Control method of water pump

Abstract

The invention relates to a water pump control method which comprises the steps that when a water pump meets a preset shutdown condition, a zero-cross detection signal of a main power circuit of the water pump is obtained; and controlling the conduction time of the main power supply circuit in a unit period based on the zero-cross detection signal so as to control the rotating speed of the water pump to be reduced to a first threshold value, and controlling the main power supply circuit to stop supplying power when the rotating speed of the water pump is reduced to the first threshold value. The water pump is gradually decelerated in the shutdown process until the water pump is stably stopped, and therefore the water hammer effect and abnormal vibration are effectively eradicated. The water pump and accessory equipment of the water pump can be protected against damage, the overall stability and safety of the water supply system can be improved, the important practical application value is achieved, the practical problems in the water pump shutdown process are effectively solved, and a safer and more reliable fluid conveying solution is provided for industrial production and daily life.

Description

Technical Field

[0001] The present disclosure relates to the technical field of water pumps, and in particular, to a control method for a water pump. Background Art

[0002] As an important fluid conveying equipment, water pumps are widely used in many fields, including agriculture, industry, construction, municipal administration, life and other aspects. The working principle of water pumps is to transfer the mechanical energy of the prime mover or other external energy to the liquid, so as to increase the energy of the liquid and complete the liquid transportation. Water pumps can be used to transport liquids including water, oil, acid and alkali liquids, emulsions, suspensions and liquid metals, etc. They can also be used to transport liquids, gas mixtures and liquids containing suspended solids. In industrial production and daily life, water pumps are key equipment for fluid transportation, and their operating stability and safety are crucial.

[0003] However, if the water pump is not properly handled during shutdown, water hammer effect and abnormal vibration are likely to occur. These problems will not only damage the water pump itself and shorten the service life of the equipment, but may also impact the pipeline system, valves and other connecting parts, causing leakage, rupture and other serious consequences, and even affecting the normal operation of the entire water supply system.

[0004] Although there are many water pump speed control methods on the market, such as frequency converter speed regulation, speed regulating motor, etc., these methods mainly focus on speed regulation during water pump operation, and pay less attention to speed control during shutdown. The traditional shutdown method is often to directly cut off the power supply to stop the water pump quickly. This method cannot effectively avoid the water hammer effect and abnormal vibration. Summary of the invention

[0005] In order to solve at least part of the defects of the prior art, the present disclosure proposes a control method for a water pump, which uses a scientific and reasonable speed control strategy to gradually slow down the water pump during the shutdown process until it stops smoothly, thereby effectively preventing the water hammer effect and abnormal vibration. This method can not only protect the water pump and its ancillary equipment from damage, but also improve the overall stability and safety of the water supply system. It has important practical application value, effectively solves practical problems during the shutdown process of the water pump, and provides a safer and more reliable fluid delivery solution for industrial production and daily life.

[0006] Based on this, one aspect of the present disclosure proposes a water pump control method, including: when the water pump meets a preset shutdown condition, obtaining a zero-crossing detection signal of a main power circuit of the water pump; based on the zero-crossing detection signal, controlling the conduction time of the main power circuit within a unit cycle to control the speed of the water pump to drop to a first threshold value, and when the speed of the water pump drops to the first threshold value, controlling the main power circuit to stop supplying power.

[0007] In a preferred embodiment of the present disclosure, the preset shutdown conditions include: the liquid level of the water pump reaches the shutdown liquid level or below, the operating power of the water pump reaches the shutdown power, or the water pump fails.

[0008] In a preferred embodiment of the present disclosure, the water pump includes a zero-crossing detection unit and a main control unit, and the zero-crossing detection unit is coupled to the main power supply circuit and the main control unit respectively. The method includes: after the zero-crossing detection unit detects an AC zero-crossing signal on the main power supply circuit, the zero-crossing detection unit outputs a square wave signal as a zero-crossing detection signal to the main control unit; the main control unit reduces the conduction time within a unit cycle of the main power supply circuit based on the zero-crossing detection signal to control the speed of the water pump to drop to a first threshold value, and when the speed of the water pump drops to the first threshold value, controls the main power supply circuit to stop supplying power.

[0009] In a preferred embodiment of the present disclosure, controlling the on-time of the main power circuit within a unit cycle based on the zero-crossing detection signal includes: controlling the on-time of the main power circuit within a unit cycle based on the number of detected zero-crossing detection signals.

[0010] In a preferred embodiment of the present disclosure, the control of the on-time within a unit cycle of the main power supply circuit based on the zero-crossing detection signal includes: when the time for the water pump to meet the preset shutdown condition reaches a preset time threshold, controlling the on-time within a unit cycle of the main power supply circuit to be zero.

