CN219067925U - Scalable low-voltage area monitoring device - Google Patents

Abstract

The utility model discloses an expandable low-voltage transformer area monitoring device which comprises a main control module, a display input module, a plurality of expansion current sampling modules and an expansion temperature module, wherein the expansion current sampling modules comprise three-phase current sampling circuits, and the main control module is respectively connected with the display input module, the expansion current sampling modules and the expansion temperature module through communication connecting wires; the main control module is connected with the background data center through the wireless radio frequency module, acquires three-phase voltage and three-phase current of the low-voltage side of the power distribution network of the low-voltage transformer area, and expands the sampling branch current of the current sampling module to realize multi-branch monitoring of the low-voltage transformer area; the secondary wires are simple in wiring, the number of cables is reduced, and the cost is reduced; and the monitoring and analysis of a plurality of electric quality data of the low-voltage transformer area are realized.

Description

An expandable low-voltage platform area monitoring device

technical field

The utility model relates to the technical field of smart grids, in particular to an expandable low-voltage platform area monitoring device.

Background technique

In the power system, the low-voltage distribution station area refers to the user area where a distribution transformer supplies power. The load of the low-voltage distribution station area can reflect the power consumption characteristics of regional users and reflect the power load density in geographical space distribution. At present, my country's intelligent research on distribution low-voltage station areas started late and developed relatively slowly. Some technology companies have conducted intelligent research on power distribution low-voltage station areas, but they have adopted the mode of power carrier communication or single equipment and single system. So far, there has not been a system that simultaneously monitors all electrical equipment in the distribution low-voltage station area and analyzes all power quality data in the station area. There are residual current operated circuit breakers, electric energy meters and reactive power compensation control devices with RS485 communication interface on the market. Using the above-mentioned low-voltage equipment, the data of the low-voltage power grid can be aggregated to a special communication terminal, and then the special communication terminal can pass through The information of the distribution low-voltage station area is uploaded to the main station system by wireless communication or wired communication. The wireless communication is mainly GPRS communication, and the wired communication is mainly carrier communication, so that the equipment operation of the distribution low-voltage station area can be remotely monitored.

The existing low-voltage station area monitoring devices mainly have the following disadvantages: 1) Only integrated monitoring devices such as display, key input, three-phase voltage sampling, three-phase current sampling, RS485 communication, and power supply can be installed on the panel of the low-voltage power distribution cabinet As a result, many wires (power supply, communication, three-phase voltage, three-phase current) must be connected to the panel from the inside of the power distribution cabinet, and there are many different cables at the terminal of the panel of the power distribution cabinet, resulting in complicated secondary line wiring , it needs to spend a lot of cables, increase the workload, and the secondary line is easy to be missed or wrongly connected; Current, branch three-phase voltage and branch three-phase current, when the number of collected branches is N, the number of branch voltage collection channels is 3N, and the number of branch current collection channels is 3N, while the traditional low-voltage station area The monitoring device generally only has one three-phase voltage acquisition channel and one three-phase current acquisition channel, which cannot meet the multi-branch monitoring of low-voltage station areas.

Contents of the invention

In view of the above deficiencies, the utility model provides an expandable low-voltage platform area monitoring device, including a main control module, a display input module, several extended current sampling modules and extended temperature modules, and the main control module communicates with the The display input module, the extended current sampling module and the extended temperature module are connected; the main control module is connected to the background data center through the radio frequency module, and the main control module collects the three-phase voltage and three-phase current of the low-voltage side of the distribution network in the low-voltage station area , The extended current sampling module samples the branch current to realize multi-branch monitoring in the low-voltage station area; the secondary line wiring is simple, which reduces the number of cables and reduces the cost; realizes the monitoring and analysis of multiple electrical quality data in the low-voltage station area.

In order to achieve the above object, the utility model adopts the following technical solutions:

An expandable low-voltage platform area monitoring device, comprising a main control module, a display input module, several extended current sampling modules and extended temperature modules, the main control module is respectively connected to the display input module, the extended current sampling module through a communication connection line The module is connected to the extended temperature module; the main control module is connected to the background data center through the radio frequency module; the extended current sampling module includes a three-phase current sampling circuit. Between the display input module and the main control module, between the main control module and multiple extended current sampling modules, and between multiple extended temperature modules are connected by RS485 communication connection lines. This device mainly collects, processes and monitors distribution automation information such as the first-stage busbar and second-stage busbar on the secondary side of the distribution transformer, and the low-voltage branch circuit on the secondary side, including fault detection, positioning, isolation, and power supply transfer; it has real-time monitoring Functions such as power quality, monitoring and management of leakage protectors in low-voltage stations, calculation and analysis of line loss in low-voltage stations, centralized meter reading, prompting and alarming when abnormal operations occur in low-voltage stations, and information interaction in low-voltage stations; real-time collection of distribution transformers , low-voltage distribution network, various operating data of large customers and low-voltage residential electricity, so as to realize harmonic control, energy saving and loss reduction, and reactive power compensation of distribution lines, so that the work efficiency of power supply enterprises can be significantly improved, and the power grid can be realized. Accurate basis for intelligence.

