A digital transmission system and method for submersible pump protection signal

Abstract

The present invention belongs to the technical field of submersible pump signal transmission, and relates to a submersible pump protection signal digital transmission system and method, the submersible pump protection signal digital transmission system comprises: a three-phase power cable, a sensor, a ground supporting device and a pump internal signal acquisition device, wherein the ground supporting device comprises a first carrier communication module, a first electromagnetic relay and a high-frequency power transmission module, and the pump internal signal acquisition device comprises a signal acquisition module, a second carrier communication module, a power frequency power supply module, a second electromagnetic relay, a high-frequency power supply module and a CPU. Compared with the prior art, the submersible pump protection signal digital transmission system according to the present invention utilizes high-frequency power supply technology, and when the three-phase power supply stops supplying power to the submersible pump, it can also supply power to the pump internal signal acquisition device, which is more in line with actual use.

Description

Technical Field

[0001] The present invention relates to the technical field of submersible pump signal transmission, and in particular to a submersible pump protection signal digital transmission system and method. Background Art

[0002] Submersible pumps are widely used in various fields such as water conservancy, irrigation, water intake, sewage discharge, water diversion, drought resistance and flood control. Since submersible pumps operate in water for a long time, the environment is very harsh. Once problems such as water immersion, leakage, overheating, etc. are not discovered in time, it will seriously affect the normal operation of the submersible pump and cause greater safety accidents.

[0003] For this reason, water leakage and overheating sensors are installed in multiple places in the submersible pump. The existing protection for the submersible pump is to use multi-core cables to directly connect various sensors inside the submersible pump. This connection method has two problems. First, a separate cable is required. When the submersible pump is far away from the control equipment, the cable cost is high and the installation and maintenance are complicated. Second, the protection signal is collected outside the pump, and the analog signal transmitted through the cable is susceptible to interference, resulting in inaccurate measurement and affecting protection. Summary of the invention

[0004] In order to solve the problems of high cost, complicated installation and maintenance, and measurement susceptibility to interference caused by the use of separate cables to transmit protection signals in existing submersible pumps, the present invention provides a submersible pump protection signal digital transmission system and method.

[0005] In order to overcome the deficiencies of the prior art, according to one aspect of the present invention, a submersible pump protection signal digital transmission system is provided, comprising: a three-phase power cable, a sensor, a ground supporting device and a signal acquisition device in a pump, wherein the ground supporting device comprises a first carrier communication module, a first electromagnetic relay and a high-frequency power transmission module, the signal acquisition device in the pump comprises a signal acquisition module, a second carrier communication module, an industrial frequency power supply module, a second electromagnetic relay, a high-frequency power supply module and a CPU, the first carrier communication module is connected to the first phase line and the second phase line of the three-phase power cable, the high-frequency power supply module is connected to the first phase line and the second phase line of the three-phase power supply ... The output end is connected to the second phase line of the three-phase power cable, and the other output end is connected to the third phase line of the three-phase power cable through the first electromagnetic relay; the input end of the signal acquisition module is electrically connected to the sensor, and the output end is electrically connected to the CPU; one end of the second carrier communication module is connected to the first phase line and the second phase line of the three-phase power cable, and the other end is connected to the CPU; the industrial frequency power supply module is connected to the second phase line and the third phase line of the three-phase power cable, one input end of the high-frequency power supply module is connected to the second phase line of the three-phase power cable, and the other input end is connected to the third phase line of the three-phase power cable through the second electromagnetic relay.

[0006] According to an exemplary embodiment of the present invention, the other output end of the high-frequency power transmission module is connected to one end of the normally closed contact of the first electromagnetic relay, the other end of the normally closed contact of the first electromagnetic relay is connected to the third phase line of the three-phase power cable, and the coil of the first electromagnetic relay is connected to the second phase line and the third phase line of the three-phase power cable.

[0007] According to an exemplary embodiment of the present invention, one end of the normally closed contact of the second electromagnetic relay is connected to the third phase line of the three-phase power cable, the other end of the normally closed contact is connected to the other input end of the high-frequency power supply module, and the coil of the second electromagnetic relay is connected to the second phase line and the third phase line of the three-phase power cable.

