Electronic PNP type draining pump automatic controller

Abstract

The invention discloses an electronic PNP type drainage pump automatic controller, which relates to the technical field of drainage pump automatic control, and comprises an electronic PNP type control main body, a stainless steel water level probe, a 12V direct-current power supply module, a three-phase alternating-current contactor, a stainless steel control box for accommodating electrical elements, and a connecting cable for connecting each part, the control end of the three-phase alternating current contactor is electrically connected with the electronic PNP type control body, the output end of the three-phase alternating current contactor is used for being electrically connected with an external three-phase drainage pump, and the three-phase alternating current contactor is controlled by an output signal of the electronic PNP type control body to achieve power-on and power-off operation of the drainage pump. By adopting high-quality electronic elements, the high-strength PCB with the thickness of 1.6 mm and the design of laying copper on the front side and the back side of the PCB and being matched with the stainless steel water level probe (without a mechanical movable part), the problem of high failure rate caused by abrasion and jamming of mechanical parts of a traditional mechanical floating ball is thoroughly solved, equipment does not need to be maintained, and the failure occurrence probability is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of drainage pump automatic control technology, specifically to an electronic PNP type drainage pump automatic controller. Background Technology

[0002] The water levels in circulating pump pits, condensate pump pits, and rainwater wells of thermal power plants must be strictly controlled within a reasonable range. Many electrical equipment are installed and operate in wells and pits below ground level. If cooling water discharged from other equipment, leaked sealing water, or rainwater backflow during heavy rain causes the drainage pits to overflow, accidents such as equipment flooding will occur, endangering the safe operation of the generator units. Therefore, the water levels in these wells and pits must be controlled by controllers to automatically start and stop the drainage pumps, so as to achieve the purpose of controlling the water levels in the wells and pits within the set range.

[0003] Currently, in order to control the water level within a reasonable range, the common method is to install mechanical floats in wells and pits to detect changes in water level. The traditional water level control scheme for wells and pits in power generation companies is as follows: using mechanical floats as water level detection mechanisms, the float outputs electrical contact signals as it flips on the water surface. When the float floats upwards under the action of buoyancy and reaches a certain height, the mechanical switch contacts inside the float close, and the drainage pump starts to drain the water accumulated in the well or pit. When the water level in the well or pit drops to a certain height, the mechanical switch inside the float opens, and the drainage pump stops draining water, thereby achieving the purpose of automatic water level control.

[0004] However, float switches for controlling water levels have certain drawbacks: 1. The mechanical switch contacts of the float are prone to failure. The mechanical switch contacts of the float often get stuck, and the switch cannot cut off the electrical circuit, causing the control circuit to be constantly energized, which keeps the drainage pump running and burns it out. Second, if the inlet of the float switch is submerged in water for a long time, the switch housing is prone to leakage. After sewage enters the switch, the switch contacts will be corroded and rusted and will not be able to operate. When the water level reaches the high water level limit, the drainage pump will not be able to start, resulting in the water level in the well or pit being too high and causing an accident that floods electrical equipment. Third, the working environment of wells and pits is harsh. Impurities, oil, and harmful gases in the water adhere to the float. Seasonal water temperature changes cause the cable sheath to become brittle and crack. The part of the float cable submerged in water flips back and forth with the water level. The cable is prone to breakage at bends. Cable breakage causes the loss of control signals, making it impossible to control the drainage pump. Sewage seeps into the float through the break, corroding the internal switch contacts, causing the switch contacts to fail and unable to output normal signals, resulting in uncontrolled water level. Fourth, the control range of the float cannot be precisely adjusted. The biggest drawback of mechanical floats is that the dead zone is very large, making it impossible to precisely control the water level to a reasonable range. 5. When repairing the float, maintenance personnel must enter the bottom of confined spaces such as wells and pits to work. Wells and pits contain oxygen deficiency and toxic and harmful gases such as methane and hydrogen sulfide, which may cause human poisoning. VI. Although the float control method has a simple circuit, it is technologically outdated, has extremely low water level control accuracy, and the drainage pump has defects such as malfunction and failure to operate, which increases the maintenance workload and maintenance safety risks for maintenance personnel.

[0005] In summary, this structure has disadvantages such as complex wiring, numerous fault points, unreliable wiring, easy breakage of the float cable, insensitive mechanical switch operation, and high price.

