Centralized low-voltage power distribution network feeder monitoring device

Abstract

The centralized low-voltage power distribution network feeder monitoring device comprises a power supply module, a plurality of monitoring units and a communication unit which are connected in sequence, and specifically comprises that a transformer area three-phase four-wire system power supply is input to the power supply module, the power supply module outputs a system power supply + 12VC required by the monitoring units, and the three-phase voltage acquisition precision meets the precision of 2.2 V; an internal system samples 2.2 V voltage through cascading a plurality of monitoring units to judge whether three phases have voltage or not, and external man-machine interaction displays whether the three phases have voltage or not and meets a voltage judgment range through an LED (Light Emitting Diode); and each monitoring unit realizes uplink data interaction with the communication unit through the CAN chip, and downlink communication with the power supply module of another transformer area branch line. According to the utility model, the communication unit is used for collecting data for unified upward communication, so that centralized, modularized, multi-branch and parallel monitoring and management are realized; and meanwhile, the interchangeability and high-efficiency adaptability of functional modules among different manufacturers can be realized.

Description

Technical Field

[0001] The utility model relates to the field of intelligent power grid fault monitoring devices, in particular to a centralized low-voltage distribution network feeder monitoring device. Background Art

[0002] The system power supply, metering sampling monitoring, and uplink and downlink communication functions of the existing traditional distributed low-voltage distribution network feeder monitoring devices are integrated into a single module. A single monitoring device can only support the monitoring and management of a single branch line in the substation area. At the same time, the single module needs to be powered by the system, which is not conducive to the rational allocation and utilization of the comprehensive resources of the substation area, and greatly reduces the efficiency of parallel management of power outage perception in the substation area. On the other hand, a number of new modular low-voltage distribution network feeder monitoring devices have emerged in the industry, including communication units, power modules, and multiple low-voltage monitoring units. However, for the products uniformly tendered by the State Grid, they have the characteristics of standardization, modularization, and generalization. In actual applications, the interchangeability and adaptability of functional modules between different manufacturers are poor, which greatly increases the operation and management costs of the substation area. Utility Model Content

[0003] The utility model provides a centralized low-voltage distribution network feeder monitoring device, which can solve at least one of the above technical problems.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A centralized low-voltage distribution network feeder monitoring device includes a power module, a plurality of monitoring units, and a communication unit connected in sequence, specifically including:

[0006] The three-phase four-wire power supply UA, UB, UC, and UN in the substation are input to the power module, and the power module outputs the system power +12V_C required by the monitoring unit. The load capacity meets the requirements of at least 10 monitoring units in the substation, and the acquisition accuracy of the three-phase voltage UA, UB, and UC meets the accuracy of 2.2V, that is, ‰5. The internal system samples the 2.2V voltage by cascading multiple monitoring units to determine whether the three phases have voltage, and the external human-computer interaction displays whether the three phases have voltage and meet the voltage determination range through LEDs;

[0007] Each monitoring unit uses the CAN chip to exchange data with the communication unit in the upstream and communicate with the power module of the branch line in another substation in the downstream.

[0008] Furthermore, the MCU of each monitoring unit adopts the HT7625S main processor. The monitoring unit realizes the substation line topology identification and phase sequence identification through the B-phase current injection method. The three-phase currents IA, IB, and IC of the substation branch line are input into the monitoring unit as the metering current through the current transformer. The main processor of the monitoring unit HT7625S performs metering data collection and processing.

[0009] Furthermore, the monitoring unit supports RS485 local maintenance and remote signaling functions.

[0010] Furthermore, the communication unit is powered by an external single-phase power supply, wherein the MCU of the communication unit adopts HC32F460KETA as the main processor, supports RS485 and Bluetooth functions for data communication of the communication unit and debugging and operation and maintenance of handheld devices, and supports HPLC or HPLC&RF dual-mode carrier communication. The uplink supports the call and active reporting of the fusion terminal, and the downlink communicates data with the monitoring unit through the CAN function, and the communication supports ESAM data encryption.

[0011] Furthermore, the communication unit also supports the communication status of the four-way remote signaling control monitoring devices YX1, YX2, YX3, and YX4.

