Electrical load monitoring system and monitoring method

Abstract

The invention discloses an electrical load monitoring system and a monitoring method. The monitoring system comprises a management master station; the electricity meter is arranged at a user side and can be in communication connection with the management master station through a power line; the socket is electrically connected with the electricity meter and comprises a power line broadband carrier communication signal transmitting module, a voltage detection module, a current detection module and a jack pressure detection module; the power line broadband carrier communication signal transmitting module is used for transmitting a broadband carrier communication signal to an electric meter; the voltage detection module is used for detecting a line voltage value of the socket; the current detection module is used for detecting the current value of each jack on the socket; the jack pressure detection module is used for detecting the pressure value of the jack. According to the invention, a traditional high-complexity data analysis solution is replaced by a simple communication solution, related functions can be realized on the basis of existing low-voltage transformer area power grid facilities and systems, the monitoring capability is strong, the malicious damage behavior resistance is strong, and the hardware cost is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of electricity consumption monitoring, and in particular relates to an electricity load monitoring system and a monitoring method. Background Art

[0002] Monitoring the key power load conditions in the power grid is a technical issue that the power grid management department is very concerned about. The current traditional solution is to adopt a non-invasive power load identification technology based on the acquisition and analysis of load power parameters. This solution is to install a sensing device at the load confluence point, perform high-frequency sampling and characteristic quantity calculation on the voltage and current at the load confluence point, and realize the state identification, type identification, and sub-item power estimation of power equipment through edge computing or cloud-edge collaboration. For example, the power load identification method based on waveform data feature analysis disclosed in Chinese Invention Patent Application No. 202110343324.5, and the real-time online monitoring and identification method of power load disclosed in Chinese Invention Patent No. 202111247143.9. However, this non-invasive power load identification technology has the following problems in practical applications:

[0003] 1) There are many types of power loads in the power grid. The power parameters of the same type of power equipment from different manufacturers may have different characteristics. In addition, the power characteristics of power equipment may change due to the iterative updates of manufacturing technology. Therefore, it is necessary to continuously update the power load power characteristics database, which requires a large amount of sampling data, a long technology development cycle, and high economic costs.

[0004] 2) The power load identification equipment needs to support high-frequency sampling and high-complexity data analysis, and also needs to report a large amount of information. The system is relatively complex, and the software and hardware costs are high.

[0005] 3) The power consumption characteristics of a large number of different types of power loads on the power supply line are superimposed on each other, making it difficult to separate and analyze the signals. The power load identification equipment currently sold on the market has poor identification accuracy in complex power consumption environments. Summary of the invention

[0006] The object of the present invention is to provide a power load monitoring system and a monitoring method which have low hardware cost, strong monitoring capability, and are simple and practical.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A power load monitoring system comprises: a management main station; an electric meter arranged at a user end, the electric meter being capable of communicating with the management main station via a power line; and a socket electrically connected to the electric meter, the socket comprising: a power line broadband carrier communication signal transmitting module, a voltage detection module, a current detection module and a socket pressure detection module; the power line broadband carrier communication signal transmitting module is used to send a broadband carrier communication signal to the electric meter, the broadband carrier communication signal comprising a socket online heartbeat signal, a state change notification signal, an electric load start operation mark signal, an electric load operation heartbeat signal and an electric load stop operation mark signal; the voltage detection module is used to detect the line voltage value of the socket; the current detection module is used to detect the current value of each socket on the socket; the socket pressure detection module is used to detect the pressure value of the socket.

[0009] Furthermore, the socket also includes a temporary power supply module for temporarily supplying power to the power line broadband carrier communication signal transmitting module, the voltage detection module, the current detection module and the jack pressure detection module.

[0010] Furthermore, the socket is provided with a main switch for controlling the physical connection relationship between the socket and the power supply line, and the power line broadband carrier communication signal transmitting module, the voltage detection module, the current detection module and the jack pressure detection module are located at the front end of the main switch.

[0011] Furthermore, the socket has three working states: state SS0: the voltage detection value is zero; state SS1: power supply state of the power supply line; and state SS2: power supply state of the temporary power supply module.

[0012] Furthermore, the jack on the socket has three working states: state S0: no plug is inserted into the jack and there is no current; state S1: a plug is inserted into the jack and the current is zero; state S2: a plug is inserted into the jack and the current is non-zero.

