KR101184160B1 - Method for remote monitering of micro grid electric power quality and thereof for system - Google Patents

Abstract

PURPOSE: A method and a system for remote monitoring of micro grid power quality received from a server are provided to perform bidirectional real time monitoring of power quality within a smart grid on a server. CONSTITUTION: A micro grid power quality remote monitoring system(100) includes a first receiver(110), a checker(120), a command unit(130), a second receiver(140), and a monitor unit(150). The first receiver receives symptom packets of power quality from smart meter nodes which measure power quality. The checker checks whether to be normal of power quality for nodes after analyzing the symptom packets. The command unit requests a measurement sample of abnormal symptom items. The second receiver receives a stamp sample packet from the node. The monitor unit monitors the received stamp sample packet.

Description

Method for remote monitering of micro grid electric power quality and about for system

The present invention relates to a method and system for remotely monitoring micro grid power quality, and more particularly, to a method and system for remotely and effectively monitoring power quality of a micro grid, a next-generation intelligent power grid.

Micro Grid is the next generation of intelligent power grid that realizes future CO ₂ reduction and energy saving.It is a renewable energy source such as solar cell, wind power, cogeneration, and plug-in hybrid electric vehicle (PHEV) and conventional energy sources (ex, hydro, It is a distributed power system in which nuclear power and thermal power are linked together.

Unlike conventional unidirectional energy distribution methods for consumers in the KEPCO, such a micro grid has the advantage that anyone can participate in the energy distribution process (ex, production, transmission, storage, consumption) in real time in both directions. Participants include public service providers, private businesses, and individuals (prosumers).

Unlike the conventional method, in order to build a smooth and customized energy distribution system under a micro grid operated in a grid-connected operation between various AC or DC distributed power supplies, quality assurance of electric power service is most important. In other words, the provision of system- and grade-specific energy services tailored to the energy needs of each home and factory is possible under the premise of quality assurance.

An object of the present invention is to provide a micro grid power quality remote monitoring method and system that can effectively control and monitor the power quality of a micro grid remotely in an effective manner.

The present invention comprises the steps of receiving a symptom packet of the power quality from the smart meter nodes measuring the power quality of each consumer, and analyzing the symptom packet to determine whether the power quality for the nodes is normal; Requesting a measurement sample of a symptom item in which an abnormality is found in a node whose power quality is found to be abnormal, receiving a stamp sample packet stamped with the measurement sample from the node, and receiving the received stamp sample Diagnosing and monitoring a packet, and displaying at least one of whether or not the abnormality is found for each node, an analysis result according to the diagnosis, a location of a node where the abnormality is found, and a time point at which the abnormality is found in the node, and the node. The symptom packet, the stamp sample packet, and whether or not the abnormality was found for each node; Results, and provides a position of the at least the found node, over found microgrid power quality comprises the step of storing at least one of the time remote monitoring method of the node.

The stamp sample packet may include one or a plurality of pieces of information selected from a serial number, an abnormal occurrence number, an abnormal occurrence time, an abnormal end time, and an abnormal duration time for the measurement sample.

After transmitting the symptom packet, the node generates and stores a stamp sample packet for a measurement sample in which the abnormality is found, and stores the stamp sample packet in a memory, and transmits the stored stamp sample packet when the request is made. The sample may be a sample measured for a certain period of time from the time of abnormality detection and stored in the sliding window.

In addition, the node may transmit the symptom packet at regular intervals, but stop the transmission of the symptom packet when receiving the transmission stop command, and resume transmission of the symptom packet when receiving the transmission restart command.

Here, while transmitting the command packet for the request of the measurement sample to the node side is confirmed that the power quality is abnormal, it is possible to transmit a command packet to stop the transmission of the symptom packet to the other nodes around.

The micro grid power quality remote monitoring method may further include displaying a series of processing contents according to respective steps on a screen.

The micro grid power quality remote monitoring method may transmit / receive various information with the nodes using power line communication or wireless network communication.

The node may enable self-monitoring of the power quality by displaying information on whether the symptom packet is normal for each symptom packet, and may store the symptom packet and the stamp sample packet as a data log.

In addition, the present invention, the first receiving unit for receiving a symptom packet of the power quality from the smart meter nodes for measuring the power quality of each customer, and confirms the normality of the power quality for the nodes by analyzing the symptom packet A verification unit configured to request a measurement sample of a symptom item in which an abnormality is found in a node in which the power quality is abnormal, and a second packet receiving a stamp sample packet stamped with the measurement sample. At least one of a receiver, a monitor unit for diagnosing and monitoring the received stamp sample packet, whether the abnormality is found for each node, the analysis result according to the diagnosis, the location of the node where the abnormality is found, and the time point for detecting the abnormality of the node. The display unit to display, and the symptom packet, the stamp sample packet by the node, and the abnormality discovery by the node The micro grid power quality remote monitoring system may include a storage unit configured to store at least one of a location of a node where the abnormality is found and a time point of finding the abnormality of the node.

