Built-in intelligent controller for water pump and intelligent control method

Abstract

The invention belongs to the technical field of water pump control devices, and relates to a built-in intelligent controller for a water pump, comprising: a current detection circuit for detecting the running current Is of a water pump motor; the pressure sensor is used for detecting pipeline pressure Ps; the single-chip microcomputer is connected with the current detection circuit and the pressure sensor, and the control logic of the single-chip microcomputer comprises the steps that through comprehensive analysis of dynamic changes of motor operation current and pipeline pressure and in combination with time parameters, accurate identification and intelligent control over various working conditions such as normal water use, water use stopping, small-flow water use, pipeline leakage and underground water shortage are achieved. The invention further relates to an intelligent control method for the water pump. According to the built-in intelligent controller for the water pump and the intelligent control method, a mechanical or electronic water flow switch is thoroughly omitted, the structure of the controller is simplified, the size is reduced, and the reliability and consistency of the system are improved.

Description

Technical Field

[0001] This invention belongs to the technical field of water pump control devices, and relates to a built-in intelligent controller and intelligent control method for water pumps. Background Technology

[0002] Conventional intelligent well water pumps typically employ a built-in controller within the pump, along with pressure sensors (or pressure switches) and flow switches. These sensors detect whether the user is using water, whether there is a water shortage in the well, whether there are leaks in the pipeline, and control low-flow water supply, thus achieving intelligent control.

[0003] However, the flow switch has a complex structure and occupies a large amount of internal space in the water pump. It is also difficult to ensure the consistency of each component. Therefore, in actual use, there are often many malfunctions, such as inaccurate leakage detection and very large deviations in small flow control, resulting in poor user satisfaction.

[0004] In existing technologies, such as Chinese patent CN203730348U, a water pump current pressure controller based on a ceramic pressure sensor is disclosed. It integrates a pressure sensor and a current transformer, and realizes basic pressure control, overload protection, and single water shortage protection. However, its water shortage protection logic is relatively simple, relying only on the single condition of "pressure is lower than 60% of the set value for a period of time", which cannot accurately distinguish between various complex operating conditions such as normal water use, low flow water use, and pipeline leakage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a built-in intelligent controller and intelligent control method for water pumps. It eliminates the need for a flow switch and achieves accurate identification and intelligent control of various operating conditions, such as normal water use, water stoppage, low-flow water use, pipeline leakage, and underground water shortage, by comprehensively analyzing the dynamic changes of motor operating current and pipeline pressure, and combining them with time parameters.

[0006] To solve the above-mentioned technical problems, the objective of this invention is achieved through the following technical solution: A built-in intelligent controller for a water pump includes: A current detection circuit is used to detect the operating current I of the water pump motor. s ; Pressure sensor used to detect pipeline pressure P s ; The microcontroller, connected to the current detection circuit and the pressure sensor, has the following control logic: (1) After startup, wait for the pipeline pressure P s Once the rated pressure P0 is reached and maintained for the first preset time T1, the water shortage indicator is cleared. (2) Gradually reduce the pump speed until the pressure P sIf the speed exceeds the first threshold P1, the rotation speed continues to decrease until the minimum maintenance speed is reached, and then the standby time T is started. d Until pressure P s Below the second pressure threshold P2; (3) If the standby time T d If the second preset time T2 is exceeded, it is determined that the user has stopped using water and there is no leakage in the pipeline. The pressure control point is then lowered to the third pressure threshold P3 to reduce the frequent start-stop of the water pump caused by minor pipeline leaks. (4) When the pressure P s When the pressure drops below the second pressure threshold P2 or the third pressure threshold P3, the water pump is accelerated to reach the rated speed F0, and the high-speed operation time T is started. g ; (5) During high-speed operation: If the operating current I s Greater than the no-load current I c And the current is close to the rated current I0, and the high-speed operation time T g If the water usage exceeds the third preset time T3, it is judged as normal water usage, and the standby time T is set to [value]. d Set to the maximum value; If the standby time T d Less than the fourth preset time T4, and the operating current I s Less than the rated current I0 and greater than the no-load current I c and close to the no-load current I c If the flow rate is low, the pressure control range will be set between the fourth pressure threshold P4 and the rated pressure P0. If the standby time T d The time is greater than the fourth preset time T4 but less than the second preset time T2, and the high-speed running time T g With standby time T d If the sum is less than the fifth preset time T5, and this condition occurs multiple times consecutively, then it is determined that there is a pipeline leak, and a leak sign is set. (6) If the water pump runs at high speed for the sixth consecutive preset time T6 and the operating current I s Less than the no-load current I c If so, it is determined to be a water shortage; If the water pump T7 runs at high speed for the seventh preset time and the operating current I... s Less than the rated current I0 and close to the no-load current I c And pressure P s If the pressure remains below the fifth pressure threshold P5, it is determined to be water shortage, and a water shortage flag is set.

