Electronic water pump control method and control system with idling condition control

Abstract

The present invention discloses an electronic water pump control method and its control system with idling condition control, which includes: obtaining the rotational speed R and bus current I of the electronic water pump; during the idling protection interruption, determining whether the working condition of the electronic water pump meets the first idling judgment condition (R ≤ the second threshold), the second idling judgment condition (I < the third threshold), and the third idling judgment condition (R > the fourth threshold). If so, the value of the idling protection numerical accumulator is accumulated; when the value of the idling protection numerical accumulator is accumulated to be greater than the idling protection threshold, the electronic water pump is transferred to the idling operation working state. The present invention mainly solves the problem of how to provide an electronic water pump control method and its control system with idling condition control; the present invention can achieve the idling protection of the electronic water pump and use several restarts of the electronic water pump to discharge the air in the pipeline, thereby improving the service life of the electronic water pump.

Description

Technical Field

[0001] The present invention relates to the technical field of motors and electronic water pump control methods, and particularly to an electronic water pump control method with idling condition control and its control system. Background Art

[0002] Electronic water pumps have high output efficiency and can achieve precise flow control. Therefore, electronic water pumps are widely used in automobiles, household appliances, and industrial equipment. In particular, new energy vehicles usually have two or more electronic water pumps. The electronic water pump is the power source of the entire cooling system of new energy vehicles. The power battery, drive motor, etc. of new energy vehicles all rely on the electronic water pump to drive the coolant to circulate and cool.

[0003] Idling is one of the common working conditions of electronic water pumps. When the electronic water pump is idling, its rotor assembly, bearings, and shaft core will all undergo dry grinding, thereby accelerating wear and reducing the service life of the electronic water pump. Simply improving the structural strength of the rotor assembly, bearings, and shaft core to improve the anti-wear performance of the electronic water pump is obviously of low cost performance.

[0004] In the application scenarios of electronic water pumps, reasons such as non-standard liquid addition, pipeline clearance, and low liquid level will all cause air to enter the pipeline, thereby causing the electronic water pump to idle. However, this is not an abnormal operation of the electronic water pump. In fact, as long as the air in the pipeline is discharged, the electronic water pump can resume normal operation.

[0005] In summary, how to provide an electronic water pump control method with idling condition control and its control system has become an urgent problem to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide an electronic water pump control method with idling condition control and its control system, which can achieve idling protection of the electronic water pump and use the electronic water pump to discharge the air in the pipeline.

[0007] To achieve the above purpose, the present invention provides the following technical solution: An electronic water pump control method with idling condition control, which is applied to the motor drive module of the electronic water pump; it includes:

[0008] Start the electronic water pump in the normal working state, obtain the rotation speed R and bus current I of the electronic water pump, and convert the bus current I into its AD value I(AD);

[0009] Define the first idling judgment condition as: And R ≤ the second threshold;

[0010] Define the second idling judgment condition as: I < the third threshold;

[0011] Define the third idling judgment condition as: R > the fourth threshold value;

[0012] When the working condition of the electronic water pump satisfies any one of the first idling judgment condition, the second idling judgment condition, and the third idling judgment condition, trigger an idling protection interruption, and establish an idling protection value accumulator in the idling protection interruption;

[0013] In the idling protection interruption, continue to judge whether the working condition of the electronic water pump satisfies any one of the first idling judgment condition, the second idling judgment condition, and the third idling judgment condition; if so, accumulate the value of the idling protection value accumulator, if not, subtract the value of the idling protection value accumulator;

[0014] When the value of the idling protection value accumulator is accumulated to be greater than the idling protection threshold value, transfer the electronic water pump to the idling operation working state.

[0015] In the above technical solution, when the electronic water pump is transferred to the idling operation working state, there is:

[0016] The electronic water pump continues to run within the first delay t1, and after the first delay t1, transfers to the shutdown state;

[0017] And, within the first delay t1, if is less than the first threshold value and maintains for 25% - 35% of the duration of the first delay t1, then transfer the electronic water pump to the normal working state.

[0018] In the above technical solution, when the electronic water pump is transferred to the shutdown state, there is:

[0019] When the restart times of the electronic water pump do not reach the fifth threshold value, then after the second delay t2, restart the electronic water pump, and transfer the electronic water pump to the normal working state to discharge the air in the pipeline, and at the same time accumulate the restart times of the electronic water pump;

[0020] When the restart times of the electronic water pump reach the fifth threshold value, then do not restart the electronic water pump.

[0021] In the above technical solution, the first threshold value is 4500 - 5500, and the second threshold value is 1600 RPM - 2000 RPM.