[0006] Therefore, it is necessary to invent an electronic PNP type automatic controller for drainage pumps to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide an electronic PNP type automatic controller for drainage pumps to solve the problems in the technology, such as high float failure rate, float fluctuations with the water surface when the water level is at the critical point, causing the switch to continuously turn on and off, emitting false signals, float mechanical parts easily getting stuck, resulting in the inability to detect water level signals, and difficult maintenance.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an electronic PNP type drainage pump automatic controller, comprising an electronic PNP type control body, a stainless steel water level probe, a 12V DC power supply module, a three-phase AC contactor, a stainless steel control box for housing electrical components, and connecting cables for connecting the various components. The stainless steel water level probe is electrically connected to the electronic PNP type control body and is used to collect the resistance signal corresponding to the water level. The 12V DC power supply module is electrically connected to the electronic PNP type control body and provides working power to the electronic PNP type control body. The control terminal of the three-phase AC contactor is electrically connected to the electronic PNP type control body, and the output terminal is used to be electrically connected to an external three-phase drainage pump and is controlled by the output signal of the electronic PNP type control body to realize the power-on and power-off operation of the drainage pump.

[0009] Preferably, the electronic PNP type control body has a built-in control chip. The control chip can receive the resistance signal transmitted by the stainless steel water level probe and analyze and process the resistance signal. When the detected resistance signal is close to infinity, it is determined that the corresponding high limit probe is not in contact with the water surface. When the detected resistance signal is in the range of 1kΩ-100KΩ, it is determined that the corresponding low limit probe is in contact with the water surface. Thus, the current water level is determined based on the detection results of the high limit and low limit probes.

[0010] Preferably, the panel of the electronic PNP type control unit is equipped with a "POWER" power indicator, a "PUMPRUN" operation indicator, a "PUMPSTOP" stop indicator, a "FORCEON" forced start button, and a "RESET" reset button; each indicator and button is electrically connected to the internal circuit of the control unit.

[0011] Preferably, the "POWER" indicator light is used to display the power on / off status, the "PUMPRUN" indicator light is used to display the drainage pump running status, the "PUMPSTOP" indicator light is used to display the drainage pump stopped status, the "FORCEON" button is used to trigger the drainage pump to start forcibly, and the "RESET" button is used to trigger the drainage pump to stop urgently.

[0012] Preferably, the stainless steel water level probe is provided with three probes: a high-limit water level probe, a low-limit water level probe, and a common-end water level probe. The high-limit water level probe corresponds to the high-limit detection position of the water level, and the low-limit water level probe corresponds to the low-limit detection position of the water level. The installation height of the detection ends of the two probes can be adjusted according to the actual water level control requirements to accurately set the high-limit threshold and low-limit threshold of the water level control.

[0013] Preferably, the stainless steel water level probe is made of corrosion-resistant stainless steel. The controller senses the change in resistance signal by collecting the resistance between the high-limit water level probe, the low-limit water level probe and the common end water level probe. The resistance change range corresponds to the air resistance and water resistance, which can accurately distinguish whether the high and low probes are in contact with the water surface, providing a precise signal for the control chip to judge the water level status.

[0014] Preferably, after receiving the "start" signal output by the control unit, the three-phase AC contactor closes its AC contacts, outputting 380V AC voltage to the external three-phase drain pump, driving the drain pump to start and perform drainage operations. At the same time, the "PUMPRUN" indicator light on the control unit panel starts flashing, indicating that the drain pump is in operation. After receiving the "stop" signal output by the control unit, the three-phase AC contactor closes its AC contacts, and the external three-phase drain pump loses power and stops drainage operations. At the same time, the "PUMPSTOP" indicator light on the electronic PNP type control unit panel remains on to indicate to the operator that the drain pump is in a stopped state.

