Intelligent low-voltage line monitoring system

Abstract

The utility model provides an intelligent low-voltage line monitoring system, which comprises a power supply module for acquiring sampling current of a sampling point and providing electric energy for the system, the power supply module is in data intercommunication with an MCU (Microprogrammed Control Unit) through a metering unit, and the metering unit is used for calculating parameter data of the sampling current according to the sampling current. The MCU master control receives the parameter data and judges whether power supply of the sampling points is abnormal or not, and the MCU master control is electrically connected with a storage module used for storing data, an LED indication module used for reminding power supply abnormity, a 485 communication module used for data intercommunication with external equipment and a topology module used for displaying a sampling point topology structure diagram. According to the utility model, the power supply characteristics of the low-voltage transformer area can be continuously monitored and displayed in real time in the form of a topological graph, so that the fault position can be accurately positioned.

Description

Technical Field

[0001] The utility model relates to the technical field of line detection, in particular to an intelligent low-voltage line monitoring system. Background Art

[0002] As the end of the distribution network, the power supply reliability of the low-voltage substation determines the quality and experience of users' electricity consumption. When a low-voltage branch or meter box fails during operation, the traditional low-voltage substation cannot accurately locate the fault in real time, and cannot actively sense and carry out maintenance; there is a lack of effective supervision measures for line loss and electricity theft; the low-voltage substation lacks effective intelligent sensing means and cannot effectively sense users' electricity consumption characteristics and habits; the data of the acquisition system is single, and no big data statistical analysis is performed, resulting in low data validity and utilization. Utility Model Content

[0003] In view of this, the problem to be solved by the utility model is to provide an intelligent low-voltage line monitoring system that can continuously monitor the power supply characteristics of the low-voltage area and display it in real time in the form of a topological diagram to accurately locate the fault location.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] An intelligent low-voltage line monitoring system comprises a power supply module for obtaining a sampling current of a sampling point and providing electric energy to the system, wherein the power supply module communicates data with an MCU main control through a metering unit, wherein the metering unit is used to calculate parameter data of the sampling current according to the sampling current, wherein the MCU main control receives the parameter data and determines whether the sampling point has power supply abnormality, wherein the MCU main control is electrically connected to a storage module for storing data, an LED indication module for power supply abnormality reminder, a 485 communication module for data communication with an external device, and a topology module for displaying a topological structure diagram of the sampling point.

[0006] Further, the power module includes an inter-sampling unit for acquiring a sampled current, the inter-sampling unit includes a mutual inductor T1 for acquiring a current between the A line and the N line, a mutual inductor T2 for acquiring a current between the B line and the N line, and a mutual inductor T3 for acquiring a current between the C line and the N line, and the circuit connection structures of the mutual inductors T1, T2, and T3 are completely the same;

[0007] The IN2 port of the mutual inductor T1 is electrically connected to the N line, and resistors R77, R76, R75 and R74 are connected in series between the IN1 port of the mutual inductor T1 and the A line in sequence. The OUT1 port and OUT2 port of the mutual inductor T1 are electrically connected to the interface P1 respectively, and the interface P1 is used to output the sampled currents collected by the mutual inductors T1, T2 and T3 respectively.

[0008] Furthermore, the metering unit includes a metering chip U1, and the metering chip U1 is electrically connected to the output end of the cross sampling unit through a current sampling circuit to obtain a current signal of a sampling point;

[0009] The current sampling circuit includes a resistor R20, an input end of the resistor R20 is connected in parallel to a resistor R26, an output end of the resistor R20 is connected in parallel to a capacitor C20, and the resistor R20 is connected in series between the cross sampling unit and the MCU main control.

[0010] Furthermore, the metering chip U1 is electrically connected to the cross sampling unit through a voltage sampling circuit to obtain a voltage signal at a sampling point;

[0011] The voltage sampling circuit includes a resistor R38, the input end of the resistor R38 is respectively connected in parallel with a capacitor C50 and a resistor R61, and the resistor R38 is connected in series between the cross sampling unit and the MCU main control.

[0012] Furthermore, the interface P1 is electrically connected to the interface P5 and the interface P6, each interface on the interface P5 communicates with the metering chip U1 through a corresponding current sampling circuit, and each interface on the interface P6 communicates with the metering chip U1 through a corresponding voltage sampling circuit.

