Distributed power quality monitoring device of intelligent socket

Abstract

The invention relates to the technical field of electric energy quality monitoring, in particular to a distributed electric energy quality monitoring device of an intelligent socket, which comprises a socket body, and is characterized in that the socket body is provided with a main control chip MCU, and a power management module, a signal acquisition unit, a storage unit and a communication module which are respectively connected with the MCU; the signal acquisition unit is used for acquiring voltage and current waveform data accessed to an electric appliance in real time, and the storage unit is used for storing a preset electric energy quality characteristic threshold value and historical monitoring data. The electric energy quality characteristic value is extracted through a short-time Fourier transform and wavelet transform combined algorithm, real-time monitoring of steady-state and transient parameters is achieved, quick response to abnormal events, a zero-power-consumption trigger device embedded into a socket and a dual protection mechanism are supported, standby zero power consumption and power utilization safety are ensured, the deployment cost can be remarkably reduced, and the method is suitable for large-scale popularization and application. And the power utilization safety and reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power quality monitoring, and particularly relates to a distributed power quality monitoring device of an intelligent socket. BACKGROUND

[0002] With the complication of power systems and the diversification of electrical equipment, power quality monitoring plays a crucial role in modern power grid management. Especially at the end of the power grid (such as the residential side), real-time monitoring and analysis of power quality become the key to ensuring the normal operation of precision equipment. However, the existing power quality monitoring technology has many shortcomings and cannot meet the actual needs. Traditional power quality analyzers (such as Fluke 435) usually adopt a centralized architecture, relying on a central server for data processing and analysis. This architecture not only has high expansion costs, but also has the risk of single point failure. Once the central server has a problem, the entire monitoring system may be paralyzed. In addition, the functions of existing devices are relatively single, only supporting steady-state parameter monitoring specified in IEC 61000-4-30 standard, which cannot effectively capture transient events (such as voltage sag, transient overvoltage, etc.), and these transient events often have the most significant impact on electrical equipment.

[0003] 61000-4-30 standard, which cannot effectively capture transient events (such as voltage sag, transient overvoltage, etc.), and these transient events often have the most significant impact on electrical equipment.

[0004] On the other hand, the high cost (usually more than $2000 per unit) of professional power quality monitoring equipment further limits its large-scale deployment at the end of the power grid. This contradiction between cost and deployment needs makes it difficult to achieve comprehensive coverage of power quality monitoring at the residential side and small users. At the same time, existing technologies generally adopt cloud analysis mode, resulting in a response delay of more than 500ms in data transmission and processing, which cannot meet the real-time requirements of precision equipment in power quality application scenarios. This delay not only affects the timeliness of monitoring, but also may cause protection action lag, thereby threatening the safety of equipment and the stability of the power grid.

[0005] Therefore, there is an urgent need for a new type of power quality monitoring device that can achieve distributed deployment while reducing costs, has the ability to capture transient events, and significantly improves response speed to meet the needs of modern power grids for high-precision, real-time, and extensive coverage of power quality monitoring. SUMMARY

[0006] The purpose of the present application is to provide a distributed power quality monitoring device of an intelligent socket to solve the problems of high expansion cost, single function, and difficulty in covering the end of the power grid of traditional power quality analysis equipment. The device realizes real-time monitoring of steady-state and transient power quality parameters through a distributed architecture design, and has the ability to quickly respond to abnormal events.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The distributed power quality monitoring device includes a socket body, on which a main control chip (MCU) and a power management module, a signal acquisition unit, a storage unit, and a communication module are respectively connected to the MCU. The signal acquisition unit is used to collect voltage and current waveform data of connected electrical appliances in real time. The storage unit is used to store preset power quality characteristic thresholds and historical monitoring data. The power quality analysis unit extracts key feature values ​​by performing time-frequency domain analysis on the acquired signals and compares them with the feature thresholds in the storage unit. If a match is found, the analysis result is output to the MCU. The MCU forms an ad hoc network communication connection with a remote control center or nearby nodes through a wireless communication module.

[0009] Furthermore, the power supply circuit of the smart socket incorporates a zero-power trigger device, consisting of a pair of elastic contacts. This device activates when a plug is inserted and automatically deactivates when no plug is inserted, achieving zero-power operation in standby mode. The MCU is also connected to a smart switch unit, used to dynamically adjust the load power supply status based on power quality analysis results. The power supply circuit features a dual protection mechanism, including an overload protection unit and a transient suppression unit. The former quickly cuts off the circuit upon detecting an overload, while the latter absorbs transient overvoltages through a built-in metal oxide varistor (MOV) to ensure electrical safety. The MCU also integrates an emergency manual control interface, allowing users to directly intervene in the power supply status in emergencies. A display unit connected to the MCU visually presents current power quality indicators and historical trend graphs. In addition, the MCU supports an infrared communication module for easy interaction with home remote control devices. The wireless communication module is compatible with multiple protocols such as ZigBee, LoRa, and NB-IoT, adapting to communication needs in different scenarios.

