A battery-powered water pump power control method

Abstract

The present invention belongs to the technical field of water pumps, and particularly relates to a method for controlling the power of a battery-powered water pump, comprising the following steps: S1, connecting the water pump to a battery; S2, detecting the current voltage to obtain V1; S3, starting the water pump; S4, accelerating the water pump; S5, calculating V according to the formula s ; S6, if the current speed reaches the rated speed or the current power reaches the rated power, execute S7; otherwise execute S14; S7, detect the current voltage to obtain V2; S8, the water pump runs stably; S9, real-time monitoring to obtain Q i ; S10, calculate V according to the formula c 、V b , Q i With V c ratio; S11, if V b is greater than Y, then execute S15; otherwise execute S12; S12, if V b If Q is greater than Z, execute S13; otherwise execute S8; S13, if Q i With V c If the ratio is less than the dimension, execute S15; otherwise execute S8; S14, if V c If it is greater than X, execute S15; otherwise execute S4; S15, set a low battery flag. The present invention can accurately determine whether various batteries are in a low battery state, effectively preventing the battery from being completely discharged.

Description

Technical Field

[0001] The present invention belongs to the technical field of water pumps, and in particular relates to a method for controlling the power of a battery-powered water pump. Background Art

[0002] Battery-powered water pumps are increasingly being used, and electric scooter batteries are also becoming increasingly common. However, one problem with using electric scooters as a power source is the fear of the battery running out, leaving the scooter unable to return, causing inconvenience for the user. Therefore, a method is needed to determine the battery level and preserve the remaining charge for the user.

[0003] Different battery types and battery cell counts have different voltage values ​​when in a low-battery state. If you know the battery type and number of cells, you can determine whether the battery is in a low-battery state by checking whether the battery voltage is below a set voltage. However, due to the wide variety of battery types and uncertain cell counts in electric scooters, the set voltage value is uncertain, so this method cannot be used for control. Summary of the Invention

[0004] The object of the present invention is to provide a battery-powered water pump power control method, which can accurately determine whether various batteries are in a low-power state and effectively avoid the battery from being completely discharged.

[0005] The present invention is achieved in that:

[0006] A battery-powered water pump power control method comprises the following steps:

[0007] S1. Connect the water pump to the battery, initialize the MCU, set the dimension M, voltage drop rate X, voltage drop rate Y, voltage drop rate Z, rated speed S0 and rated power P0. The voltage drop rates X, Y and Z satisfy the following conditions: X>Y>Z.

[0008] S2, detect the current voltage to obtain the battery initial voltage V1;

[0009] S3, start the water pump and monitor the current I in real time i 、Current voltage V i , current speed S i and the current power P i ;

[0010] S4, the water pump accelerates;

[0011] S5. According to formula V s = (V1-V i )*100% / V1, calculate the acceleration voltage drop rate V s ;

[0012] S6. If the current speed S iReach rated speed S0 or current power P i If the rated power P0 is reached, step S7 is executed; otherwise, step S14 is executed;

[0013] S7, detecting the current voltage to obtain the operating voltage V2;

[0014] S8, the water pump operates stably;

[0015] S9, real-time monitoring to obtain the discharge power Q i ;

[0016] S10, according to formula V c =V2-V i , calculate the voltage difference V c According to formula V b =V c *100% / V2, calculate the stable operating voltage drop rate V b ; According to the formula R=Q i / V c , calculate the discharge capacity Q i and the voltage difference V c The ratio R;

[0017] S11, if the voltage drop rate is stable V b If the voltage drop rate is greater than the voltage drop rate Y, then execute step S15; otherwise, execute step S12;

[0018] S12, if the voltage drop rate is stable V b If the voltage drop rate is greater than Z, then execute step S13; otherwise, execute step S8;

[0019] S13, if the discharge capacity Q i and the voltage difference V c If the ratio R is less than the dimension M, then execute step S15; otherwise, execute step S8;

[0020] S14, if the voltage drop rate V s If the voltage drop rate is greater than X, then execute step S15; otherwise, execute step S4;

[0021] S15. Set the low battery flag and stop driving the water pump.

[0022] In the above-mentioned battery-powered water pump power control method, in step S3, the current I i and the current voltage V i The current I is obtained by taking the average value. A buffer is set up to save the N latest current values ​​and the N latest voltage values. When a new value is obtained, the oldest value is sent out. The current I is obtained by taking the average value of the N current values. i, remove the extreme values ​​of N voltage values ​​and take the average to get the current voltage V i .