Preferably, the main control module includes a first MCU, a first temperature sampling circuit, a voltage sampling circuit, a current sampling circuit, a first signal conditioning circuit, a relay output circuit, a first output isolation circuit, a first expansion interface, and an RS485 interface , a first communication isolation circuit and a power supply, the voltage sampling circuit and the current sampling circuit are connected to the first signal conditioning circuit and then connected to the first MCU; the first expansion interface and the RS485 interface are connected to the first communication isolation The circuit is then connected to the first MCU; the relay output circuit is connected to the first output isolation circuit and then connected to the first MCU; the first temperature sampling circuit is connected to the first MCU. The first MCU uses the DFT algorithm to quickly calculate the power factor, active power, reactive power, frequency and other electrical parameters of the three-phase power grid. The main control module is the core of the device, and its main functions include real-time sampling of the three-phase voltage, three-phase current, leakage current, cable joint temperature and line fault monitoring of the low-voltage station area.

Preferably, the display input module includes an LCD display screen, touch keys of the input module and a communication power supply interface. The display input module provides human-computer interaction functions, displays output information, and inputs information through touch keys of the input module. The display input module is connected to the main control module through the communication power supply interface and the RS485 communication connection line. The utility model only needs to install the display input module on the panel of the power distribution cabinet, avoiding a large number of secondary cables such as multi-channel three-phase voltage and three-phase current sampling lines from being connected to the panel of the power distribution cabinet, reducing the construction amount of cables and reducing the cable costs.

Preferably, the extended current sampling module further includes a second MCU, a second expansion interface, a second communication isolation circuit, a first power conversion circuit, and a second signal conditioning circuit, and the second expansion interface is connected to the second communication After the isolation circuit is connected to the second MCU; the first power conversion circuit is respectively connected to the second expansion interface and the second MCU; after the three-phase current sampling circuit is connected to the second signal conditioning circuit, it is connected to the Second MCU. The main control module of this device is connected with the extended current sampling module through the RS485 line. The main control module collects the three-phase voltage and three-phase current on the low-voltage side of the distribution network in the low-voltage station area, and the extended current sampling module samples the branch current to realize the low-voltage station area. Multi-branch monitoring overcomes the traditional monitoring device that can only monitor the three-phase voltage and three-phase current of one channel. The device includes several extended current sampling modules. In actual use, the number of extended current sampling modules to be connected is determined according to the number of collected branches to realize "expandability".

Preferably, the extended temperature module includes a third MCU, a third extended interface, a third communication isolation circuit, a second power conversion circuit, a second temperature sampling circuit, a fan relay, an alarm circuit and a second output isolation circuit, the The third expansion interface is connected to the third communication isolation circuit and then connected to the third MCU; the second power conversion circuit is respectively connected to the third expansion interface and the third MCU; the second temperature sampling circuit is connected to the third MCU. The third MCU; the fan relay and the alarm circuit are connected to the second output isolation circuit and then connected to the third MCU.

Preferably, the first signal conditioning circuit is configured to perform A/D conversion on the analog signals sampled by the voltage sampling circuit and the current sampling circuit to obtain digital signals.

Preferably, the second signal conditioning circuit is used to control the three-phase current sampling circuit to simultaneously sample three-phase voltage signals and three-phase current signals, and perform A/D conversion on the sampled analog signals to obtain digital signals.

Preferably, the background data center includes a server, the server is used to process the data uploaded by the main control module, and according to the pre-set early warning algorithm, when the data is abnormal, the source of the abnormality is judged and the source of the abnormality is fed back to the dispatcher in time center. The device is equipped with an NB-IoT wireless radio frequency module, which can be remotely and wirelessly connected to the background data center. The background data center monitors the fault according to the data uploaded by the main control module and promptly informs the dispatching center of the fault information through telephone, SMS, and WeChat alarm information.

Preferably, the first MCU is connected with a clock unit, and the clock unit is used to provide a real-time clock.