[0008] According to an exemplary embodiment of the present invention, the sensors include overheat signal sensors installed in the windings and bearings of the submersible pump, water leakage signal sensors installed in the motor cavity, oil chamber and junction box of the submersible pump, and humidity sensors installed inside the motor of the submersible pump.

[0009] According to an exemplary embodiment of the present invention, the signal acquisition module is used to convert an analog signal into a digital signal.

[0010] According to an exemplary embodiment of the present invention, a CPU includes a low power consumption mode and a high performance mode.

[0011] According to an exemplary embodiment of the present invention, the industrial frequency power supply module converts the industrial frequency AC voltage into a second DC output.

[0012] According to an exemplary embodiment of the present invention, the high-frequency power extraction module converts the high-frequency AC voltage into a first DC output.

[0013] According to another aspect of the present invention, a signal digital transmission method of the submersible pump protection signal digital transmission system as described above is provided, comprising:

[0014] When the three-phase power cable transmits the industrial frequency AC power signal, the normally closed contacts of the first electromagnetic relay and the second electromagnetic relay are disconnected, the CPU is in high-performance mode, and the sensor signal converted by the signal acquisition module is digitally filtered. At the same time, the second carrier communication module is controlled to send a carrier modulation signal with a relatively high power.

[0015] When the three-phase power cable stops transmitting the industrial frequency AC power signal, the high-frequency power transmission module generates a high-frequency power signal, the normally closed contacts of the first electromagnetic relay close, and the high-frequency power signal is loaded into the three-phase power cable. The normally closed contacts of the second electromagnetic relay close, and the high-frequency power extraction module converts the high-frequency AC voltage into the first DC output. The CPU is in low power consumption mode, the sensor adopts low-speed sampling mode, and at the same time, the second carrier communication module is controlled to send a carrier modulation signal with a lower power.

[0016] Compared with the prior art, the beneficial effects of the present invention are: through the signal acquisition device in the pump, the sensor signal installed in the pump is collected and digitized, and the measurement is accurate. At the same time, through the built-in CPU software, the digital filtering process is adaptively performed according to the operating conditions of the pump, which further improves the anti-interference ability of the measurement. The original power supply line of the submersible pump is used for data transmission, and no additional cables are required, which reduces costs and improves reliability. Different from other power carrier transmission schemes, the present invention uses high-frequency power supply technology. When the three-phase power supply stops supplying power to the submersible pump, it can also power the signal acquisition device in the pump, which is more in line with actual usage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 4 is a structural block diagram of a digital transmission system for submersible pump protection signals according to an embodiment of the present invention.

[0018] In the figure: 1. Ground supporting device; 11: First carrier communication module; 12: High-frequency power transmission module; 13: First electromagnetic relay; 2. Three-phase power cable; 3. Sensor; 4: Signal acquisition device in the pump; 41: Signal acquisition module; 42: Second carrier communication module; 43: CPU; 44: Second electromagnetic relay; 45: High-frequency power supply module; 46: Industrial frequency power supply module. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

[0020] The present invention first provides a submersible pump protection signal digital transmission system. Figure 1 As shown, the digital transmission system for submersible pump protection signals of the present invention comprises a ground supporting device 1, a three-phase power cable 2, a sensor 3, and a signal acquisition device 4 inside the pump.

[0021] The three-phase power cable 2 includes a phase line U, a phase line V, and a phase line W (corresponding to the first, second, and third phase lines of the three-phase power cable 2, respectively, in the present invention). The three-phase power cable 2 supplies power to the submersible pump. In the present invention, the three-phase power cable 2 is also used for collecting communication signals for transmitting pump protection signals and transmitting power signals of the signal collection device 4 in the pump.