Here, the command unit transmits a command packet to stop transmission of the symptom packet to other neighboring nodes while transmitting a command packet for requesting the measurement sample to the node side where the power quality is abnormally confirmed. Can be.

The micro grid power quality remote monitoring system may further include a display unit configured to display a series of processing contents according to the first receiver, the confirmation unit, the second receiver, the command unit, and the monitor unit on a screen. have.

When the power line communication is used, the node may include a coupler unit for dropping and outputting a power signal received from an AC power line, an LPF for filtering low frequency components of the power signal dropped in the coupler unit, and An A / D converter for A / D converting and sampling an AC signal among the power signals filtered by the LPF, a digital signal processor for receiving and processing the AC signal sampled by the A / D converter, and the digital signal processor Compares the pre-stored AC signal with the pre-stored reference signal to determine whether the symptom item is normal for the AC signal, generates the symptom packet according to the determination result, and measures the measurement sample of the symptom item in which the abnormality is found. A control unit for generating a stamp sample packet, and a memo for storing the generated symptom packet or the stamp sample packet as a data log And a display unit that enables self-monitoring of power quality by displaying normal status information for each symptom item corresponding to the generated symptom packet, a modem for modulating the symptom packet or the stamp sample packet, and in the modem. A coupler including a modulated symptom packet or a D / A converter for D / A converting the stamp sample packet, and an HPF for filtering high frequency components of the symptom packet or stamp sample packet converted from the D / A converter, and the coupler The unit may transmit the symptom packet or the stamp sample packet filtered by the HPF to the system through power line communication.

In addition, when the wireless network communication is used, the node may include a coupler unit for dropping and outputting a power signal received from an AC power line, an LPF for filtering low frequency components of the power signal dropped in the coupler unit, An A / D converter for A / D converting and sampling an AC signal among the power signals filtered by the LPF, a digital signal processor for receiving and processing an AC signal sampled by the A / D converter, and the digital signal processor Comparing the processed AC signal and the pre-stored reference signal to determine the normal status for each symptom item for the AC signal, generate the symptom packet according to the determination result, the measurement sample of the corresponding symptom item found abnormality A control unit for generating a stamp sample packet for the memory, and a memory for storing the generated symptom packet or the stamp sample packet as a data log And a display unit configured to enable self-monitoring of power quality by displaying normal status information for each symptom item corresponding to the generated symptom packet, a modem for modulating the symptom packet or the stamp sample packet, and a modulation in the modem. A D / A converter for D / A converting the symptom packet or the stamp sample packet, an RF converter for converting the symptom packet or the stamp sample packet converted in the D / A converter into an RF communication band, and the RF conversion The packet may include an antenna for wirelessly transmitting the symptom packet or the stamp sample packet converted by the unit to the system.

Also, the node determines whether the signal output from the LPF is AC or DC so that the DC signal of the power signal is directly input to the controller without being processed through the A / D converter and converts the corresponding signal into the A / D. The converter may further include a switch for transmitting to the controller. In this case, the digital signal processor may determine whether the DC signal is normal by symptom items for the DC signal by comparing the previously stored other reference signals.

According to the micro-grid power quality remote monitoring method and system according to the present invention, the AC and DC power quality measurement data measured on the node installed in each customer receives the remote server via power line communication or wireless communication, The advantage is the ability to remotely monitor and monitor power quality in the meat grid remotely.

In addition, according to the method and system described above, when receiving symptom packets from a node while receiving symptom items that are a problem in power quality, requesting and receiving stamp sample packets from the node for accurate analysis, thereby limiting the power line channel bandwidth. Can be effectively utilized, and real-time and stable simultaneous monitoring of power quality for multiple nodes in the grid can be performed.

In addition, if the information on the normal status of each symptom is directly displayed on each node, self-monitoring of power quality is possible in the node, and log data is stored every time an event occurs to perform a function like a black box later. Can be.

1 is a flow chart of a micro-grid power quality remote monitoring method according to an embodiment of the present invention.
2 is a schematic diagram of a system for the method of FIG.
3 is a conceptual diagram illustrating an example of storing a stamp sample packet in the node of FIG. 1.
4 is a conceptual diagram illustrating a specific example of the method of FIG. 1.
FIG. 5 is a detailed configuration diagram of the node shown in FIG. 1.
6 is a flowchart illustrating an embodiment of processing information at a node illustrated in FIG. 1.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

The present invention relates to a microgrid power quality remote monitoring method and system. Here, the micro grid refers to a local power supply system centered on a distributed power source independent from the existing wide area power system, and has a complementary relationship with the existing power system.

1 is a flow chart of a micro-grid power quality remote monitoring method according to an embodiment of the present invention. 2 is a schematic diagram of a system for the method of FIG.