[0015] Preferably, it includes the following steps: S1: Install and wire the stainless steel water level probe, electronic PNP type control body, 12V DC power supply module, and three-phase AC contactor according to the preset wiring diagram, and ensure that each component is reliably electrically connected through the connecting cable. S2: Adjust the high limit detection position of the high limit water level probe and the low limit detection position of the low limit water level probe according to the actual water level control requirements to ensure that the water level probe at the common end is below the low limit water level probe. S3: When the power switch is turned on, the 12V DC power module supplies power to the electronic PNP type control unit, the "POWER" indicator light on the controller panel stays on, and the controller enters the "automatic control" state. S4: When the water level rises to the high limit detection position, the high limit water level probe contacts the water surface and transmits a resistance signal of about 1kΩ-100KΩ to the electronic PNP type control unit (the resistance changes dynamically within this range depending on the water quality being measured). After receiving the signal, the electronic PNP type control unit sends a "start" signal, the "PUMPRUN" indicator light on the controller panel flashes, the three-phase AC contactor closes, and outputs 380V voltage to the three-phase drainage pump, which then starts to drain water. S5: When the water level drops to the low limit detection position, the low limit water level probe leaves the water surface and transmits a near-infinite resistance signal to the electronic PNP type control body. After receiving the signal, the electronic PNP type control body sends a "stop" signal, the "PUMPSTOP" indicator light on the controller panel stays on, the three-phase AC contactor is disconnected, the three-phase drainage pump loses power, and the drainage pump stops draining. S6: When forced drainage is required, manually press the "FORCEON" button on the controller panel. The electronic PNP type control unit outputs a forced start signal, which drives the three-phase AC contactor to close and the drainage pump to start draining. When the water level drops to the low limit detection position, the drainage pump will stop automatically. S7: Regardless of whether the controller is in manual or automatic control mode, pressing the "RESET" button will immediately output a stop signal to the electronic PNP type control unit, disconnect the three-phase AC contactor, and immediately stop the drainage pump from draining water.

[0016] Preferably, in step S4, before the electronic PNP type control unit sends out the "start" signal, the control chip will perform a secondary verification on the resistance signal transmitted by the high limit water level probe. After confirming that the resistance signal is in the range of about 1kΩ-100KΩ for 1-2 seconds, the "start" signal will be output to avoid the drainage pump from starting erroneously due to instantaneous signal interference.