[0010] The distributed power quality monitoring device of this invention employs a joint analysis algorithm based on Short-Time Fourier Transform (STFT) and Wavelet Transform (WT) to extract power quality feature values. The specific formula is as follows:

[0011] Where S(t,f) represents the signal x(τ) at time t and frequency f. The time-frequency distribution on the graph is given, where w(t-τ) is a window function used to localize the time characteristics of the signal. This algorithm, combined with the multi-resolution characteristics of wavelet transform, can effectively capture transient events such as voltage drops and transient overvoltages, and calculates the eigenvalues ​​using the following formula: Where E k Indicates the first Energy characteristic value of power quality events, W(a) i ,b i ) are wavelet coefficients, ai and b i are scale and translation parameters respectively. Through the above algorithm, the device can complete the identification and classification of power quality events within milliseconds.

[0012] Compared with the prior art, the application has the beneficial effects that:

[0013] 1. The distributed power quality monitoring device has distributed data processing capability, and each smart socket can independently complete the power quality monitoring task, while supporting cooperative work with other nodes to form a monitoring network covering the entire power grid terminal. In the independent mode, the device can provide real-time power quality reports for users, including voltage deviation, harmonic distortion rate, three-phase imbalance degree and other key indicators. Through the self-organizing network technology, the device can realize plug and play without additional configuration, significantly reducing the deployment cost.

[0014] 2. Users can view real-time and historical power quality data at any time through mobile terminals or local display screens, understand potential risks and take preventive measures. In addition, the device can complete the protection action within 20ms when detecting power quality problems (such as overvoltage, undervoltage, and harmonic overlimit), avoiding damage to precision equipment and improving the safety and reliability of power consumption.

[0015] The above description is only a summary of the technical solutions of the application. In order to more clearly understand the technical means of the application, and can be implemented according to the content of the specification, the following is a preferred embodiment of the application and the accompanying drawings are described in detail. The specific embodiments of the application are given in detail by the following examples and their accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0016] The drawings described herein are used to provide further understanding of the application, and form a part of the application. The schematic embodiments of the application and their descriptions are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0017] Fig. 1 It is the overall structure block diagram of the smart socket distributed power quality monitoring device of the application.

[0018] Fig. 2 It is the structure schematic diagram of the zero-power trigger device.

[0019] Fig. 3 It is the flow chart of the joint analysis algorithm based on short-time Fourier transform (STFT) and wavelet transform (WT). DETAILED DESCRIPTION

[0020] The principles and features of the present application are described below in conjunction with the accompanying drawings, which are presented only for the purpose of illustrating the present application and are not intended to limit the scope of the present application. In the following paragraphs, the present application is described in more detail with reference to the accompanying drawings. It should be noted that the drawings are all very simplified and use non-precise proportions, only for the purpose of facilitating, clarifying and assisting in the description of the embodiments of the present application.

[0021] Please refer to Figs. 1-3 In the embodiments of the present application, the present application relates to a distributed power quality monitoring device of a smart socket, the core design of which is to realize real-time monitoring and rapid response of power quality at the end of the power grid through a distributed architecture. The following describes the present application in conjunction with the accompanying drawings Fig. 1 to the accompanying drawings Fig. 3 The specific embodiments of the present application are described in detail. Fig. 1 The overall structure diagram of the smart socket is shown, which includes the connection relationship of the main control chip MCU, the power management module, the signal acquisition unit, the storage unit, the communication module and other functional units; Fig. 2 is a structure diagram of a zero-power trigger device, which details the position of the elastic contact and its on-off mechanism in the plug insertion and removal state; Fig. 3 is a flowchart of a joint analysis algorithm based on short-time Fourier transform STFT and wavelet transform WT, which is used to illustrate the specific steps of signal processing and power quality characteristic value extraction.