The system 100 includes a first receiver 110, a confirmation unit 120, a command unit 130, a second receiver 140, a monitor unit 150, and a first display unit 160. Each consumer (home, factory, etc.) has Smart Quality Meter (SQM) nodes 10 that measure power quality. The system 100 corresponds to a server performing bidirectional communication with the nodes 10. Hereinafter, the system 100 will be referred to as a 'server 100'.

The present invention transmits the power quality measurement data of AC (three-phase, single-phase) and DC measured on the node 10 installed in each customer in the micro grid of the small and medium size to the remote server 100 through power line communication or wireless communication. By transmitting, it is possible to remotely monitor and monitor the power quality in the summit grid on the server 100 in real time.

Here, an example of the small and medium-sized micro grid may be an apartment complex accommodating N (> 10000) nodes 10 or a micro grid covering one technopark scale. Of course, the embodiment of the present invention is not limited to the small and medium-sized micro grid, it is obvious that the same can be applied on different scale micro grid.

Hereinafter, the micro grid power quality remote monitoring method will be described in detail with reference to FIGS. 1 to 2.

First, the server 100 receives the node ID from the smart meter nodes 10 that measure the power quality of each customer, checks this, and then sends a command packet to start the power quality measurement and transmission to each node 10. It transmits to (S110).

In step S110, the server 100 receives a node ID through the first receiver 110 and transmits a command packet through the command unit 130. From this point in time, bidirectional communication between the server 100 and the nodes 10 becomes possible.

Then, the nodes 10 receiving the command packet from the server 100 measures the power quality of its own node and generates a symptom packet that is symptom information for each symptom item. Here, the symptom items are meant to encompass AC and DC items such as instantaneous power failure, harmonic generation, instantaneous voltage rise, instantaneous voltage drop, flicker, surge, and phase imbalance. In addition, the symptom packet may be a short packet within several tens of bytes including a normal bit and symptom category byte.

The nodes 10 transmit the generated symptom packet to the first receiver 110 at a predetermined period (eg, within a few seconds). Here, the nodes 10 transmits a symptom packet at a predetermined period, and when receiving a transmission stop command from the command unit 130 of the server 100, stops the transmission of the symptom packet and receives a restart transmission command. The transmission of the symptom packet is resumed. That is, the operation of the node 10 is controlled according to the command of the server 100.

In accordance with the above process, the first receiving unit 110 of the server 100 receives the symptom packet that is normal (normal, abnormal) information for each symptom item of power quality from the nodes 10. (S120). In addition, the checking unit 120 analyzes the symptom packet to check whether the power quality of the nodes is normal (S130).

Thereafter, the command unit 130 requests a measurement sample of a corresponding symptom item in which abnormality is found to the node 10 in which power quality is abnormally confirmed at the time of confirmation of normality (S140).

At this time, while the command unit 130 transmits a command packet for requesting the measurement sample to the node 10 side in which the power quality is determined to be abnormal, the neighboring nodes 10 side transmits a symptom packet for a while. Send a command packet to stop. Since the actual power line communication uses a low data rate, the transmission of the neighboring nodes 10 is temporarily stopped to maintain the speed.

3 is a conceptual diagram illustrating an example of storing a stamp sample packet in the node of FIG. 1. After the node 10 transmits the symptom packet to the server 100, a node generates a stamp sample packet for a measurement sample in which an abnormality is found, and stores the same in a memory 17. The measurement sample is a sample that is measured for a certain period of time from the time of abnormal discovery and stored in a sliding window. For example, the measurement sample may correspond to a measurement sample for a period of ± T before and after the time of abnormal discovery.

The stamp sample packet is a packet stamped with the measurement sample. The stamp sample packet includes one or a plurality of pieces of information selected from a serial number, an error occurrence frequency, an error occurrence time, an abnormal end time, and an abnormal duration time for a measurement sample in which an abnormality is found. It includes.

If, as in step S140, the server 100 has a request for the measurement sample, the node 10 transmits a corresponding stamp sample packet stored in the memory 17 to the server 100. .

Accordingly, the second receiver 140 receives the stamp sample packet from the node 10 (S150). That is, the server 100 may transmit a command requesting a stamp sample packet to the node 10 and then receive it from the node 10 in order to check if the received corresponding symptom packet is abnormal. .

Thereafter, the monitor unit 150 precisely diagnoses and monitors the received stamp sample packet (S160). That is, the server 100 allows real-time comprehensive diagnosis of the corresponding power quality for each node 10.

Of course, the server 100 displays a series of processing contents according to the steps S110 to S160 in real time on the screen through the first display unit 160, thereby allowing the administrator to remotely control the micro grid power quality. It enables monitoring and confirmation in real time, and enables quick response in case of emergency.

Next, the first display unit 160 determines whether or not the abnormality is found for each node 10, the analysis result according to the diagnosis, the position of the node 10 in which the abnormality is found, and the time of finding the abnormality of the node 10. At least one is displayed (S170).