[0017] The technical effects and advantages provided by the present invention in the above technical solution are as follows: 1. This invention, by employing high-quality electronic components, a 1.6mm thick high-strength PCB board, and a copper-plated design on both sides of the PCB, combined with a stainless steel water level probe (without mechanical moving parts), completely solves the high failure rate problem caused by wear and jamming of mechanical parts in traditional mechanical floats. This achieves maintenance-free equipment, significantly reducing the probability of failure. Furthermore, combined with the control chip's precise analysis of resistance signals (identifying only water resistance signals of approximately 1kΩ-100KΩ and near-infinite air resistance signals), it effectively avoids electromagnetic interference generated by 6KV high-voltage motors and 380V motors operating on-site. At the same time, electromagnetic interference tests conducted by mobile phones and walkie-talkies have verified that there is no impact, demonstrating strong anti-interference capabilities and ensuring stable and reliable water level detection signals, thus preventing controller malfunctions. 2. This invention, by setting two adjustable water level probes (high limit and low limit), allows for flexible setting of water level control thresholds according to actual site requirements. Combined with the 1-2 second secondary verification mechanism of the high limit water level signal in step S4 of the control chip, it can filter out instantaneous false signals caused by irregular water surface fluctuations, and is less affected by irregular water surface fluctuations. This ensures that the drainage pump only starts when the water level truly reaches the high limit threshold, thereby improving the stability and accuracy of water level control. 3. This invention utilizes the automatic control logic of an electronic PNP-type control unit (real-time detection of water level signals and automatic start / stop of the drainage pump), eliminating the need for manual intervention in the water level monitoring and drainage pump control process. Compared to the traditional float-based operation mode that requires operators to frequently inspect the water level, this invention saves on the inspection workload of operators and avoids water level anomalies caused by delays in manual operation, thus significantly improving work efficiency. 4. This invention uses a modular design to connect the electronic PNP type control body with connectors. When the controller fails, a new controller can be quickly replaced simply by unplugging the connector. The entire replacement process takes less than a minute, which completely solves the problem of difficult and time-consuming maintenance caused by disassembling cables and adjusting mechanical structures when repairing traditional floats. This greatly shortens maintenance time, reduces on-site operation and maintenance difficulty, and reduces safety risks in confined space operations. 5. This invention, through precise resistance signal acquisition of the water level probe (distinguishing between water resistance of approximately 1kΩ-100KΩ and infinite air resistance), real-time signal analysis of the control chip, and the height-adjustable design of the high / low limit probe, can limit the water level control error to a very small range, avoiding the problems of "incomplete drainage" or "over-drainage". The water level control is precise, meeting the needs of industrial scenarios with high water level accuracy requirements. 6. This invention uses a 12V DC power module to power the core control unit. 12V is within the safe voltage range. Even if there is slight damage to the wiring in a humid environment (such as underground garages or basement drainage scenarios), it will not pose a risk of electric shock to the operator. The use of a safe voltage design greatly improves the safety of the equipment in humid environments. 7. This invention utilizes corrosion-resistant stainless steel probes (to resist water corrosion), stable control chip logic (to avoid frequent start-stop losses of components), and a reliable switching design of a three-phase AC contactor (to adapt to the long-term operation of a 380V drainage pump). Actual testing shows that it can achieve continuous operation without failure for more than a year, demonstrating strong long-term safe operation capability. This reduces drainage interruption caused by equipment failure and lowers subsequent maintenance costs. 8. This invention features a "FORCEON" forced start button and a "RESET" emergency stop button on the main control panel. When the water level is below the limit but drainage is required (e.g., in an emergency flood control scenario), the drainage pump can be driven by the forced start button. In case of equipment malfunction or emergency, the drainage pump can be stopped immediately by pressing the reset button, regardless of whether the equipment is in manual or automatic mode. The controller can be operated by force and stopped urgently, fully meeting the emergency operation needs in actual on-site operation and improving the flexibility and safety of equipment use. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a circuit diagram of the electronic PNP type drainage pump controller of the present invention; Figure 2 This is a physical image of the main body of the electronic PNP type drainage pump controller of the present invention. Figure 3 This is a 3D design drawing of the controller housing of the present invention; Figure 4 This is a physical diagram of the internal circuit board of the controller of the present invention; Figure 5 This is a physical image of the water level probe of the present invention; Figure 6 This is a physical diagram of the internal equipment of the control box of the present invention; Figure 7 This is a physical diagram of the electromagnetic interference resistance test device of the present invention. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0022] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] This invention provides, for example Figure 1-7 The illustrated electronic PNP type automatic controller for a drainage pump includes an electronic PNP type control body, a stainless steel water level probe, a 12V DC power supply module, a three-phase AC contactor, a stainless steel control box for housing electrical components, and connecting cables for connecting the various components. The stainless steel water level probe is electrically connected to the electronic PNP type control body and is used to collect the resistance signal corresponding to the water level. The 12V DC power supply module is electrically connected to the electronic PNP type control body and provides working power to the electronic PNP type control body. The control terminal of the three-phase AC contactor is electrically connected to the electronic PNP type control body, and the output terminal is used to connect to an external three-phase drainage pump and is controlled by the output signal of the electronic PNP type control body to realize the power-on and power-off operation of the drainage pump.

[0026] This embodiment uses a 2×1000MW coal-fired power generating unit circulating pump butterfly valve well water level control project as the application scenario. The controller consists of an electronic PNP type control body, three stainless steel water level probes (high limit, low limit, and common terminal), a 12V DC power supply module, a three-phase AC contactor, a stainless steel control box, and connecting cables. The component selection and functional adaptation of each core component are as follows: In this embodiment, all circuit components of the electronic PNP type control unit have been selected for scenario adaptation to ensure stable operation under strong electromagnetic interference in thermal power plants (6KV high-voltage motor, 380V motor operating environment). The specific component configuration and function correspondence are shown in the table below:

[0027] The electronic PNP type control unit has a built-in control chip that receives and analyzes the resistance signal transmitted by the stainless steel water level probe. When the detected resistance signal is close to infinity, it is determined that the corresponding probe is not in contact with the water surface. When the detected resistance signal is in the range of approximately 1kΩ-100KΩ, it is determined that the corresponding probe is in contact with the water surface. Based on the detection results of the high-limit and low-limit probes, the current water level is determined. Three stainless steel water level probes are provided: a high-limit probe, a low-limit probe, and a common-end probe. The high-limit probe corresponds to the high-limit detection position of the water level, and the low-limit probe... The level probes correspond to the low-limit detection position of the water level. The installation height of the detection ends of the high-limit and low-limit probes can be adjusted according to the actual water level control requirements to accurately set the high-limit and low-limit thresholds for water level control. The stainless steel level probes are made of corrosion-resistant stainless steel. The controller senses the change in resistance signal by collecting the resistance between the high-limit, low-limit, and common-end level probes. The resistance change range corresponds to the air resistance (close to infinity) and the water resistance (approximately 1kΩ-100KΩ), which can accurately distinguish whether the high-limit and low-limit probes are in contact with the water surface, providing a precise signal for the control chip to determine the water level status.

