Full-frequency-conversion constant-pressure water supply control system with auxiliary pump

Abstract

The utility model relates to the field of constant-pressure water supply control, and provides a full-frequency-conversion constant-pressure water supply control system with an auxiliary pump. The system mainly comprises a three-phase four-wire power supply, four circuit breakers, three frequency converters, three potentiometers, an alternating current contactor, a thermal relay, a controller and a touch screen. Wherein each frequency converter is connected with the corresponding circuit breaker and the corresponding water pump, and the controller is in communication connection with all the frequency converters and the touch screen. The system has the advantages of being high in compatibility, high in intelligent degree, reliable, capable of saving energy, convenient to operate and suitable for various water supply scenes.

Description

Technical Field

[0001] The utility model relates to a constant pressure water supply control technology, in particular to a constant pressure water supply control technology with a full frequency conversion and an auxiliary pump. Background Art

[0002] In the current rapid development of industrialization and urbanization, constant pressure water supply systems are becoming more and more important. At present, there are many types of constant pressure water supply pump control systems on the market to meet the various needs of different users. These systems are mainly responsible for maintaining the pressure stability in the water supply system to ensure the continuity and safety of water supply. With the development of technology, the control system of constant pressure water pumps continues to develop in the direction of automation, intelligence and informatization to improve the operating efficiency and reliability of the system.

[0003] However, although the existing constant pressure water supply pump control systems can meet general control needs, they still have some significant shortcomings, such as: the operation of the water pump is not efficient and energy-saving enough, the pressure of the water supply system needs to be further stabilized, and it cannot fully meet different water supply needs, etc.

[0004] Therefore, there is an urgent technical problem, that is, how to design a constant pressure water supply control system that can more effectively realize the efficient and energy-saving operation of the water pump while maintaining the pressure stability of the water supply system to meet different water supply needs. Utility Model Content

[0005] The purpose of the utility model is to provide a full-frequency variable constant pressure water supply control system with an attached pump to solve the problems raised in the above-mentioned background technology.

[0006] The present application discloses a full frequency conversion constant pressure water supply control system with an auxiliary pump, comprising:

[0007] A three-phase four-wire power supply is respectively connected to a first circuit breaker, a second circuit breaker, a third circuit breaker, and a fourth circuit breaker;

[0008] a first frequency converter, which connects the first circuit breaker and the first water pump; a second frequency converter, which connects the second circuit breaker and the second water pump; and a third frequency converter, which connects the third circuit breaker and the third water pump;

[0009] An AC contactor and a thermal relay, which are connected in series to connect the fourth circuit breaker and the auxiliary pump;

[0010] A first potentiometer, a second potentiometer, and a third potentiometer, which are respectively connected to the input ends of the first frequency converter, the second frequency converter, and the third frequency converter;

[0011] A controller and a touch screen, wherein the controller is respectively connected to the first frequency converter, the second frequency converter, and the third frequency converter for communication, and is connected to the touch screen.

[0012] In a preferred embodiment, it also includes:

[0013] A pressure transmitter and a float switch, wherein the controller receives signals from the pressure transmitter and the float switch.

[0014] In a preferred embodiment, it also includes:

[0015] The intermediate relay, whose contacts and coils are connected with the controller, the first frequency converter, the second frequency converter, the third frequency converter and the AC contactor, realizes the on-off control of each device according to the control signal of the controller.

[0016] In a preferred embodiment, it also includes:

[0017] Indicator light: used to indicate the system operating status.

[0018] In a preferred embodiment, it also includes:

[0019] The switching power supply is used to provide power to the controller, the pressure transmitter and the float switch.

[0020] In a preferred embodiment, it also includes:

[0021] Cooling fan is used to cool the control cabinet.

[0022] In a preferred example, the three-phase four-wire power supply is also connected to a fuse.

[0023] In a preferred embodiment, it also includes:

[0024] A conversion switch and a varistor, wherein the conversion switch and the varistor are electrically connected to the controller and are used to manually switch the operating mode of the system and to provide overvoltage protection for the system.