Therefore, the utility model has the advantages of:

(1) The main control module collects the three-phase voltage and three-phase current on the low-voltage side of the distribution network in the low-voltage station area, and the extended current sampling module samples the branch current to realize multi-branch monitoring in the low-voltage station area, overcoming the fact that traditional monitoring devices can only monitor Three-phase voltage and three-phase current of one channel;

(2) It is only necessary to install the display input module on the panel of the power distribution cabinet, avoiding a large number of secondary cables such as multi-channel three-phase voltage and three-phase current sampling lines from being connected to the panel of the power distribution cabinet, reducing the amount of cable construction and reducing the reduce the cable cost;

(3) This device mainly collects, processes and monitors distribution automation information such as the first-stage busbar and second-stage busbar on the secondary side of the distribution transformer, and the low-voltage branch circuit on the secondary side, including fault detection, positioning, isolation, and power supply transfer;

(4) It has the functions of real-time monitoring of the power quality of the low-voltage station area, monitoring and management of leakage protectors, calculation and analysis of line loss in the low-voltage station area, centralized meter reading, prompting and alarming when the low-voltage station area operates abnormally, and information interaction in the low-voltage station area. .

Description of drawings

Fig. 1 is a schematic structural diagram of an expandable low-voltage platform area monitoring device in Embodiment 1 of the present utility model.

Fig. 2 is a schematic structural diagram of the main control module in Embodiment 1 of the present utility model.

Fig. 3 is a schematic structural diagram of a display input module in Embodiment 1 of the present utility model.

Fig. 4 is a schematic structural diagram of an extended current sampling module in Embodiment 1 of the present invention.

Fig. 5 is a schematic structural diagram of an extended temperature module in Embodiment 1 of the present invention.

1. Main control module 2, display input module 3, extended current sampling module 4, extended temperature module 5, first MCU 6, first temperature sampling circuit 7, voltage sampling circuit 8, current sampling circuit 9, first signal conditioning circuit 10. Relay output circuit 11, first output isolation circuit 12, first expansion interface 13, RS485 interface 14, first communication isolation circuit 15, power supply 16, LCD display screen 17, input module touch key 18, communication power supply interface 19, The second MCU 20, the second expansion interface 21, the second communication isolation circuit 22, the first power conversion circuit 23, the second signal conditioning circuit 24, the third MCU 25, the third expansion interface 26, the third communication isolation circuit 27, The second power conversion circuit 28, the second temperature sampling circuit 29, the fan relay 30, the alarm circuit 31, the second output isolation circuit 32, and the three-phase current sampling circuit.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

Embodiment one:

An expandable low-voltage platform area monitoring device, as shown in Figure 1, includes a main control module 1, a display input module 2, several extended current sampling modules 3 and extended temperature modules 4, and the main control module 1 communicates with the The display input module 2, the extended current sampling module 3 and the extended temperature module 4 are connected; the main control module 1 is connected to the background data center through a radio frequency module; the extended current sampling module 3 includes a three-phase current sampling circuit 32 . This embodiment provides an expandable low-voltage platform area monitoring device, including a main control module 1, and a display input module 2 connected to the main control module 1 by wire, several extended current sampling modules 3 and extended temperature modules 4, the main control module Module 1 is wirelessly connected to the background data center through the wireless radio frequency module, between the display input module 2 and the main control module 1, between the main control module 1 and multiple extended current sampling modules 3, and between multiple extended temperature modules 4 by RS485 Communication cable connection. This device mainly collects, processes and monitors distribution automation information such as the first-stage busbar and second-stage busbar on the secondary side of the distribution transformer, and the low-voltage branch circuit on the secondary side, including fault detection, positioning, isolation, and power supply transfer; it has real-time monitoring Functions such as power quality, monitoring and management of leakage protectors in low-voltage stations, calculation and analysis of line loss in low-voltage stations, centralized meter reading, prompting and alarming when abnormal operation occurs in low-voltage stations, and information interaction in low-voltage stations; real-time collection of distribution transformers , Low-voltage distribution network, various operating data of large customers and low-voltage residential electricity, so as to realize harmonic control of distribution lines, energy saving and loss reduction, reactive power compensation, and provide an accurate basis for realizing the intelligentization of the power grid.