[0013] The monitoring method of the above-mentioned power load monitoring system comprises the following steps:

[0014] The socket is connected to the power supply line, and the plug of the electrical device is inserted into the socket of the socket. After the electrical device is powered on, the power line broadband carrier communication signal transmission module, the voltage detection module, the current detection module and the socket pressure detection module continuously detect the working state of the socket and the working state of each socket;

[0015] When the working state of the socket or the jack changes, the power line broadband carrier communication signal transmitting module immediately sends a state change notification signal to the electric meter;

[0016] When the socket is in a power supply state, the power line broadband carrier communication signal transmitting module periodically sends a socket online heartbeat signal to the electric meter;

[0017] When a plug is inserted into a socket on the socket and the current detection value changes from zero to non-zero, the power line broadband carrier communication signal transmitting module sends a power load start operation marking signal to the electric meter;

[0018] When a plug is inserted into a socket on the socket and the current detection value is non-zero, the power line broadband carrier communication signal transmission module periodically sends a power load operation heartbeat signal to the electric meter;

[0019] When a plug is inserted into a certain jack of the socket and the current detection value changes from non-zero to zero, the power line broadband carrier communication signal transmitting module sends a power load stop operation marking signal to the electric meter.

[0020] Furthermore, the broadband carrier communication signal sent by the power line broadband carrier communication signal transmitting module only includes a frame control part, and a frame payload part is empty.

[0021] Furthermore, the frequency of sending the heartbeat signal by the power line broadband carrier communication signal transmitting module when powered by the power supply line is higher than the frequency when powered by the temporary power supply module.

[0022] It can be known from the above technical scheme that the present invention sets a power line broadband carrier communication signal transmitting module, a voltage detection module, a current detection module and a jack pressure detection module in the socket. The voltage detection module and the current detection module can detect whether the connection between the socket and the power supply line is interrupted by detecting the current and the current. The pressure detection module detects whether the plug of the electrical equipment is pulled out of the jack, and the power line broadband carrier communication signal transmitting module periodically sends a heartbeat signal to the electric meter, so that the electric meter knows the existence of the socket, and sends a response identification signal according to the change of the socket or jack status during the monitoring process, so that the electric meter knows the operating status of the electrical equipment and whether malicious sabotage occurs during the monitoring process, so as to accurately grasp the operating information of the electrical equipment. The present invention replaces the traditional high-complexity data analysis solution with a simple communication solution, and can realize related functions on the basis of the existing low-voltage power grid facilities and systems. It has strong monitoring capabilities, strong anti-malicious sabotage capabilities, and low hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 is a block diagram of a power load monitoring system according to an embodiment of the present invention;

[0025] Figure 2 is a block diagram of a socket according to an embodiment of the present invention;

[0026] Figure 3 This is a working state diagram of the socket according to an embodiment of the present invention;

[0027] Figure 4 This is a working state diagram of the jack on the socket according to an embodiment of the present invention;

[0028] Figure 5 This is the frame signal format sent by the power line broadband carrier communication signal transmitting module in the embodiment of the present invention.

[0029] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the accompanying drawings. When describing the embodiments of the present invention in detail, for the convenience of explanation, the drawings representing the device structure will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. It should be noted that the drawings are simplified in form and use non-precise proportions, which are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention. At the same time, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated; the terms "positive", "negative", "bottom", "upper", "lower", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two elements, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] With the construction of the power Internet of Things, power demand side management is gradually developing in a refined direction. The identification / monitoring of key power loads has strong application prospects in many fields of production and life. For example, enterprises need to monitor the use of some of their own high-power electrical equipment, such as whether the office air conditioner is turned off during non-working hours; environmental protection departments need to monitor whether the environmental protection treatment equipment of the company's pollution emissions continues to operate as required and whether it stops operating in violation of regulations; parents need to know whether their children watch TV or use desktop computers for a long time when they are alone at home. Existing non-invasive power load identification technology has problems in practical applications, such as large amount of sampling data, complex analysis algorithms, high cost, and low identification accuracy in complex power consumption environments.