That is, the server 100 performs a comprehensive analysis on packet information of all the nodes 10 in the microgrid through the overall diagnosis and analysis process for each node 10, and thus, the location of discovery of power failure, the discovery time, and the like. Display in real time.

In addition, the storage unit 170 displays information displayed through the symptom packet, the stamp sample packet, and the first display unit 160 for each node 10 (whether the node 10 has found the abnormality, As a result of the analysis according to the diagnosis, at least one of the location of the node 10 where the abnormality is found and the time of discovery of the abnormality of the node 10) is stored to build a database for each node distributed in a predetermined area in real time (S180). ).

4 is a conceptual diagram illustrating an example of the method of FIG. 1. Hereinafter, with reference to Figure 4 will be described in detail with respect to specific embodiments of the power quality monitoring using wired and wireless communication according to the present invention.

First, a method of using wired communication, that is, power line communication, for transmitting and receiving various data between the server 100 and the nodes 10 will be described. The symptom packet of the nodes 10 installed in each customer is connected to the PLC router 20 (transformer installation, MAC protocol: CSMA-CA, routing protocol: RIP, IGRP, EIGRP, OSPF) through the LV power line (usually 600V or less). ) The low-speed power line transmission (eg, transmission speed: 5Kbps or less, carrier frequency: 450KHz) at a certain period.

The PLC router 20 collects the symptom packets from several nodes 10 and transmits them to the PLC repeater 30 (relaying at long distance transmission), and the PLC repeater 30 also receives them and transmits them to the PLC gateway 40 side. . In the section between the PLC router 20, the PCL repeater 30, and the PLC gateway 40, a high-speed power line transmission (ex, transmission rate: 20Mbps ~ 200Mbps, frequency: 2M ~ 30MHz) through the MV power line (600V or more). In the section between the PLC gateway 40 and the server 100, an optical cable or a DSL (digital subscriber line) is used for transmission.

The symptom packet measured at the node 10 is transmitted to the server 100 at regular intervals through the PLC router 20 or the like. In addition to the symptom packet transmission, the node 10 makes a measurement sample in which an abnormality is found into a stamp sample packet and stores it in the memory 17 (buffer). The size of the buffer is designed to be larger than a size that can store a certain observation time, and if a packet accumulates over time and overflow occurs, the buffer is automatically deleted from the memory 17 in the order in which it was stored first.

The server 100 receiving the symptom packet checks whether the power quality of the node 10 is normal from the symptom packet, and stamps a sample packet to the corresponding node 10 only when an abnormality is found, that is, when an abnormality is found. (Several thousands to tens of thousands or more bits). This effectively utilizes the limited power line channel bandwidth due to poor channel characteristics such as interference and fading, thereby enabling real-time and stable simultaneous monitoring of power quality for multiple nodes 10 in the grid. This series of processes is provided on the first display unit 160 (GUI environment) of the server 100, so that all the nodes 10 in the grid can be monitored in real time.

In practice, the node 10 receiving the stamp sample transmission command from the server 100 transmits the stored stamp sample packet (including the header) to the PLC router 20. At this time, the PLC router 20 transmits the stamp sample packet. In order to transmit to the server 100 at high speed by using a spare band separately.

The server 100 performs a precise diagnosis on the received stamp sample packet by applying a power measurement precision algorithm, and then displays the diagnosis result on the screen on the first display unit 160. Of course, in some cases, the server 100 switches the transmission mode of the node 10 from the stamp sample transmission mode to the continuous sample transmission mode, so that accurate quality measurement can be performed using data continuously transmitted from the node 10. It can be done. Of course, in the continuous sample transfer mode, the sample rate can also be changed remotely.

In addition, if a problem (ex, power failure) occurs in a large number of nodes 10 in a certain area (or entire area) of the grid at the same time, the transmission is limited only within the margin of the PLC router 20. Prevents congestion of poetry

The existing power quality measurement or monitoring method can be divided into web-based method using LAN and power line method. LAN-based method is designed to have power monitoring function of large-scale precision plant that requires precision and is very expensive and separate. LAN is required.

On the other hand, the power line using method does not require additional equipment, but has a disadvantage in that precision is limited due to bandwidth limitation. In addition, the conventional method using a power line having such a limited bandwidth generally has a 1: 1 power quality monitoring structure between the node and the server, and even if it has an N: 1 structure, it is designed to have only the simple function of the existing remote power meter. .

In contrast, the present invention is a system capable of monitoring power quality at the same time having an N: 1 structure, and enables accurate measurement and transmission of AC (single phase / 3 phase) as well as DC in preparation for the micro grid in the future. For example, the items of power quality include AC voltage, AC current, Harmonics, Sag, Swell, Interruption and , DC voltage on DC, DC current, surge, and the like. At this time, the measurement criteria are to be in accordance with IEEE 1159, a power quality-related standard. In addition, the information transmitted from the node 10 can be transmitted in both single phase and three phase.