[0007] In the aforementioned built-in intelligent controller for a water pump, control logic (1) is used for initialization and stability judgment. Control logics (2) and (3) are used for speed reduction standby and leakage prediction. Control logics (4) and (5) are used for water usage identification and operating condition differentiation; control logic (5) can make precise judgments: normal water usage judgment, low flow water usage judgment, and pipeline leakage judgment. In control logic (6), during high-speed operation, two levels of water shortage judgment are performed: rapid water shortage judgment and precise water shortage judgment.

[0008] In the above-mentioned built-in intelligent controller for water pumps, the first threshold P1 is 95% of the rated pressure P0, the second pressure threshold P2 is 90% of the rated pressure P0, the third pressure threshold P3 is 85% of the rated pressure P0, the fourth pressure threshold P4 is 90% of the rated pressure P0, and the fifth pressure threshold P5 is 70% of the rated pressure P0.

[0009] In the aforementioned built-in intelligent controller for a water pump, the no-load current I c It is less than the rated current I0, and the operating current I is determined to be... s Close to no-load current I c The condition is I s Less than (I0 + I) c ) / 2.

[0010] In the aforementioned built-in intelligent controller for a water pump, the current detection circuit includes a sampling resistor and an operational amplifier, used to sample and amplify the motor current and output it to the ADC interface of the microcontroller.

[0011] In the aforementioned built-in intelligent controller for a water pump, the pressure sensor is a voltage output type pressure sensor, and its output signal is connected to the ADC interface of the microcontroller through an RC filter circuit.

[0012] In the aforementioned built-in intelligent controller for a water pump, the microcontroller is also connected to a frequency converter drive module for adjusting the speed of the water pump motor.

[0013] The present invention also provides an intelligent control method for a water pump, the method comprising the following steps: detecting the operating current I of the water pump motor. s and pipeline pressure P s Based on I s P s The system uses pump speed, multiple time parameters, and pressure thresholds to distinguish the following operating conditions through a logical judgment algorithm: normal water use, user water stoppage, low flow water use, pipeline leakage, and underground water shortage. The logical judgment algorithm includes: (1) After startup, wait for the pipeline pressure P sOnce the rated pressure P0 is reached and maintained for the first preset time T1, the water shortage indicator is cleared. (2) Gradually reduce the pump speed until the pressure P s If the speed exceeds the first threshold P1, the rotation speed continues to decrease until the minimum maintenance speed is reached, and then the standby time T is started. d Until pressure P s Below the second pressure threshold P2; (3) If the standby time T d If the second preset time T2 is exceeded, it is determined that the user has stopped using water and there is no leakage in the pipeline, and the pressure control point is lowered to the third pressure threshold P3; (4) When the pressure P s When the pressure drops below the second pressure threshold P2 or the third pressure threshold P3, the water pump is accelerated to reach the rated speed F0, and the high-speed operation time T is started. g ; (5) During high-speed operation: If the operating current I s Greater than the no-load current I c And the current is close to the rated current I0, and the high-speed operation time T g If the water usage exceeds the third preset time T3, it is judged as normal water usage, and the standby time T is set to [value]. d Set to the maximum value; If the standby time T d Less than the fourth preset time T4, and the operating current I s Less than the rated current I0 and greater than the no-load current I c and close to the no-load current I c If the flow rate is low, the pressure control range will be set between the fourth pressure threshold P4 and the rated pressure P0. If the standby time T d The time is greater than the fourth preset time T4 but less than the second preset time T2, and the high-speed running time T g With standby time T d If the sum is less than the fifth preset time T5, and this condition occurs multiple times consecutively, then it is determined that there is a pipeline leak, and a leak sign is set. (6) If the water pump runs at high speed for the sixth consecutive preset time T6 and the operating current I s Less than the no-load current I c If so, it is determined to be a water shortage; If the water pump T7 runs at high speed for the seventh preset time and the operating current I... s Less than the rated current I0 and close to the no-load current I c And pressure P s If the pressure remains below the fifth pressure threshold P5, it is determined to be water shortage, and a water shortage flag is set.