[0033] Power line carrier communication technology is a technology that uses power lines to transmit communication signals, and is widely used in power grids. The electric meter is the core equipment in the low-voltage distribution network, and has many functions such as user electricity metering, power grid operation parameter monitoring and communication. With the release of the communication standards Q / GDW 11612-2016 "Technical Specifications for Interoperability of Low-Voltage Power Line Broadband Carrier Communication" and Q / GDW12087.43-2020 "Technical Specifications for Interoperability of Dual-Mode Communication", the electric meters currently used in the power grid system basically have the ability to receive and send power line broadband carrier communication signals. In response to the above problems, the present invention improves the smart socket based on the power line carrier communication technology, and provides a power load monitoring system and monitoring method using smart sockets and power line carrier communication technology.

[0034] like Figure 1 As shown, the power load monitoring system of this embodiment includes: a management main station 1, an electric meter 2 arranged at the user end, and a socket 3 arranged at the user end, and the electric meter 2 and the socket 3 each include a plurality of them. The electric meter 2 is embedded with a power line broadband carrier communication module or a power line broadband carrier + wireless dual-mode communication module, and can be connected to the management main station 1 through the power line. The electric meter 2 can collect the power consumption information of the user end. In this embodiment, the power load of the electric device plugged into the socket 3 is monitored in real time through the socket 3. When the socket 3 is plugged in, the operating status of each electric device plugged into the socket can be sent to the management main station 1 through the electric meter 2 through the power line, thereby realizing the management main station 1 to monitor the operating status of the electric device connected to the socket 3.

[0035] like Figure 2 As shown, the socket 3 of this embodiment, in addition to having the basic functions of a conventional electrical socket (i.e., providing access to power supply lines for various electrical devices), is also provided with a power line broadband carrier communication signal transmitting module 3-1, a voltage detection module 3-2, a current detection module 3-3 and a jack pressure detection module 3-4.

[0036] The power line broadband carrier communication signal transmitting module 3-1 is used to send broadband carrier communication signals to the electric meter 2. The broadband carrier communication signals sent include socket online heartbeat signals, status change notification signals, power load start operation mark signals, power load operation heartbeat signals, and power load stop operation mark signals, etc. Among them, the socket online heartbeat signal carries the current working status information of each socket on the socket 3.

[0037] The voltage detection module 3-2 is used to detect the line voltage value of the socket 3. By detecting whether the line voltage value of the socket 3 is zero, it is determined whether the power supply line connected to the socket 3 has a power outage or whether the electrical connection between the two is interrupted. Generally speaking, there are only two situations that will cause the line voltage value of the socket 3 to be zero. One situation is that there is no connection between the socket 3 and the power supply line, such as the main switch of the socket is turned off, the socket is powered off, or the plug of the socket is pulled out of the power supply line. The other situation is that the power supply line is out of power.

[0038] The current detection module 3-3 is used to detect the current value of each socket on the socket 3. Each socket on the socket 3 can be connected to an electrical device. By detecting whether the current value of the socket is zero, it is determined whether the electrical device connected to the socket is in operation. Generally speaking, the current value of the socket is zero in the following situations: the sub-switch of the socket is turned off or the main switch of the socket 3 is turned off, the power supply line is out of power, the socket is not plugged into an electrical device, or the electrical device connected to the socket is not powered on.

[0039] The jack pressure detection module 3-4 is used to detect the pressure value of the jack. By detecting the jack pressure, it is determined whether a plug is inserted or pulled out.

[0040] Optionally, a physical switch (main switch) can be designed for socket 3 to control the physical connection relationship between socket 3 and the power supply line. When socket 3 is provided with a physical switch, the power line broadband carrier communication signal transmitting module 3-1, the voltage detection module 3-2, the current detection module 3-3, and the socket pressure detection module 3-4 are all connected to the front end of the physical switch, so that when the socket 3 is opened or closed by the physical switch, the working status of the above modules will not be affected.

[0041] Preferably, the socket 3 of this embodiment also includes a temporary power supply module (not shown). The temporary power supply module can be a rechargeable battery or a capacitor module. The temporary power supply module is used to supply power to the power line broadband carrier communication signal transmission module 3-1, the voltage detection module 3-2, the current detection module 3-3, and the jack pressure detection module 3-4, so that in the event of a power outage / power failure, the above modules can continue to work normally for a certain period of time, generally to ensure that the above modules continue to work for 24 hours. When the temporary power supply module is exhausted, the various parameters of the socket 3 are restored to the initial state values.