[0022] In the above technical solution, the third threshold value is 0.3 A - 0.5 A.

[0023] In the above technical solution, the fourth threshold value is 6000 RPM - 7000 RPM.

[0024] In the above technical solution, the idling protection threshold is 2000 - 3000.

[0025] In the above technical solution, the first delay t1 is 4s - 6s.

[0026] In the above technical solution, the second delay t2 is 4s - 6s, and the fifth threshold is 8 - 12 times.

[0027] An electronic water pump control system with idling condition control is applied to the motor drive module of an electronic water pump; it includes:

[0028] An electronic water pump condition acquisition module for acquiring the rotational speed R and bus current I of the electronic water pump, and converting the bus current I into its AD value I(AD);

[0029] An idling protection interrupt trigger module for determining whether the condition of the electronic water pump meets any one of the first idling judgment condition, the second idling judgment condition, and the third idling judgment condition, and triggering the idling protection interrupt module when it is met;

[0030] An idling protection interrupt module, which includes an idling protection value accumulator, for continuing to determine whether the condition of the electronic water pump meets any one of the first idling judgment condition, the second idling judgment condition, and the third idling judgment condition; if so, the value of the idling protection value accumulator is accumulated, if not, the value of the idling protection value accumulator is subtracted; and when the value of the idling protection value accumulator is accumulated to be greater than the idling protection threshold, the electronic water pump is switched to the idling operation working state;

[0031] Among them, the first idling judgment condition is: And R ≤ the second threshold;

[0032] The second idling judgment condition is: I < the third threshold;

[0033] The third idling judgment condition is: R > the fourth threshold.

[0034] Compared with the prior art, the beneficial effects of the present invention are: The electronic water pump control method and its control system with idling condition control of the present invention, when the condition of the electronic water pump meets the first idling judgment condition ( When any one of the first idling determination condition (R ≤ the second threshold value), the second idling determination condition (I < the third threshold value), and the third idling determination condition (R > the fourth threshold value) is satisfied, the value of the idling protection value accumulator will be accumulated, which can more comprehensively determine whether the electric water pump enters the idling condition, thereby realizing the idling protection of the electric water pump, and using several restarts of the electric water pump to discharge the air in the pipeline to eliminate the idling condition of the electric water pump, so as to improve the service life of the electric water pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic electrical structure diagram of the electric water pump in the present invention.

[0036] Figure 2 It is a schematic flow chart of the first embodiment of the present invention.

[0037] Figure 3 It is a schematic flow chart of the first embodiment of the present invention when entering the shutdown state. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Embodiment 1:

[0040] This embodiment provides an electric water pump control method with idling condition control, which is applied to the motor drive module of the electric water pump.

[0041] The schematic electrical structure diagram of the electric water pump is as Figure 1 shown. The motor drive module is based on an MCU such as a single-chip microcomputer or a dedicated motor drive chip, making it suitable for programming; the motor drive module obtains a speed regulation signal from the host computer, and this speed regulation signal is converted into a PWM signal through an internal signal converter for driving the motor and controlling the start, stop, and speed of the motor; the U-phase, V-phase, and W-phase currents of the motor can all be sampled by the current sampling module inside the motor drive module and converted into the bus current I; the motor drive module also includes an angle observer, which can obtain the rotation shaft angle of the motor through this angle observer and then convert it into the rotation speed (RPM) of the motor, and the rotation speed of this motor is the rotation speed R of the electric water pump.

[0042] Please refer to Figure 2 , the electric water pump control method with idling condition control in this embodiment includes:

[0043] Start the electric water pump in its normal working state, obtain the rotational speed R and the bus current I of the electric water pump, and convert the bus current I into its AD value I(AD);

[0044] Define the first no-load judgment condition as: and R ≤ the second threshold value;

[0045] Define the second no-load judgment condition as: I < the third threshold value;

[0046] Define the third no-load judgment condition as: R > the fourth threshold value;

[0047] When the operating condition of the electric water pump satisfies any one of the first no-load judgment condition, the second no-load judgment condition, and the third no-load judgment condition, trigger a no-load protection interrupt, and establish a no-load protection value accumulator in the no-load protection interrupt;

[0048] In the no-load protection interrupt, continue to judge whether the operating condition of the electric water pump satisfies any one of the first no-load judgment condition, the second no-load judgment condition, and the third no-load judgment condition; if so, accumulate the value of the no-load protection value accumulator, if not, subtract the value of the no-load protection value accumulator;

[0049] When the value of the no-load protection value accumulator is accumulated to be greater than the no-load protection threshold value, transfer the electric water pump to the no-load running working state.