[0011] In a preferred embodiment of the present disclosure, the water pump includes a main control unit and a power detection unit, and a method for determining whether the water pump meets a preset shutdown condition includes: when the water pump operates in a manual mode, the main control unit obtains the operating power of the water pump through the power detection unit, and when the operating power is less than the shutdown power of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition.

[0012] In a preferred embodiment of the present disclosure, the water pump includes a main control unit and a liquid level detection unit, and a method for judging whether the water pump meets a preset shutdown condition includes: when the water pump operates in an automatic mode, the main control unit obtains the real-time liquid level of the water pump through the liquid level detection unit, and when the real-time liquid level is less than the shutdown liquid level of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition.

[0013] In a preferred embodiment of the present disclosure, the method for acquiring the shutdown liquid level of the water pump includes: the main control unit remotely receives the shutdown liquid level set by the main control unit from the mobile user terminal through the wireless communication unit.

[0014] In a preferred embodiment of the present disclosure, the liquid level detection unit includes: a first electrode piece and a second electrode piece, the first electrode piece and the second electrode piece are parallel to each other and vertically arranged relative to the liquid surface; a detection chip, connected to the first electrode piece and the second electrode piece, for detecting the capacitance difference between the first electrode piece and the second electrode piece; a processing unit, connected to the detection chip, for receiving the capacitance difference to calculate the real-time liquid level.

[0015] In a preferred embodiment of the present disclosure, the liquid level detection unit includes a temperature sensing unit, and the method includes: obtaining temperature information of the measured liquid through the temperature sensing unit; and calculating the real-time liquid level after temperature compensation based on the temperature information and the capacitance difference through the processing unit.

[0016] The present invention controls the rotation speed of the water pump based on the zero-crossing detection signal during the water pump shutdown process, so that the water pump gradually slows down during the shutdown process until it stops smoothly, thereby effectively preventing the water hammer effect and abnormal vibration. The method can not only protect the water pump and its ancillary equipment from damage, but also improve the overall stability and safety of the water supply system. It has important practical application value, effectively solves practical problems during the water pump shutdown process, and provides a safer and more reliable fluid delivery solution for industrial production and daily life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The embodiments are shown and explained with reference to the accompanying drawings, and other features and advantages of the present disclosure will be better understood through the preferred embodiments described in detail below in conjunction with the accompanying drawings, in which:

[0018] Figure 1 A block diagram of a water pump control system according to an embodiment of the present disclosure is shown.

[0019] Figure 2 A circuit diagram of a power detection unit according to an embodiment of the present disclosure is shown.

[0020] Figure 3 A circuit diagram of a leakage detection unit according to an embodiment of the present disclosure is shown.

[0021] Figure 4 A circuit diagram of a zero-crossing detection unit according to an embodiment of the present disclosure is shown.

[0022] Figure 5 A circuit diagram of an output control unit according to an embodiment of the present disclosure is shown.

[0023] Figure 6 A schematic structural diagram of a liquid level detection unit according to an embodiment of the present disclosure is shown.

[0024] Figure 7A schematic diagram of a bipolar structure layout according to an embodiment of the present disclosure is shown.

[0025] Figure 8 A schematic diagram of a water pump control method according to an embodiment of the present disclosure is shown.

[0026] Fig. 9 A flow chart of another method for controlling a water pump according to an embodiment of the present disclosure is shown.

[0027] Fig.10 A flow chart of another method for controlling a water pump according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0028] In the following specific description of the preferred embodiments, reference will be made to the attached drawings that form a part of the present disclosure. The attached drawings show, by way of example, specific embodiments that can implement the present disclosure. The illustrative embodiments are not intended to be exhaustive of all embodiments according to the present disclosure. It will be understood that other embodiments may be utilized, and structural or logical modifications may be made without departing from the scope of the present disclosure. Therefore, the following specific description is not restrictive, and the scope of the present disclosure is defined by the attached claims.

[0029] Before introducing the embodiments of the present disclosure, some terms involved in the present disclosure are first explained to facilitate a better understanding of the present disclosure.