[0025] In a preferred example, the controller controls the on and off of the first frequency converter, the second frequency converter, the third frequency converter and the AC contactor through an intermediate relay according to a preset control strategy and a received feedback signal, thereby achieving constant pressure water supply control of the system.

[0026] In a preferred example, the pressure transmitter detects the pressure signal of the water supply network, the float switch detects the water level signal of the pool, and the controller determines whether to start or stop the first to third water pumps and the auxiliary pump based on the received pressure signal and water level signal.

[0027] The control system of the present application can realize efficient and energy-saving operation of the water pump, while maintaining stable pressure of the water supply system and meeting different water supply needs, and has broad application prospects.

[0028] The specification of the utility model records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features of the utility model (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above utility model content, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a full-frequency variable constant pressure water supply control system with an attached pump according to the first embodiment of the utility model.

[0030] Figure 2 It is a partial electrical schematic diagram of a full-frequency variable constant-pressure water supply control system with an attached pump according to the first embodiment of the utility model.

[0031] Figure 3 A control system schematic diagram of a full-frequency variable constant pressure water supply control system with an attached pump according to the first embodiment of the utility model.

[0032] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0033] Q11~QF14: First circuit breaker~fourth circuit breaker

[0034] VVVF1~VVVF3: First inverter~third inverter

[0035] RT1~RT3: The first potentiometer to the third potentiometer

[0036] KM1: AC contactor

[0037] KH1: Thermal relay

[0038] FU1: Fuse

[0039] HMI: Touch screen

[0040] PLC: Controller

[0041] S: Switching power supply

[0042] KA1~KA14: The first intermediate relay~the fourteenth intermediate relay

[0043] HL1~HL10: The first indicator light to the tenth indicator light

[0044] SA1~SA5: First to fifth switching switches

[0045] U1: Varistor

[0046] SL: Float switch

[0047] PT: Pressure Transmitter

[0048] FM1~FM2: First cooling fan~Second cooling fan DETAILED DESCRIPTION

[0049] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the claims of the present application can be implemented. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0051] First embodiment

[0052] See also Figure 1 , Figure 2 and Figure 3 The full frequency conversion constant pressure water supply control system with an attached pump of this embodiment includes:

[0053] A three-phase four-wire power supply is respectively connected to the first circuit breaker QF11, the second circuit breaker QF12, the third circuit breaker QF13, and the fourth circuit breaker QF14; a first frequency converter VVVF1 is connected to the first circuit breaker QF11 and the first water pump; a second frequency converter VVVF2 is connected to the second circuit breaker QF12 and the second water pump; a third frequency converter VVVF3 is connected to the third circuit breaker QF13 and the third water pump; an AC contactor KM1 and a thermal relay KH1 are connected to the first frequency converter VVVF1. The fourth circuit breaker QF14 and the auxiliary pump are connected in series; the first potentiometer RT1, the second potentiometer RT2, and the third potentiometer RT3 are respectively connected to the input ends of the first frequency converter VVVF1, the second frequency converter VVVF2, and the third frequency converter VVVF3; the controller PLC and the touch screen HMI, wherein the controller PLC is respectively communicated with the first frequency converter VVVF1, the second VVVF2, and the third VVVF3, and is connected to the touch screen HMI.

[0054] Optionally, the full-frequency variable constant pressure water supply control system with an attached pump of this embodiment further comprises: a pressure transmitter PT and a float switch SL, wherein the controller PLC receives signals from the pressure transmitter PT and the float switch SL.

[0055] Optionally, the full-frequency variable constant pressure water supply control system with an attached pump of this embodiment further includes: intermediate relays KA1 to KA14, whose contacts and coils are connected to the controller PLC, the first frequency converter VVVF1, the second VVVF2, the third VVVF3, and the AC contactor KM1, and the on-off control of each device is realized according to the control signal of the controller PLC.

[0056] Optionally, the full-frequency variable constant pressure water supply control system with an auxiliary pump of this embodiment further comprises indicator lights HL1 to HL10 for indicating the operating status of the system.

[0057] Optionally, the full-frequency variable constant pressure water supply control system with an attached pump of this embodiment further includes: a switching power supply S, which is used to provide power for the controller PLC, the pressure transmitter PT, and the float switch SL.