[0013] Furthermore, the model of the metering chip U1 is ATT7022.

[0014] Furthermore, the MCU main control includes a main control chip U5, and the LED indication module includes a light emitting diode D13, the output end of the light emitting diode D13 is electrically connected to the ground, and the input end of the light emitting diode D13 is electrically connected to the LED port of the main control chip U5 through a resistor R56.

[0015] Furthermore, the storage module includes a storage chip U2 for storing system parameters and a storage chip U9 for storing system events.

[0016] Further, the 485 communication module includes a communication chip U7, which communicates with the main control chip U5 through the RO port and the RE port, and the A port and the B port of the communication chip U7 are electrically connected to the interface P7, and the interface P7 is used to connect to an external device;

[0017] A resistor R89 ​​and a protection diode D10 are respectively connected in series between the A port and the B port of the communication chip U7, and a thermistor RT1 is connected in series between the A port of the communication chip U7 and the interface P7.

[0018] Furthermore, the power module includes a power supply unit for providing electric energy to the system, and the power supply unit includes a first conversion circuit for providing 12V electric energy and a second conversion circuit for converting the 12V electric energy into 3.3V.

[0019] The advantages and positive effects of the utility model are:

[0020] By setting up a line monitoring system, it is possible to collect parameter data of the current flowing on the power supply wires in the low-voltage substation, and determine whether the power supply current at the sampling point is abnormal based on the parameter data. The abnormal location can be displayed through the topology module to achieve continuous monitoring of the power supply characteristics of the low-voltage substation, and display it in real time in the form of a topology map to accurately locate the fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is an overall system diagram of an intelligent low-voltage line monitoring system of the utility model;

[0023] Figure 2 This is a circuit connection diagram of an exchange unit in an intelligent low-voltage line monitoring system of the utility model;

[0024] Figure 3 This is a circuit connection diagram of VR3 varistor, VR2 varistor and VR1 varistor in an intelligent low-voltage line monitoring system of the utility model;

[0025] Figure 4 This is a circuit diagram of a metering chip U1 in an intelligent low-voltage line monitoring system of the utility model;

[0026] Figure 5 This is a current sampling circuit diagram in an intelligent low-voltage line monitoring system of the utility model;

[0027] Figure 6 This is a circuit diagram of interface P5 in an intelligent low-voltage line monitoring system of the utility model;

[0028] Figure 7 This is a voltage sampling circuit diagram in an intelligent low-voltage line monitoring system of the utility model;

[0029] Figure 8 This is a circuit diagram of interface P6 in an intelligent low-voltage line monitoring system of the utility model;

[0030] Fig. 9 This is a circuit diagram of the main control chip U5 in an intelligent low-voltage line monitoring system of the utility model;

[0031] Fig.10 This is a circuit diagram of an LED indicator module in an intelligent low-voltage line monitoring system of the utility model;

[0032] Fig.11 This is a 485 communication module circuit diagram in an intelligent low-voltage line monitoring system of the utility model;

[0033] Fig.12 It is a circuit diagram of a storage module in an intelligent low-voltage line monitoring system of the utility model;

[0034] Fig.13 It is the first conversion circuit diagram in an intelligent low-voltage line monitoring system of the utility model;

[0035] Fig.14 The utility model discloses a second conversion circuit diagram in an intelligent low-voltage line monitoring system. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0038] The utility model provides an intelligent low-voltage line monitoring system, such as Figure 1 As shown, the low-voltage substation supplies power to residents in different areas through several groups of power supply wires. The power module is connected to the power supply wires (sampling points). The power module directly collects the current flowing through the power supply wires and forms a sampling current.

[0039] The power module communicates data with the MCU main control through the metering unit; the metering unit is used to obtain the voltage signal and current signal of the sampled current to measure the active power, reactive power, apparent power, active energy and reactive energy of each phase and the combined phase respectively, and at the same time measure the parameter data such as the current, effective value of voltage, power factor, phase angle, frequency of each phase, and transmit the parameter data to the MCU main control. The MCU main control determines whether there is an abnormality in the power supply wire based on the parameter data and gives a power supply abnormality reminder.