In addition, when the transmission mode is specifically switched to symptom packet transmission mode, stamp sample packet transmission mode, and continuous transmission mode, only symptomatic packet data can be transmitted at all times to effectively utilize the limited power line bandwidth, and the large node 10 Facilitates quality monitoring and monitoring. In addition, when the symptom is found, the server 100 receives the stamp sample packet by changing the transmission mode through a notification (command), thereby enabling precise monitoring accordingly.

On the other hand, in the transmission and reception of various data between the server 100 and the nodes 10, in the case of using a wireless network communication method (ex, cellular, Wi-Fi, etc.) other than the power line communication described above, the PLC router 20 ), Instead of the PLC repeater 30 or the PLC gateway 40, a wireless router, a wireless repeater or a wireless gateway is used. In FIG. 4, an example in which the wireless repeater 50 is used for wireless communication is not necessarily limited thereto, and it is apparent that various embodiments may exist within the technical category.

FIG. 5 is a detailed configuration diagram of the node shown in FIG. 1. FIG. 5A illustrates a node configuration for wired communication, and FIG. 5B illustrates a node configuration for wireless network communication.

Unlike the general expensive power quality meter (PQM), the node 10 has a digital signal processor function, a low speed power line modem function, a central function along with sensing functions (filter, A / D converter, D / A converter). It can be implemented as a single SoC chip including processor (controller) function and memory function, and it can be assumed that it is designed within a limited size (portable) and has some limited functions in measuring power quality. For example, although harmonics require up to 63th order in IEEE 1159, the smart meter corresponding to the node 10 may be designed to a level capable of up to 50th order, but is not necessarily limited thereto.

First, referring to FIG. 5A, the node 10 for wired communication includes a coupler unit 11, an LPF 12a, a switch 13, an A / D converter 14a, and a controller 15. And a digital signal processor 16, a memory 17, a modem 18, a D / A converter 14b, and an HPF 12b.

Here, the coupler unit 11 drops the power signal received from the AC power line and outputs the voltage. The coupler unit 11 is composed of a sensor for detecting a signal, and a coupler for voltage drop.

The LPF 12a filters low frequency components with respect to a power signal having a voltage drop in the coupler unit 11. In particular, it serves to cut the frequency of 60Hz.

The A / D converter 14a performs A / D conversion and sampling of an AC signal among the power signals filtered by the LPF 12a. The digital signal processor 16 receives and processes an AC signal sampled by the A / D converter 14a.

The controller 15 compares the AC signal processed by the digital signal processor 16 with a pre-stored reference signal to determine whether the symptom item is normal for the AC signal, and generates the symptom packet according to the determination result. A stamp sample packet is generated for the measurement sample of the symptom item in which abnormality is found as a result of the determination.

The memory 17 stores a symptom packet or a stamp sample packet generated as described above as a data log. That is, the measurement sample having the abnormality is stamped and stored in the memory 17. In other words, when the node 10 transmits data in a slide manner and an item having a problem in power quality occurs, the node 10 stores the item as a stamp sample packet and stores it in the memory 17. According to the function of the memory 17 as described above, it is possible to perform the same function as the black box later by storing the log data every time the event occurs.

The second display unit 19 displays the normal condition information for each symptom item corresponding to the generated symptom packet, thereby enabling self-monitoring of power quality on the node 10. The self-monitoring function as described above is not only mainly used for initial confirmation at the time of installation of the node but also can be used for regular monitoring when necessary.

Here, notable in the present invention is the node 10 using the second display unit 19 as well as its own monitoring function in the server 100 using the monitor unit 150 and the first display unit 160 described above. In addition, its own monitoring function can be performed, so that the monitoring efficiency can be improved.

The modem 18 modulates the generated symptom packet or the stamp sample packet. The D / A converter 14b performs D / A conversion on the symptom packet or the stamp sample packet modulated by the modem 18.

In addition, the HPF 12b filters high frequency components of the symptom packet or the stamp sample packet converted by the D / A converter 14b. The coupler unit 11 also transmits the symptom packet or the stamp sample packet filtered by the HPF 12b to the server 100.

In this case, when the DC distributed power supply (ex, sunlight, PHEV, etc.) is measured, the switch 13 is used. That is, in the case of the DC signal of the power signal, the switch 13 is inputted to the control unit 15 without going through the A / D converter 14a after the voltage drop, so that the switch 13 in the LPF 12a It determines whether the output signal is AC or DC and transmits the corresponding signal to the A / D converter 14a or the controller 15.

Accordingly, the digital signal processing unit 16 compares the DC signal with other previously stored reference signals to determine whether the DC signal is normal for each symptom item. That is, the digital signal processor 16 determines whether the symptom items are normal for both AC and DC power supplies.

