A dual-power supply, high-reliability electric centrifugal pump set control system

Abstract

This utility model relates to a dual-power supply, high-reliability electric centrifugal pump set control system, including a frequency converter, an electrical control box, an asynchronous motor, and a centrifugal pump. The output shaft of the asynchronous motor is connected to the centrifugal pump. The frequency converter is electrically connected to the electrical control box. The electrical control box is connected to the input terminal of the asynchronous motor and the power frequency power supply. The output terminal of the frequency converter is connected to the input terminal of the asynchronous motor through a first relay inside the electrical control box. A second relay is provided inside the electrical control box, connected in series between the power frequency power supply and the asynchronous motor. The electrical control box receives fault signals output by the frequency converter and outputs control signals to the first and second relays to switch the power supply mode. This system has a relatively simple structure and low cost, and can improve the stability and reliability of the system while ensuring the efficient operation of the pump set, avoiding losses caused by downtime due to faults.

Description

Technical Field

[0001] This utility model belongs to the field of fluid machinery, specifically relating to a dual-power supply high-reliability electric centrifugal pump control system, which is particularly suitable for applications requiring high pump reliability. Background Technology

[0002] Conventional electric pumps are controlled by an electrical control box to start and stop. When the pump unit needs to run, the control box directly connects the input power frequency to the motor. The motor rotates, driving the pump rotor to rotate, thus achieving the purpose of conveying liquid. This type of pump unit can only adjust the flow rate by regulating the pipeline resistance characteristics, i.e., the opening degree of the pump outlet valve. This adjustment method causes the pump unit to operate under unfavorable conditions, reducing efficiency, and also increasing the vibration and noise of the pump unit and outlet valve.

[0003] With increasing awareness of energy conservation, pump sets controlled by frequency converters for starting, stopping, and speed adjustment are widely used. The frequency converter converts the input industrial frequency power into variable frequency power, driving the motor and pump set to control their speed. For this type of pump set, flow adjustment does not require changing the pipeline resistance characteristics; instead, it adjusts the pump set's flow rate by changing its speed and hydraulic performance. This adjustment method allows the electric pump to always operate within its high-efficiency range at different speeds, resulting in high pump set efficiency and lower vibration and noise from the pump set and outlet valves. However, the complex internal structure of the frequency converter and the large number of electronic components (often thousands) reduce the overall reliability of the pump set. In applications where shutdown is not feasible, such as solar power generation and marine propulsion, pump set failure could lead to system damage or loss of power.

[0004] In existing related technologies, such as patent document (CN119196046A), a dual-drive high-efficiency and high-reliability electric centrifugal pump set is disclosed. This set uses dual drive motors (an asynchronous motor and a permanent magnet motor within the same frame) to drive the centrifugal pump. While this improves reliability to some extent, the dual-drive motor structure is relatively complex, resulting in higher manufacturing costs. Furthermore, the coordinated control of the two motors is difficult, potentially leading to instability during switching. Patent document (CN221762158U) discloses a circulating water pump joint start-up and dual-power supply modification structure. This structure improves reliability by jointly starting a backup water pump. However, this structure requires an additional backup water pump, increasing the system's size and cost. Moreover, the backup water pump requires a certain startup time, which may cause fluctuations in water supply pressure, affecting the stable operation of the system. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned problems in the prior art and provide a dual-power supply, high-reliability electric centrifugal pump control system. This system has a relatively simple structure and low cost, and can improve the stability and reliability of the system while ensuring the efficient operation of the pump unit, thus avoiding losses caused by downtime due to malfunctions.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is: a dual-power supply high-reliability electric centrifugal pump group control system, including a frequency converter, an electrical control box, an asynchronous motor, and a centrifugal pump. The output shaft of the asynchronous motor is connected to the centrifugal pump. The frequency converter is electrically connected to the electrical control box. The electrical control box is connected to the input terminal of the asynchronous motor and the power frequency power supply respectively. The output terminal of the frequency converter is connected to the input terminal of the asynchronous motor through a first relay in the electrical control box. A second relay is provided in the electrical control box. The second relay is connected in series between the power frequency power supply and the asynchronous motor. The electrical control box receives the fault signal output by the frequency converter and outputs control signals to the first and second relays to switch the power supply mode.

[0007] Furthermore, the frequency converter has a fault signal output module.

[0008] Furthermore, a signal transmission module is provided between the frequency converter and the electrical control box, and the signal transmission module uses shielded cables to transmit fault signals.

[0009] Furthermore, the frequency converter is an adjustable frequency converter, used to change the speed of the centrifugal pump by adjusting the output frequency of the frequency converter, thereby changing the hydraulic performance of the pump set.

[0010] Furthermore, when the pump unit is running, both the electrical control box and the frequency converter have power frequency input. The frequency converter supplies the frequency converter with frequency-converted power, which is converted from the power frequency power, to the electrical control box. The first relay is energized, the second relay is de-energized, and the electrical control box uses the frequency converter to drive the asynchronous motor.

[0011] Furthermore, when the frequency converter malfunctions, it sends a fault signal to the electrical control box, the first relay disconnects, the second relay engages, and the electrical control box directly outputs power frequency to the asynchronous motor, allowing the centrifugal pump to continue operating.

[0012] The beneficial effects of this utility model are:

[0013] 1. When the pump set is running normally, the flow rate of the pump set can be adjusted by adjusting the output frequency of frequency converter 1, which improves the efficiency of the pump set when running under unfavorable conditions and reduces the vibration and noise of the pump set.