[0014] In the above-mentioned intelligent control method for water pumps, the first threshold P1 is 95% of the rated pressure P0, the second pressure threshold P2 is 90% of the rated pressure P0, the third pressure threshold P3 is 85% of the rated pressure P0, the fourth pressure threshold P4 is 90% of the rated pressure P0, and the fifth pressure threshold P5 is 70% of the rated pressure P0.

[0015] In the aforementioned intelligent control method for a water pump, the no-load current I c It is less than the rated current I0, and the operating current I is determined to be... s Close to no-load current I c The condition is I s Less than (I0 + I) c ) / 2.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a built-in intelligent controller for water pumps, which completely eliminates mechanical or electronic flow switches, simplifies the controller structure, reduces the size, improves system reliability and consistency, and fundamentally avoids malfunctions caused by faults or drift in the characteristics of the flow switch itself.

[0017] 2. This invention creatively proposes a set of methods based on motor current (I s Pipeline pressure (P) s ), pump speed and multiple time parameters (T) d , T g The dynamic fusion judgment algorithm (T2-T7) can accurately distinguish five typical operating conditions: normal water use, water use stoppage, low flow water use, pipeline leakage, and underground water shortage. This is something that the simple threshold comparison method in the existing technology cannot achieve.

[0018] 3. This invention can significantly reduce the number of times the water pump starts and stops under light load by intelligently identifying low water flow and micro-leakage, and dynamically adjusting the pressure control point (such as from P2 to P3), which saves energy and extends the service life of the water pump.

[0019] 4. This invention provides two water shortage judgment mechanisms: rapid and precise. It can quickly respond to severe water shortage situations to protect the water pump, and avoid false triggering of protection when water usage fluctuates, thus ensuring the safety and stability of the system. Attached Figure Description

[0020] Figure 1 This is a circuit block diagram of the intelligent controller of the present invention; Figure 2 This is a software flowchart of the control logic of the present invention; Detailed Implementation

[0021] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1-2 : Comparison Appendix Figure 1 A built-in intelligent controller for water pumps, the core of which includes a microcontroller IC1 (e.g., STM8S series), a frequency converter drive module M1, a pressure sensor S1, and a current detection circuit.

[0022] The current detection circuit consists of a sampling resistor and an operational amplifier LM2904. After sampling and amplifying the motor operating current, the output signal is sent to the ADC interface of the microcontroller IC1.

[0023] The pressure sensor S1 is a ceramic piezoresistive pressure sensor that outputs a 0~5V voltage signal. This signal is filtered by an RC filter circuit composed of R1 and C2 and then sent to another ADC interface of the microcontroller IC1.

[0024] The microcontroller IC1 calculates and judges based on the collected current signal Is and pressure signal Ps according to the built-in program algorithm, and sends control commands to the frequency converter drive module M1 to adjust the speed of the water pump motor.

[0025] In this embodiment, the software flow of the control logic is as follows: Figure 2 As shown, the specific execution steps are as follows: (1) After the system is powered on and initialized, start the water pump.

[0026] (2) Continuous monitoring of pressure P s Determine if the rated pressure P0 is reached continuously for T1=5 seconds. If so, clear the water shortage indicator and proceed to step 3.

[0027] (3) The controller begins to gradually reduce the pump speed. If P s If P1 (95% of P0) is reached, the speed will continue to decrease until the minimum speed is reached, and the standby time T will begin. d .

[0028] (4) Determine the pressure P s Is it lower than P2 (90% of P0)? If yes, proceed to step (5); otherwise, continue to determine T. d Does it exceed T2 = 30 seconds? If T... d If T2 is reached, it is assumed that the user has stopped using water and there is no leakage. The pressure control point is then adjusted to P3 (85% of P0) and maintained in a low-speed standby state, waiting for the pressure to drop.