[0012] Furthermore, the three-phase four-wire power supply UA, UB, UC, and UN in the substation are input into current transformers, and the secondary improves its cascade load capacity through the IV conversion circuit. The phase shift compensation and self-resonant frequency adjustment of the output voltage are realized through the negative feedback regulation circuit, and the output voltage accuracy reaches 2.2V, that is, ‰5 accuracy.

[0013] It can be seen from the above technical scheme that in order to improve the ability of low-voltage substations to perceive power outages, deepen the practical application of fusion terminals, and realize accurate judgment of single-household, low-voltage branches, and substation power outages, this utility model proposes a new type of centralized low-voltage distribution network feeder monitoring device, which can measure real-time voltage, current, power and other electrical parameters at each branch of the substation, accumulate active and reactive power, and judge short-circuit faults and grounding faults in real time, and interact with the substation fusion terminal to comprehensively realize line topology recognition, phase sequence recognition, line loss analysis, substation account management, branch expandable capacity, harmonic source positioning and other functions. This new type of centralized low-voltage distribution network feeder monitoring device consists of a communication unit, a power module and multiple low-voltage monitoring units.

[0014] Specifically, the advantages of the utility model are:

[0015] 1. The new centralized low-voltage distribution network feeder monitoring device is a single monitoring device that supports access to multiple branch lines in different areas. It collects and communicates data upward in a unified manner through a communication unit, thus realizing centralized, modular, multi-branch, and parallel monitoring and management.

[0016] 2. The new centralized low-voltage distribution network feeder monitoring device realizes the interchangeability and high-efficiency adaptability of functional modules between different manufacturers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural block diagram of this embodiment;

[0018] Figure 2 It is a structural schematic diagram of this embodiment;

[0019] Figure 3 2 is a schematic diagram of the circuit structure of this embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings 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.

[0021] like Figure 1 As shown, in order to improve the power outage perception capability of low-voltage substations, deepen the practical application of fusion terminals, and realize the accurate judgment of single-household, low-voltage branches, and substation power outages, this embodiment proposes a new centralized low-voltage distribution network feeder monitoring device, which can measure the real-time voltage, current, power and other electrical parameters at each branch of the substation, accumulate active and reactive power, judge short-circuit faults and grounding faults in real time, and interact with the substation fusion terminal to comprehensively realize line topology identification, phase sequence identification, line loss analysis, substation ledger management, branch expandable capacity, harmonic source location and other functions. This new centralized low-voltage distribution network feeder monitoring device consists of a communication unit, a power module and multiple low-voltage monitoring units, namely, a power module, multiple monitoring units, a communication unit and a fusion terminal connected in sequence.

[0022] The following are specific instructions:

[0023] In the specific implementation, the specific structural diagram of this embodiment is as follows Figure 2As shown; the three-phase four-wire power supply UA, UB, UC, UN of the substation area is input into the power module of the low-voltage distribution network feeder monitoring device, and the system power supply +12V_C required by the monitoring unit is output, wherein the load capacity meets at least 10 monitoring units in the substation area, and the three-phase voltage UA, UB, UC acquisition accuracy meets 2.2V (‰5 accuracy), the internal system samples 2.2V voltage by cascading multiple monitoring units to determine whether the three phases have voltage, and the external human-computer interaction displays whether the three phases have voltage and meet the voltage determination range through LED. The MCU of each monitoring unit adopts the HT7625S main processor, which is an SOC that integrates metering, high-precision RTC, main control, etc., to meet the management of the monitoring unit system. The monitoring unit realizes the substation line topology identification and phase sequence identification through the B-phase current injection method. The three-phase current IA, IB, IC of the substation branch line is input into the monitoring unit as the metering current through the current transformer, and the main processor HT7625S of the monitoring unit performs metering data collection and processing. Each monitoring unit uses the CAN chip to achieve data exchange with the communication unit in the uplink, and communicates with the power module of the branch line of another substation in the downlink. At the same time, the monitoring unit supports RS485 local maintenance and remote signaling functions. The communication unit is powered by an external single-phase power supply. The MCU uses HC32F460KETA as the main processor, supports RS485 and Bluetooth functions for data communication of the communication unit and debugging and operation of handheld devices, and supports HPLC or HPLC&RF dual-mode carrier communication. The uplink supports the call and active reporting of the fusion terminal, and the downlink communicates with the monitoring unit through the CAN function. The communication supports ESAM data encryption. At the same time, the communication unit also supports the communication status of the four-way remote signaling control monitoring device of YX1, YX2, YX3, and YX4.