[0058] Optionally, the full-frequency variable constant pressure water supply control system with an auxiliary pump of this embodiment further includes cooling fans FM1 and FM2 for cooling and dissipating heat from the control cabinet.

[0059] Optionally, in the full-frequency conversion constant pressure water supply control system with an attached pump of this embodiment, the three-phase four-wire power supply is also connected to a fuse FU1.

[0060] Optionally, the full-frequency constant pressure water supply control system with an attached pump of this embodiment further includes: a first conversion switch SA1 to a fifth conversion switch SA5 and a varistor U1, wherein the first conversion switch SA1 to the fifth conversion switch SA5 and the varistor U1 are electrically connected to the controller PLC for manually switching the operating mode of the system and protecting the system from overvoltage.

[0061] Optionally, in the full-frequency constant pressure water supply control system with an attached pump of the present embodiment, the controller PLC controls the on and off of the first frequency converter VVVF1, the second frequency converter VVVF2, the third frequency converter VVVF3 and the AC contactor KM1 through intermediate relays KA1 to KA14 according to a preset control strategy and the received feedback signal, so as to realize constant pressure water supply control of the system.

[0062] Optionally, in the full-frequency constant pressure water supply control system with auxiliary pump of this embodiment, the pressure transmitter PT detects the pressure signal of the water supply network, the float switch SL detects the water level signal of the water pool, and the controller PLC determines whether to start or stop the first to third water pumps and the auxiliary pump based on the received pressure signal and water level signal.

[0063] The controller mentioned in this application, as a component of the control system, belongs to the scope of the prior art. In the context of the present invention, the controller is not an innovative point, nor is it the focus of the present application. Therefore, the specific technical details of the controller are not described in detail. The controller is widely available in the prior art, and this information is not necessary for understanding and implementing the constant pressure water supply control system disclosed in the present invention.

[0064] Combine the following Figures 1 to 3 , the structure of the constant pressure water supply control system with full frequency conversion and attached pump of the above embodiment is further described in detail.

[0065] like Figure 1 As shown, the full-frequency variable constant pressure water supply control system with attached pump of this embodiment includes a three-phase four-wire power supply (AC380V 50Hz) connected to the first circuit breaker QF11, the second circuit breaker QF12, the third circuit breaker QF13, the fourth circuit breaker QF14, and the fuse FU1. The first circuit breaker QF11 is connected to the first frequency converter VVVF1, and the first frequency converter VVVF1 is connected to the first water pump terminal; the second circuit breaker QF12 is connected to the second frequency converter VVVF2, and the second frequency converter VVVF2 is connected to the second water pump terminal; the third circuit breaker QF13 is connected to the third frequency converter VVVF3, and the third frequency converter VVVF3 is connected to the third water pump terminal; the fourth circuit breaker QF14 is connected to the AC contactor KM1, and the current contactor KM1 is connected to the thermal relay KH1, and the thermal relay KH1 is connected to the attached pump terminal.

[0066] Further, such as Figure 1 As shown, the input terminal of the first frequency converter VVVF1 is connected to the first potentiometer RT1, the input terminal of the first frequency converter VVVF1 is connected to the normally open contact of the first intermediate relay KA1 and the normally open contact of the second intermediate relay KA2, and the communication interface of the first frequency converter VVVF1 is connected to the communication interface RS485 of the RS485 controller PLC; the input terminal of the second frequency converter VVVF2 is connected to the second potentiometer RT2, the input terminal of the second frequency converter VVVF2 is connected to the normally open contact of the third intermediate relay KA3 and the normally open contact of the fourth intermediate relay KA4, and the communication interface RS485 of the second frequency converter VVVF2 is connected to the communication interface RS485 of the controller PLC; the input terminal of the third frequency converter VVVF3 is connected to the third potentiometer RT3, the input terminal of the third frequency converter VVVF3 is connected to the normally open contact of the fifth intermediate relay KA5 and the normally open contact of the sixth intermediate relay KA6, and the communication interface RS485 of the third frequency converter VVVF3 is connected to the communication interface RS485 of the controller PLC.

