A method and system for identifying non-intrusive loads

Abstract

The present invention discloses a method and system for identifying non-intrusive loads, and relates to the technical field of power systems. The method of the present invention comprises: sampling the current and voltage data of electrical appliances of high-voltage industrial users at a preset sampling frequency to obtain sampling data; monitoring the state of the electrical appliances according to the decomposed total load power to obtain the actual current curve of typical equipment in the electrical appliances; obtaining the number of typical equipment included in the high-voltage industrial users in operation at a certain moment, that is, completing the identification of non-intrusive loads of high-voltage industrial users, and obtaining the identification results. The present invention has a high accuracy rate, is easy to run in a low-power embedded operating system, has low hardware requirements, and is conducive to large-scale promotion.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more particularly, to a method and system for identifying non-intervention loads. Background Art

[0002] High-voltage industrial users are the driving force of my country's national economic development, accounting for 85.9% of the total electricity consumption in the society (2018 data). Their diverse industrial equipment types, highly random current waveform characteristics, and the frequency and amplitude of migration changes make it difficult for traditional online monitoring methods to grasp the electricity consumption patterns, internal faults, and illegal electricity consumption of high-voltage industrial users, and it is impossible to build a load feature library and accumulate load big data, making it difficult to meet the diversified business needs of electricity. The specific problems are as follows:

[0003] The ability to monitor the power consumption patterns of users is weak, and it is impossible to recommend personalized services based on the power consumption characteristics of high-voltage industrial users, which affects the orderly power supply of the power grid. Due to the coarse monitoring granularity, only a 96-point daily frozen curve can be formed, and only macro statistics of user power consumption behavior are stored. The ability to monetize power consumption data is insufficient, and the user's internal equipment status cannot be controlled. Not only can the data-driven value-added services fail to meet the current power grid requirements, but there are also technical bottlenecks in the ability to improve the scalable business analysis capabilities of user needs.

[0004] There is a lack of identification methods for internal faults in users. The internal electrical equipment and lines of high-voltage industrial users are complex, and overload, leakage, and short-circuit accidents occur frequently, making it difficult to implement effective identification. According to statistics, in recent years, electrical fires in my country have accounted for more than 89.7% of fires excluding human factors. For example, the fire at Notre Dame de Paris in April 2019 was suspected to be caused by a power supply system failure, and the fire accident at Xihongmen in Beijing in November 2017 was caused by a line failure buried in the insulation material.

[0005] It is difficult to achieve technical constraints on users' electricity usage order. Due to the large number of high-energy-consuming and high-polluting enterprises, there is a phenomenon of grassroots environmental protection management personnel shielding enterprises. Traditional methods such as home inspections and installation of air / water pollution monitoring equipment have defects. It is necessary to use certain electricity identification methods to identify the start and shutdown status of operating polluting equipment and emission reduction equipment, achieve technical constraints, provide strong support for environmental protection supervision, and exert precise efforts and precise control.

[0006] User power quality issues need to be taken seriously. User power quality not only causes direct harm to the user's own equipment, but also causes economic losses to nearby loads such as the biological and medical equipment industry, chip and intelligent manufacturing industry. Impact and fluctuating loads, such as arc furnaces, large rolling mills, electric locomotives, etc., will not only generate a large number of high-order harmonics during operation, but also cause a series of power quality problems such as voltage fluctuations, flicker, and three-phase imbalance. Summary of the invention

[0007] In view of the above problems, the present invention provides a method for identifying non-intrusive loads, comprising:

[0008] The current and voltage data of electrical appliances of high-voltage industrial users are sampled at a preset sampling frequency to obtain sampling data;

[0009] According to the sampling data, the total load power and power characteristics of the electrical appliances are determined, the total load power is decomposed, the status of the electrical appliances is monitored according to the decomposed total load power, and the actual current curve of typical equipment in the electrical appliances is obtained;

[0010] The relationship between industrial industry types and typical equipment in the high-voltage industrial user load type database is called up to decompose the actual current curve of the typical equipment, and the number of typical equipment put into operation at a certain moment included in the high-voltage industrial user is obtained, thus completing the identification of the non-intrusive load of the high-voltage industrial user and obtaining the identification result.

[0011] Optionally, the identification result is verified by comparing the rated current of the typical equipment in steady state with the total current amplitude of the electrical appliances of high-voltage industrial users. If the verification error is within the preset empirical value, the verification passes and the verification result is obtained. The operating status of the typical equipment of high-voltage industrial users is analyzed based on the verification result.