Next, referring to FIG. 5B, the node 10 for wireless network communication includes a coupler unit 11a, an LPF 12a, a switch 13, an A / D converter 14a, and a controller 15. And a digital signal processor 16, a memory 17, a modem 18, a D / A converter 14b, an RF converter 11b, and an antenna 11c.

At this time, the coupler unit 11a, LPF 12a, switch 13, A / D converter 14a, control unit 15, digital signal processing unit 16, memory 17, modem 18, D The configuration of the / A converter 14b performs the same function as that of the case of FIG. However, the coupler unit 11a performs the power signal reception function as it is but does not perform the packet transmission function.

The portion of the wireless communication node (Fig. 5 (b)) is different from the wire communication node (Fig. 5 (a)) is the RF converter 11b and the antenna (11c) portion for the wireless data transmission. .

That is, the RF converter 11b converts the symptom packet or the stamp sample packet converted by the D / A converter 14b into an RF communication band. The communication band may vary depending on the wireless scheme used. The antenna 11c wirelessly transmits the symptom packet or the stamp sample packet converted by the RF converter 11b to the server 100.

Accordingly, the node 10 may transmit / receive various packet information including the symptom packet to the remote server 100 by wire. In addition, as described above, a means such as a wireless router (for multiple access) or a wireless repeater may be used for long-range wireless communication.

6 is a flowchart illustrating an embodiment of processing information at a node illustrated in FIG. 1.

First, after the node 10 is installed in each home, company, factory, etc., the node 10 transmits its ID to the server 100 (S610). Thereafter, when the server 100 checks the ID and gives a transmission start command to the node 10, the node 10 measures the power quality and classifies the symptom items to provide a symptom packet regarding whether the server 100 is normal. In step S620, it is periodically transmitted.

 It should be noted that normally, only an item of power quality is transmitted, and when a sample transmission command, a transmission stop command, etc. are received from the server 100 (S630), the content of the command is analyzed and operated (S640). That is, step S630 is a step of continuously determining whether a specific command (control signal) comes from the server 100, and if there is no specific command, the step S620 is maintained.

After the step S640, the node 10 determines whether the corresponding command is a command (control == 000) to terminate communication at the server 100 (S650). In such a case, the communication of the node 10 is terminated.

If not, the node 10 determines whether the corresponding command is a command (control == 001) to stop data transmission from the server 100 (S660). As a result of the determination, when control == 001, the data transmission is paused and held (S661). Thereafter, the node 10 determines whether there is a command to restart communication at the server 100 (S662), and if so, switches to the step S620 to resume transmission, otherwise the holding state is changed. Hold (S661).

Next, as a result of the determination in step S660, if control == 001, it is determined whether the corresponding command is a command (control == 011) to transmit the measurement sample including the stamp sample from the server 100 (S670). In this case, the time information of the corresponding measurement sample is checked, and then a stamp sample packet corresponding to the corresponding time is transmitted to the server 100 (S671). Thereafter, the server 100 determines whether there is a command to terminate communication (control == 000), in which case, the communication of the node 10 is terminated, and otherwise, the operation S671 is maintained.

If, as a result of the determination of step S670, the command analysis fails or control == 011, the node 10 requests the server 100 to resend the command (S680) and proceeds to step S630.

See Table 1 below for an example of the above-described control signal and a description thereof.

control Explanation 000 end; When the server commands end of communication 001 stop; When the server commands stop sending data
010 (re) start; When the server initially sends a command to communicate with a node, resumes a paused transmission, or tells it to resume communication that has ended. 011 sampling; When the server requests a measurement sample containing a stamp sample 100 measure; When nodes measure power quality and send item-specific symptoms 101 sampling; When sending a measurement sample with a stamp sample from a node 110 no problem; When a node initially sends a node ID or communicates with the server, there is no problem with power quality.

In the present invention, it should be noted that the server 100 receives a symptom packet from the node 10 and receives one of the symptom items that are a problem in power quality, the stamp is stamped on the node 10 for accurate analysis. Sample packets can be requested and received.

In this case, since the LV power line uses a low data rate, the neighboring nodes 10 may be requested to stop transmitting the symptom packet for a while to maintain the speed. In other words, the server 100 receives ID information from the node, checks the corresponding node 10, and transmits a command to start measuring and transmitting power quality. Subsequently, it is determined whether the symptom item that is a problem in power quality is received from the node 10, and if there is a symptom item that is a problem, a request is made to transmit a stamp sample packet to the corresponding node 10, and other nodes 10 in the vicinity of the node 10. ) Is sending a command packet to stop transmission.

Table 2 shows an example of the data format used in the present invention.

Frame control Address1
(node) Address2
(router) Time
Info. Data CRC Type
(Server / node) Subtype
(mode) 2 bytes 6byte 6byte 2 bytes 0-2312byte 4 bytes 1 bit (0/1) 2 bit

The start bit and stop bit are included in the preamble and sync code. Data and cyclic redundancy check (CRC) parts are included in the data field, and Frame Control, Address 1, 2, and Time Info. Are PCC (Portable C). Compiler).