[0028] In this embodiment, the stainless steel water level probe has three probes, from left to right (in combination with...). Figure 4 The following are the components shown: High water level probe (high high water level contact): Used to detect the high limit water level position. When the water level rises to the height of the probe and makes contact, it transmits a signal corresponding to the water resistance (range of approximately 1kΩ-100KΩ) to the electronic PNP type control unit, triggering the drainage pump start logic; Probe common terminal (com probe common terminal): Serves as a common reference terminal for water level detection. It works with the high and low water level probes to form a complete water level detection loop, ensuring the stability and accuracy of the resistance signal acquisition; Low water level probe (low low water level contact): Used to detect the low limit water level position. When the water level drops to the point where it leaves the probe, it transmits a near-infinite air resistance signal to the control unit, triggering the drainage pump stop logic.

[0029] The electronic PNP type control unit's panel is equipped with a "POWER" power indicator, a "PUMPRUN" operation indicator, a "PUMPSTOP" stop indicator, a "FORCEON" forced start button, and a "RESET" reset button. Each indicator and button is electrically connected to the internal circuitry of the control unit. The "POWER" indicator shows the power on / off status, the "PUMPRUN" indicator shows the pump's running status, the "PUMPSTOP" indicator shows the pump's stopped status, the "FORCEON" button triggers a forced start of the pump, and the "RESET" button triggers a forced stop of the pump. In case of emergency stop, the three-phase AC contactor receives the "start" signal from the control unit and closes its AC contacts, outputting 380V AC voltage to the external three-phase drain pump to start the drainage operation. At the same time, the "PUMPRUN" indicator light on the control unit panel starts flashing, indicating that the drain pump is running. After the three-phase AC contactor receives the "stop" signal from the control unit and closes its AC contacts, the external three-phase drain pump loses power and stops the drainage operation. At the same time, the "PUMPSTOP" indicator light on the electronic PNP type control unit panel remains on to indicate to the operator that the drain pump is stopped.

[0030] In this embodiment, the resistance signal collected by the stainless steel water level probe is transmitted in real time to the electronic PNP type control unit via a connecting cable. The control unit's built-in control chip analyzes and processes the signal, and combined with the working power provided by the 12V DC power module and the on / off control of the three-phase AC contactor, it realizes the function of automatically starting and stopping the drainage pump according to the water level. At the same time, the indicator lights such as "POWER", "PUMPRUN", and "PUMPSTOP" on the control unit panel display the corresponding working status according to the signal transmitted by the water level probe and the operating status of the drainage pump. The "FORCEON" forced start button and the "RESET" reset button can manually intervene in the start and stop of the drainage pump under special working conditions. They complement the automatic control logic formed by the water level probe detection and meet the diverse control needs on site.

[0031] Includes the following steps: S1: Install and wire the stainless steel water level probe, electronic PNP type control body, 12V DC power supply module, and three-phase AC contactor according to the preset wiring diagram, and ensure that each component is reliably electrically connected through the connecting cable. S2: Adjust the high limit detection position of the high limit water level probe and the low limit detection position of the low limit water level probe according to the actual water level control requirements to ensure that the water level probe at the common end is below the low limit water level probe. S3: When the power switch is turned on, the 12V DC power module supplies power to the electronic PNP type control unit, the "POWER" indicator light on the controller panel stays on, and the controller enters the "automatic control" state. S4: When the water level rises to the high limit detection position, the high limit water level probe contacts the water surface and transmits a resistance signal of about 1kΩ-100KΩ to the electronic PNP type control unit (the resistance changes dynamically within this range depending on the water quality being measured). After receiving the signal, the electronic PNP type control unit sends a "start" signal, the "PUMPRUN" indicator light on the controller panel flashes, the three-phase AC contactor closes, and outputs 380V voltage to the three-phase drainage pump, which then starts to drain water. S5: When the water level drops to the low limit detection position, the low limit water level probe leaves the water surface and transmits a near-infinite resistance signal to the electronic PNP type control body. After receiving the signal, the electronic PNP type control body sends a "stop" signal, the "PUMPSTOP" indicator light on the controller panel stays on, the three-phase AC contactor is disconnected, the three-phase drainage pump loses power, and the drainage pump stops draining. S6: When forced drainage is required, manually press the "FORCEON" button on the controller panel. The electronic PNP type control unit outputs a forced start signal, which drives the three-phase AC contactor to close and the drainage pump to start draining. When the water level drops to the low limit detection position, the drainage pump will stop automatically. S7: Regardless of whether the controller is in manual or automatic control mode, pressing the "RESET" button will immediately output a stop signal to the electronic PNP type control unit, disconnect the three-phase AC contactor, and immediately stop the drainage pump from draining water.