[0022] The sensor 3 detects the protection signal of the submersible pump, and the detected signals include but are not limited to temperature, water immersion, humidity, etc. In this embodiment, it includes an overheating signal sensor installed on the winding and bearing of the submersible pump, a water leakage signal sensor installed in the submersible pump motor cavity, oil chamber, junction box, etc., and a humidity sensor installed inside the motor.

[0023] The ground supporting device 1 can be installed on the ground, connected to the three-phase power cable 2, receives the carrier modulation signal sent by the signal acquisition device 4 in the pump, and obtains the acquisition result of the pump protection signal. At the same time, when the submersible pump stops running, the ground supporting device 1 provides high-frequency power to the signal acquisition device 4 in the pump.

[0024] The ground supporting device 1 includes a first carrier communication module 11, a first electromagnetic relay 13, and a high-frequency power transmission module 12, and is arranged on the ground.

[0025] The first carrier communication module 11 is connected to the first phase line and the second phase line of the three-phase power cable 2, and in this embodiment is connected to the phase lines U and V. The carrier modulation signal sent by the signal acquisition device 4 in the pump is demodulated into communication data to obtain the digital acquisition result of the submersible pump protection signal.

[0026] The high-frequency power transmission module 12 generates high-frequency power, and the output end has two wires, one of which is connected to the second phase line of the three-phase power cable, and in this embodiment is connected to the phase line V. The other is connected to one end of the normally closed contact of the first electromagnetic relay 13, and the other end of the normally closed contact of the first electromagnetic relay 13 is connected to the third phase line of the three-phase power cable 2, and in this embodiment is connected to the phase line W. The coil of the first electromagnetic relay 13 is connected to the phase lines V and W.

[0027] When there is no industrial frequency AC power on the phase lines V and W, the normally closed contact of the first electromagnetic relay 13 is closed, and the high-frequency power is sent to the phase lines V and W to power the signal acquisition device 4 in the pump. When there is industrial frequency AC power on the phase lines V and W, the normally closed contact of the first electromagnetic relay 13 is disconnected, and the high-frequency power is disconnected from the phase lines V and W. In order to avoid conflicts with the power line carrier communication of the first carrier communication module 11, one of the three-phase power cables connected to the output of the high-frequency power transmission module 12 is different from the first carrier communication module 11.

[0028] The signal acquisition device 4 in the pump can be installed in the submersible pump junction box. One end is connected to the sensor 3 to collect the pump protection signal detected by the sensor 3; the other end is connected to the three-phase power cable 2 to obtain power. At the same time, the collected pump protection signal data is converted into a carrier modulation signal, loaded into the three-phase power cable 2, and sent to the ground supporting device 1.

[0029] The signal acquisition device 4 in the pump includes a signal acquisition module 41 , a second carrier communication module 42 , an industrial frequency power acquisition module 46 , a second electromagnetic relay 44 , a high frequency power acquisition module 45 and a CPU 43 .

[0030] The input end of the signal acquisition module 41 is connected to the sensor 3, and the output end is connected to the CPU 43. The pump protection signal detected by the sensor 3 is conditioned, and the analog signal collected by the sensor can be converted into a digital signal and sent to the CPU 43.

[0031] One end of the second carrier communication module 42 is connected to the three-phase power cable connected to the first carrier communication module 11, and in this embodiment is connected to the phase lines U and V, and the other end is connected to the CPU 43. It is used to convert the communication data sent by the CPU 43 into a carrier modulation signal and send it to the ground supporting device 1 through the phase lines U and V.

[0032] The power frequency power supply module 46, the second electromagnetic relay 44, and the high-frequency power supply module 45 provide the working power supply for the signal acquisition device 4 in the pump. The coil and the normally closed contact of the second electromagnetic relay 44 are connected to the three-phase power cable, which is the same as the first electromagnetic relay 13 and is connected to the phase lines V and W in this embodiment. One end of the normally closed contact of the second electromagnetic relay 44 is connected to the phase line W, and the other end of the normally closed contact is connected to the input of the high-frequency power supply module 45.