[0029] (5) Increase the pump speed to supplement water pressure. When the speed reaches the rated speed F0, start timing the high-speed running time T. g .

[0030] (6) Determine whether the steady-state condition (P) has been reached again. s If the time is T1 and P0 is reached, then return to step (3) to reduce the speed; otherwise, continue with the subsequent judgment.

[0031] (7) Branch for determining water usage status: Judgment I s Is it greater than I? c And close to I0, while T g T3 = 5 seconds. If so, it is considered normal water usage, and T... d Set it to the maximum value (e.g., 255) and return to step (5).

[0032] If not, then determine T. d Is it less than T4=5 seconds and I s < I0 and I s Close to I c If so, it is determined to be low-flow water use, the pressure control target is set between P4 (90% of P0) and P0, and the process returns to step (5).

[0033] If not, then determine T. d Does T4 < T? d < T2, and (T g + T d If T5 is less than 15 seconds, and this pattern occurs three times consecutively, then it is determined to be a pipe leak, and a leak indicator is set.

[0034] (8) The water shortage judgment branch runs in parallel with or follows step (7): Determine whether the high-speed operation lasts continuously for T6=3 seconds and I s < I c If so, then it is determined to be a water shortage.

[0035] If not, then determine whether it runs at high speed continuously for T7=20 seconds, and I s < I0 and close to I c And P s < P5 (70% of P0). If so, it is considered a water shortage.

[0036] If a water shortage is detected, a water shortage flag is set, and the controller can perform protective operations such as shutdown and alarm, and can attempt to restart after waiting for a period of time.

[0037] The controller in this embodiment successfully eliminates the need for a flow switch, utilizing only two key parameters—current and pressure—and through the aforementioned complex logic state machine, achieves comprehensive intelligent monitoring and efficient control of the water pump system's operating status.

[0038] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A built-in intelligent controller for a water pump, characterized in that, include: A current detection circuit is used to detect the operating current I of the water pump motor. s ; Pressure sensor used to detect pipeline pressure P s ; The microcontroller, connected to the current detection circuit and the pressure sensor, has the following control logic: (1) After startup, wait for the pipeline pressure P s Once the rated pressure P0 is reached and maintained for the first preset time T1, the water shortage indicator is cleared. (2) Gradually reduce the pump speed until the pressure P s If the speed exceeds the first threshold P1, the rotation speed continues to decrease until the minimum maintenance speed is reached, and then the standby time T is started. d Until pressure P s Below the second pressure threshold P2; (3) If the standby time T d If the second preset time T2 is exceeded, it is determined that the user has stopped using water and there is no leakage in the pipeline, and the pressure control point is lowered to the third pressure threshold P3; (4) When the pressure P s When the pressure drops below the second pressure threshold P2 or the third pressure threshold P3, the water pump is accelerated to reach the rated speed F0, and the high-speed operation time T is started. g ; (5) During high-speed operation: If the operating current I s Greater than the no-load current I c And the current is close to the rated current I0, and the high-speed operation time T g If the water usage exceeds the third preset time T3, it is judged as normal water usage, and the standby time T is set to [value]. d Set to the maximum value; If the standby time T d Less than the fourth preset time T4, and the operating current I s Less than the rated current I0 and greater than the no-load current I c and close to the no-load current I c If the flow rate is low, the pressure control range will be set between the fourth pressure threshold P4 and the rated pressure P0. If the standby time T d The time is greater than the fourth preset time T4 but less than the second preset time T2, and the high-speed running time T g With standby time T d If the sum is less than the fifth preset time T5, and this condition occurs multiple times consecutively, then it is determined that there is a pipeline leak, and a leak sign is set. (6) If the water pump runs at high speed for the sixth consecutive preset time T6 and the operating current I s Less than the no-load current I c If so, it is determined to be a water shortage; If the water pump T7 runs at high speed for the seventh preset time and the operating current I... s Less than the rated current I0 and close to the no-load current I c And pressure P s If the pressure remains below the fifth pressure threshold P5, it is determined to be water shortage, and a water shortage flag is set.