As shown in Figure 2, the main control module 1 includes a first MCU5, a first temperature sampling circuit 6, a voltage sampling circuit 7, a current sampling circuit 8, a first signal conditioning circuit 9, a relay output circuit 10, and a first output isolation circuit 11 , the first expansion interface 12, the RS485 interface 13, the first communication isolation circuit 14 and the power supply 15, the voltage sampling circuit 7 and the current sampling circuit 8 are connected to the first signal conditioning circuit 9 and then connected to the first MCU5; the first expansion interface 12 and RS485 The interface 13 is connected to the first communication isolation circuit 14 and then connected to the first MCU5; the relay output circuit 10 is connected to the first output isolation circuit 11 and then connected to the first MCU5; the first temperature sampling circuit 6 is connected to the first MCU5. The first MCU5 uses the DFT algorithm to quickly calculate the power factor, active power, reactive power, frequency and other electrical parameters of the three-phase grid. The main control module 1 is the core of the device, and its main functions include real-time sampling of the three-phase voltage, three-phase current, leakage current, cable joint temperature and line fault monitoring of the low-voltage station area.

As shown in FIG. 3 , the display input module 2 includes an LCD display screen 16 , input module touch keys 17 and a communication power supply interface 18 . The display input module 2 provides human-computer interaction function, displays output information, and inputs information through the touch keys 17 of the input module. In this embodiment, it is only necessary to install the display input module 2 on the panel of the power distribution cabinet to avoid a large number of secondary cables such as multi-channel three-phase voltage and three-phase current sampling lines from being connected to the panel of the power distribution cabinet.

As shown in Figure 4, the extended current sampling module 3 also includes a second MCU19, a second extension interface 20, a second communication isolation circuit 21, a first power conversion circuit 22 and a second signal conditioning circuit 23, and the second extension interface 20 is connected to The second communication isolation circuit 21 is connected to the second MCU19; the first power conversion circuit 22 is respectively connected to the second expansion interface 20 and the second MCU19; the three-phase current sampling circuit 32 is connected to the second signal conditioning circuit 23 and then connected to the second MCU19. The main control module 1 of the device collects the three-phase voltage and three-phase current on the low-voltage side of the distribution network in the low-voltage station area, and the extended current sampling module 3 samples the branch current to realize multi-branch monitoring in the low-voltage station area. The device includes several extended current sampling modules 3. In actual use, the number of extended current sampling modules 3 to be connected is determined according to the number of collected branches, so as to realize "expandability".

As shown in Figure 5, the extended temperature module 4 includes a third MCU24, a third extended interface 25, a third communication isolation circuit 26, a second power conversion circuit 27, a second temperature sampling circuit 28, a fan relay 29, an alarm circuit 30 and The second output isolation circuit 31, the third expansion interface 25 is connected to the third MCU24 after connecting the third communication isolation circuit 26; the second power conversion circuit 27 is respectively connected to the third expansion interface 25 and the third MCU24; the second temperature sampling circuit 28 The third MCU24 is connected; the fan relay 29 and the alarm circuit 30 are connected to the second output isolation circuit 31 and then connected to the third MCU24.

The first signal conditioning circuit 9 is used to perform A/D conversion on the analog signals sampled by the voltage sampling circuit 7 and the current sampling circuit 8 to obtain digital signals.

The second signal conditioning circuit 23 is used to control the three-phase current sampling circuit 32 to synchronously sample the three-phase voltage signal and the three-phase current signal, and perform A/D conversion on the sampled analog signal to obtain a digital signal.

The background data center includes a server. The server is used to process the data uploaded by the main control module 1, and according to the pre-set early warning algorithm, judge the source of the abnormality when the data is abnormal and feed back the source of the abnormality to the dispatching center in time. The device is equipped with an NB-IoT wireless radio frequency module, which can be remotely and wirelessly connected to the background data center. The background data center monitors the fault according to the data uploaded by the main control module 1 and promptly informs the dispatching center of the fault information through telephone, SMS, and WeChat alarm information.

The first MCU5 is connected with a clock unit, and the clock unit is used to provide a real-time clock.

Embodiment two:

An expandable low-voltage platform area monitoring device. The main board part adopts a high-performance 32-bit floating-point DSP chip TMS320F28335 as the main board CPU, which is composed of the following parts: CPU power supply circuit, current signal acquisition and processing circuit, voltage signal acquisition and processing circuit, open Input state input circuit, trip output circuit, reactive power compensation control output circuit, communication interface circuit. The communication interface circuit includes an interface for communication between the main board and the man-machine interface, and an interface for communication between the device and the background system. The main control module collects electrical parameters such as current and voltage of the line in real time online, and stores them in corresponding arrays for use by the main processor of the measurement and control device to calculate the protection control algorithm. The device samples 1024 points per cycle. In order to realize the protection fast action requirements, the required calculation and protection methods are all completed in the interrupt program of the timer. The measurement and control device uses the 1024-point Fourier algorithm to sample the AC current and voltage to obtain the measurement analog and related data; the main processor of the measurement and control device host is the source of all measurement and communication data, and needs to respond to the host computer human-machine interface processor internally request (the station area measurement and control device designed in this embodiment uses CAN communication to receive interrupts, and sends measurement parameters, protection status, protection settings, other parameters, event records, etc. to it through the CAN bus); externally through the RS485 bus (or carrier communication ), upload voltage, current, reactive power, active power measurement parameters, protection action alarms and other information to it, and receive operation commands from the power distribution master station, and use 101 protocol for external communication.