[0023] In the above-mentioned battery-powered water pump power control method, it also includes a current detection circuit and a voltage detection circuit. The current detection circuit uses resistor RS to sample the current, and sends it to the microcontroller after filtering by resistor R1 and capacitor C1, and converts it into a current value after ADC1 (analog-to-digital converter); the voltage detection circuit uses resistors R2 and R3 to divide the voltage, and sends it to the microcontroller after filtering by resistor R4 and capacitor C2, and converts it into a voltage value after ADC2 (analog-to-digital converter).

[0024] In the above-mentioned battery-powered water pump power control method, in step S3, the current I i and the current voltage V i To monitor once every T time to get a current I i and a current voltage V i ; In step S3, real-time monitoring of the current speed S i and the current power P i To monitor every T time to get a current speed S i and a current power P i .

[0025] In the above-mentioned battery-powered water pump power control method, in step S9, the discharge power Q i The current I is obtained by integration. i Multiply them by T respectively and then add them up.

[0026] In the above-mentioned battery-powered water pump power control method, in step S3, the current speed S i It is measured by the frequency converter board or the Hall sensor connected to the water pump motor.

[0027] In the above-mentioned battery-powered water pump power control method, in step S3, the current power P i It is measured by a frequency converter board or a power sensor connected to the water pump motor.

[0028] The advantages of the present invention compared to the prior art are:

[0029] The present invention judges whether the battery is in a low power state when the water pump is in the accelerated operation and stable operation states respectively. When the water pump is in the accelerated operation, if the accelerated operation voltage drop rate V sIf the voltage drop rate is greater than X, it means that the voltage of the water pump drops too fast when it is running at an accelerated speed, and the battery is already in a low-power state. It is no longer necessary to continue running and the pump should be shut down in time to avoid excessive discharge of the battery. When the water pump is in a stable running state, the voltage drop rate V b Compared with the voltage drop rate Y, if the voltage drop rate V is stable b If the voltage drop rate is greater than the voltage drop rate Y, it means that the voltage drops too fast when the pump is running stably, and the battery is in a low power state. Then, when the voltage drop rate V b When the voltage drop rate is less than or equal to Y, the voltage drop rate V will be stabilized. b Compared with the voltage drop rate Z and the discharge capacity Q i and the voltage difference V c The ratio R is compared with the dimension M. When the voltage drop rate V is stable b Greater than the voltage drop rate Z, discharge capacity Q i and the voltage difference V c The ratio R is less than the dimension M, which means that the discharge power Q i When the voltage difference V c If the voltage drop rate Y is too high, it is also a sign that the battery is in a low-power state. Therefore, the judgment is more accurate, thereby effectively avoiding missed judgments. At the same time, the voltage drop rate Y can be set as high as possible, so that the water pump can use more electricity while ensuring the remaining power. The present invention can accurately determine whether various batteries are in a low-power state and effectively avoid battery discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a control flow chart of the present invention;

[0031] Figure 2 It is a circuit diagram of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to specific embodiments. Figure 1 、 2 :

[0033] A battery-powered water pump power control method comprises the following steps:

[0034] S1. Connect the water pump to the battery, initialize the MCU, set the dimension M, voltage drop rate X, voltage drop rate Y, voltage drop rate Z, rated speed S0 and rated power P0. The voltage drop rates X, Y and Z satisfy the following conditions: X>Y>Z.

[0035] S2, detect the current voltage to obtain the battery initial voltage V1;

[0036] S3, start the water pump and monitor the current I in real time i 、Current voltage Vi , current speed S i and the current power P i ;

[0037] S4, the water pump accelerates;

[0038] S5. According to formula V s = (V1-V i )*100% / V1, calculate the acceleration voltage drop rate V s ;

[0039] S6. If the current speed S i Reach rated speed S0 or current power P i If the rated power P0 is reached, step S7 is executed; otherwise, step S14 is executed;

[0040] S7, detecting the current voltage to obtain the operating voltage V2;

[0041] S8, the water pump operates stably;

[0042] S9, real-time monitoring to obtain the discharge power Q i ;

[0043] S10, according to formula V c =V2-V i , calculate the voltage difference V c According to formula V b =V c *100% / V2, calculate the stable operating voltage drop rate V b ; According to the formula R=Q i / V c , calculate the discharge capacity Q i and the voltage difference V c The ratio R;

[0044] S11, if the voltage drop rate is stable V b If the voltage drop rate is greater than the voltage drop rate Y, then execute step S15; otherwise, execute step S12;

[0045] S12, if the voltage drop rate is stable V b If the voltage drop rate is greater than Z, then execute step S13; otherwise, execute step S8;

[0046] S13, if the discharge capacity Q i and the voltage difference V c If the ratio R is less than the dimension M, then execute step S15; otherwise, execute step S8;

[0047] S14, if the voltage drop rate V s If the voltage drop rate is greater than X, then execute step S15; otherwise, execute step S4;

[0048] S15. Set the low battery flag and stop driving the water pump.