[0050] Among them, the AD value I(AD) of the bus current I is specifically the value after the bus current I is converted into digital data, and the specific conversion method is:

[0051] Among them, is the ratio of the square of the rotational speed R of the electric water pump to the bus current I, and it does not have a physical unit.

[0052] Among them, the no-load protection interrupt is a section of interrupt program in the MCU of the motor drive module, which has a higher execution priority. The no-load protection value accumulator is the accumulator temporarily established in the interrupt program. In this embodiment, the duration of the no-load protection interrupt is 1 ms; in the no-load protection interrupt, the period of continuing to judge whether the operating condition of the electric water pump satisfies any one of the first no-load judgment condition, the second no-load judgment condition, and the third no-load judgment condition is a certain multiple of the crystal oscillator period of the MCU of the motor drive module.

[0053] When the electric water pump is in the no-load operating condition, it is mainly manifested as an increase in rotational speed and a decrease in current. On this premise, if the operating condition of the electric water pump satisfies any one of the first no-load judgment condition, the second no-load judgment condition, and the third no-load judgment condition, it may indicate that the electric water pump has entered the no-load operating condition.

[0054] Among them, the first threshold, the second threshold, the third threshold, the fourth threshold, and the idling protection threshold are all user-defined thresholds, which can be defined according to the application scenarios of the electric water pump, the characteristics of the fluid medium, the head, and the input / output power and other characteristics.

[0055] In this embodiment, the first threshold is 4500 - 5500, preferably 5000; the second threshold is 1600 RPM - 2000 RPM, preferably 1800 RPM.

[0056] In this embodiment, the third threshold is 0.3 A - 0.5 A, preferably 0.4 A.

[0057] In this embodiment, the fourth threshold is 6000 RPM - 7000 RPM, preferably 6500 RPM.

[0058] In this embodiment, the idling protection threshold is 2000 - 3000, preferably 2500.

[0059] The above first threshold, second threshold, third threshold, fourth threshold, and idling protection threshold are applicable to most electric water pumps applied to automobiles, household appliances, and industrial equipment, with high universality and improving the application range of the electric water pump.

[0060] Furthermore, when the electric water pump enters the idling operation working state, there is:

[0061] The electric water pump continues to run within the first delay t1 and enters the shutdown state after the first delay t1;

[0062] And, within the first delay t1, if is less than the first threshold and maintains for 25% - 35% (preferably 30%) of the duration of the first delay t1, then the electric water pump is transferred to the normal working state.

[0063] In this embodiment, the first delay t1 is 4 s - 6 s, preferably 5 s.

[0064] Within the first delay t1, if is less than the first threshold and maintains for 25% - 35% of the duration of the first delay t1, it indicates that the idling condition of the electric water pump may have been excluded. At this time, the electric water pump should be transferred to the normal working state.

[0065] Please refer to Figure 3 , furthermore, when the electric water pump enters the shutdown state, there is:

[0066] When the restart times of the electric water pump do not reach the fifth threshold, then after the second delay t2, the electric water pump is restarted and transferred to the normal working state to discharge the air in the pipeline, and at the same time, the restart times of the electric water pump are accumulated;

[0067] When the restart count of the electric water pump reaches the fifth threshold, the electric water pump will no longer be restarted.

[0068] In this embodiment, the second delay t2 is 4s to 6s, preferably 5s; the fifth threshold is 8 to 12 times, preferably 10 times.

[0069] During the interruption of the second delay t2, the liquid in the pipeline may flow to other places and settle down. At this time, the air in the pipeline may be discharged, so that the electric water pump is no longer in the idling condition. At this time, the electric water pump should be transferred to the normal working state; after the electric water pump is restarted a certain number of times, if the idling condition still cannot be eliminated, in order to protect the hardware of the electric water pump, the electric water pump needs to be shut down for maintenance. In this case, the motor drive module can also report an error to the host computer.

[0070] Embodiment 2:

[0071] This embodiment provides an electric water pump control system with idling condition control, which is applied to the motor drive module of the electric water pump.

[0072] The electrical structure schematic diagram of the electric water pump is as Figure 1 shown. The motor drive module is based on an MCU such as a single-chip microcomputer or a dedicated motor drive chip, making it suitable for programming; the motor drive module obtains a speed regulation signal from the host computer, and this speed regulation signal is converted into a PWM signal through an internal signal converter for driving the motor and controlling the start, stop and speed of the motor; the U-phase, V-phase and W-phase currents of the motor can all be sampled by the current sampling module inside the motor drive module and converted into the bus current I; the motor drive module also includes an angle observer, which can obtain the shaft angle of the motor through this angle observer and then convert it into the speed (RPM) of the motor, and the speed of this motor is the speed R of the electric water pump.