Embodiment three:

The first MCU of the main control module is also connected with a data processing and analysis unit, and the data processing and analysis unit includes a low-pass filter, a signal amplifier, a photoelectric isolator and a driving buffer circuit, and the input end of the low-pass filter is connected with the first MCU, and the low-pass filter is connected to the first MCU. The output end of the pass filter is connected to the input end of the signal amplifier, the output end of the signal amplifier is connected to the input end of the photoelectric isolator, the output end of the photoelectric isolator is connected to the input end of the driving buffer circuit, and the output end of the driving buffer circuit is connected to the server. The first MCU of the main control module is connected with a data processing and analysis unit, which is used to process and analyze the sampled data, and upload it to the server to realize online monitoring and comprehensive analysis of multiple power quality data in the low-voltage station area.

The above content is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application, and should covered within the scope of protection of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (9)

1. The expandable low-voltage area monitoring device is characterized by comprising a main control module, a display input module, a plurality of expansion current sampling modules and an expansion temperature module, wherein the main control module is respectively connected with the display input module, the expansion current sampling modules and the expansion temperature module through communication connecting wires; the main control module is connected with a background data center through a wireless radio frequency module; the extended current sampling module comprises a three-phase current sampling circuit.

2. The expandable low-voltage area monitoring device according to claim 1, wherein the main control module comprises a first MCU, a first temperature sampling circuit, a voltage sampling circuit, a current sampling circuit, a first signal conditioning circuit, a relay output circuit, a first output isolation circuit, a first expansion interface, an RS485 interface, a first communication isolation circuit and a power supply, and the voltage sampling circuit and the current sampling circuit are connected with the first signal conditioning circuit and then are connected with the first MCU; the first expansion interface and the RS485 interface are connected with the first communication isolation circuit and then connected with the first MCU; the relay output circuit is connected with the first output isolation circuit and then connected with the first MCU; the first temperature sampling circuit is connected with the first MCU.

3. The expandable low-voltage station area monitoring device according to claim 1, wherein the display input module comprises an LCD display screen, an input module touch key and a communication power supply interface.

4. The expandable low-voltage station area monitoring device according to claim 1, wherein the expansion current sampling module further comprises a second MCU, a second expansion interface, a second communication isolation circuit, a first power conversion circuit and a second signal conditioning circuit, and the second expansion interface is connected with the second communication isolation circuit and then is connected with the second MCU; the first power conversion circuit is connected with the second expansion interface and the second MCU respectively; the three-phase current sampling circuit is connected with the second signal conditioning circuit and then connected with the second MCU.

5. The expandable low-voltage station area monitoring device according to claim 1, wherein the expansion temperature module comprises a third MCU, a third expansion interface, a third communication isolation circuit, a second power conversion circuit, a second temperature sampling circuit, a fan relay, an alarm circuit and a second output isolation circuit, and the third expansion interface is connected with the third communication isolation circuit and then is connected with the third MCU; the second power conversion circuit is respectively connected with the third expansion interface and the third MCU; the second temperature sampling circuit is connected with the third MCU; the fan relay and the alarm circuit are connected with the second output isolation circuit and then connected with the third MCU.

6. The expandable low-voltage transformer area monitoring device according to claim 2, wherein the first signal conditioning circuit is configured to perform a/D conversion on the analog signals sampled by the voltage sampling circuit and the current sampling circuit to obtain digital signals.

7. The scalable low-voltage distribution monitoring apparatus of claim 4, wherein the second signal conditioning circuit is configured to control the three-phase current sampling circuit to sample the three-phase voltage signal and the three-phase current signal synchronously, and to perform a/D conversion on the sampled analog signal to obtain the digital signal.

8. The scalable low-voltage station monitoring device of claim 1, wherein the background data center comprises a server for processing data uploaded by the main control module.

9. An expandable low voltage station monitoring device according to claim 2 or 6, wherein the first MCU is connected to a clock unit for providing a real time clock.

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