[0049] In this embodiment, the voltage drop rate X is 15%, the voltage drop rate Y is 5%, the voltage drop rate Z is 3%, and the dimension M is 30.

[0050] After the water pump is started, it is in the accelerated running state. When the current speed S i Reach rated speed S0 or current power P i After reaching the rated power P0, the pump will no longer accelerate, that is, the current speed S i and the current power P i When one or both of them reach the specified value, the pump will be in a stable operating state.

[0051] like Figure 1 As shown, the present invention judges whether the battery is in a low power state when the water pump is in the accelerated operation and stable operation states respectively. When the water pump is in the accelerated operation, if the accelerated operation voltage drop rate V s If the voltage drop rate is greater than X, it means that the voltage of the water pump drops too fast when it is running at an accelerated speed, and the battery is already in a low-power state. It is no longer necessary to continue running and the pump should be shut down in time to avoid excessive discharge of the battery. When the water pump is in a stable running state, the voltage drop rate V b Compared with the voltage drop rate Y, if the voltage drop rate V is stable b If the voltage drop rate is greater than the voltage drop rate Y, it means that the voltage drops too fast when the pump is running stably, and the battery is in a low power state. Then, when the voltage drop rate V b When the voltage drop rate is less than or equal to Y, the voltage drop rate V will be stabilized. b Compared with the voltage drop rate Z and the discharge capacity Q i and the voltage difference V c The ratio R is compared with the dimension M. When the voltage drop rate V is stable b Greater than the voltage drop rate Z, discharge capacity Q i and the voltage difference V c The ratio R is less than the dimension M, which means that the discharge power Q i When the voltage difference V c If the value is too large, it is also a sign that the battery is in a low power state, so the judgment is more accurate, which effectively avoids missed judgment. At the same time, the voltage drop rate Y can be set as high as possible, so that the water pump can use more electricity while ensuring the margin.

[0052] In order to obtain the accurate current I i and the current voltage V i In step S3, the current I iand the current voltage V i The current I is obtained by taking the average value. A buffer is set up to save the N latest current values ​​and the N latest voltage values. When a new value is obtained, the oldest value is sent out. The current I is obtained by taking the average value of the N current values. i , remove the extreme values ​​of N voltage values ​​and take the average to get the current voltage V i .

[0053] Current and voltage detection methods: such as Figure 2 As shown, it also includes a current detection circuit and a voltage detection circuit. The current detection circuit uses resistor RS to sample the current, and sends it to the microcontroller after filtering by resistor R1 and capacitor C1, and forms a current value after conversion by ADC1 (analog-to-digital converter); the voltage detection circuit uses resistors R2 and R3 to divide the voltage, and sends it to the microcontroller after filtering by resistor R4 and capacitor C2, and forms a voltage value after conversion by ADC2 (analog-to-digital converter).

[0054] Figure 2 In the figure, U1 is the inverter drive circuit, which is a conventional circuit. The resistor RS is the current sampling resistor. The inverter circuit is connected to GND through the resistor RS after being collected. The current measured here is equivalent to the battery discharge current. The resistor R1 and the capacitor C1 form a filter circuit. The filtered signal is sent to the ADC1 (analog-to-digital converter) input of the microcontroller, and the analog signal is converted into a digital signal to form a current value; the battery voltage is divided by the resistor R2 and the resistor R3, and is filtered by the resistor R4 and the capacitor C2 and sent to the ADC2 (analog-to-digital converter) input of the microcontroller, and the analog signal is converted into a digital signal to form a voltage value.

[0055] In this embodiment, the single chip microcomputer adopts ES8P0283.

[0056] Furthermore, in step S3, the current I is monitored in real time. i and the current voltage V i To monitor once every T time to get a current I i and a current voltage V i ; In step S3, real-time monitoring of the current speed S i and the current power P i To monitor every T time to get a current speed S i and a current power P i .