[0040] The MCU main control is connected to a storage module for storing data, an LED indicator module for power supply abnormality reminder, a 485 communication module for data exchange with external devices, and a topology module for displaying the sampling point topology diagram. The topology module forms a topology diagram based on the connection relationship between the sampling points, and displays the location of the abnormal sampling point in the topology diagram based on the feedback results of the MCU main control, so that the staff can quickly determine the abnormal sampling point for immediate maintenance.

[0041] This application takes a three-phase four-wire power supply conductor as an example, which are wire A, wire B, wire C and wire N.

[0042] like Figure 2 As shown, the power module includes an inter-sampling unit, which is used to obtain the current on the power supply wire and output the sampled current. The inter-sampling unit includes a transformer T1 connected in series to the current between the A line and the N line, a transformer T2 connected in series to the current between the B line and the N line, and a transformer T3 connected in series to the current between the C line and the N line. The connection structures of the transformers T1, T2 and T3 are the same, and they are all current-type voltage transformers.

[0043] Take the circuit connection structure of the mutual inductor T1 as an example: the IN2 port of the mutual inductor T1 is electrically connected to the N line, and the resistors R77, R76, R75 and R74 are connected in series between the IN1 port of the mutual inductor T1 and the A line in sequence. Multiple resistors connected in series can be used to share the accuracy deviation caused by temperature changes and improve the accuracy of the sampled current. The OUT1 port and OUT2 port of the mutual inductor T1 are electrically connected to the 1 port and 2 port of the interface P1 respectively, and are used to output the sampled current.

[0044] Similarly, the OUT1 port and OUT2 port of the transformer T2 are electrically connected to the 3 port and 4 port of the interface P1 respectively, and the OUT1 port and OUT2 port of the transformer T3 are electrically connected to the 5 port and 6 port of the interface P1 respectively, so as to output the sampled current on the A line, the B line, and the C line respectively.

[0045] like Figure 3 As shown, in order to improve the accuracy and safety of sampling of the transformers T1, T2 and T3, VR3 varistors, VR2 varistors and VR1 varistors are respectively connected in series between the A line, the B line and the C line and the N line. When the input voltage is too large and exceeds the threshold voltage value of the varistor, the varistor plays an overvoltage protection function, and the resistance value becomes smaller, so that the current flowing through the varistor increases, thereby protecting the subsequent transformers T1, T2 and T3 from being damaged.

[0046] like Figure 4As shown, the metering unit includes a metering chip U1, which is electrically connected to the cross-sampling unit through a current sampling circuit to collect current signals; the metering chip U1 is electrically connected to the cross-sampling unit through a voltage sampling circuit to collect voltage signals.

[0047] like Figure 5 As shown, the current sampling circuit includes a resistor R20, the input end of the resistor R20 is connected in parallel with a resistor R26, the output end of the resistor R20 is connected in parallel with a capacitor C20, the input end of the resistor R20 is electrically connected to the output end of the cross sampling unit, the current is shunted by the resistor R26 and the resistor R20, and after the capacitor C20 stabilizes the voltage, it is input to the metering chip U1 to complete the current sampling.

[0048] like Figure 6 As shown, the metering unit outputs the sampled currents of line A, line B, and line C respectively through interface P1, interface P1 is electrically connected to interface P5, interface P5 provides IA+ port, IA- port, IB+ port, IB- port, IC+ port, and IC- port for easy sampling, and the above six ports are electrically connected to V1P port, V1N port, V3P port, V3N port, V5P port, and V5N port of the metering chip U1 through corresponding current sampling circuits, so as to transmit the collected current signal to the metering chip U1.

[0049] like Figure 7 As shown, the voltage sampling circuit includes a resistor R38, and the input end of the resistor R38 is connected in parallel with a capacitor C50 and a resistor R61. The input end of the resistor R38 is connected to the output end of the cross sampling unit, and the capacitor C50 is used to adjust the voltage at the input end of the resistor R38, and then input to the metering chip U1 after the voltage drop of the resistor R38 to complete the voltage sampling.