[0030] The terms "one", "a group" or "an" and the like used in the present disclosure do not indicate a quantitative limitation, but indicate the existence of at least one. The terms "include", "comprise" and similar terms used in the present disclosure should be understood as open terms, i.e. "include / include but not limited to", indicating that other contents may also be included. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment" and the like. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] like Figure 1As shown, an embodiment of the present disclosure proposes a control system 100 for a water pump, and the control system 100 includes a main control unit 102, a wireless communication unit 104 and a liquid level detection unit 106. Among them, the liquid level detection unit 106 is installed on the pump body of the water pump, and is used to detect and obtain real-time liquid level information of the water pump. In some examples, the liquid level detection unit 106 is a continuous liquid level detection unit, which can realize continuous linear detection of the liquid level within a certain range. The wireless communication unit 104 is used to receive the start and / or stop liquid level setting information of the water pump from the user end 108. The main control unit 102 is connected to the continuous liquid level detection unit 106 and the wireless communication unit 104, and is used to receive real-time liquid level information and start and / or stop liquid level setting information to output corresponding control signals to control the start and stop of the water pump.

[0032] In some examples, the control system 100 further includes a power detection unit 110 , a leakage detection unit 112 , a zero-crossing detection unit 114 , a mode switching unit 116 and / or an output control unit 118 , which are connected to the main control unit 102 .

[0033] In some examples, the control system 100 also includes a power supply unit 120 for supplying power to various units of the control system 100 such as the main control unit 102, the wireless communication unit 104, the liquid level detection unit 106, the power detection unit 110, the leakage detection unit 112, the zero crossing detection unit 114, the mode switching unit 116 and / or the output control unit 118.

[0034] In some examples, the power supply unit 120 includes an AC-DC part and a DC-DC part. In some examples, after the power input terminal of the power supply unit 120 inputs 85-230V and 50 / 60HZ AC power, the AC-DC part first converts the AC power into 12V DC power, and the DC-DC part then steps down the 12V DC power into 5V and 3.3V DC power, where 12V is the power supply voltage of the liquid level detection unit 106, 3.3V is the power supply voltage of the main control unit 102, the power detection unit 110 and the wireless communication unit 104, and 5V is the power supply voltage of the leakage detection unit 112.

[0035] In some examples, the power detection unit 110 is used to monitor the current operating voltage, current, power, and power factor values ​​of the water pump. The power detection unit 110 is connected to the main control unit 102, and the currently acquired voltage, current, power, and power factor values ​​are sent to the main control unit 102 through the serial port so that the main control unit 102 can determine the current operating status of the water pump.

[0036] like Figure 2As shown, an embodiment of the present disclosure proposes a circuit diagram of a power detection unit 110, wherein the resistors R8, R9, R10, R11, R12, R7 and the capacitor C11 connected to the VP pin of the power detection chip U4 form a voltage detection circuit for detecting the voltage of the water pump, wherein the series connection of R8, R9, R10, R11 and R12 can meet the requirements of ensuring electrical clearance, reducing power and reducing volume. The resistors R13, R14 (sampling resistors), R20 and the capacitors C12 and C14 connected to the TN1 and TP1 pins of the power detection chip U4 form a sampling circuit for detecting the current of the water pump. C9 and C10 are bypass capacitors for filtering the chip U4. The resistors R15, R17, R18 and R19 connected to the TX and RX pins of the power detection chip U4 form an output circuit to output the detection results to the main control unit.

[0037] In some examples, the leakage detection unit 112 is connected to the main control unit 102 to detect whether the entire water pump has leakage. In some examples, when the water pump operates normally, the leakage detection unit 112 outputs a 3.3V high level, and when the leakage current of the water pump is detected to be greater than 6mA, the leakage detection unit outputs a 0V low level. Figure 3 As shown, an embodiment of the present disclosure proposes a circuit diagram of a leakage detection unit 112, wherein the zero-sequence mutual inductor TA, resistors R2, R3, R6 and capacitors C5, C6, C8 connected to the pins RCI1 and RCI2 of the leakage detection chip U1 form a sampling circuit for detecting leakage current. Resistor R1 and capacitors C3 and C4 form a filter circuit. The DLY pin of the chip U1 is grounded via capacitor C7 to achieve a delay function. The pin TRIG of the chip U1 is connected to the transistor Q1, and the transistor Q1 and the resistors R4, R5 and R7 form an output circuit for the leakage detection result, and output the detection result to the main control unit.

[0038] In some examples, the zero-crossing detection unit 114 is connected to the main control unit 102, and outputs a square wave signal to the main control unit 102 after detecting the AC zero-crossing signal. Figure 4 As shown, an embodiment of the present disclosure proposes a circuit diagram of a zero-crossing detection unit 114, wherein the pin ACIN of the zero-crossing detection chip U3 is connected to the power line L_IN through the current limiting resistor R6, and the pins ZO and GND of the zero-crossing detection chip U3 and the diode D3, resistors R37, R38 and capacitor C25 form an output circuit to output the alternating current zero-crossing detection result AC-ZERO to the main control unit, and the voltage dividing effect of R37 and R38 can prevent the voltage input to the main control unit from being too large to damage the components.