[0033] When there is industrial frequency AC power in the phase lines V and W, the normally closed contact of the second electromagnetic relay 44 is disconnected, cutting off the input of the high-frequency power supply module 45. When there is no industrial frequency AC power in the phase lines V and W, the normally closed contact is closed, connecting the phase line W to the input of the high-frequency power supply module 45. The high-frequency power supply module 45 converts the high-frequency power in the phase lines V and W into a DC output 1 isolated from the power cable. The input end of the industrial frequency power supply module 46 is connected to the phase lines V and W, and when the submersible pump is running, it converts the industrial frequency AC voltage that powers the pump into a DC output 2 isolated from the power cable. The DC output 1 and the DC output 2 jointly provide a DC power supply to the signal acquisition device 4 in the pump.

[0034] It should be understood that the coil impedance of the submersible pump motor will prevent the high-frequency signal from passing through, so the high-frequency power supply signal and the carrier modulation signal will not affect the action of the motor. At the same time, when the first carrier communication module 11, the second carrier communication module 42, the high-frequency power transmission module 12, and the high-frequency power extraction module 45 are connected to the three-phase power cable 2, high-voltage capacitors and transformers are arranged inside to isolate the power frequency power supply for the pump, so as to prevent high-voltage electricity from entering the device, causing damage to the device and generating safety hazards.

[0035] CPU43 has two operating modes, one is low power mode and the other is high performance mode. When the three-phase power cable 2 has industrial frequency AC power, the pump is in startup operation, and the sensor 3 is subject to large interference noise generated by the operation of the pump. At this time, the signal acquisition device in the pump is powered by the power frequency of the power grid, and the power supply capacity is strong. The CPU runs in high performance mode, adopts high-speed sampling mode, and has a built-in high-performance digital filtering processing algorithm to digitally filter the sensor signal converted by the signal acquisition module 41 to filter out interference noise. When the three-phase power cable 2 does not have industrial frequency AC power, the pump is in a shutdown state, and the sensor 3 is less interfered by the pump. At this time, the signal acquisition device 4 in the pump is powered by the high-frequency power transmission module 12, and the power supply capacity is weak. CPU43 runs in low power mode and adopts low-speed sampling mode to save power consumption.

[0036] Accordingly, the present invention also provides a method for digitally transmitting a submersible pump protection signal. Figure 1 , the method comprises the following steps:

[0037] The high-frequency power transmission module 12 generates a high-frequency power signal, and when the first electromagnetic relay contact 13 is closed, the high-frequency power signal is loaded onto the three-phase power cable 2 .

[0038] The three-phase power cable 2 transmits the industrial frequency AC power signal and the high frequency power signal.

[0039] When the submersible pump is stopped, the second electromagnetic relay 44 and the high-frequency power supply module 45 convert the high-frequency power supply signal transmitted by the three-phase power supply cable 2 into a DC output 1 isolated from the power supply cable. When the submersible pump is running, the industrial frequency power supply module 46 converts the industrial frequency AC voltage that supplies power to the pump into a DC output 2 isolated from the three-phase power supply cable 2. The DC output 1 and the DC output 2 jointly provide a DC power supply to the signal acquisition device 4 in the pump.

[0040] CPU43 controls the signal acquisition module 41 to condition the pump protection signal detected by the sensor 3 and convert it into a digital quantity for CPU43. CPU43 operates in different modes according to the power supply. When the three-phase power cable 2 has industrial frequency AC power, CPU43 operates in high-performance mode and performs high-speed digital conversion and digital filtering on the sensor signal. When the three-phase power cable 2 does not have industrial frequency AC power, CPU43 operates in low-power mode and performs low-speed digital conversion on the sensor signal to save power consumption.

[0041] Furthermore, the submersible pump protection signal digital transmission method further comprises the following steps:

[0042] The CPU 43 packages the processed sensor signal digital conversion result into communication data and sends it to the second carrier communication module 42. The second carrier communication module 42 converts the communication data into a carrier modulation signal and loads it to the three-phase power cable 2.

[0043] The three-phase power cable 2 transmits a carrier modulation signal while transmitting a power signal.