[0024] The specific circuit structure principle block diagram of this embodiment is as follows Figure 3As shown; UA, UB, UC, UN input current transformers, the secondary improves its cascade load-bearing capacity through the IV conversion circuit, and the output voltage phase shift compensation and self-resonant frequency adjustment are realized through the negative feedback regulation circuit. The output voltage accuracy reaches 2.2V (‰5 accuracy). When the voltage of any phase of the three-phase UA, UB, UC is greater than 80% of the rated value, the sampling value UAP or UBP or UCP is compared with the reference voltage VREF of the comparator CP to determine whether it meets the sampling standard. When UAP>VREF, the output is high level, and the LEDA light is on; UBP and UCP are the same, and vice versa. When the power module is charged to +VCAP, the system is in the +VDD power supply state, the charge and discharge circuit is not enabled, and the +VDD power supply is instantaneously passed through the self-regulating feedback circuit, and the maximum load-bearing capacity can support 700mA; when the power is off and the voltage value +VCC meets the charge and discharge start voltage, the charge and discharge circuit is enabled, and the system is powered on again as +V_CAP. At this time, the power-off load-bearing can maintain the stable operation of 10 cascaded monitoring units for 45s. The system +V_CAP can be switched with +12V_C through a switch, and the switch status is displayed through LED_12V. It meets modular interchangeability to achieve adaptive adjustment of load capacity, and the system can continue to work and report information management when power is off.

[0025] To sum up, the embodiment of the utility model is specifically a new type of centralized low-voltage distribution network feeder monitoring device, which is a single monitoring device that supports access to multiple branch lines in different substations. It collects and communicates data upward in a unified manner through a communication unit, thereby realizing centralized, modular, multi-branch, and parallel monitoring and management; at the same time, it can realize the interchangeability of functional modules between different manufacturers and high-efficiency adaptability.

[0026] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A centralized low-voltage distribution network feeder monitoring device, comprising a power module, a plurality of monitoring units, and a communication unit connected in sequence, characterized in that: Specifically include: The three-phase four-wire power supply UA, UB, UC, and UN in the substation are input to the power module, and the power module outputs the system power +12V_C required by the monitoring unit. The acquisition accuracy of the three-phase voltage UA, UB, and UC meets the accuracy requirement of 2.2V. The internal system samples the 2.2V voltage separately by cascading multiple monitoring units to determine whether the three phases have voltage, and the external human-computer interaction displays whether the three phases have voltage and meet the voltage determination range through LEDs; Each monitoring unit uses the CAN chip to exchange data with the communication unit in the upstream and communicate with the power module of the branch line in another substation in the downstream.

2. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The MCU of each monitoring unit adopts the HT7625S main processor. The monitoring unit realizes the line topology identification and phase sequence identification of the substation through the B-phase current injection method. The three-phase current IA, IB, and IC of the substation branch line are input into the monitoring unit as the metering current through the current transformer. The main processor of the monitoring unit HT7625S performs metering data collection and processing.

3. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The monitoring unit supports RS485 local maintenance and remote signaling functions.

4. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The communication unit is powered by an external single-phase power supply. The MCU of the communication unit uses HC32F460KETA as the main processor, supports RS485 and Bluetooth functions for data communication of the communication unit and debugging and maintenance of handheld devices, and supports HPLC or HPLC&RF dual-mode carrier communication. The uplink supports the call and active reporting of the fusion terminal, and the downlink communicates data with the monitoring unit through the CAN function. The communication supports ESAM data encryption.

5. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The communication unit also supports the communication status of the four-way remote signaling control and monitoring devices YX1, YX2, YX3, and YX4.

6. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The three-phase four-wire power supply UA, UB, UC, and UN in the substation input current transformers. The secondary improves its cascade load capacity through the IV conversion circuit, and the output voltage phase shift compensation and self-resonant frequency adjustment are achieved through the negative feedback regulation circuit. The output voltage accuracy meets the 2.2V accuracy requirement.

7. The centralized low-voltage distribution network feeder monitoring device according to claim 1, characterized in that: The power module's load capacity is sufficient for at least 10 monitoring units in the substation.

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