[0039] In some examples, the output control unit 118 is connected to the main control unit 102. When the main control unit outputs a high level, the power of the controlled device is turned on; when the main control unit outputs a low level, the power of the controlled device is turned off. Figure 5 As shown, an embodiment of the present disclosure proposes a circuit diagram of an output control unit 118, wherein the left side of the optocoupler thyristor U6 is connected to bidirectional thyristor TR1, R21 and R40 to form a high-voltage AC controlled circuit and connected to the controlled device; the right side of the optocoupler thyristor U6 is connected to R22 (current limiting resistor), R24, R25 and transistor QH1 to form a low-voltage DC control circuit. When the Motor terminal inputs a low level, the transistor QH1 is not turned on, and the circuit on the left is not turned on, that is, TR1 is not turned on; when the Motor terminal inputs a high level, the transistor QH1 is turned on, and the circuit on the left is turned on, that is, TR1 is turned on. The controlled device is connected to pin 1 of the thyristor TR1.

[0040] In some examples, the mode switching unit 116 is connected to the main control unit 102, and the main control unit 102 receives a signal from the mode switching unit 116 to determine the working mode of the water pump. The working mode of the water pump includes an automatic mode and a manual mode. In some examples, the mode switching unit 116 includes a magnetic element and a permanent magnet (not shown). The user can control the distance between the magnetic element and the permanent magnet by operating a knob or other types of operating members to change the working mode of the water pump. When the permanent magnet is not close to the magnetic element, the IO port connected to the mode switching unit of the main control unit detects a high level, and the water pump works in the automatic mode; when the permanent magnet is close to the magnetic element, the IO port connected to the mode switching unit of the main control unit detects a low level, and the water pump works in the manual mode. In some examples, the user can remotely control the switching of the working mode of the water pump. Specifically, the main control unit receives the working mode switching instruction of the water pump from the user end via the wireless communication unit, and controls the working mode of the water pump to switch between the automatic mode and the manual mode in response to the working mode switching instruction.

[0041] In some examples, the wireless communication unit 104 is connected to the user terminal 108 through the cloud server 122. The user terminal 108 can be a mobile terminal, such as a mobile phone, iPad, laptop computer, smart wearable device, etc. In some examples, the wireless communication unit 104 can be a WiFi communication unit, a Bluetooth communication unit (which can be connected to the cloud server through a gateway) and / or a ZigBee communication unit. When the user connects the water pump configuration to the cloud server, the user can view the current operating status of the water pump through the user-side APP, and can also remotely start and stop the water pump. It is also possible to set the start liquid level, stop liquid level and / or alarm liquid level of the water pump and other liquid level-related thresholds, and it is also possible to set the operating time period of the water pump (the device starts and stops according to the set start and stop liquid levels during the operating time period, and the default setting is to run all day).

[0042] In some examples, the wireless communication unit 104 is connected to the main control unit 102 via a serial port, and is connected to the cloud server through a router via a 2.4G / 5G (2.4GHz band or 5GHz band) WIFI signal. When the device is running, when the leakage detection unit detects that a leakage fault has occurred in the device, the main control unit will upload the leakage information to the cloud server via a WIFI signal, so that the user can view the relevant information on the APP side. When the device is running, when the power detection unit detects that the device has abnormal operating voltage, no load or stall, etc., the main control unit will upload the relevant information to the cloud server via a WIFI signal, so that the user can view the relevant information on the APP side.

[0043] like Figure 6 As shown, in some examples, the liquid level detection unit 106 includes: a first pole piece 1068, a second pole piece 1069, a detection chip 1066 and a processing unit 1064 (such as an MCU), wherein the first pole piece and the second pole piece are parallel to each other and are vertically arranged relative to the liquid surface; the detection chip is connected to the first pole piece and the second pole piece, and is used to detect the capacitance difference between the first pole piece and the second pole piece; the processing unit is connected to the detection chip, and is used to receive the capacitance difference to calculate the real-time liquid level information. In some examples, the continuous liquid level detection unit 106 is connected to the main control unit 102 for communication, and the liquid level detection unit 106 senses the liquid level height through multiple sensing pole pieces on the circuit board (this example takes two pole pieces as an example, but the number of pole pieces is not limited to two. When the number of pole pieces changes, the deployment method on the circuit board can also be adjusted accordingly). The detection chip 1066 sends a variable frequency pulse signal to the common electrode (1068 or 1069). When the liquid level rises (for example, submerging the electrode), a charge effect is generated on the sensing electrode, thereby causing the capacitance between multiple electrode pieces to change. The larger the area of ​​the electrode submerged by the liquid, the larger the capacitance value. The processing unit 1064 determines the current liquid level state by calculating the current electrode capacitance value, and sends the relevant information to the main control unit 102 through the serial port level conversion circuit 1062.