[0012] Optionally, when calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, import the current waveform within a preset time period, and verify whether there is a non-periodic transient component in the current waveform. If so, determine the non-periodic transient component as a startup process, shutdown process or periodic transition process, and substituted it into the load type database for matching for identifying typical equipment.

[0013] Optionally, preset sampling frequency > 10k / s.

[0014] The present invention also proposes a system for identifying non-intrusive loads, comprising:

[0015] The sampling unit samples the current and voltage data of the electrical appliances of the high-voltage industrial users at a preset sampling frequency to obtain sampling data;

[0016] The monitoring unit determines the total load power and power characteristics of the electrical appliances based on the sampled data, decomposes the total load power, monitors the state of the electrical appliances based on the decomposed total load power, and obtains the actual current curve of typical equipment in the electrical appliances;

[0017] The identification unit calls the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, decomposes the actual current curve of the typical equipment, obtains the number of typical equipment put into operation at a certain moment included in the high-voltage industrial user, and completes the identification of the non-intrusive load of the high-voltage industrial user and obtains the identification result.

[0018] Optionally, the identification result is verified by comparing the rated current of the typical equipment in steady state with the total current amplitude of the electrical appliances of high-voltage industrial users. If the verification error is within the preset empirical value, the verification passes and the verification result is obtained. The operating status of the typical equipment of high-voltage industrial users is analyzed based on the verification result.

[0019] Optionally, when calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, import the current waveform within a preset time period, and verify whether there is a non-periodic transient component in the current waveform. If so, determine the non-periodic transient component as a startup process, shutdown process or periodic transition process, and substituted it into the load type database for matching for identifying typical equipment.

[0020] Optionally, preset sampling frequency > 10k / s.

[0021] The present invention extracts steady-state characteristic quantities and transient characteristics of industrial user loads, identifies user equipment start and stop events, and adopts a characteristic mapping method for the total measured curve of different user loads to achieve automatic mapping according to the basic characteristics listed in the load characteristic library. The present invention has high accuracy, is easy to run in a low-power embedded operating system, has low hardware requirements, and is conducive to large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a method for identifying non-intrusive loads according to the present invention;

[0023] Figure 2 This is a system structure diagram for identifying non-intrusive loads according to the present invention. DETAILED DESCRIPTION

[0024] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0025] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0026] The present invention provides a method for identifying non-intrusive loads, such as Figure 1 As shown, including:

[0027] The current and voltage data of electrical appliances of high-voltage industrial users are sampled at a preset sampling frequency to obtain sampling data;

[0028] According to the sampling data, the total load power and power characteristics of the electrical appliances are determined, the total load power is decomposed, the status of the electrical appliances is monitored according to the decomposed total load power, and the actual current curve of typical equipment in the electrical appliances is obtained;

[0029] The relationship between industrial industry types and typical equipment in the high-voltage industrial user load type database is called up to decompose the actual current curve of the typical equipment, and the number of typical equipment put into operation at a certain moment included in the high-voltage industrial user is obtained, thus completing the identification of the non-intrusive load of the high-voltage industrial user and obtaining the identification result.

[0030] Among them, the identification result is verified by comparing the rated current of the typical equipment in the steady state with the total current amplitude of the electrical appliances of the high-voltage industrial users. If the verification error is within the preset empirical value, the verification is passed and the verification result is obtained. The operating status of the typical equipment of the high-voltage industrial users is analyzed through the verification result.

[0031] When calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, import the current waveform within the preset time period, and verify whether there is a non-periodic transient component in the current waveform. If so, determine the non-periodic transient component as a startup process, shutdown process or periodic transition process, and substitute it into the load type database for matching to identify typical equipment.

[0032] The preset sampling frequency is >10k / s.

[0033] The present invention will be further described below in conjunction with embodiments:

[0034] Store the current and voltage sampling data of high-voltage industrial household electrical appliances, with a data sampling frequency of >10k / s, and compress the load identification voltage and current data to facilitate data upload;

[0035] For some electric mechanical equipment, since the mechanical work is a periodic output, the electrical characteristics of the equipment also have a certain fluctuation law. The characteristic quantity of steady-state fluctuation period time constant is often used to characterize it. The active and reactive power can be obtained by collecting the three-phase voltage and current data collected by the acquisition system. The expression is as follows:

[0036]

[0037]

[0038] Where P, Q, V, and I are active power, reactive power, voltage, and current, respectively. is the phase difference between voltage and current, k is the harmonic order;

[0039] The power characteristics of different electrical appliances are calculated by sampling the voltage and current, and then the total load power is decomposed to realize the status monitoring of different electrical appliances. Active power is the total power consumed during the operation of the load. If the load is a pure resistor, the current and voltage waveforms will always be in phase, and there will be no reactive component. For a pure reactance load, the phase shift is 90 degrees, and there will be no active power.