[0042] The electrical equipment monitored by the power load monitoring system is often a key electrical equipment that runs for a long time in a fixed position. In the absence of malicious human behavior, the connection between the socket and the power line, and the connection between the electrical equipment and the socket are stable and unchanged, and the plug will not be pulled out and reinserted. The purpose of setting up a temporary power supply module in this embodiment is to be able to monitor the electrical equipment in the event of a temporary power outage or a malicious power outage.

[0043] In practical applications, under non-extreme circumstances (i.e., excluding extreme circumstances such as typhoons and earthquakes), temporary planned local area power outages for maintenance during the normal operation of the power grid or unexpected power grid failures usually do not cause long power outages of more than 24 hours. For the electrical equipment to be monitored, it can be assumed that the connection between the socket where the electrical equipment is plugged in and the power supply line is normal, so each module of the socket can work normally, so that it can accurately determine whether the plug is pulled out and inserted, and notify the meter when the above situation occurs. Even if the connection between the socket and the power supply line is maliciously damaged by human beings, the temporary power supply module can ensure that the above behavior is detected and the meter is notified. If the connection between the socket and the power supply line is restored after the power supply time of the temporary power supply module has exceeded, since the parameters of the socket will be restored to the initial state value, when the meter receives the signal sent by the socket again, it can also combine its own power supply situation to determine that the connection between the socket and the power supply line has been damaged by human beings.

[0044] The power load monitoring system of this embodiment can be applied to the following two monitoring scenarios. One is that the power load user actively implements monitoring. For example, a residential user wants to know the operating conditions of the electrical equipment at home, such as the operating conditions of the air conditioner, etc. In this case, the user has no motivation to maliciously damage the monitoring. Therefore, the electrical equipment and the socket will generally not change after being connected, so the user can monitor the power load of the electrical equipment at any time.

[0045] Another monitoring scenario is that the user of the power load passively cooperates with the monitoring. For example, the environmental protection department monitors the operation of the environmental protection treatment equipment of the enterprise. In this case, the user of the power load (the enterprise) may have the motivation to disrupt the monitoring and implement behaviors that disrupt the monitoring process, such as destroying the connection between the power equipment and the socket, destroying the connection between the socket and the power supply line, replacing the monitored object to mislead the implementer of the monitoring behavior (superior management department), etc. After setting up the temporary power supply module, the operating status of the power equipment can be monitored in the event of a power outage.

[0046] For a certain socket on the socket of this embodiment, it has three working states: state S0: no plug is inserted into the socket and there is no current; state S1: a plug is inserted into the socket and the current is zero; state S2: a plug is inserted into the socket and the current is non-zero. Figure 3 As shown, when the state of the jack changes from S0 to S1, it is judged that a plug is inserted, and when it changes from state S1 to S0, it is judged that a plug is pulled out. When the state of the jack changes from S0 to S2, it is judged that a plug is inserted, and the detection current is non-zero; when it changes from state S2 to S0, it is judged that a plug is pulled out, and the detection current is zero. When the state of the jack changes from S1 to S2, it is judged that the detection current is non-zero; when it changes from state S2 to S1, it is judged that the detection current is zero.

[0047] The socket of this embodiment also has three working states: state SS0: the voltage detection value is zero, and the temporary power supply module has no power; state SS1: the power supply line is in power supply state; SS2: the temporary power supply module is in power supply state. Figure 4 As shown, when the socket state changes from SS0 to SS1, the voltage detection value of the socket is greater than the voltage threshold C; when the socket state changes from SS1 to SS2, the voltage detection value of the socket is zero; when the socket state changes from SS2 to SS1, the voltage detection value of the socket is greater than the voltage threshold C; when the socket state changes from SS2 to SS0, the temporary power supply module is exhausted.