[0044] In some examples, the liquid level detection unit 106 adopts a bipolar connection method. This type of bipolar detection method can further enhance the anti-interference ability of the entire system, that is, the interference of the first pole piece and the second pole piece on the sensing result can offset each other, thereby ensuring the normal operation of the system and avoiding abnormal operation due to external interference. In some examples, the liquid level detection unit 106 converts the serial port signal containing the detection result from 3.3V to 12V through the serial port level conversion circuit 1062 and sends it out. This serial port level conversion circuit can enhance the anti-interference ability of data during transmission. The liquid level detection unit 106 always detects the current capacitance value and sends the detection result to the main control unit 102 through the serial port level conversion circuit 1062. The main control unit 102 determines whether the current liquid level reaches the starting liquid level. When it is determined that the liquid level reaches the starting liquid level, the main control unit 102 controls the water pump to start pumping out the liquid through the output control unit 118.

[0045] like Figure 7 The schematic diagram of the structural layout of the bipolar pieces 1068 and 1069 is shown. The continuous liquid level detection unit 106 includes a PCB board 1060. The first pole piece 1068 and the second pole piece 1069 are integrated on the front side of the PCB board 1060 (shown), and the detection chip 1066 and the processing unit 1064 are integrated on the back side of the PCB board 1060 (not shown). In some examples, an anti-interference mesh shielding layer 1061 is deployed behind the first pole piece 1068 and the second pole piece 1069, which can further enhance the anti-interference capability of the liquid level detection unit and allow the system to work more safely.

[0046] In some examples, the continuous liquid level detection unit 106 includes: a temperature sensing unit for obtaining temperature information of the measured liquid; a processing unit 1064 receives the temperature information and the capacitance difference to calculate the real-time liquid level information after temperature compensation. In some examples, when the temperature compensation program is executed, the temperature of the current capacitor module accessories (such as the first pole piece and the second pole piece) is collected, and the correction coefficient at different temperatures is selected based on this temperature. The coefficient, temperature and capacitance value are corrected and calculated to calculate a capacitance value closer to the actual liquid level height, and the liquid level height is determined based on the corrected capacitance value. In this way, the operation of real-time detection of the liquid level height is realized, so that the start and stop of the water pump and other functional operations can be controlled according to the liquid level height.

[0047] In some examples, the main control unit 102 includes an MCU and some signal processing circuits. The MCU of the main control unit receives a signal from the mode switching unit, and determines whether the current mode is an automatic mode or a manual mode by identifying the high and low level changes of the signal. When the current mode is determined to be an automatic mode, the water pump works based on the set start and / or stop liquid level; when the current mode is determined to be a manual mode, the water pump starts immediately and stops after the preset stop conditions are met. Among them, the preset stop conditions include: the liquid level of the water pump reaches the stop liquid level or below, the operating power of the water pump reaches the stop power, or the water pump fails.

[0048] In some examples, the main control unit 102 receives data from the liquid level detection unit, that is, real-time liquid level information. When the real-time liquid level is greater than or equal to the start liquid level, the water pump starts; when the real-time liquid level is less than the stop liquid level, the water pump stops. In some examples, the shutdown control process of the water pump is as follows: the speed of the water pump is adjusted based on the zero-crossing detection signal, and the speed of the water pump is gradually reduced until the power supply of the water pump is finally disconnected, which can avoid the water hammer effect and abnormal vibration caused by the sudden stop of the water pump.

[0049] In some examples, the main control unit 102 monitors the leakage and operation of the water pump at the same time. The main control unit monitors the leakage of the water pump through the leakage detection unit, and actively disconnects the live wire of the water pump when the leakage current of the water pump is >6mA. The main control unit monitors the operation of the water pump through the power detection unit, such as monitoring the power supply voltage and operating power of the water pump. When the voltage of the water pump is not within the normal operating voltage range, the water pump cannot be started. The main control unit uploads the relevant information to the cloud server through the wireless communication unit and reminds the user through the user-side APP. After the water pump is started, the main control unit obtains the current operating status of the water pump. When the operating power of the water pump is lower than the normal power, it can be regarded as that the cavity of the water pump is in a waterless state. The main control unit controls the disconnection of the live wire of the water pump, and uploads the relevant information to the cloud server through the wireless communication unit and reminds the user through the user-side APP.