[0044] The first carrier communication module 11 demodulates the received carrier modulation signal to obtain communication data. The communication data includes the digital conversion result of the submersible pump protection signal and is provided to the submersible pump protection device for use.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A submersible pump protection signal digital transmission system, characterized in that: The submersible pump protection signal digital transmission system includes: a three-phase power cable, a sensor, a ground supporting device and a signal acquisition device in the pump, wherein the ground supporting device includes a first carrier communication module, a first electromagnetic relay and a high-frequency power transmission module, and the signal acquisition device in the pump includes a signal acquisition module, a second carrier communication module, an industrial frequency power supply module, a second electromagnetic relay, a high-frequency power supply module and a CPU, the first carrier communication module is connected to the first phase line and the second phase line of the three-phase power cable, one output end of the high-frequency power transmission module is connected to the second phase line of the three-phase power cable, and the other output end is connected to the third phase line of the three-phase power cable through the first electromagnetic relay; the input end of the signal acquisition module is electrically connected to the sensor, and the output end is electrically connected to the CPU; one end of the second carrier communication module is connected to the first phase line of the three-phase power cable and the second phase line, and the other end is connected to the CPU; the industrial frequency power supply module is connected to the second phase line and the third phase line of the three-phase power supply cable, one input end of the high-frequency power supply module is connected to the second phase line of the three-phase power supply cable, and the other input end is connected to the third phase line of the three-phase power supply cable through the second electromagnetic relay; the other output end of the high-frequency power transmission module is connected to one end of the normally closed contact of the first electromagnetic relay, the other end of the normally closed contact of the first electromagnetic relay is connected to the third phase line of the three-phase power supply cable, and the coil of the first electromagnetic relay is connected to the second phase line and the third phase line of the three-phase power supply cable; one end of the normally closed contact of the second electromagnetic relay is connected to the third phase line of the three-phase power supply cable, and the other end of the normally closed contact is connected to the other input end of the high-frequency power supply module, and the coil of the second electromagnetic relay is connected to the second phase line and the third phase line of the three-phase power supply cable.

2. The submersible pump protection signal digital transmission system according to claim 1 is characterized in that: The sensors include overheat signal sensors installed in the windings and bearings of the submersible pump, water leakage signal sensors installed in the motor cavity, oil chamber and junction box of the submersible pump, and humidity sensors installed inside the motor of the submersible pump.

3. The submersible pump protection signal digital transmission system according to claim 1 is characterized in that: The signal acquisition module is used to convert analog signals into digital signals.

4. The submersible pump protection signal digital transmission system according to claim 1 is characterized in that: The CPU includes a low power mode and a high performance mode.

5. The submersible pump protection signal digital transmission system according to claim 1 is characterized in that: The industrial frequency power supply module converts the industrial frequency AC voltage into a second DC output.

6. The submersible pump protection signal digital transmission system according to claim 1 is characterized in that: The high-frequency power supply module converts the high-frequency AC voltage into a first DC output.

7. A signal digital transmission method for a submersible pump protection signal digital transmission system as claimed in any one of claims 1 to 6, characterized in that: The signal digital transmission method comprises: When the three-phase power cable transmits the industrial frequency AC power signal, the normally closed contacts of the first electromagnetic relay and the second electromagnetic relay are disconnected, the CPU is in high-performance mode, and the sensor signal converted by the signal acquisition module is digitally filtered. At the same time, the second carrier communication module is controlled to send a carrier modulation signal with a relatively high power. When the three-phase power cable stops transmitting the industrial frequency AC power signal, the high-frequency power transmission module generates a high-frequency power signal, the normally closed contacts of the first electromagnetic relay close, and the high-frequency power signal is loaded into the three-phase power cable. The normally closed contacts of the second electromagnetic relay close, and the high-frequency power extraction module converts the high-frequency AC voltage into the first DC output. The CPU is in low power consumption mode, the sensor adopts low-speed sampling mode, and at the same time, the second carrier communication module is controlled to send a carrier modulation signal with a lower power.

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