[0048] The power load monitoring method of the present invention comprises the following steps:

[0049] The socket is connected to the power supply line, and the power line broadband carrier communication signal transmission module, voltage detection module, current detection module, and socket pressure detection module of the socket start to operate. The plug of the electrical device is inserted into the socket of the socket. After the device is powered on, each module continuously detects the working status of the socket and the working status of each socket;

[0050] When the working state of the socket or jack changes, the power line broadband carrier communication signal transmission module immediately sends a state change notification signal to the electric meter, so that the electric meter is informed of the change in the working state of the socket or jack;

[0051] When the socket working state is in SS1 or SS2, that is, when the socket is in the power supply state (powered by the power supply line or by the temporary power supply module), the power line broadband carrier communication signal transmitting module periodically sends the socket online heartbeat signal to the electric meter, carrying the current working state information of each socket in turn, so that the electric meter knows the existence of the socket and the various states of the current socket; further, in state SS1 and state SS2, the frequency of sending the heartbeat signal by the power line broadband carrier communication signal transmitting module may be different. In state SS2, the sending frequency may be relatively low to save the power of the temporary power supply module. For example, in state SS1, the sending frequency is to send a heartbeat signal once every 10 minutes, and in state SS2, the sending frequency may be to send a heartbeat signal once every 20 minutes;

[0052] When the working state of a socket on the socket changes from S1 to S2, it means that the electrical equipment on the socket starts to be powered on and run, and the power line broadband carrier communication signal transmitting module sends a power load start running mark signal to the electric meter, so that the electric meter knows that the electrical equipment starts to run;

[0053] When a socket on the socket is in state S2, that is, in the power-on operation stage, the power line broadband carrier communication signal transmission module periodically sends the power load operation heartbeat signal to the electric meter, so that the electric meter knows that the electric equipment is in operation; the power load operation heartbeat signal can be sent once per minute;

[0054] When the working state of a socket on the socket changes from S2 to S1, it means that the electrical equipment on the socket has stopped running. The power line broadband carrier communication signal transmitting module sends a power load stop running mark signal to the electric meter to let the electric meter know that the electrical equipment has stopped running.

[0055] After the meter receives the broadband carrier communication signal sent by the socket for the first time, it will establish a dedicated information storage space for the socket. Since the meter itself has the ability to synchronize and maintain time, after receiving the broadband carrier communication signal sent by the socket, it can timestamp the information that the monitoring implementer is concerned about, including: the time when the socket is online, the time when the socket working status changes, the time when the socket working status changes, the time when the electrical equipment on the socket starts to power on and stops running, etc., and report the above information to the management master station through the electricity information collection system.

[0056] In order to reduce the amount of communication data and not affect the reading of the electricity consumption parameter information of the electricity consumption information collection system, the frame format of the broadband carrier communication signal sent by the power line broadband carrier communication signal transmitting module of this embodiment is as follows: Figure 5As shown, the signal only includes the frame control part, and the byte of the frame payload part is 0, that is, the frame payload part is empty. Therefore, the broadband carrier communication signal sent by the power line broadband carrier communication signal transmitting module is the shortest in the physical layer signal supported by the power line broadband carrier communication standard. Therefore, the impact on the original communication process of the electric meter can be ignored.

[0057] Specifically, the field definition of the frame control part of this embodiment is shown in Table 1. The field content of the frame control part is based on the existing standard definition, and the content is extended for the reserved bits to achieve compatibility with the existing standard.

[0058] Table 1

[0059]

[0060] The definitions of other fields with a length of 101 bits in Table 1 are shown in Table 2.

[0061] Table 2

[0062]

[0063]

[0064] The function of the voltage threshold C is to determine whether the socket is connected to the power line, so its specific value is set according to the working environment of the socket. For example, on a 220V AC power supply line, the voltage threshold C can be set to 180V.

[0065] At present, the electric meters in the power grid have their own line power failure detection devices. Therefore, if the number of power-on or power-off times of the socket changes when there is no power failure, it means that someone has damaged the connection between the socket and the power supply line. If the number of insertions and unplugging times of a socket changes, it also means that someone has damaged the connection between the socket and the electrical device plugged into it.

[0066] In specific applications, the sockets will be attached with a unique product serial number. The monitoring implementer can bind the socket by scanning the QR code on the socket or in the product manual. For example, after scanning the QR code of the socket through the corresponding app, the product serial number corresponding to the socket will be added to the app. To ensure the security of the user's electricity information, each product serial number can only be bound to one real-name user. After the management master station finds that the socket is bound, it can send information related to the bound socket to the monitoring implementer, so that the monitoring implementer can obtain the operating information of the electrical equipment connected to the socket in real time through the app.

