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

Scalable low-voltage area monitoring device

Technical Field

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

Background

In the power system, the low-voltage distribution transformer area refers to a user area for power supply by a distribution transformer, and the load of the low-voltage distribution transformer area can intensively reflect the power utilization characteristics of users in the area and reflect the power load density on the geospatial distribution. At present, the intelligent research of the distribution low-voltage area in China starts later and develops relatively slowly. Some scientific and technological companies conduct intelligent research on distribution low-voltage areas, but adopt a mode of power carrier communication or single equipment and single system. To date, there has not been a system for simultaneously monitoring all electrical equipment in a distribution low voltage area and analyzing all electrical quality data in the area. The residual current operated circuit breaker, the electric energy meter, the reactive compensation control device and the like with the RS485 communication interface are existing in the market, the low-voltage equipment is adopted, data of a low-voltage power grid can be gathered to a special communication terminal, and then information of a distribution low-voltage station area is uploaded to a master station system through the special communication terminal in a wireless communication or wired communication mode, wherein the wireless communication is mainly GPRS communication, the wired communication is mainly carrier communication, so that the operation of the equipment of the distribution low-voltage station area can be monitored remotely.

The existing low-voltage station monitoring device mainly has the following defects: 1) Only the integrated monitoring devices such as display, key input, three-phase voltage sampling, three-phase current sampling, RS485 communication, power supply and the like can be installed on the panel of the low-voltage power distribution cabinet, so that a plurality of wires (power supply, communication, three-phase voltage and three-phase current) are required to be connected onto the panel from the inside of the power distribution cabinet, and a plurality of different cables are arranged at the wiring terminals of the panel of the power distribution cabinet, so that the secondary wires are complicated in wiring, a large number of cables are required, the workload is increased, and the secondary wires are easy to be missed or misplaced; 2) The number of secondary branch circuits of the low-voltage transformer area is relatively large, the low-voltage transformer area monitoring device needs to collect bus three-phase voltage, bus three-phase current, branch three-phase voltage and branch three-phase current, when the number of branches collected is N, the number of voltage collection channels of the branches is 3N, the number of current collection channels of the branches is 3N, and the traditional low-voltage transformer area monitoring device generally only has 1 three-phase voltage collection channel and 1 three-phase current collection channel, so that the low-voltage transformer area multi-branch monitoring cannot be met.

Disclosure of Invention

The utility model provides an expandable low-voltage 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 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.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

the expandable low-voltage area monitoring device comprises 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. The display input module is connected with the main control module, the main control module is connected with the plurality of expansion current sampling modules and the plurality of expansion temperature modules through RS485 communication connecting wires. The device is mainly used for collecting, processing and monitoring distribution automation information such as a primary bus, a secondary bus and a secondary low-voltage branch of a distribution transformer in real time, and comprises fault detection, positioning, isolation and power supply switching; the system has the functions of monitoring the electric energy quality of the low-voltage transformer area in real time, monitoring and managing the leakage protector, calculating and analyzing the line loss of the low-voltage transformer area, intensively reading meter, prompting and alarming when the low-voltage transformer area operates abnormally, interacting information of the low-voltage transformer area and the like; various operation data of the distribution transformer, the low-voltage distribution network, the large customer and the low-voltage domestic electricity are collected in real time, so that harmonic treatment, energy conservation, loss reduction and reactive compensation of a distribution line are realized, the working efficiency of a power supply enterprise is obviously improved, and an accurate basis for realizing the intelligent power grid is provided.

Preferably, 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, wherein the voltage sampling circuit and the current sampling circuit are connected with the first signal conditioning circuit and then 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. The first MCU adopts a DFT algorithm to rapidly calculate three-phase power factors, active power, reactive power, frequency and other electrical parameters of the power grid. The main control module is the core of the device, and the main functions of the main control module comprise real-time sampling of three-phase voltage, three-phase current, leakage current, cable joint temperature and line fault monitoring of a low-voltage transformer area.