[0067] Further, such as Figure 2 As shown, the first circuit breaker QF11 is connected to the fuse FU1 at the outlet terminal, and the fuse FU1 is respectively connected to the first conversion switch SA1, the operation output terminal of the first inverter VVVF1, the fault output terminal of the first inverter VVVF1, the operation output terminal of the second inverter VVVF2, the fault output terminal of the second inverter VVVF2, the operation output terminal of the third inverter VVVF3, the fault output terminal of the third inverter VVVF3, the normally open contact of the AC contactor KM1, the normally open contact of the eighth intermediate relay KA8, the normally open contact of the tenth intermediate relay KA10, the normally open contact of the twelfth intermediate relay KA12, and the power supply terminal of the switching power supply S; the first conversion switch SA1 is respectively connected to the control coil of the seventh intermediate relay KA7, the second conversion switch SA2, the third conversion switch SA3, the fourth conversion switch SA4, the fifth conversion switch SA5, and the control coil of the seventh intermediate relay KA7 are connected to the neutral line N; the second conversion switch SA2 is connected to the normally closed contact of the seventh intermediate relay KA7, and the normally closed contact of the seventh intermediate relay KA7 is connected to the second output terminal Q0.1 of the controller PLC, the third conversion switch SA3 is connected to the normally closed contact of the seventh intermediate relay KA7, and the normally closed contact of the seventh intermediate relay KA7 is connected to the fourth output terminal Q0.5 of the controller PLC, the fourth conversion switch SA4 is connected to the normally closed contact of the seventh intermediate relay KA7, and the normally closed contact of the seventh intermediate relay KA7 is connected to the sixth output terminal Q0.7 of the controller PLC, and the fifth conversion switch SA5 is connected to the seventh output terminal Q1.0 of the controller PLC;

[0068] Further, such as Figure 2As shown, the running output terminals of the first frequency converter VVVF1 are respectively connected to the control coil of the eighth intermediate relay KA8 and the second indicator light HL2, and the control coil of the eighth intermediate relay KA8 and the second indicator light HL2 are connected to the neutral line N; the fault output terminals of the first frequency converter VVVF1 are respectively connected to the control coil of the ninth intermediate relay KA9 and the third indicator light HL3, and the control coil of the ninth intermediate relay KA9 and the third indicator light HL3 are connected to the neutral line N; the running output terminals of the second frequency converter VVVF2 are respectively connected to the control coil of the tenth intermediate relay KA10 and the fourth indicator light HL4, and the control coil of the tenth intermediate relay KA10 and the fourth indicator light HL4 are connected to the neutral line N; the second frequency converter VVVF2 is respectively connected to the control coil of the tenth intermediate relay KA10 and the fourth indicator light HL4 are connected to the neutral line N; The fault output terminals of the frequency converter VVVF2 are respectively connected to the control coil of the eleventh intermediate relay KA11 and the fifth indicator light HL5, and the control coil of the eleventh intermediate relay KA11 and the fifth indicator light HL5 are connected to the neutral line N; the running output terminals of the third frequency converter VVVF3 are respectively connected to the control coil of the twelfth intermediate relay KA12 and the sixth indicator light HL6, and the control coil of the twelfth intermediate relay KA12 and the sixth indicator light HL6 are connected to the neutral line N; the fault output terminals of the third frequency converter VVVF3 are respectively connected to the control coil of the thirteenth intermediate relay KA13 and the seventh indicator light HL7, and the control coil of the thirteenth intermediate relay KA13 and the eighth indicator light HL8 are connected to the neutral line N.

[0069] Further, such as Figure 2 As shown, fuse FU1 is respectively connected to the first indicator light HL1, the normally open contact of the AC contactor KM1, the normally open contact of the eighth intermediate relay KA8, the normally open contact of the tenth intermediate relay KA10, and the normally open contact of the twelfth intermediate relay KA12; the normally open contact of the AC contactor KM1 is connected to the eighth indicator light HL8, and the normally open contact of the eighth intermediate relay KA8, the normally open contact of the tenth intermediate relay KA10, and the normally open contact of the twelfth intermediate relay KA12 are connected to the first cooling fan FM1 and the second cooling fan FM2; the first indicator light HL1, the eighth indicator light HL8, the first cooling fan FM1, the second cooling fan FM2, and the switching power supply S are connected to the neutral line N; the positive pole of the switching power supply S is respectively connected to the float switch SL and the pressure transmitter PT, the float switch SL is connected to the control coil of the fourteenth intermediate relay KA14, and the control coil of the fourteenth intermediate relay KA14 is connected to the negative pole of the switching power supply S.