[0032] In step S4, before the electronic PNP type control unit sends out the "start" signal, the control chip will perform a secondary verification on the resistance signal transmitted by the high limit water level probe. After confirming that the resistance signal is within the range of 1kΩ-100KΩ for 1-2 seconds, the "start" signal will be output to avoid the drainage pump from starting erroneously due to instantaneous signal interference.

[0033] This embodiment controls the water level in the circulating pump butterfly valve well of the 2X1000MW coal-fired power generating unit, the circulating connection pit of the 2X1000MW coal-fired power generating unit, and the condensate pump pit of the 4X330MW coal-fired power generating unit. The equipment operates reliably, with water level control accuracy reaching the millimeter level. It is low in cost and highly economical, greatly reducing the burden of inspection and operation on the operators, and also reducing the safety risks for maintenance personnel entering confined spaces.

[0034] Working principle of this invention: Refer to the instruction manual appendix Figure 1-7When using this invention, in thermal power plants, in order to ensure that the water level in wells and pits is within a reasonable range to ensure the safe operation of equipment, a water level controller needs to be installed. First, model building work is carried out. A water tank is set up on the training platform and water level changes are artificially simulated. The resistance value of the water level probe at different water levels is recorded to establish a correlation model between the water level probe resistance and the water level. Next, a data mining model is established, and the data mining model is trained using the dataset obtained from the above correlation model. Then, the trained model is tested with test data from the same source. The tests are repeated until the model accuracy meets the requirements. After that, the model data that meets the accuracy requirements is solidified into the controller chip. Then, the control loop is designed. A digital electronic circuit is designed to compare the signal measured by the water level probe with the model data embedded in the controller chip. The compared signal is amplified by a PNP transistor and the output command drives the water pump to work. Finally, a comprehensive verification was conducted. On the training platform, the on-site working conditions were simulated again, a complete control device was set up, the water level in the tank was manually changed, and the start and stop data of the drainage pump were recorded. Through this series of operations, the water level in the well and pit was automatically controlled to ensure that the water level was maintained within a reasonable range.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electronic PNP type automatic controller for drainage pump comprising an electronic PNP type control main body, a stainless steel water level probe, a 12V DC power module, a three-phase AC contactor, a stainless steel control box for accommodating electrical components, and a connecting cable for connecting the components, characterized in that: The stainless steel water level probe is electrically connected with the electronic PNP type control main body, used for collecting the resistance signal corresponding to the water level, the 12V DC power module is electrically connected with the electronic PNP type control main body, providing working power for the electronic PNP type control main body, the control end of the three-phase AC contactor is electrically connected with the electronic PNP type control main body, and the output end is used for being electrically connected with the external three-phase drainage pump, and the drainage pump is controlled to realize on-off operation under the control of the output signal of the electronic PNP type control main body.

2. The electronic PNP type automatic controller for drain pump according to claim 1, characterized in that: The control chip built in the electronic PNP type control main body can receive the resistance signal transmitted by the stainless steel water level probe, and analyze and process the resistance signal, when the resistance signal is detected to be close to infinity, it is determined that the corresponding probe does not contact the water surface, when the resistance signal is detected to be in the range of 1kΩ-100KΩ, it is determined that the corresponding probe contacts the water surface, so as to determine the current water level according to the detection results of the high limit and low limit probes.

3. The electronic PNP type automatic controller for drain pump according to claim 2, characterized in that: The panel of the electronic PNP type control main body is provided with a "POWER" power indicator, a "PUMPRUN" running indicator, a "PUMPSTOP" stop indicator, a "FORCEON" forced start button and a "RESET" reset button; each indicator and button is electrically connected with the internal circuit of the control main body.