[0073] The electric water pump control system with idling condition control in this embodiment includes:

[0074] An electric water pump working condition acquisition module, which is used to acquire the speed R and the bus current I of the electric water pump, and convert the bus current I into its AD value I(AD);

[0075] An idling protection interruption trigger module, which is used to judge whether the working condition of the electric water pump meets any one of the first idling judgment condition, the second idling judgment condition and the third idling judgment condition, and trigger the idling protection interruption module when it is satisfied;

[0076] An idling protection interruption module, which includes an idling protection value accumulator for continuously determining whether the operating condition of the electronic water pump meets any one of a first idling determination condition, a second idling determination condition, and a third idling determination condition; if so, the value of the idling protection value accumulator is accumulated, and if not, the value of the idling protection value accumulator is subtracted; and when the value of the idling protection value accumulator is accumulated to be greater than the idling protection threshold, the electronic water pump is transferred to the idling operation working state;

[0077] Among them, the first idling determination condition is: and R ≤ the second threshold;

[0078] The second idling determination condition is: I < the third threshold;

[0079] The third idling determination condition is: R > the fourth threshold.

[0080] Among them, the AD value I(AD) of the bus current I is specifically the value after the bus current I is converted into digital data, and the specific conversion method is:

[0081] Among them, is the ratio of the square of the rotational speed R of the electronic water pump to the bus current I, and it does not have a physical unit.

[0082] Among them, the idling protection interruption is an interruption program in the MCU of the motor drive module, which has a relatively high execution priority. The idling protection value accumulator is an accumulator temporarily established in the interruption program. In this embodiment, the duration of the idling protection interruption is 1 ms; in the idling protection interruption, the period for continuously determining whether the operating condition of the electronic water pump meets any one of the first idling determination condition, the second idling determination condition, and the third idling determination condition is a certain multiple of the crystal oscillator period of the MCU of the motor drive module.

[0083] When the electronic water pump is in the idling condition, it is mainly manifested as an increase in rotational speed and a decrease in current. Under this premise, if the operating condition of the electronic water pump meets any one of the first idling determination condition, the second idling determination condition, and the third idling determination condition, it may indicate that the electronic water pump has entered the idling condition.

[0084] Among them, the first threshold, the second threshold, the third threshold, the fourth threshold, and the idling protection threshold are all user-defined thresholds, which can be defined by themselves according to the application scenario of the electronic water pump, the characteristics of the fluid medium, the head, and the input / output power and other characteristics.

[0085] In this embodiment, the first threshold is 4500 - 5500, preferably 5000; the second threshold is 1600 RPM - 2000 RPM, preferably 1800 RPM.

[0086] In this embodiment, the third threshold is 0.3A to 0.5A, preferably 0.4A.

[0087] In this embodiment, the fourth threshold is 6000 RPM to 7000 RPM, preferably 6500 RPM.

[0088] In this embodiment, the idling protection threshold is 2000 to 3000, preferably 2500.

[0089] The above first threshold, second threshold, third threshold, fourth threshold, and idling protection threshold are applicable to most electronic water pumps used in automobiles, household appliances, and industrial equipment, having high universality and improving the application range of the electronic water pump.

[0090] Furthermore, when the electronic water pump enters the idling operation working state, there is:

[0091] The electronic water pump continues to operate within the first delay t1 and enters the shutdown state after the first delay t1.

[0092] And within the first delay t1, if is less than the first threshold and maintains for 25% to 35% (preferably 30%) of the duration of the first delay t1, the electronic water pump is transferred to the normal working state.

[0093] In this embodiment, the first delay t1 is 4s to 6s, preferably 5s.

[0094] Within the first delay t1, if is less than the first threshold and maintains for 25% to 35% of the duration of the first delay t1, it indicates that the idling condition of the electronic water pump may have been excluded. At this time, the electronic water pump should be transferred to the normal working state.

[0095] Furthermore, when the electronic water pump enters the shutdown state, there is:

[0096] When the restart count of the electronic water pump has not reached the fifth threshold, after the second delay t2, the electronic water pump is restarted and transferred to the normal working state to discharge the air in the pipeline, and at the same time, the restart count of the electronic water pump is incremented.

[0097] When the restart count of the electronic water pump reaches the fifth threshold, the electronic water pump is no longer restarted.

