Submersible pump overheat protection device
Patent Information
- Application Number
- CN202521772982.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-20
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-08-20
AI Technical Summary
潜水泵在使用中经常出现各种异常工况导致潜水泵线圈烧毁，比如电源缺相、过载、堵转、潜水泵未浸没散热不良等，分析得出大部分故障导致潜水泵烧毁的原因都体现在温度升高上，因此如何进行潜水泵过热检测以及当潜水泵出现温度升高后如何进行防护是潜水泵防护的主要问题
[0012]本申请公开的潜水泵过热保护装置通过设置温控开关和温度传感器，在实现过热保护之前能利用在主控模块能主动降频调速——当检测到温度接近阈值时，通过PWM降低变频器输出频率，既维持水泵运行又控制温升。通过在三相电流中连接电流互感器识别三相电流/缺相/过载或堵转、不平衡负载时进行识别，提前降低潜水泵的频率，实现过热前主动降速而非单纯依赖被动断电。
Smart Images
Figure CN224919420U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water pump overheat protection technology, and in particular to an overheat protection device for submersible pumps. Background Technology
[0002] Submersible pumps are common electrical tools often used to transport liquid media, such as for drainage in ditches. During use, various abnormal operating conditions frequently occur, leading to coil burnout. These include power phase loss, overload, locked rotor, and insufficient heat dissipation due to the pump not being fully submerged. Analysis shows that most of these failures are caused by overheating. Therefore, how to detect overheating in submersible pumps and how to protect them when overheating occurs are key issues in submersible pump protection.
[0003] However, in the existing technology, the common approach is to use a temperature sensor installed at the coil or stator of the submersible pump. When the temperature of the submersible pump exceeds the preset range, the power to the submersible pump is cut off. However, the potential problem is that the submersible pump does not heat up instantaneously but slowly over a period of time. If the power is cut off only when overheating occurs, it will also damage the submersible pump and seriously affect its service life. Utility Model Content
[0004] Therefore, the purpose of this utility model is to provide a submersible pump overheat protection device, which detects the temperature of the submersible pump motor by a temperature sensor and uses the PWM regulation of the main control chip to control the duty cycle of the motor, thereby realizing the regulation of the motor speed and realizing the overheat protection device for the submersible pump.
[0005] To achieve the above objectives, this utility model provides an overheat protection device for a submersible pump, comprising a main circuit, a control circuit, and a main control module; the main circuit includes a submersible pump motor connected to a three-phase input power supply, with a circuit breaker and a contactor connected in sequence to the three-phase input power supply; the control circuit includes a start button, a stop button, a temperature control switch contact, and a contactor coil connected in series between the L line and the N line. The signal input terminals of the main control module are connected to the temperature sensor, current sensor, and liquid level sensor, respectively; the PWM output terminal of the microcontroller of the main control module is connected to the frequency converter, and the output terminal of the frequency converter is connected to the three-phase input power supply of the submersible pump; the power input terminal of the main control module is connected to the start button.
[0006] In a further preferred embodiment, a temperature sensor and a temperature control switch are attached to the stator core of the water pump near the coil.
[0007] More preferably, all parts of the main control module, except for the temperature sensor, current sensor, and liquid level sensor, are installed in a separate control box.
[0008] More preferably, the power input terminal of the main control module is connected to a rectifier bridge and a voltage regulator circuit after the start button is connected.
[0009] More preferably, the main control module uses an STM32F103C8T6 series chip.
[0010] More preferably, the current sensor is connected to the three-phase power supply line of the submersible pump using a current transformer.
[0011] Preferably, the signal output terminal of the microcontroller in the main control module is connected to the alarm.
[0012] The submersible pump overheat protection device disclosed in this application, by setting up a temperature control switch and a temperature sensor, can actively reduce the frequency and speed of the main control module before overheat protection is implemented. When the temperature is detected to be close to the threshold, the inverter output frequency is reduced through PWM, which maintains the operation of the water pump while controlling the temperature rise. By connecting a current transformer in the three-phase current, it identifies three-phase current / phase loss / overload or stalled / unbalanced load, and reduces the frequency of the submersible pump in advance, realizing active speed reduction before overheating rather than simply relying on passive power cut-off. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the circuit structure of the submersible pump overheat protection device of this utility model.
[0014] Figure 2 This is a schematic diagram of the circuit structure of the main circuit of this utility model.
[0015] Figure 3 This is a schematic diagram of the circuit structure of the control loop of this utility model.
