... Figure 9 As shown, the protection module includes a first enabling module, a first processing module, and a first exit module. The protection module continuously detects whether the electric pump 10 is overloaded by polling and processes the electric pump 10 when it is overloaded.

[0056] The first enabling module includes a power comparator module. Figure 10 This is based on the system operation block diagram of the power comparison module in the embodiments of this application, such as... Figure 10 As shown, in the power comparison module, the electric pump protection power is selected based on the temperature collected by the NTC, and the actual power of the electric pump is obtained by multiplying the bus current value and the bus voltage value of the motor; through the comparator in the power comparison module, the power difference e(t) between the actual power of the electric pump and the protection power of the electric pump is output.

[0057] Please continue reading. Figure 9In the first enabling module, after the power comparison module outputs the power difference e(t), it is determined whether the power difference e(t) is greater than 0. If the power difference e(t) is greater than 0, the first processing module determines the first target speed. For example, the first processing module includes a power PI controller, which outputs the first target speed according to the input power difference e(t). Another example is that the relationship between the power difference e(t) and the first target speed is obtained and stored in advance through experimental data, and a database is established. When determining the first target speed, the database is called to obtain the first target speed corresponding to the power difference e(t).

[0058] A speed command is sent to the motor 13 installed in the electric pump 10, wherein the speed command indicates that the speed of the motor 13 is set to the first target speed. For example, when the power difference e(t) is greater than 0, the first enable module enables the first flag bit, the first processing module determines the first target speed, and sends a speed command to the motor 13 installed in the electric pump 10, wherein the speed command indicates that the speed of the motor 13 is set to the first target speed.

[0059] In the first exit module, the first target speed is processed by a filter and then compared with the target speed given by the host computer. If the first target speed is greater than the target speed given by the host computer, a speed command is sent to the motor 13. The speed command instructs the motor 13 to set its speed to the target speed given by the host computer. For example, if the first target speed is greater than the target speed given by the host computer, the first exit module closes the first flag and sends a speed command to the motor 13. The speed command instructs the motor 13 to set its speed to the target speed given by the host computer.

[0060] With the cooperation of the first enabling module, the first processing module and the first exit module, the motor 13 operates at the first target speed when overloaded, which avoids the PCB board 11 from overheating due to the long-term high-power operation of the motor 13, which would shorten the life of the components and thus shorten the life of the PCB board 11, thus helping to maintain the life of the electric pump 10.

[0061] Figure 11 This is a flowchart illustrating the operation of the protection module according to an embodiment of this application, as follows: Figure 11As shown, when the power difference e(t) is greater than 0, the first flag bit becomes enabled. At this time, the first enable module is no longer operated. The program cycle only runs the first processing module. The power PI controller obtains the first target speed according to the power difference e(t). When the first target speed is less than or equal to the target speed given by the host computer, the motor 13 runs according to the first target speed. When the first target speed is greater than the target speed given by the host computer, the first exit module exits the overload, and the motor 13 runs according to the target speed given by the host computer.

[0062] Figure 12 This is a structural block diagram of the electric pump and host computer interaction system according to an embodiment of this application, such as... Figure 12 As shown, the system includes ECU121, MCU12 and motor 13. ECU121 is the host computer, and the electric pump 10 is controlled by the input signal from the host computer to operate itself.

[0063] The MCU12 includes a communication module, a control module, a PWM module, and an ADC module. The communication module converts the signals from the ECU121 into the target speed given by the host computer to control the operation of the electric pump, and reports the actual speed of the motor 13, the coolant temperature, and the voltage and current values ​​on the PCB board 11 electrically connected to the MCU12 to the ECU121. The control module processes the signals collected by the ADC, converts the signals into actual current, voltage, and temperature, and controls the electric pump to operate normally. This control module includes a protection module, a speed module, and an electric pump control module. The protection module provides overload protection for the electric pump 10. The speed module selects the speed of the motor 13, which can be obtained from the ECU121 (i.e., the target speed given by the host computer) or from the protection module (i.e., the first target speed). The electric pump control module is responsible for executing the control program of the electric pump 10. The PWM module is used to output a three-phase sinusoidal PWM wave. The ADC module is used to collect the current and voltage signals on the PCB board 11.