[0098] In this embodiment, the second delay t2 is 4s to 6s, preferably 5s; the fifth threshold is 8 to 12 times, preferably 10 times.

[0099] During the interruption of the second delay t2, the liquid in the pipeline may flow elsewhere and settle down. At this time, the air in the pipeline may be discharged, so that the electronic water pump is no longer in the idling condition. At this time, the electronic water pump should be transferred to the normal working state; after the electronic water pump is restarted a certain number of times, if the idling condition cannot be eliminated, in order to protect the hardware of the electronic water pump, the electronic water pump needs to be shut down for maintenance. In this case, the motor drive module can also report an error to the host computer.

[0100] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electronic water pump control method with idling condition control, which is applied to the motor drive module of the electronic water pump; characterized in that, Including: Start the electronic water pump in its normal working state and obtain the rotational speed of the electronic water pump and the busbar current , and convert the busbar current to its AD value ; Define the first idling judgment condition as: > the first threshold, and ≤ the second threshold; Define the second idling judgment condition as: <the third threshold; Define the third idling judgment condition as: > the fourth threshold value; When the operating condition of the electronic water pump satisfies any one of the first idle running judgment condition, the second idle running judgment condition, and the third idle running judgment condition, an idle running protection interruption is triggered, and an idle running protection value accumulator is established during the idle running protection interruption; During the idle running protection interruption, continue to judge whether the operating condition of the electronic water pump satisfies any one of the first idle running judgment condition, the second idle running judgment condition, and the third idle running judgment condition; if so, accumulate the value of the idle running protection value accumulator, if not, subtract the value of the idle running protection value accumulator; When the value of the idle running protection value accumulator is accumulated to be greater than the idle running protection threshold, the electronic water pump is transferred to the idle running working state; The first threshold is 4500 - 5500, and the second threshold is 1600 RPM - 2000 RPM; The third threshold is 0.3 A - 0.5 A; The fourth threshold is 6000 RPM - 7000 RPM; The idle running protection threshold is 2000 - 3000.

2. The electronic water pump control method with idling condition control according to claim 1, characterized in that, When the electronic water pump is transferred to the idle running working state, there is: The electric water pump continues to operate within the first delay period and enters the shutdown state after the first delay period ends; And, within the first delay if is less than the first threshold and maintains for 25% - 35% of the duration of the first delay then transfer the electronic water pump to the normal working state.

3. The electronic water pump control method with idling condition control according to claim 2, characterized in that, When the electronic water pump is transferred to the shutdown state, there is: When the restart times of the electronic water pump do not reach the fifth threshold, after a second delay restart the electronic water pump and transfer the electronic water pump to the normal working state to discharge the air in the pipeline, and at the same time accumulate the restart times of the electronic water pump; When the restart times of the electronic water pump reach the fifth threshold, the electronic water pump is no longer restarted.

4. The electronic water pump control method with idling condition control according to claim 2, characterized in that, The first delay is 4 s to 6 s.

5. The electronic water pump control method with idling condition control according to claim 3, characterized in that, The second delay is 4 s to 6 s, and the fifth threshold is 8 to 12 times.

6. An electronic water pump control system with idling condition control is applied to the motor drive module of an electronic water pump; it is characterized in that Including: An electronic water pump operating condition acquisition module for acquiring the rotational speed of the electronic water pump and the bus current , and converting the bus current into its AD value ; An idle running protection interruption trigger module, configured to judge whether the operating condition of the electronic water pump satisfies any one of the first idle running judgment condition, the second idle running judgment condition, and the third idle running judgment condition, and trigger the idle running protection interruption module when satisfied; An idle running protection interruption module, which includes an idle running protection value accumulator, configured to continue to judge whether the operating condition of the electronic water pump satisfies any one of the first idle running judgment condition, the second idle running judgment condition, and the third idle running judgment condition; if so, accumulate the value of the idle running protection value accumulator, if not, subtract the value of the idle running protection value accumulator; and when the value of the idle running protection value accumulator is accumulated to be greater than the idle running protection threshold, the electronic water pump is transferred to the idle running working state; Among them, the first idling judgment condition is: > the first threshold value, and ≤ the second threshold value; The second idle rotation judgment condition is as follows: <the third threshold value; The third idle rotation determination condition is as follows: > the fourth threshold value; The first threshold is 4500 - 5500, and the second threshold is 1600 RPM - 2000 RPM; The third threshold is 0.3 A - 0.5 A; The fourth threshold is 6000 RPM - 7000 RPM; The idle running protection threshold is 2000 - 3000.

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