4. The electronic PNP type automatic controller for drain pump according to claim 3, characterized in that: The "POWER" indicator is used to display the on-off state of the power supply, the "PUMPRUN" indicator is used to display the running state of the drainage pump, the "PUMPSTOP" indicator is used to display the stop state of the drainage pump, the "FORCEON" button is used to trigger the forced start of the drainage pump, and the "RESET" button is used to trigger the emergency stop of the drainage pump.

5. The electronic PNP type automatic controller for drain pump according to claim 1, characterized in that: The stainless steel water level probe is provided with three, which are high limit water level probe, low limit water level probe and common end water level probe, the high limit water level probe corresponds to the high limit detection position of the water level, the low limit water level probe corresponds to the low limit detection position of the water level, and the installation height of the detection end of the two probes can be adjusted according to the actual water level control requirement, so as to accurately set the high limit threshold and low limit threshold of the water level control.

6. An electronic PNP type automatic controller for a drainage pump according to claim 4, characterized in that: The stainless steel water level probe is made of corrosion-resistant stainless steel material, the controller collects the resistance between the high limit water level probe, the low limit water level probe and the common end water level probe, senses the change of the resistance signal, and the resistance change range corresponds to the air resistance and the water resistance, which can accurately distinguish whether the high and low probes contact the water surface, and provides accurate signal for the control chip to judge the water level state.

7. The electronic PNP type automatic controller for drain pump according to claim 1, characterized in that: The three-phase AC contactor receives the "start" signal output by the control body and closes the AC contact, outputs 380-volt AC voltage to the external three-phase drainage pump, drives the drainage pump to start and perform drainage work, and at the same time, the "PUMP RUN" indicator light on the control body panel starts to flash, indicating that the drainage pump is in operation. After receiving the "stop" signal output by the control body, the three-phase AC contactor closes the AC contact, the external three-phase drainage pump loses power and stops the drainage work, and at the same time, the "PUMP STOP" indicator light on the electronic PNP type control body panel is always on to prompt the operator that the drainage pump is in a stopped state.

8. A water level control method based on the electronic PNP type drain pump automatic controller according to claim 1, characterized in that, The method comprises the following steps: S1: Install and connect the stainless steel water level probe, electronic PNP type control body, 12V DC power module, and three-phase AC contactor according to the preset wiring diagram, and ensure that each component is reliably electrically connected through the connecting cable; S2: According to the actual water level control requirements, adjust the high-limit detection position of the high-limit water level probe and the low-limit detection position of the low-limit water level probe, and ensure that the public end water level probe is below the low-limit water level probe; S3: Turn on the power switch, and the 12V DC power module supplies power to the electronic PNP type control body, the "POWER" indicator light on the controller panel is always on, and the controller enters the "automatic control" state; S4: When the water level rises to the high-limit detection position, the high-limit water level probe contacts the water surface and transmits a resistance signal of about 1kΩ-100KΩ (the resistance dynamically changes in this range according to the measured water quality) to the electronic PNP type control body, and the electronic PNP type control body sends out a "start" signal after receiving the signal, the "PUMP RUN" indicator light on the controller panel flashes, the three-phase AC contactor is closed, 380-volt voltage is output to the three-phase drainage pump, and the drainage pump starts to drain water; S5: When the water level drops to the low-limit detection position, the low-limit water level probe is separated from the water surface and transmits an almost infinite resistance signal to the electronic PNP type control body, and the electronic PNP type control body sends out a "stop" signal after receiving the signal, the "PUMP STOP" indicator light on the controller panel is always on, the three-phase AC contactor is disconnected, the three-phase drainage pump loses power, and the drainage pump stops draining water; S6: When forced drainage is needed, press the "FORCE ON" button on the controller panel once, the electronic PNP type control body outputs a forced start signal, drives the three-phase AC contactor to close, and the drainage pump starts to drain water; when the water level drops to the low-limit detection position, the drainage pump automatically stops; S7: Regardless of whether the controller is in a manual control state or an automatic control state, press the "RESET" button, and the electronic PNP type control body immediately outputs a stop signal, the three-phase AC contactor is disconnected, and the drainage pump immediately stops draining water.

9. The water level control method according to claim 8, characterized in that: Before the electronic PNP type control main body sends the "start" signal in step S4, the control chip will perform secondary verification on the resistance signal transmitted by the high limit water level probe. After confirming that the resistance signal is in the range of about 1 kΩ-100 kΩ for 1-2 seconds, the "start" signal is output again to avoid false start of the drainage pump caused by transient signal interference.

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