[0064] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electric pump, characterized in that, The electric pump includes a PCB board and an MCU mounted on the PCB board; The MCU acquires the temperature value of the PCB board; When the temperature value is greater than or equal to the first preset temperature value, the MCU configures the first preset power as the electric pump protection power; When the temperature value is less than the first preset temperature value, the MCU configures a second preset power as the electric pump protection power, wherein the first preset power is less than the second preset power; The MCU includes a first enable module, a first processing module, and a first exit module. The first enabling module includes a power comparison module, which is used to select the electric pump protection power according to the temperature value and output the power difference between the actual power of the electric pump and the electric pump protection power. The first processing module is used to determine a first target speed when the power difference is greater than 0, and the motor runs at the first target speed; The first exit module is used to compare the first target speed with the target speed given by the host computer. If the first target speed is greater than the target speed given by the host computer, the motor runs at the target speed given by the host computer.

2. The electric pump according to claim 1, characterized in that, When the temperature value is less than or equal to the second preset temperature value, the MCU configures the second preset power as the electric pump protection power; when the temperature value is in a hysteresis region greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value rises from less than or equal to the second preset temperature value into the hysteresis region, the MCU configures the second preset power as the electric pump protection power; when the temperature value is in a hysteresis region greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value falls from greater than or equal to the first preset temperature value into the hysteresis region, the MCU configures the first preset power as the electric pump protection power, wherein the first preset temperature value is greater than the second preset temperature value.

3. The electric pump according to claim 1, characterized in that, The electric pump includes a motor electrically connected to the MCU, after the MCU selects the electric pump protection power: The MCU determines the actual power of the electric pump, wherein the actual power is proportional to the product of the bus current value and the bus voltage value; The MCU compares the actual power of the electric pump with the protection power of the electric pump. If the actual power of the electric pump is greater than the protection power of the electric pump, the MCU determines a first target speed and sends a speed command to the motor, wherein the speed command instructs the motor to set the speed of the motor to the first target speed.

4. The electric pump according to claim 3, characterized in that, The MCU includes a PI controller, and the MCU determines the first target speed by: the PI controller outputting the first target speed based on the power difference between the input actual power and the electric pump protection power.

5. The electric pump according to claim 3 or 4, characterized in that, When the actual power of the electric pump is greater than the protection power of the electric pump, the MCU enables the first flag bit; If the first target rotational speed is greater than the target rotational speed given by the host computer, the MCU turns off the first flag bit.

6. A protection method for an electric pump, characterized in that, The method includes: Obtain the temperature value of the PCB board located inside the electric pump; When the temperature value is greater than or equal to the first preset temperature value, the first preset power is configured as the electric pump protection power; When the temperature value is less than the first preset temperature value, a second preset power is configured as the electric pump protection power, wherein the first preset power is less than the second preset power; The electric pump protection power is selected based on the temperature value, and the power difference between the actual power of the electric pump and the electric pump protection power is output. When the power difference is greater than 0, a first target speed is determined, and the motor runs at the first target speed. By comparing the first target speed with the target speed given by the host computer, if the first target speed is greater than the target speed given by the host computer, the motor runs at the target speed given by the host computer.

7. The method according to claim 6, characterized in that, The method includes: configuring the second preset power as the electric pump protection power when the temperature value is less than or equal to a second preset temperature value; configuring the second preset power as the electric pump protection power when the temperature value is in a hysteresis region greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value rises from less than or equal to the second preset temperature value into the hysteresis region; configuring the first preset power as the electric pump protection power when the temperature value is in a hysteresis region greater than the second preset temperature value and less than the first preset temperature value, and if the temperature value falls from greater than or equal to the first preset temperature value into the hysteresis region, wherein the first preset temperature value is greater than the second preset temperature value.

8. The method according to claim 6, characterized in that, After configuring the electric pump protection power, the method includes: Determine the actual power of the electric pump, wherein the actual power is proportional to the product of the bus current value and the bus voltage value; The actual power of the electric pump is compared with the protection power of the electric pump. If the actual power of the electric pump is greater than the protection power of the electric pump, a first target speed is determined, and a speed command is sent to the motor installed in the electric pump, wherein the speed command instructs the motor to set the speed of the motor to the first target speed.

9. The method according to claim 8, characterized in that, Determining the first target speed includes: the PI controller set in the MCU of the electric pump outputs the first target speed based on the power difference between the input actual power and the electric pump protection power.

10. The method according to claim 8 or 9, characterized in that, After configuring the electric pump protection power, the method includes: When the actual power of the electric pump is greater than the protection power of the electric pump, the first flag bit is enabled; If the first target speed is greater than the target speed given by the host computer, the first flag bit is turned off.

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