[0050] like Figure 8 As shown, an embodiment of the present disclosure provides a schematic diagram of a water pump control method 800, and the control method 800 includes the following steps:

[0051] S802, receiving the start and / or stop liquid level setting information of the water pump from the user end through the wireless communication unit.

[0052] S804, obtaining real-time liquid level information of the water pump through continuous liquid level detection unit detection.

[0053] S806, controlling the start and stop of the water pump based on the real-time liquid level information and the start and / or stop liquid level setting information.

[0054] In some implementations of the present embodiment, the continuous liquid level detection unit includes: a first electrode piece, a second electrode piece, a detection chip and a processing unit, wherein the first electrode piece and the second electrode piece are parallel to each other and vertically arranged relative to the liquid surface; the detection chip is connected to the first electrode piece and the second electrode piece, and is used to detect the capacitance difference between the first electrode piece and the second electrode piece; the processing unit is connected to the detection chip, and is used to receive the capacitance difference to calculate real-time liquid level information.

[0055] In some implementations of this embodiment, the continuous liquid level detection unit further includes: a temperature sensing unit for acquiring temperature information of the measured liquid; and a processing unit receiving the temperature information and the capacitance difference to calculate the real-time liquid level information after temperature compensation.

[0056] In some implementations of this embodiment, the main control unit receives a working mode switching instruction of the water pump from the user end via the wireless communication unit, and controls the working mode of the water pump to switch between the automatic mode and the manual mode in response to the working mode switching instruction; when the water pump works in the automatic mode, the main control unit outputs a corresponding control signal to control the start and stop of the water pump based on the received real-time liquid level information and the start and / or stop liquid level setting information; when the water pump works in the manual mode, the main control unit controls the water pump to start directly until it stops after the preset stop condition is met. Among them, the preset stop condition can be that the liquid level of the water pump reaches the stop liquid level or below, the operating power of the water pump reaches the stop power, or the water pump fails, etc. This embodiment is similar to the implementation of the embodiment described above, and will not be repeated here.

[0057] like Fig. 9As shown, another embodiment of the present disclosure proposes a flow chart of a control method for a water pump, which is specifically described as follows. After the device (water pump) is powered on, it is determined whether the device has been connected to the cloud. When the device has been connected to the cloud, remote start and stop control of the device can be realized to control the start or shutdown of the device. When the device has been connected to the cloud, it is determined whether the start and stop liquid level of the device is to be set through the cloud. If so, the start and stop liquid level is set, and after the setting is completed, it is determined whether the device is in the running time period; if not, it is determined whether the device is in the running time period. When the device is in the running time period, the start and stop control of the device is entered: when the start liquid level is reached, the device is controlled to start; after the device is started, it is determined whether the shutdown liquid level is reached or below, and when the shutdown liquid level is reached or below, the device is controlled to stop, and the relevant information is reported to the cloud when the device is connected to the cloud. When the shutdown liquid level is not reached or below, it is determined whether no-load protection is required. If so, the device is controlled to stop, and the relevant information is reported to the cloud when the device is connected to the cloud. When no-load protection is not required, determine whether blocking load protection is required. If so, control the device to shut down, and report relevant information to the cloud when the device is connected to the cloud. After the device is shut down, return to the step of determining whether the start liquid level has been reached. After the device is powered on, when the device is not connected to the cloud, determine whether the device has a network distribution requirement. When the judgment result is yes, the device enters the network distribution mode. When the judgment result is no, perform leakage detection on the device. When leakage is detected in the device, disconnect the internal power supply, determine whether the device is connected to the cloud, and if so, report relevant information to the cloud. When it is detected that the device is operating normally without leakage, read the mode to determine whether the device is working in automatic mode or manual mode. When the device is working in manual mode, the device starts. When the device is working in automatic mode, the start and stop control of the device is realized based on the start liquid level and the shutdown liquid level. After the device is started, determine whether the shutdown liquid level is reached or below, whether no-load protection is required, and whether blocking load protection is required. If the judgment result is yes, shut down the device, and determine whether the device is connected to the cloud after the device is shut down. If so, report relevant information to the cloud.

[0058] like Fig.10 As shown, an embodiment of the present disclosure provides a flow chart of another water pump control method 1000. The control method 1000 includes the following steps:

[0059] S1002, when the water pump meets the preset shutdown condition, obtain the zero-crossing detection signal of the main power supply circuit of the water pump. The preset shutdown condition may be that the liquid level of the water pump reaches the shutdown liquid level or below, the operating power of the water pump reaches the shutdown power, or the water pump fails (for example, no-load, blocked load, leakage, etc.). The judgment process can be implemented by the main control unit. The main power supply circuit provides electrical energy to the motor of the water pump to drive the impeller of the water pump to rotate. The zero-crossing detection signal can be obtained using the zero-crossing detection unit described above.