[0022] In specific implementation, the distributed power quality monitoring device of the smart socket includes a socket body, the socket body is provided with a main control chip MCU and a plurality of functional modules connected thereto respectively. The main control chip MCU serves as the core processor, responsible for coordinating the work of each functional module and processing the collected data. The power management module provides stable power supply support for the entire device, and has dynamic adjustment capability to adapt to different load requirements. The signal acquisition unit acquires real-time voltage and current waveform data of the connected electrical appliances through high-precision sensors, which are transmitted to the MCU for further processing after analog-to-digital conversion. The storage unit is used to store the preset power quality characteristic threshold and historical monitoring data for subsequent comparison and analysis. The power quality analysis unit extracts key characteristic values by performing time-frequency domain analysis on the collected signals, and compares them with the characteristic threshold in the storage unit, and outputs the analysis results to the MCU after successful matching. The MCU forms a self-organizing network communication connection with the remote control center or adjacent nodes through the wireless communication module, thereby realizing distributed data processing and collaborative work.

[0023] In order to realize zero power consumption operation in standby state, a zero power consumption trigger device is embedded in the power supply circuit of the intelligent socket. The device is composed of a pair of elastic contacts. When the plug is inserted into the socket, the elastic contacts are turned on due to mechanical pressure, thereby starting the normal working mode of the device. When the plug is pulled out, the elastic contacts are automatically disconnected, so that the device enters a complete power-off state. This design significantly reduces standby power consumption and meets the requirements of energy saving and environmental protection. In addition, the MCU is also connected with a smart switch unit, which can dynamically adjust the load power supply state according to the power quality analysis results. For example, when abnormal conditions such as overvoltage or undervoltage are detected, the smart switch unit will quickly cut off the circuit to protect the connected equipment. A double protection mechanism is provided on the power supply circuit, including an overload protection unit and a transient suppression unit. The overload protection unit monitors the current size in real time and quickly cuts off the circuit when overload is detected; the transient suppression unit absorbs transient overvoltage through the built-in metal oxide varistor MOV to ensure safe use of electricity. The MCU also integrates an emergency manual control interface, allowing users to directly intervene in the power supply state in emergency situations. The display unit is connected with the MCU, which can intuitively present the current power quality indicators and historical trend chart, facilitating users to understand the power consumption situation. In addition, the MCU also supports an infrared communication module, which facilitates interaction with household remote control devices. The wireless communication module is compatible with ZigBee, LoRa, NB-IoT and other protocols, adapting to communication needs in different scenarios.

[0024] The present application adopts a joint analysis algorithm based on short-time Fourier transform (STFT) and wavelet transform (WT) to extract power quality characteristic values. The specific formula is as follows:

[0025]

[0026] Where S(t,f) represents the time-frequency distribution of signal x(τ) at time t and frequency The window function w(t-τ) is used to localize the time characteristics of the signal. This algorithm combines the multi-resolution characteristics of wavelet transform, which can effectively capture transient events such as voltage sag and transient overvoltage, and calculate the characteristic values through the following formula: Where E k represents the energy characteristic value of the nth power quality event, and W(a i ,b i ) is the wavelet coefficient, a i and b i are the scale and translation parameters respectively. Through the above algorithm, the device can complete the identification and classification of power quality events within milliseconds. For example, when a voltage sag is detected, the device will immediately analyze its duration and amplitude change, and determine whether protective measures need to be taken. In practical applications, this algorithm can accurately identify a variety of power quality problems, including harmonic distortion, three-phase imbalance and flicker, etc.

[0027] The distributed power quality monitoring device of the present application has distributed data processing capability, and each smart socket can independently complete the power quality monitoring task, while supporting cooperation with other nodes to form a monitoring network covering the entire power grid terminal. In independent mode, the device can provide real-time power quality reports for users, including voltage deviation, harmonic distortion rate, three-phase imbalance degree, and other key indicators. Through self-organizing network technology, the device can achieve plug-and-play without additional configuration, significantly reducing deployment costs. Users can view real-time and historical power quality data at any time through mobile terminals or local display screens to understand potential risks and take preventive measures. For example, in a home environment, users can view the voltage and current waveforms and historical trend charts of the current socket through a mobile phone APP to discover abnormal conditions in a timely manner and take appropriate measures. In addition, the device can complete protection actions within 20ms when detecting power quality problems such as overvoltage, undervoltage, and harmonic overlimit, avoiding damage to precision equipment and improving power safety and reliability.