In addition, according to the information of the frame control (Frame Control), it is possible to distinguish whether the type of data (Data) refers to the error type or pure sampling (sampling) information in the future. For reference, the data length is different for the error type and the sampling information.

Address 1 and address 2 represent the addresses of the node 10 and the router 20, respectively. The reason for dividing the address into two parts is to manage the address system efficiently. If the server 100 transmits data, the address part contains an address of the node 20 to be received and the router 20 to pass through.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: node 11, 11a: coupler portion
11b: RF conversion unit 11c: antenna unit
12a: LPF 12b: HPF
13: switch 14a: A / D converter
14b: D / A converter 15: control unit
16: digital signal processor 17: memory
18: modem 19: display unit
20: Router 30: Repeater
40: gateway
100: micro grid power quality remote monitoring system
110: first receiving unit 120: confirming unit
130: command unit 140: second receiving unit
150: monitor unit 160: display unit

Claims (18)

In the micro grid power quality remote monitoring system in a micro grid power quality remote monitoring method,
Receiving a symptom packet of power quality from smart meter nodes measuring power quality of each consumer;
Analyzing the symptom packet to determine whether power quality of the nodes is normal;
Requesting a measurement sample of a symptom item in which an abnormality is found in a node whose power quality is identified as abnormal;
Receiving a stamp sample packet stamped with the measurement sample from the node;
Diagnosing and monitoring the received stamp sample packet;
Displaying at least one of whether the abnormality is found for each node, a result of analysis according to the diagnosis, a location of a node where the abnormality is found, and a time point of finding the abnormality of the node; And
Storing at least one of the symptom packet, the stamp sample packet, and whether or not the abnormality is found for each node, the analysis result according to the diagnosis, the position of the node where the abnormality is found, and the node's abnormality discovery time point for each node; Include,
The micro grid power quality remote monitoring method, and transmits and receives various information with the nodes using power line communication or wireless network communication,
When using the wireless network communication, the node,
A coupler unit for dropping and outputting a power signal received from an AC power line;
An LPF for filtering low frequency components of the power signal having the voltage drop in the coupler;
An A / D converter for A / D converting and sampling an AC signal among the power signals filtered by the LPF;
A digital signal processing unit for receiving and processing the AC signal sampled by the A / D converter:
Comparing the AC signal processed by the digital signal processing unit and the pre-stored reference signal to determine whether or not the normal condition for each symptom item for the AC signal, generate the symptom packet according to the determination result, and the abnormality is found A control unit for generating a stamp sample packet for a measurement sample of symptom items;
A memory for storing the generated symptom packet or the stamp sample packet as a data log;
A display unit that enables self-monitoring of power quality by displaying normal status information for each symptom item corresponding to the generated symptom packet;
A modem for modulating the symptom packet or the stamp sample packet;
A D / A converter for D / A converting the symptom packet or the stamp sample packet modulated by the modem;
An RF converter converting the symptom packet or the stamp sample packet converted by the D / A converter into an RF communication band; And
And an antenna configured to wirelessly transmit the symptom packet or the stamp sample packet converted by the RF converter to the system. The method according to claim 1,
The stamp sample packet is,
Micro-grid power quality remote monitoring method comprising one or a plurality of information selected from the serial number, the number of occurrences of abnormality, the abnormal occurrence time, the abnormal end time, the abnormal duration time for the measurement sample. The method according to claim 1,
The node is,
After the symptom packet is transmitted, a stamp sample packet for the measurement sample in which the abnormality is found is generated and stored in a memory, and when the request is made, the stored stamp sample packet is transmitted.
The measurement sample is a micro-grid power quality remote monitoring method is a sample that is measured for a certain period from the time of discovery of the abnormality and stored in the sliding window. The method according to claim 1,
The node is,
And transmitting the symptom packet at regular intervals, stopping the transmission of the symptom packet upon receiving a transmission stop command, and resuming the transmission of the symptom packet upon receiving a transmission restart command. The method of claim 4,
A micro grid power quality remote that transmits a command packet to stop transmission of the symptom packet to other neighboring nodes while transmitting a command packet for requesting the measurement sample to the node side where the power quality is found to be abnormal. Monitoring method. The method according to any one of claims 1 to 5,
And displaying a series of processing contents according to the respective steps on the screen. delete The method according to claim 1,
The node is,
Micro-grid power quality remote monitoring method for enabling the self-monitoring of the power quality by displaying the normal status information for each symptom item corresponding to the symptom packet, and storing the symptom packet and the stamp sample packet as a data log. In the micro grid power quality remote monitoring system,
A first receiver receiving a symptom packet of power quality from smart meter nodes measuring power quality of each customer;
A check unit for analyzing whether the symptom packet is normal to determine whether power quality of the nodes is normal;
A command unit for requesting a measurement sample of a symptom item in which an abnormality is found in a node in which the power quality is identified as abnormal;