[0050] like Figure 8 As shown, interface P1 is electrically connected to interface P6, and interface P5 provides VAP port, VAN port, VBP port, VBN port, VCP port and VCN port for easy sampling. The above six ports are electrically connected to V2P port, V2N port, V4P port, V4N port, V6P port and V6N port of the metering chip U1 through corresponding voltage sampling circuits, so as to transmit the collected voltage signal to the metering chip U1.

[0051] The model of the metering chip U1 is ATT7022. ATT7022 integrates multiple second-order sigma-delta ADCs, reference voltage circuits, and digital signal processing circuits for all power, energy, effective value, power factor, and frequency measurements. It can measure the active power, reactive power, apparent power, active energy, and reactive energy of each phase and the combined phase. It can also measure the current, effective value of voltage, power factor, phase angle, frequency and other parameter data of each phase, fully meeting the needs of a three-phase multi-rate multi-functional energy meter.

[0052] like Fig. 9 As shown, the MCU main control includes a main control chip U5, which communicates with the metering chip U1 through the SPI interface to receive parameter data. The main control chip U5 communicates with the metering chip U1 through RESET to control the metering chip U1 to reset.

[0053] like Fig.10 As shown, the LED indication module includes a light emitting diode D13, the output end of the light emitting diode D13 is electrically connected to the ground, and the input end of the light emitting diode D13 is electrically connected to the LED port of the main control chip U5 through a resistor R56. When the main control chip U5 gives abnormal feedback, the main control chip U5 controls to light up to remind that a power supply abnormality occurs.

[0054] like Fig.11 As shown, the 485 communication module includes a communication chip U7, which communicates data with the main control chip U5 through the RO port and the RE port. The A port and the B port of the communication chip U7 are electrically connected to the interface P7, and the interface P7 is used to connect to an external device to communicate data with the external device.

[0055] A resistor R89 ​​and a protection diode D10 are connected in series between the A port and the B port of the communication chip U7. The protection diode D10 has low impedance and quick overvoltage response, which can filter out the clutter voltage on the signal line and improve the accuracy of the transmitted data. A thermistor RT1 is connected in series between the A port of the communication chip U7 and the interface P7 to play the role of overcurrent protection.

[0056] like Fig.12 As shown, the storage module includes a storage chip U2 for storing system parameters and a storage chip U9 for storing system events. The model of the storage chip U2 is MB85RC04, and the model of the storage chip U9 is EEPROM. The system parameters include meter calibration parameters and parameter data that need to be updated in real time; the system events include detection target data and detection result data.

[0057] like Fig.13 As shown, the power supply module includes a power supply unit for providing electric energy to the system, the power supply unit includes a first conversion circuit, the first conversion circuit includes a mutual inductor T4, the 3-port of the mutual inductor T4 is connected to the N line (ground wire), the 3-port of the mutual inductor T4 is connected to the L line (live wire), the 6-port and the 7-port of the mutual inductor T4 are respectively connected to the AC port of the rectifier bridge D17, the V-port of the rectifier bridge D17 is grounded, and the V+ port of the rectifier bridge D17 outputs 12V electric energy.

[0058] A VR4 varistor is connected in series between the N line and the L line, and a t thermistor is connected in series between the L line and the transformer T4. The VR4 varistor and the t thermistor play a role in overvoltage and overcurrent protection, and improve the stability of the operation of the transformer T4. In order to improve the stability of the output voltage of the rectifier bridge D17, the V+ port of the rectifier bridge D17 is connected in parallel with a rectifier circuit.

[0059] like Fig.14 As shown, the power supply unit includes a second conversion circuit for converting 12V electric energy into 3.3V. The second conversion circuit includes a power conversion chip U4. The model of the power conversion chip U4 is ETA2001.

[0060] The Vin port of the power conversion chip U4 is connected to a 12V voltage, the LX port of the power conversion chip U4 is connected in series with the filter inductor L1, a capacitor C38 and a resistor R4 are connected in series between the output end of the filter inductor L1 and the FB port of the power conversion chip U4, respectively, a resistor R5 is connected in series between the resistor R4 and the ground, and the voltage at the output end of the filter inductor L1 is adjusted by adjusting the resistance values ​​of the resistors R4 and R5 to output 3.3V of electrical energy.

[0061] The above embodiments of the utility model are described in detail, but the above contents are only preferred embodiments of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of the utility model should still fall within the scope of this patent.