Preferably, the display input module comprises an LCD display screen, an input module touch key and a communication power supply interface. The display input module provides a man-machine interaction function, displays output information and inputs information by touching keys through the input module. The display input module is connected with the main control module through the communication power supply interface and the RS485 communication connecting line. According to the utility model, only the display input module is required to be arranged on the panel of the power distribution cabinet, so that a large number of secondary cables such as multi-channel three-phase voltage and three-phase current sampling wires are prevented from being connected to the panel of the power distribution cabinet, the construction amount of the arranged cables is reduced, and the cable cost is reduced.

Preferably, the extended current sampling module further comprises a second MCU, a second extended interface, a second communication isolation circuit, a first power conversion circuit and a second signal conditioning circuit, wherein the second extended 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. The main control module of the device is connected with the extension current sampling module through the RS485 line, the main control module collects three-phase voltage and three-phase current of the low-voltage side of the distribution network of the low-voltage transformer area, the extension current sampling module samples branch current, multi-branch monitoring of the low-voltage transformer area is achieved, and the defect that the traditional monitoring device can only monitor three-phase voltage and three-phase current of 1 channel is overcome. The device comprises a plurality of expansion current sampling modules, and when in actual use, the number of the expansion current sampling modules which are connected is determined according to the number of the acquired branches, so that the expansion is realized.

Preferably, the extended temperature module comprises a third MCU, a third extended interface, a third communication isolation circuit, a second power supply conversion circuit, a second temperature sampling circuit, a fan relay, an alarm circuit and a second output isolation circuit, wherein the third extended 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.

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 configured to control the three-phase current sampling circuit 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.

Preferably, the background data center comprises a server, wherein the server is used for processing the data uploaded by the main control module, judging an abnormal source when the data is abnormal according to a preset early warning algorithm, and feeding the abnormal source back to the dispatching center in time. The device is provided with an NB-IoT wireless radio frequency module, can be remotely and wirelessly connected to a background data center, and the background data center monitors faults according to data uploaded by the main control module and timely informs the fault information to the dispatching center through telephone, short messages and WeChat alarm information.

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

Therefore, the utility model has the advantages that:

(1) The main control module collects three-phase voltage and three-phase current of the low-voltage side of the distribution network of the low-voltage transformer area, the expanded current sampling module samples branch current, multi-branch monitoring of the low-voltage transformer area is realized, and the defect that the traditional monitoring device can only monitor three-phase voltage and three-phase current of 1 channel is overcome;

(2) Only the display input module is required to be installed on the panel of the power distribution cabinet, so that a large number of secondary cables such as multi-channel three-phase voltage and three-phase current sampling wires are prevented from being connected to the panel of the power distribution cabinet, the construction amount of the arranged cables is reduced, and the cable cost is reduced;

(3) The device is mainly used for collecting, processing and monitoring distribution automation information such as a primary bus, a secondary bus and a secondary low-voltage branch of a distribution transformer in real time, and comprises fault detection, positioning, isolation and power supply switching;

(4) The system has the functions of monitoring the electric energy quality of the low-voltage transformer area in real time, monitoring and managing the leakage protector, calculating and analyzing the line loss of the low-voltage transformer area, centralized meter reading, prompting and alarming when the low-voltage transformer area operates abnormally, information interaction of the low-voltage transformer area and the like.

Drawings

Fig. 1 is a schematic structural diagram of an expandable low-voltage area monitoring device according to a first embodiment of the present utility model.

Fig. 2 is a schematic structural diagram of a main control module according to a first embodiment of the present utility model.

Fig. 3 is a schematic structural diagram of an input module according to a first embodiment of the utility model.

Fig. 4 is a schematic structural diagram of an extended current sampling module according to a first embodiment of the present utility model.

Fig. 5 is a schematic structural diagram of an extended temperature module according to a first embodiment of the present utility model.