[0057] Discharge capacity Q i The method of obtaining: In step S9, the discharge power Q i The current I is obtained by integration. i Multiply them by T and add them up. When T is 1s, each current I iAccumulate and you can get the discharge capacity Q i When T is 100ms, each current I i Multiply them by 100ms respectively and then add them together to get the discharge capacity Q i In this embodiment, T is 1s, and the discharge capacity Q i After the pump is running stably, the current I i Accumulate.

[0058] Current speed S i Measurement method: In step S3, the current speed S i It is measured by the frequency converter board or the Hall sensor connected to the water pump motor. In this embodiment, the current speed S i Read through the frequency converter board.

[0059] Current power P i Measurement method: In step S3, the current power P i It is measured by the frequency converter board or the power sensor connected to the water pump motor. In this embodiment, the current power P i Read through the frequency converter board.

[0060] The above embodiment is only one of the preferred embodiments of the present invention and is not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes made based on the shape, structure, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery-powered water pump power control method, characterized by: The following steps are involved: S1. Connect the water pump to the battery, initialize the MCU, set the dimension M, voltage drop rate X, voltage drop rate Y, voltage drop rate Z, rated speed S0 and rated power P0. The voltage drop rates X, Y and Z satisfy the following conditions: X>Y>Z. S2, detect the current voltage to obtain the battery initial voltage V1; S3, start the water pump and monitor the current I in real time i 、Current voltage V i , current speed S i and the current power P i ; S4, the water pump accelerates; S5. According to formula V s = (V1-V i )*100% / V1, calculate the acceleration voltage drop rate V s ; S6. If the current speed S i Reach rated speed S0 or current power P i When the rated power P0 is reached, step S7 is executed; Otherwise, execute step S14; S7, detecting the current voltage to obtain the operating voltage V2; S8, the water pump operates stably; S9, real-time monitoring to obtain the discharge power Q i ; S10, according to formula V c =V2-V i , calculate the voltage difference V c According to formula V b =V c *100% / V2, calculate the stable operating voltage drop rate V b ; According to the formula R=Q i / V c , calculate the discharge capacity Q i and the voltage difference V c The ratio R; S11, if the voltage drop rate is stable V b If the voltage drop rate is greater than the voltage drop rate Y, then execute step S15; otherwise, execute step S12; S12, if the voltage drop rate is stable V b If the voltage drop rate is greater than Z, step S13 is executed; Otherwise, execute step S8; S13, if the discharge capacity Q i and the voltage difference V c If the ratio R is less than the dimension M, then execute step S15; otherwise, execute step S8; S14, if the voltage drop rate V s If the voltage drop rate is greater than X, then execute step S15; otherwise, execute step S4; S15. Set the low battery flag and stop driving the water pump.

2. A battery-powered water pump power control method according to claim 1, characterized in that: In step S3, the current I i and the current voltage V i The current I is obtained by averaging. A buffer is set up to save the N latest current values ​​and the N latest voltage values. When a new value is available, the oldest value is sent out. The current I is obtained by averaging the N current values ​​in the buffer to get the current value. i , remove the extreme values ​​of N voltage values ​​and take the average to get the current voltage V i .

3. A battery-powered water pump power control method according to claim 2, characterized in that: It also includes a current detection circuit and a voltage detection circuit. The current detection circuit uses resistor RS to sample the current, which is filtered by resistor R1 and capacitor C1 and sent to the microcontroller, and converted by ADC1 to form a current value; the voltage detection circuit uses resistors R2 and R3 to divide the voltage, which is filtered by resistor R4 and capacitor C2 and sent to the microcontroller, and converted by ADC2 to form a voltage value.

4. The battery-powered water pump power control method according to claim 1, characterized in that: In step S3, the current I is monitored in real time. i and the current voltage V i To monitor once every T time to get a current I i and a current voltage V i ; In step S3, real-time monitoring of the current speed S i and the current power P i To monitor every T time to get a current speed S i and a current power P i .

5. The battery-powered water pump power control method according to claim 4, characterized in that: In step S9, the discharge quantity Q i The current I is obtained by integration. i Multiply them by T respectively and then add them up.

6. The battery-powered water pump power control method according to claim 1, characterized in that: In step S3, the current speed S i It is measured by the frequency converter board or the Hall sensor connected to the water pump motor.

7. The battery-powered water pump power control method according to claim 1, characterized in that: In step S3, the current power P i It is measured by a frequency converter board or a power sensor connected to the water pump motor.

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