[0028] In actual application scenarios, the distributed power quality monitoring device of the present application can be widely used in homes, factories, commercial buildings, and other places. For example, in a smart office building, multiple smart sockets are distributed on different floors and rooms, and each socket independently monitors the power quality of the area. When voltage fluctuations occur on a floor, the smart sockets on that floor will immediately send relevant information to the central control center and start protection measures to prevent equipment damage. The central control center can generate an overall power quality report based on the received data and guide maintenance personnel to carry out targeted maintenance. In addition, smart sockets can also share information through self-organizing network technology to form a monitoring network covering the entire building. In a home environment, users can use smart sockets to monitor the power consumption of various appliances in real time and optimize power consumption strategies based on historical data. For example, when detecting high harmonic distortion rate in a certain appliance, users can choose to replace the device or adjust the usage time to reduce the impact on the power grid.

[0029] The core advantage of the present application is the distributed architecture design, which not only solves the problem of high expansion cost and single function of traditional power quality analysis equipment centralized architecture, but also realizes real-time monitoring of steady-state and transient power quality parameters. Through the cooperative work of zero-power trigger device, double protection mechanism, intelligent switch unit and other functional modules, the device can complete the identification and classification of power quality events within milliseconds, and take corresponding protection measures. In addition, the joint analysis algorithm based on short-time Fourier transform (STFT) and wavelet transform (WT) further improves the performance of the device, enabling it to accurately capture transient events and extract key feature values. With the support of the wireless communication module, the device can flexibly adapt to the communication needs in different scenarios and work collaboratively with other nodes to form a monitoring network covering the entire power grid. Ultimately, the present application not only improves the safety and reliability of electricity, but also provides users with a convenient electricity management tool, with wide application prospects and market value.

[0030] The above is only a preferred embodiment of the present application, and does not limit the present application in any form; any person skilled in the art can easily implement the present application according to the drawings and the above description; however, any equivalent changes, modifications and evolutions made by those skilled in the art within the scope of the technical solutions of the present application, using the disclosed technical content, are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolutions made according to the essence of the present application to the above embodiments are still within the protection scope of the technical solutions of the present application.

Claims

1. A distributed power quality monitoring device of a smart socket comprising a socket body, characterized in that, The socket body is provided with a master control chip MCU and a power management module, a signal acquisition unit, a storage unit and a communication module connected with the MCU respectively, the signal acquisition unit is used for real-time acquisition of voltage and current waveform data of the connected electrical appliances, the storage unit is used for storage of preset power quality characteristic threshold and historical monitoring data, and the MCU forms a self-organizing network communication connection with a remote control center or a neighboring node through the communication module.

2. The distributed power quality monitoring device of the intelligent socket according to claim 1, characterized in that, Further comprising an electric energy quality analysis unit, the electric energy quality analysis unit extracts key characteristic values by time-frequency domain analysis on the signals collected by the signal acquisition unit, and compares the extracted characteristic values with the characteristic threshold in the storage unit, and outputs the analysis result to the MCU after successful matching.

3. The distributed power quality monitoring device of the intelligent socket according to claim 2, characterized in that, The zero-power trigger device is embedded in the power supply circuit of the socket body, the zero-power trigger device is composed of a pair of elastic contacts, and the zero-power trigger device is turned on when the plug is inserted, and is automatically disconnected when the plug is not inserted.

4. The distributed power quality monitoring device of the intelligent socket according to claim 3, characterized in that, Further comprising an intelligent switch unit connected with the MCU, used for dynamically adjusting the load power supply state according to the electric energy quality analysis result.

5. The distributed power quality monitoring device of the intelligent socket according to claim 4, characterized in that, The power supply circuit is provided with a double protection mechanism, including an overload protection unit and a transient suppression unit, the overload protection unit rapidly cuts off the circuit when detecting overload, and the transient suppression unit absorbs transient overvoltage through the built-in metal oxide varistor.

6. The distributed power quality monitoring device of the smart socket according to claim 5, wherein, Further comprising an emergency manual control interface connected with the MCU, used for allowing the user to directly intervene in the power supply state in an emergency.

7. The distributed power quality monitoring device of the smart socket according to claim 6, wherein, Further comprising a display unit connected with the MCU, used for visually presenting the current electric energy quality index and historical trend chart.

8. The distributed power quality monitoring device of the smart socket according to claim 7, wherein, Further comprising an infrared communication module connected with the MCU, used for interacting with a household remote control device.

9. The distributed power quality monitoring device of the intelligent socket according to claim 8, characterized in that, The communication module is compatible with ZigBee, LoRa and NB-IoT protocols.

10. The distributed power quality monitoring device of the intelligent socket according to claim 9, characterized in that, The electric energy quality analysis unit adopts a joint analysis algorithm based on short-time Fourier transform and wavelet transform, used for extracting electric energy quality characteristic values and calculating the energy characteristic values of the kth electric energy quality event.

Images