[0014] 2. After the frequency converter 1 fails, the electrical control box 2 directly outputs the power frequency to the motor 3 to ensure that the pump set continues to operate, and avoids damage to the system or emergency shutdown of the system caused by the pump set stopping.

[0015] 3. This utility model is mainly used to solve the problems of low reliability of variable frequency pump sets and low efficiency, high vibration and noise of fixed frequency pump sets under unbalanced operating conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the principle of this utility model;

[0017] Explanation of reference numerals in the attached diagram: 1-Inverter, 2-Electrical control box, 3-Asynchronous motor, 4-Centrifugal pump. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 As shown, the present invention discloses a dual-power supply high-reliability electric centrifugal pump control system, comprising a frequency converter 1, an electrical control box 2, an asynchronous motor 3, and a centrifugal pump 4.

[0020] The frequency converter 1 is electrically connected to the electrical control box 2. The electrical control box 2 is connected to the input terminal of the asynchronous motor 3 and the power frequency power supply. The output terminal of the frequency converter 1 is connected to the input terminal of the asynchronous motor 3 through the first relay KM1 in the electrical control box 2. The output shaft of the asynchronous motor 3 is connected to the rotor of the centrifugal pump 4.

[0021] Inverter 1 has a fault signal output function. The control box 2 can receive the fault signal output by inverter 1, cut off the inverter power supply output by inverter, and directly supply the power frequency to the motor.

[0022] In this embodiment, the electrical control box 2 is equipped with a second relay KM2, which is connected in series between the power frequency power supply and the asynchronous motor 3. When the first relay KM1 is energized, the second relay KM2 is de-energized, and the inverter power output from the inverter 1 is supplied to the asynchronous motor 3 through the first relay KM1. When the inverter 1 malfunctions, the electrical control box 2 receives a fault signal, controls the first relay KM1 to de-energize, and simultaneously energizes the second relay KM2, so that the power frequency power supply is supplied to the asynchronous motor 3 through the second relay KM2.

[0023] This utility model is also equipped with an electrical control box 2, which can receive fault signals output by the frequency converter 1. When the frequency converter 1 fails, it sends a fault signal to the electrical control box 2. The electrical control box 2 directly outputs power frequency to the motor 3 to ensure that the pump group continues to operate and avoids damage to the system or emergency shutdown of the system caused by the pump group stopping.

[0024] When the pump set is running, both the electrical control box 2 and the frequency converter 1 receive power frequency input. The frequency converter 1 converts the power frequency power into variable frequency power and supplies it to the electrical control box 2. At this time, the first relay KM1 is activated, and the second relay KM2 is deactivated. The electrical control box 2 uses the variable frequency power supplied by the frequency converter 1 to drive the motor 3. The motor 3 drives the rotor of the centrifugal pump 4 to rotate through its shaft, thereby realizing the transportation of the liquid medium. When the pump set needs to adjust the flow rate, the output frequency of the frequency converter 1 can be adjusted to change the speed of the centrifugal pump 4, thereby changing the hydraulic performance of the pump set and achieving the purpose of adjusting the flow rate. When the frequency converter 1 malfunctions, it sends a fault signal to the electrical control box 2. The first relay KM1 deactivates, the second relay KM2 is activated, and the electrical control box 2 cuts off the power output of the frequency converter 1 and directly outputs power frequency power to the motor 3 to ensure that the pump set continues to operate.

[0025] This utility model is achieved through the following means:

[0026] The first step is to design the centrifugal pump and motor according to conventional design methods;

[0027] The second part involves designing a frequency converter for the pump set, which should have a fault signal output function.

[0028] The third step is to design an electrical control box for the pump set. The electrical control box should be able to receive fault signals output by the frequency converter, cut off the frequency converter power supply, and directly supply power to the motor at the power frequency.

Claims

1. A dual power high reliability electric centrifugal pump set control system, characterized by: The system includes a frequency converter, an electrical control box, an asynchronous motor, and a centrifugal pump. The output shaft of the asynchronous motor is connected to the centrifugal pump. The frequency converter is electrically connected to the electrical control box. The electrical control box is connected to the input terminal of the asynchronous motor and the power frequency power supply. The output terminal of the frequency converter is connected to the input terminal of the asynchronous motor through a first relay inside the electrical control box. The electrical control box is equipped with a second relay, which is connected in series between the power frequency power supply and the asynchronous motor. The electrical control box receives fault signals output by the frequency converter and outputs control signals to the first and second relays to switch the power supply mode.

2. The dual powered high reliability electric centrifugal pump package control system of claim 1, wherein: The frequency converter has a fault signal output module.

3. The dual powered high reliability electric centrifugal pump package control system of claim 1, wherein: A signal transmission module is provided between the frequency converter and the electrical control box, and the signal transmission module uses shielded cables to transmit fault signals.

4. The dual powered high reliability electric centrifugal pump package control system of claim 1, wherein: The inverter is an adjustable frequency inverter, used to change the speed of the centrifugal pump by adjusting the output frequency of the inverter, thereby changing the hydraulic performance of the pump set.

5. The dual powered high reliability electric centrifugal pump package control system of claim 1, wherein: When the pump unit is running, both the electrical control box and the frequency converter have power frequency input. The frequency converter supplies the frequency converter power frequency power to the electrical control box, the first relay is energized, the second relay is de-energized, and the electrical control box uses the frequency converter power frequency power to drive the asynchronous motor.

6. The dual powered high reliability electric centrifugal pump package control system of claim 5, wherein: When the frequency converter malfunctions, it sends a fault signal to the electrical control box. The first relay disconnects, the second relay engages, and the electrical control box directly outputs power frequency to the asynchronous motor, allowing the centrifugal pump to continue operating.

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