1. The main control module 2, the display input module 3, the extended current sampling module 4, the extended temperature module 5, the first MCU 6, the first temperature sampling circuit 7, the voltage sampling circuit 8, the current sampling circuit 9, the first signal conditioning circuit 10, the relay output circuit 11, the first output isolation circuit 12, the first extended interface 13, the RS485 interface 14, the first communication isolation circuit 15, the power supply 16, the LCD display 17, the input module touch key 18, the communication power supply interface 19, the second MCU 20, the second extended interface 21, the second communication isolation circuit 22, the first power supply conversion circuit 23, the second signal conditioning circuit 24, the third MCU 25, the third extended interface 26, the third communication isolation circuit 27, the second power supply 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 Description

The utility model is further described below with reference to the drawings and detailed description.

Embodiment one:

an expandable low-voltage area monitoring device is shown in fig. 1, and comprises a main control module 1, a display input module 2, a plurality of expansion current sampling modules 3 and an expansion temperature module 4, wherein the main control module 1 is respectively connected with the display input module 2, the expansion current sampling modules 3 and the expansion temperature module 4 through communication connecting wires; the main control module 1 is connected with a background data center through a wireless radio frequency module; the extension current sampling module 3 includes a three-phase current sampling circuit 32. The embodiment provides an expandable low-voltage platform area monitoring device, which comprises a main control module 1, a display input module 2, a plurality of expansion current sampling modules 3 and an expansion temperature module 4, wherein the display input module 2, the expansion current sampling modules 3 and the expansion temperature module 4 are in wired connection with the main control module 1, the main control module 1 is in wireless connection with a background data center through a wireless radio frequency module, the display input module 2 and the main control module 1 are connected with each other, the main control module 1 and the expansion current sampling modules 3 are connected with each other, and the expansion temperature modules 4 are connected with each other through RS485 communication connection wires. The device is mainly used for collecting, processing and monitoring distribution automation information such as a primary bus, a secondary bus and a secondary low-voltage branch of a distribution transformer in real time, and comprises fault detection, positioning, isolation and power supply switching; the system has the functions of monitoring the electric energy quality of the low-voltage transformer area in real time, monitoring and managing the leakage protector, calculating and analyzing the line loss of the low-voltage transformer area, intensively reading meter, prompting and alarming when the low-voltage transformer area operates abnormally, interacting information of the low-voltage transformer area and the like; various operation data of the distribution transformer, the low-voltage distribution network, the large customer and the low-voltage domestic electricity are collected in real time, so that harmonic wave management, energy conservation, loss reduction and reactive compensation of a distribution line are realized, and an accurate basis for realizing the intelligent of a power grid is provided.

As shown in fig. 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, a first output isolation circuit 11, a first expansion interface 12, an RS485 interface 13, a first communication isolation circuit 14 and a power supply 15, where 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 the RS485 interface 13 are connected with the first communication isolation circuit 14 and then connected with the first MCU5; the relay output circuit 10 is connected with the first output isolation circuit 11 and then connected with the first MCU5; the first temperature sampling circuit 6 is connected to the first MCU5. The first MCU5 adopts a DFT algorithm to rapidly calculate three-phase power factors, active power, reactive power, frequency and other electric parameters of the power grid. The main control module 1 is the core of the device, and the main functions of the main control module include real-time sampling of three-phase voltage, three-phase current, leakage current, cable joint temperature and line fault monitoring of a low-voltage transformer area.

As shown in fig. 3, the display input module 2 includes an LCD display 16, input module touch keys 17, and a communication power interface 18. The display input module 2 provides a man-machine interaction function, displays output information, and inputs information by touching the keys 17 through the input module. In the embodiment, the display input module 2 is only required to be installed on the panel of the power distribution cabinet, so that a large number of secondary cables such as multichannel three-phase voltage and three-phase current sampling lines are prevented from being connected to the panel of the power distribution cabinet.