[0060] S1004, based on the zero-crossing detection signal, control the conduction time of the main power circuit within a unit cycle to control the speed of the water pump to decrease to a first threshold, and when the speed of the water pump decreases to the first threshold, control the main power circuit to stop supplying power. In some examples, the first threshold can be set to one-third to one-half of the rated speed. For example, when the rated speed is 3000r / min, the first threshold can be set to any value between 1000r / min and 2000r / min, such as 1300r / min.

[0061] In some examples, controlling the on-time within a unit cycle of the main power circuit based on the zero-crossing detection signal includes: controlling the on-time within a unit cycle of the main power circuit based on the number of zero-crossing detection signals detected. For example, when the zero-crossing detection signal is detected for the first time, the on-time within the unit cycle T of the main power circuit is controlled to be 90%T; when the zero-crossing detection signal is detected for the third time, the on-time within the unit cycle of the main power circuit is controlled to be 80%T; and so on, until the speed of the water pump is reduced to the first threshold, the on-time within the unit cycle of the main power circuit is controlled to be zero. For another example, when the zero-crossing detection signal is detected for the first time, the on-time within the unit cycle T of the main power circuit is controlled to be 95%T; when the zero-crossing detection signal is detected for the second time, the on-time within the unit cycle of the main power circuit is controlled to be 85%T; when the zero-crossing detection signal is detected for the third time, the on-time within the unit cycle of the main power circuit is controlled to be 70%T; and so on, until the speed of the water pump is reduced to the first threshold, the on-time within the unit cycle of the main power circuit is controlled to be zero. In other examples, when the time for which the water pump meets the preset shutdown condition reaches a preset time threshold, the on-time of the main power circuit within a unit cycle is controlled to be zero.

[0062] In some examples, the water pump includes a zero-crossing detection unit and a main control unit, the zero-crossing detection unit is coupled to the main power supply circuit and the main control unit, respectively, and the control method 1000 also includes: after the zero-crossing detection unit detects an AC zero-crossing signal on the main power supply circuit, the zero-crossing detection unit outputs a square wave signal to the main control unit as a zero-crossing detection signal; the main control unit reduces the conduction time within a unit cycle of the main power supply circuit based on the zero-crossing detection signal to control the speed of the water pump to drop to a first threshold value, and when the speed of the water pump drops to the first threshold value, controls the main power supply circuit to stop supplying power.

[0063] In some examples, the water pump includes a main control unit and a power detection unit, and a method for determining whether the water pump meets a preset shutdown condition includes: when the water pump operates in manual mode, the main control unit obtains the operating power of the water pump through the power detection unit, and when the operating power is less than the shutdown power of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition, and then the water pump speed is controlled to slowly decrease until it stops.

[0064] In some examples, the water pump includes a main control unit and a liquid level detection unit, and a method for determining whether the water pump meets a preset shutdown condition includes: when the water pump operates in automatic mode, the main control unit obtains the real-time liquid level of the water pump through the liquid level detection unit, and when the real-time liquid level is less than the shutdown liquid level of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition, and then the water pump speed is controlled to slowly decrease until it stops.

[0065] In some examples, the method for acquiring the shutdown liquid level of the water pump includes: the main control unit remotely receives the shutdown liquid level set by the mobile user terminal through the wireless communication unit.

[0066] In some examples, the liquid level detection unit includes: a first electrode piece and a second electrode piece, the first electrode piece and the second electrode piece are parallel to each other and vertically arranged relative to the liquid surface; a detection chip, connected to the first electrode piece and the second electrode piece, for detecting the capacitance difference between the first electrode piece and the second electrode piece; a processing unit, connected to the detection chip, for receiving the capacitance difference to calculate the real-time liquid level.

[0067] In some examples, the liquid level detection unit includes a temperature sensing unit, and the control method 1000 includes: acquiring temperature information of the measured liquid through the temperature sensing unit; and calculating the real-time liquid level after temperature compensation based on the temperature information and the capacitance difference through the processing unit.

[0068] This embodiment is similar to the above-described implementation mode, so it will not be described in detail.