[0070] Further, such as Figure 3As shown, the touch screen HMI is connected to the controller PLC, the controller PLC is connected to the expansion module EM, and the expansion module EM is connected to the pressure transmitter PT; the input terminal of the controller PLC is respectively connected to the normally open contact of the eighth intermediate relay KA8, the normally open contact of the ninth intermediate relay KA9, the normally open contact of the tenth intermediate relay KA10, the normally open contact of the eleventh intermediate relay KA11, the normally open contact of the twelfth intermediate relay KA12, the normally open contact of the thirteenth intermediate relay KA13, the normally open contact of the AC contactor KM1, the normally open contact of the thermal relay KH1, the normally open contact of the fourteenth intermediate relay KA14, and the normally open contact of the seventh intermediate relay KA7; the output terminals of the controller PLC are respectively connected to The control coil of the first intermediate relay KA1, the control coil of the second intermediate relay KA2, the control coil of the third intermediate relay KA3, the control coil of the fourth intermediate relay KA4, the control coil of the fifth intermediate relay KA5, the varistor U1, the control coil of the AC contactor KM1, the ninth indicator light HL9, and the tenth indicator light HL10; the control coil of the first intermediate relay KA1, the control coil of the second intermediate relay KA2, the control coil of the third intermediate relay KA3, the control coil of the fourth intermediate relay KA4, the control coil of the fifth intermediate relay KA5, the normally closed contact of the thermal relay KH1, the ninth indicator light HL1, and the tenth indicator light HL10 are connected to the neutral line N.

[0071] Working process:

[0072] The working process of the full frequency conversion with pump constant pressure water supply control system of this embodiment is described as follows:

[0073] 1) Initialization:

[0074] When starting, first turn off all circuit breakers (QF11 to QF14) in the control cabinet, and then close fuse FU1 to power on the control cabinet.

[0075] 2) Mode selection:

[0076] By switching on switch SA1, select the system operating mode as automatic or manual, and set the corresponding operating parameters on the inverter (VVVF1 to VVVF3) and touch screen HMI.

[0077] 3) Manual operation mode:

[0078] Use the second selector switch SA2 to manually start and stop water pump No. 1;

[0079] Use the third selector switch SA3 to manually start and stop water pump No. 2;

[0080] Use the fourth selector switch SA4 to manually start and stop water pump No. 3;

[0081] Use the fifth selector switch SA5 to manually start and stop the additional pump.

[0082] 4) Automatic operation mode:

[0083] According to the 4-20mA signal sent by the pressure transmitter PT, the set pressure threshold and the status of the float switch SL, the controller PLC automatically controls the start and stop and output frequency of the frequency converter (VVVF1 to VVVF3), thereby adjusting the speed of each water pump.

[0084] PLC automatically rotates the water pumps, adds or reduces pumps based on data such as the number of water pump operations and operating time, in order to achieve efficient operation.

[0085] The PID adjustment function of the frequency converter is used to achieve constant pressure water supply control of the system. At the same time, based on pressure feedback, running time and other information, the PLC controls the start and stop of the additional pump to optimize energy consumption and performance.

[0086] Technical effect:

[0087] Through the system structure and working process of the above-mentioned embodiment, it is possible to more effectively realize the efficient and energy-saving operation of the water pump, while maintaining the pressure stability of the water supply system to meet different water supply needs.

[0088] More specifically, the above embodiments have the following technical effects:

[0089] Strong compatibility: This system uses the controller as the control core, which is compatible with water pumps with different starting methods, realizing unified control, avoiding the problem of needing to configure multiple control cabinets due to different water pump starting methods, and improving the compatibility and versatility of the system.