2. The built-in intelligent controller for a water pump according to claim 1, characterized in that, The first threshold P1 is 95% of the rated pressure P0, the second pressure threshold P2 is 90% of the rated pressure P0, the third pressure threshold P3 is 85% of the rated pressure P0, the fourth pressure threshold P4 is 90% of the rated pressure P0, and the fifth pressure threshold P5 is 70% of the rated pressure P0.

3. The built-in intelligent controller for a water pump according to claim 1, characterized in that, The no-load current I c It is less than the rated current I0, and the operating current I is determined to be... s Close to no-load current I c The condition is I s Less than (I0 + I) c ) / 2.

4. The built-in intelligent controller for a water pump according to claim 1, characterized in that, The current detection circuit includes a sampling resistor and an operational amplifier, which are used to sample and amplify the motor current and output it to the ADC interface of the microcontroller.

5. A built-in intelligent controller for a water pump according to claim 1, characterized in that, The pressure sensor is a voltage output type pressure sensor, and its output signal is connected to the ADC interface of the microcontroller through an RC filter circuit.

6. A built-in intelligent controller for a water pump according to claim 1, characterized in that, The microcontroller is also connected to a frequency converter drive module, which is used to adjust the speed of the water pump motor.

7. A smart control method for a water pump, characterized in that, The method includes the following steps: detecting the operating current I of the water pump motor. s and pipeline pressure P s Based on I s P s The system uses pump speed, multiple time parameters, and pressure thresholds to distinguish the following operating conditions through a logical judgment algorithm: normal water use, user water stoppage, low flow water use, pipeline leakage, and underground water shortage. The logical judgment algorithm includes: (1) After startup, wait for the pipeline pressure P s Once the rated pressure P0 is reached and maintained for the first preset time T1, the water shortage indicator is cleared. (2) Gradually reduce the pump speed until the pressure P s If the speed exceeds the first threshold P1, the rotation speed continues to decrease until the minimum maintenance speed is reached, and then the standby time T is started. d Until pressure P s Below the second pressure threshold P2; (3) If the standby time T d If the second preset time T2 is exceeded, it is determined that the user has stopped using water and there is no leakage in the pipeline, and the pressure control point is lowered to the third pressure threshold P3; (4) When the pressure P s When the pressure drops below the second pressure threshold P2 or the third pressure threshold P3, the water pump is accelerated to reach the rated speed F0, and the high-speed operation time T is started. g ; (5) During high-speed operation: If the operating current I s Greater than the no-load current I c And the current is close to the rated current I0, and the high-speed operation time T g If the water usage exceeds the third preset time T3, it is judged as normal water usage, and the standby time T is set to [value]. d Set to the maximum value; If the standby time T d Less than the fourth preset time T4, and the operating current I s Less than the rated current I0 and greater than the no-load current I c and close to the no-load current I c If the flow rate is low, the pressure control range will be set between the fourth pressure threshold P4 and the rated pressure P0. If the standby time T d The time is greater than the fourth preset time T4 but less than the second preset time T2, and the high-speed running time T g With standby time T d If the sum is less than the fifth preset time T5, and this condition occurs multiple times consecutively, then it is determined that there is a pipeline leak, and a leak sign is set. (6) If the water pump runs at high speed for the sixth consecutive preset time T6 and the operating current I s Less than the no-load current I c If so, it is determined to be a water shortage; If the water pump T7 runs at high speed for the seventh preset time and the operating current I... s Less than the rated current I0 and close to the no-load current I c And pressure P s If the pressure remains below the fifth pressure threshold P5, it is determined to be water shortage, and a water shortage flag is set.

8. The intelligent control method for a water pump according to claim 7, characterized in that, The first threshold P1 is 95% of the rated pressure P0, the second pressure threshold P2 is 90% of the rated pressure P0, the third pressure threshold P3 is 85% of the rated pressure P0, the fourth pressure threshold P4 is 90% of the rated pressure P0, and the fifth pressure threshold P5 is 70% of the rated pressure P0.

9. The intelligent control method for a water pump according to claim 7, characterized in that, The no-load current I c It is less than the rated current I0, and the operating current I is determined to be... s Close to no-load current I c The condition is I s Less than (I0 + I) c ) / 2.

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