A second receiver configured to receive a stamp sample packet stamped with the measurement sample from the node;
A monitor unit for diagnosing and monitoring the received stamp sample packet;
A display unit configured to display at least one of whether the abnormality is found for each node, a result of analysis according to the diagnosis, a position of a node where the abnormality is found, and a time point of finding the abnormality of the node; And
A storage unit for storing at least one of the symptom packet, the stamp sample packet, and whether or not the abnormality is found for each node, the analysis result according to the diagnosis, the position of the node where the abnormality is found, and the timing of the abnormality discovery of the node for each node; Include,
The micro grid power quality remote monitoring system, and transmits and receives various information with the nodes using power line communication or wireless network communication,
When using the wireless network communication, the node,
A coupler unit for dropping and outputting a power signal received from an AC power line;
An LPF for filtering low frequency components of the power signal having the voltage drop in the coupler;
An A / D converter for A / D converting and sampling an AC signal among the power signals filtered by the LPF;
A digital signal processing unit for receiving and processing the AC signal sampled by the A / D converter:
Comparing the AC signal processed by the digital signal processing unit and the pre-stored reference signal to determine whether the symptom item for the AC signal is normal, generate the symptom packet according to the determination result, and the abnormality is found A control unit for generating a stamp sample packet for a measurement sample of symptom items;
A memory for storing the generated symptom packet or the stamp sample packet as a data log;
A display unit that enables self-monitoring of power quality by displaying normal status information for each symptom item corresponding to the generated symptom packet;
A modem for modulating the symptom packet or the stamp sample packet;
A D / A converter for D / A converting the symptom packet or the stamp sample packet modulated by the modem;
An RF converter converting the symptom packet or the stamp sample packet converted by the D / A converter into an RF communication band; And
And an antenna configured to wirelessly transmit the symptom packet or the stamp sample packet converted by the RF converter to the system. The method according to claim 9,
The stamp sample packet is,
Micro-grid power quality remote monitoring system including one or a plurality of information selected from the serial number for the measurement sample, the number of occurrences of the error, the abnormal occurrence time, the abnormal end time, the abnormal duration time. The method according to claim 9,
The node is,
After the symptom packet is transmitted, a stamp sample packet for the measurement sample in which the abnormality is found is generated and stored in a memory, and when the request is made, the stored stamp sample packet is transmitted.
The measurement sample is a micro-grid power quality remote monitoring system is a sample that is measured for a period of time from the time of abnormal discovery and stored in the sliding window. The method according to claim 9,
The node is,
And transmitting the symptom packet at regular intervals, stopping the transmission of the symptom packet upon receiving a transmission stop command, and resuming the transmission of the symptom packet upon receiving a transmission restart command. The method of claim 12,
The command unit,
A micro grid power quality remote that transmits a command packet to stop transmission of the symptom packet to other neighboring nodes while transmitting a command packet for requesting the measurement sample to the node side where the power quality is found to be abnormal. Monitoring system. The method according to any one of claims 9 to 13,
The display unit includes:
The micro-grid power quality remote monitoring system further displays a series of processing contents according to the first receiver, the confirmation unit, the second receiver, the command unit, and the monitor unit. delete The method according to claim 9,
When using the power line communication, the node,
A coupler unit for dropping and outputting a power signal received from an AC power line;
An LPF for filtering low frequency components of the power signal having the voltage drop in the coupler;
An A / D converter for A / D converting and sampling an AC signal among the power signals filtered by the LPF;
A digital signal processing unit for receiving and processing the AC signal sampled by the A / D converter:
Comparing the AC signal processed by the digital signal processing unit and the pre-stored reference signal to determine whether or not the normal condition for each symptom item for the AC signal, generate the symptom packet according to the determination result, and the abnormality is found A control unit for generating a stamp sample packet for a measurement sample of symptom items;
A memory for storing the generated symptom packet or the stamp sample packet as a data log;
A display unit that enables self-monitoring of power quality by displaying normal status information for each symptom item corresponding to the generated symptom packet;
A modem for modulating the symptom packet or the stamp sample packet;
A D / A converter for D / A converting the symptom packet or the stamp sample packet modulated by the modem; And
HPF for filtering the high frequency components for the symptom packet or the stamp sample packet converted in the D / A converter,
The coupler unit,
And a symptom packet or stamp sample packet filtered by the HPF to the system via power line communication. delete The method according to claim 9 or 16,
The node is,
The DC signal of the power signal is directly input to the digital signal processor without being processed through the A / D converter to determine whether the AC or DC signal output from the LPF and the corresponding signal to the A / D converter or the digital Further comprising a switch for transmitting to the signal processing unit,
The control unit is a micro-grid power quality remote monitoring system for comparing the DC signal and other stored reference signal to determine whether the normal status by the symptom item for the DC signal.

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