[0067] The present invention improves the socket and adds a corresponding module to the socket to realize the monitoring of the state of the electric device plugged into the socket. The added functions can be realized by low-cost hardware, and the hardware cost is low. In addition, the communication between the socket (electrical device), the electric meter and the management master station is realized through the power line, and the relevant functions can be realized on the existing power grid system. The relevant technologies are very mature, and the technical development difficulty is low. There is no need to add and deploy any new hardware equipment, and there is no additional cost. The utilization rate of the infrastructure of the power grid system is also improved. The monitoring process of the present invention can be carried out entirely on a dedicated system inside the power grid, and the user's electricity information security is relatively high.

[0068] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power load monitoring system, characterized in that: include: Manage the main site; An electric meter arranged at the user end, the electric meter being communicatively connected to the management master station via a power line; A socket electrically connected to the electric meter, the socket comprising: a power line broadband carrier communication signal transmission module, a voltage detection module, a current detection module and a jack pressure detection module; The power line broadband carrier communication signal transmitting module is used to send a broadband carrier communication signal to the electric meter, and the broadband carrier communication signal includes a socket online heartbeat signal, a state change notification signal, a power load start operation mark signal, a power load operation heartbeat signal and a power load stop operation mark signal; The voltage detection module is used to detect the line voltage value of the socket; The current detection module is used to detect the current value of each jack on the socket; The jack pressure detection module is used to detect the pressure value of the jack.

2. The power load monitoring system according to claim 1, characterized in that: The socket also includes a temporary power supply module for temporarily supplying power to the power line broadband carrier communication signal transmission module, the voltage detection module, the current detection module and the jack pressure detection module.

3. The power load monitoring system according to claim 1, characterized in that: The socket is provided with a main switch for controlling the physical connection relationship between the socket and the power supply line, and the power line broadband carrier communication signal transmitting module, the voltage detection module, the current detection module and the jack pressure detection module are located at the front end of the main switch.

4. The power load monitoring system according to claim 1, characterized in that: The socket has three working states: state SS0: the voltage detection value is zero; state SS1: power supply state of the power supply line; and state SS2: power supply state of the temporary power supply module.

5. The power load monitoring system according to claim 1, characterized in that: The jack on the socket has three working states: state S0: no plug is inserted into the jack and there is no current; state S1: a plug is inserted into the jack and the current is zero; state S2: a plug is inserted into the jack and the current is non-zero.

6. The monitoring method of the power load monitoring system according to any one of claims 1 to 5, characterized in that: The following steps are involved: The socket is connected to the power supply line, and the plug of the electrical device is inserted into the socket of the socket. After the electrical device is powered on, the power line broadband carrier communication signal transmission module, the voltage detection module, the current detection module and the socket pressure detection module continuously detect the working state of the socket and the working state of each socket; When the working state of the socket or the jack changes, the power line broadband carrier communication signal transmitting module immediately sends a state change notification signal to the electric meter; When the socket is in a power supply state, the power line broadband carrier communication signal transmitting module periodically sends a socket online heartbeat signal to the electric meter; When a plug is inserted into a socket on the socket and the current detection value changes from zero to non-zero, the power line broadband carrier communication signal transmitting module sends a power load start operation marking signal to the electric meter; When a plug is inserted into a socket on the socket and the current detection value is non-zero, the power line broadband carrier communication signal transmission module periodically sends a power load operation heartbeat signal to the electric meter; When a plug is inserted into a certain jack of the socket and the current detection value changes from non-zero to zero, the power line broadband carrier communication signal transmitting module sends a power load stop operation marking signal to the electric meter.

7. The monitoring method according to claim 6, characterized in that: The broadband carrier communication signal sent by the power line broadband carrier communication signal transmitting module only includes a frame control part, and a frame payload part is empty.

8. The monitoring method according to claim 6, characterized in that: When powered by the power supply line, the frequency at which the power line broadband carrier communication signal transmitting module sends the heartbeat signal is higher than the frequency when powered by the temporary power supply module.

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