Claims

1. An intelligent low-voltage line monitoring system, characterized in that: The system comprises a power supply module for obtaining a sampling current of a sampling point and providing electric energy to the system. The power supply module communicates data with an MCU main control through a metering unit. The metering unit is used to calculate parameter data of the sampling current according to the sampling current. The MCU main control receives the parameter data and determines whether the sampling point has power supply abnormality. The MCU main control is electrically connected to a storage module for storing data, an LED indication module for power supply abnormality reminder, a 485 communication module for data communication with an external device, and a topology module for displaying a topological structure diagram of the sampling point.

2. The intelligent low-voltage line monitoring system according to claim 1 is characterized in that: The power module includes an inter-sampling unit for acquiring a sampled current, and the inter-sampling unit includes a mutual inductor T1 for acquiring a current between the A line and the N line, a mutual inductor T2 for acquiring a current between the B line and the N line, and a mutual inductor T3 for acquiring a current between the C line and the N line, and the circuit connection structures of the mutual inductors T1, T2, and T3 are completely the same; The IN2 port of the mutual inductor T1 is electrically connected to the N line, and resistors R77, R76, R75 and R74 are connected in series between the IN1 port of the mutual inductor T1 and the A line in sequence. The OUT1 port and OUT2 port of the mutual inductor T1 are electrically connected to the interface P1 respectively, and the interface P1 is used to output the sampled currents collected by the mutual inductors T1, T2 and T3 respectively.

3. The intelligent low-voltage line monitoring system according to claim 1 is characterized in that: The metering unit includes a metering chip U1, and the metering chip U1 is electrically connected to the output end of the cross sampling unit through a current sampling circuit to obtain a current signal at a sampling point; The current sampling circuit includes a resistor R20, an input end of the resistor R20 is connected in parallel to a resistor R26, an output end of the resistor R20 is connected in parallel to a capacitor C20, and the resistor R20 is connected in series between the cross sampling unit and the MCU main control.

4. The intelligent low-voltage line monitoring system according to claim 3 is characterized in that: The metering chip U1 is electrically connected to the cross sampling unit through a voltage sampling circuit to obtain a voltage signal at a sampling point; The voltage sampling circuit includes a resistor R38, the input end of the resistor R38 is respectively connected in parallel with a capacitor C50 and a resistor R61, and the resistor R38 is connected in series between the cross sampling unit and the MCU main control.

5. The intelligent low-voltage line monitoring system according to claim 2 is characterized in that: The interface P1 is electrically connected to the interface P5 and the interface P6. Each interface on the interface P5 communicates with the metering chip U1 through a corresponding current sampling circuit. Each interface on the interface P6 communicates with the metering chip U1 through a corresponding voltage sampling circuit.

6. The intelligent low-voltage line monitoring system according to claim 3 is characterized in that: The model of the metering chip U1 is ATT7022.

7. The intelligent low-voltage line monitoring system according to claim 1 is characterized in that: The MCU main control includes a main control chip U5, and the LED indication module includes a light emitting diode D13. The output end of the light emitting diode D13 is electrically connected to the ground, and the input end of the light emitting diode D13 is electrically connected to the LED port of the main control chip U5 through a resistor R56.

8. The intelligent low-voltage line monitoring system according to claim 1, characterized in that: The storage module includes a storage chip U2 for storing system parameters and a storage chip U9 for storing system events.

9. The intelligent low-voltage line monitoring system according to claim 1, characterized in that: The 485 communication module includes a communication chip U7, which communicates with the main control chip U5 through the RO port and the RE port. The A port and the B port of the communication chip U7 are electrically connected to the interface P7, and the interface P7 is used to connect to an external device; A resistor R89 ​​and a protection diode D10 are respectively connected in series between the A port and the B port of the communication chip U7, and a thermistor RT1 is connected in series between the A port of the communication chip U7 and the interface P7.

10. The intelligent low-voltage line monitoring system according to claim 1, characterized in that: The power supply module includes a power supply unit for providing electric energy to the system, and the power supply unit includes a first conversion circuit for providing 12V electric energy and a second conversion circuit for converting the 12V electric energy into 3.3V.

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