[0016] Figure 4 This is a schematic diagram of the circuit structure of the main control module of this utility model. Detailed Implementation
[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0018] like Figure 1 As shown, one embodiment of this utility model provides a submersible pump overheat protection device, including a main circuit, a control circuit, and a main control module; as shown... Figure 2 The main circuit includes a submersible pump motor connected to a three-phase input power supply, with a circuit breaker and a contactor connected sequentially to the three-phase input power supply; such as Figure 3 The control circuit includes a start button SB, a stop button SA, a temperature control switch contact K, and a contactor KM coil connected in series between the L line and the N line. The signal input terminals of the main control module are connected to the temperature sensor, current sensor, and liquid level sensor, respectively; the PWM output terminal of the microcontroller of the main control module is connected to the frequency converter, and the output terminal of the frequency converter is connected to the three-phase input power supply of the submersible pump; the power input terminal of the main control module is connected to the start button.
[0019] Among them, a temperature sensor and a temperature control switch are attached to the stator core of the water pump near the coil.
[0020] The three-phase power supply is connected to the stator coil of the submersible pump in sequence through circuit breaker QF, contactor KM, and frequency converter. When the start button SB is pressed, the contactor KM coil is energized and engaged, and the normally open auxiliary contact of the contactor closes to form a self-locking mechanism. When the stop button is pressed, the control circuit is disconnected, and the contactor KM coil is de-energized and disconnected. When the temperature of the submersible pump exceeds the rated temperature of the temperature control switch, the normally closed contact K of the temperature control switch opens, the control circuit is disconnected, and the contactor KM coil is de-energized and disconnected, realizing the pump body over-temperature power-off protection.
[0021] like Figure 4 As shown, all components of the main control module, except for the temperature sensor, current sensor, and level sensor, are installed in a separate control box. The power input terminal of the main control module is connected to the start button, and then to a rectifier bridge and a voltage regulator circuit. In this application, the rectifier bridge and voltage regulator circuit use common components found in the prior art, and their operation depends on the voltage requirements of the sensors and chips used; therefore, the conventional principles will not be elaborated upon here.
[0022] The main control module uses the STM32F103C8T6 series chip. The STM32F103C8T6 chip has a 12-bit ADC that can support up to 16 channels, fully meeting the sampling requirements of five sensors (three-phase current + temperature + liquid level); in the figure, the PA6 pin outputs PWM, which is regulated by the Q4 MOSFET and then input to the frequency converter.
[0023] The current sensor is connected to the three-phase power supply line of the submersible pump via a current transformer. The current transformer collects data using the principle of electromagnetic induction. This application also includes frequency conversion control for the submersible pump. When abnormal data is collected by the temperature sensor, current sensor, or level sensor—for example, if the temperature gradient changes rapidly but the temperature value has not yet reached the threshold for the temperature switch to activate; or if the level value is close to the set threshold; or if the current data collected by the three-phase current sensor shows that the current changes too rapidly—the main control module adjusts the frequency of the frequency converter by outputting the PEM duty cycle through the STM32F103C8T6 chip. This precisely controls the output of the frequency converter, enabling dynamic adjustment of parameters such as motor speed and power.
[0024] In a further preferred embodiment, the signal output terminal of the microcontroller in the main control module is connected to the alarm. It should be noted that the STM32F103C8T6 series chip used in this application can also be expanded with an RS485 interface communication module, employing Modbus RTU functionality to connect to a SCADA system, enabling remote modification of protection parameters. SCADA (Supervisory Control and Data Acquisition) systems are the core hub in the industrial control field, specifically designed for real-time monitoring, data acquisition, and centralized management of widely distributed equipment groups.
[0025] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A submersible pump overheat protection device, characterized in that, It includes a main circuit, a control circuit, and a main control module; the main circuit includes a submersible pump motor connected to a three-phase input power supply, and a circuit breaker and a contactor connected in sequence to the three-phase input power supply; the control circuit includes a start button, a stop button, a temperature control switch contact, and a contactor coil connected in series between the L line and the N line; The signal input terminals of the main control module are connected to the temperature sensor, current sensor, and liquid level sensor, respectively; the PWM output terminal of the microcontroller of the main control module is connected to the frequency converter, and the output terminal of the frequency converter is connected to the three-phase input power supply of the submersible pump; the power input terminal of the main control module is connected to the start button.
2. The submersible pump overheat protection device according to claim 1, characterized in that, A temperature sensor and a temperature control switch are attached to the stator core of the submersible pump, close to the coil.
3. The submersible pump overheat protection device according to claim 1, characterized in that, Except for the temperature sensor, current sensor, and liquid level sensor, all other parts of the main control module are installed in a separate control box.
4. The submersible pump overheat protection device according to claim 1, characterized in that, The main control module's power input terminal is connected to the start button, as well as a rectifier bridge and a voltage regulator circuit.
5. The submersible pump overheat protection device according to claim 1, characterized in that, The main control module uses an STM32F103C8T6 series chip.
6. The submersible pump overheat protection device according to claim 1, characterized in that, The current sensor is connected to the three-phase power supply line of the submersible pump using a current transformer.
7. The submersible pump overheat protection device according to claim 1, characterized in that, The signal output terminal of the microcontroller in the main control module is connected to the alarm.