[0069] This article is described with reference to various exemplary embodiments. However, those skilled in the art will recognize that changes and modifications can be made to the exemplary embodiments without departing from the scope of this article. Although the principles of this article have been shown in various embodiments, many modifications of structures, arrangements, proportions, elements, materials and components that are particularly suitable for specific environments and operational requirements can be used without departing from the principles and scope of this disclosure. The above modifications and other changes or modifications will be included in the scope of this article. The foregoing specific description has been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of this disclosure. Therefore, consideration of this disclosure will be in an illustrative rather than restrictive sense, and all these modifications will be included in its scope. Similarly, the advantages, other advantages and solutions to the problems of various embodiments have been described above. However, the benefits, advantages, solutions to the problems and any elements that can produce these, or solutions that make them more clear should not be interpreted as critical, necessary or necessary. As used herein, the term "include" and any other variations thereof are non-exclusive inclusions, such that a process, method, article, or device that includes a list of elements includes not only those elements, but also other elements that are not explicitly listed or that are not part of the process, method, system, article, or device. In addition, as used herein, the term "coupled" and any other variations thereof refer to physical, electrical, magnetic, optical, communicative, functional, and / or any other connection.

[0070] Those skilled in the art will appreciate that many changes may be made to the details of the above-described embodiments without departing from the basic principles of the present disclosure. Therefore, the scope of the present disclosure should be determined solely by the claims.

Claims

1. A method for controlling a water pump, comprising: When the water pump meets the preset shutdown condition, a zero-crossing detection signal of the main power circuit of the water pump is obtained; The conduction time of the main power circuit within a unit cycle is controlled based on the zero-crossing detection signal to control the rotation speed of the water pump to decrease to a first threshold value, and when the rotation speed of the water pump decreases to the first threshold value, the main power circuit is controlled to stop supplying power.

2. The water pump control method according to claim 1, wherein: The preset shutdown conditions include: the liquid level of the water pump reaches the shutdown liquid level or below, the operating power of the water pump reaches the shutdown power, or the water pump fails.

3. The water pump control method according to claim 1, wherein: The water pump comprises a zero-crossing detection unit and a main control unit, wherein the zero-crossing detection unit is coupled to the main power supply circuit and the main control unit respectively, and the method comprises: After the zero-crossing detection unit detects an alternating current zero-crossing signal on the main power circuit, the zero-crossing detection unit outputs a square wave signal as a zero-crossing detection signal to the main control unit; The main control unit reduces the on-time of the main power circuit within a unit cycle based on the zero-crossing detection signal to control the rotation speed of the water pump to drop to a first threshold, and when the rotation speed of the water pump drops to the first threshold, controls the main power circuit to stop supplying power.

4. The water pump control method according to claim 1, wherein: The controlling the on-time of the main power circuit within a unit cycle based on the zero-crossing detection signal includes: controlling the on-time of the main power circuit within a unit cycle based on the number of times the zero-crossing detection signal is detected.

5. The water pump control method according to claim 1, wherein: The controlling the on-time of the main power circuit within a unit cycle based on the zero-crossing detection signal includes: when the time for the water pump to meet the preset shutdown condition reaches a preset time threshold, controlling the on-time of the main power circuit within a unit cycle to be zero.

6. The water pump control method according to claim 1, wherein: The water pump includes a main control unit and a power detection unit. The method for determining whether the water pump meets the preset shutdown condition includes: When the water pump works in manual mode, the main control unit obtains the operating power of the water pump through the power detection unit. When the operating power is less than the shutdown power of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition.

7. The water pump control method according to claim 1, wherein: The water pump includes a main control unit and a liquid level detection unit. The judgment method of whether the water pump meets the preset shutdown condition includes: When the water pump works in automatic mode, the main control unit obtains the real-time liquid level of the water pump through the liquid level detection unit. When the real-time liquid level is less than the shutdown liquid level of the water pump, a judgment result is obtained that the water pump meets the preset shutdown condition.

8. The water pump control method according to claim 7, wherein: The method for acquiring the shutdown liquid level of the water pump includes: the main control unit remotely receives the shutdown liquid level set by the main control unit from the mobile user terminal through the wireless communication unit.

9. The water pump control method according to claim 7, wherein: The liquid level detection unit comprises: A first pole piece and a second pole piece, wherein the first pole piece and the second pole piece are parallel to each other and vertically arranged relative to the liquid surface; A detection chip, connected to the first pole piece and the second pole piece, and used for detecting a capacitance difference between the first pole piece and the second pole piece; A processing unit is connected to the detection chip and is used to receive the capacitance difference to calculate the real-time liquid level.

10. The water pump control method according to claim 9, wherein: The liquid level detection unit includes a temperature sensing unit, and the method includes: Acquiring temperature information of the measured liquid through the temperature sensing unit; The processing unit calculates the real-time liquid level after temperature compensation based on the temperature information and the capacitance difference.

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