[0090] High reliability: This system adopts a variety of protection measures, such as short circuit protection, overload protection, etc., to effectively prevent damage to the water pump and control equipment. At the same time, the water tank level and pipe network pressure are monitored in real time through the float switch and pressure transmitter, and the water pump can be automatically started and stopped according to actual needs, avoiding the problem of water pump idling and pipe network overpressure, and improving the reliability of the system.

[0091] Good energy-saving effect: This system adopts frequency conversion control technology to adjust the speed of the water pump according to the actual water supply demand, avoiding the problem of energy waste caused by the long-term full-load operation of the water pump. In addition, when meeting the water supply demand, the small-power auxiliary pump is used first, which further reduces energy consumption and achieves the purpose of energy saving.

[0092] Flexible and convenient operation: This system provides two control modes: local manual and remote automatic. Manual control of a single water pump can be achieved through the touch screen to meet the control requirements under special working conditions; it reduces manual intervention, improves the automation of the system, and makes the operation more flexible and convenient.

[0093] To sum up, the full-frequency conversion band constant pressure water supply control system with a pump provided by the utility model has strong compatibility, high intelligence, good reliability, good energy-saving effect, and flexible and convenient operation. It solves the problems existing in the prior art well and effectively improves the performance and practicality of the constant pressure water supply system.

[0094] It should be noted that all documents mentioned in this utility model are cited as references in this application, just as each document is cited as reference separately. In addition, it should be understood that after reading the above teaching content of the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0095] Furthermore, in the claims and specification of this patent, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the claims and specification of this patent, if it is mentioned that an action is performed according to an element, it means at least the meaning of performing the action according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements.

[0096] Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that various changes may be made in form and details without departing from the spirit and scope of the present invention.

Claims

1. A full frequency conversion constant pressure water supply control system with an auxiliary pump, characterized in that: include: A three-phase four-wire power supply is respectively connected to a first circuit breaker, a second circuit breaker, a third circuit breaker, and a fourth circuit breaker; a first frequency converter, connected to the first circuit breaker and the first water pump; a second frequency converter connected to the second circuit breaker and the second water pump; a third frequency converter connected to the third circuit breaker and the third water pump; An AC contactor and a thermal relay, which are connected in series to connect the fourth circuit breaker and the auxiliary pump; A first potentiometer, a second potentiometer, and a third potentiometer, which are respectively connected to the input ends of the first frequency converter, the second frequency converter, and the third frequency converter; A controller and a touch screen, wherein the controller is respectively connected to the first frequency converter, the second frequency converter, and the third frequency converter for communication, and is connected to the touch screen.

2. The system according to claim 1, characterized in that Also includes: A pressure transmitter and a float switch, wherein the controller receives signals from the pressure transmitter and the float switch.

3. The system according to claim 1, characterized in that Also includes: The intermediate relay, whose contacts and coils are connected with the controller, the first frequency converter, the second frequency converter, the third frequency converter and the AC contactor, realizes the on-off control of each device according to the control signal of the controller.

4. The system according to claim 1, characterized in that Also includes: Indicator light: used to indicate the system operating status.

5. The system according to claim 1, wherein: Also includes: The switching power supply is used to provide power to the controller, the pressure transmitter and the float switch.

6. The system according to claim 1, wherein: Also includes: Cooling fan is used to cool the control cabinet.

7. The system according to claim 1, characterized in that The three-phase four-wire power supply is also connected to a fuse.

8. The system of claim 1, wherein: Also includes: A conversion switch and a varistor, wherein the conversion switch and the varistor are electrically connected to the controller and are used to manually switch the operating mode of the system and to provide overvoltage protection for the system.

9. The system according to claim 1, characterized in that The controller controls the on and off of the first frequency converter, the second frequency converter, the third frequency converter and the AC contactor through an intermediate relay according to a preset control strategy and a received feedback signal, thereby realizing constant pressure water supply control of the system.

10. The system according to claim 2, characterized in that The pressure transmitter detects the pressure signal of the water supply network, the float switch detects the water level signal of the pool, and the controller determines whether to start or stop the first to third water pumps and the auxiliary pump based on the received pressure signal and water level signal.

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