As shown in fig. 4, the extended current sampling module 3 further includes a second MCU19, a second extended interface 20, a second communication isolation circuit 21, a first power conversion circuit 22, and a second signal conditioning circuit 23, where the second extended interface 20 is connected to the second communication isolation circuit 21 and then connected to the second MCU19; the first power conversion circuit 22 is connected with the second expansion interface 20 and the second MCU19 respectively; the three-phase current sampling circuit 32 is connected to the second signal conditioning circuit 23 and then to the second MCU19. The main control module 1 of the device collects three-phase voltage and three-phase current of the low-voltage distribution network of the low-voltage transformer area, and the extension current sampling module 3 samples branch current to realize multi-branch monitoring of the low-voltage transformer area. The device comprises a plurality of expansion current sampling modules 3, and when in actual use, the number of the expansion current sampling modules 3 which are connected is determined according to the number of the acquired branches, so that 'expandable' is realized.

As shown in fig. 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 a second output isolation circuit 31, where the third extended interface 25 is connected to the third communication isolation circuit 26 and then to the third MCU24; the second power conversion circuit 27 is connected with the third expansion interface 25 and the third MCU24 respectively; the second temperature sampling circuit 28 is connected with the third MCU24; the fan relay 29 and the alarm circuit 30 are connected to the second output isolation circuit 31 and then to the third MCU24.

The first signal conditioning circuit 9 is configured 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 configured 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 comprises a server, wherein the server is used for processing data uploaded by the main control module 1, judging an abnormal source when the data is abnormal according to a preset early warning algorithm and feeding the abnormal source back to the dispatching center in time. The device is provided with an NB-IoT wireless radio frequency module, can be remotely and wirelessly connected to a background data center, and the background data center monitors faults according to data uploaded by the main control module 1 and timely informs the fault information to the dispatching center through telephone, short messages and WeChat alarm information.

The first MCU5 is connected with a clock unit for providing a real-time clock.

Embodiment two:

an expandable low-voltage station area monitoring device adopts a high-performance 32-bit floating point DSP chip TMS320F28335 as a main board CPU, and comprises the following circuits: the system comprises a CPU power supply circuit, a current signal acquisition and processing circuit, a voltage signal acquisition and processing circuit, an on-off state input circuit, a tripping output circuit, a reactive compensation control output circuit and a communication interface circuit. The communication interface circuit comprises 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 acquires current, voltage and other electrical parameters of the line on line in real time, and stores the current, voltage and other electrical parameters in a corresponding array for the main processor of the measurement and control device to calculate a protection control algorithm. The device samples 1024 points every cycle, and in order to realize the protection fast-acting requirement, the required calculation and protection methods are all put in the interrupt program of the timer to finish. The measurement and control device samples alternating current and voltage by using a 1024-point Fourier algorithm to obtain measurement analog quantity and related data; the main processor of the measurement and control device host is the source of all measurement and communication data, and responds to the request of the upper computer man-machine interface processor (the platform area measurement and control device designed in the embodiment adopts CAN communication to receive interruption and sends measurement parameters, protection state, protection fixed value, other parameters, event records and the like to the host through a CAN bus); and the information such as voltage, current, reactive power, active measurement parameters, protection action alarms and the like is uploaded to the power distribution system through an RS485 bus (or carrier communication), and an operation command sent by the power distribution main station is received, and a 101 protocol is adopted for external communication.

Embodiment III:

the first MCU of the main control module is also connected with a data processing and analyzing unit, the data processing and analyzing unit comprises a low-pass filter, a signal amplifier, a photoelectric isolator and a driving buffer circuit, the input end of the low-pass filter is connected with the first MCU, the output end of the low-pass filter is connected with the input end of the signal amplifier, the output end of the signal amplifier is connected with the input end of the photoelectric isolator, the output end of the photoelectric isolator is connected with the input end of the driving buffer circuit, and the output end of the driving buffer circuit is connected with the server. The first MCU of the main control module is connected with a data processing and analyzing unit and is used for processing and analyzing sampled data and uploading the processed data to the server so as to realize on-line monitoring and comprehensive analysis of a plurality of electric quality data of the low-voltage transformer area.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to 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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