[0040] However, due to the presence of inductance and capacitance, there is always a phase shift between the current and voltage waveforms, which will generate or consume reactive power. As mentioned above, by using active power or the step change of active power and reactive power as characteristic quantities to decompose the load, high-power loads with obvious power consumption characteristics are easy to identify. Considering that some equipment has a steady-state fluctuation period, the maximum and minimum values ​​of steady-state active power and the power factor angle are used as identification features.

[0041] By obtaining the relationship between the user enterprise type and the typical equipment in the high-voltage industrial user load type database, it is assumed that the typical equipment array contained in user E is Ed[d1,d2,...,d n ], decompose the actual current curve of each typical device;

[0042] By Fourier transform, the I harmonic at time t is:

[0043]

[0044] but:

[0045]

[0046] ......

[0048]

[0049] Ignoring the DC component for now, we have:

[0050]

[0051]

[0052] in is the amplitude of the mth harmonic of the typical equipment included in user E, is the content of this typical device, by finding:

[0053]

[0054] The number of devices that may be put into operation at time t by E users is obtained, that is, the identification of E user load is completed. The rated current of each device in steady state is compared with the total current amplitude to verify the result:

[0055]

[0056] If the error is within a certain empirical value, it is considered to have passed the self-verification (currently within ±10%).

[0057] By analyzing Ed[d1,d2,...,d n ], and finally obtain the set of all running devices of the user Ed[d1,d2,...,d i ], the frequently appearing running equipment set Ed[d1,d2,...,d j ], the average content of each typical device Complete equipment operation status analysis of end-user loads;

[0058] By obtaining the relationship between the user enterprise type and the typical equipment in the high-voltage industrial user load type database, it is assumed that the typical equipment array contained in user E is Ed[d1,d2,...,d n ], import a time period current waveform Check whether there is a non-periodic transient component, and select the current in the time period where the current transient component exists. It is judged as a startup process, shutdown process or cycle transition process. Assume that the cycle of the change process is tc, the peak difference is wpd, substitute it into the database for matching, and realize device identification.

[0059] Then The harmonics are analyzed and the following formula is used for self-verification:

[0060]

[0061] To extract the harmonic coefficients a n +b n j, satisfies an ≥0 and b n ≥0, then the self-verification is passed, through the different time periods The waveform analysis and extraction of the startup process, shutdown process or cycle transition process finally obtains the set of all running devices of the user, Ed[d1,d2,...,d i ], and the set of frequently occurring running devices Ed[d1,d2,...,d j ].

[0062] The present invention also provides a system 200 for identifying non-intrusive loads, such as Figure 2 As shown, including:

[0063] The sampling unit 201 samples the current and voltage data of the electrical appliances of the high-voltage industrial users at a preset sampling frequency to obtain sampling data;

[0064] The monitoring unit 202 determines the total load power of the electrical appliances and the power characteristics of the electrical appliances according to the sampled data, decomposes the total load power, monitors the state of the electrical appliances according to the decomposed total load power, and obtains the actual current curve of the typical equipment in the electrical appliances;

[0065] The identification unit 203 calls the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, decomposes the actual current curve of the typical equipment, obtains the number of typical equipment included in the high-voltage industrial user in operation at a certain moment, and completes the identification of the non-intrusive load of the high-voltage industrial user and obtains the identification result.

[0066] Among them, the identification result is verified by comparing the rated current of the typical equipment in the steady state with the total current amplitude of the electrical appliances of the high-voltage industrial users. If the verification error is within the preset empirical value, the verification is passed and the verification result is obtained. The operating status of the typical equipment of the high-voltage industrial users is analyzed through the verification result.

[0067] When calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, import the current waveform within the preset time period, and verify whether there is a non-periodic transient component in the current waveform. If so, determine the non-periodic transient component as a startup process, shutdown process or periodic transition process, and substitute it into the load type database for matching to identify typical equipment.

[0068] The preset sampling frequency is >10k / s.

[0069] The present invention extracts steady-state characteristic quantities and transient characteristics of industrial user loads, identifies user equipment start and stop events, and adopts a characteristic mapping method for the total measured curve of different user loads to achieve automatic mapping according to the basic characteristics listed in the load characteristic library. The present invention has high accuracy, is easy to run in a low-power embedded operating system, has low hardware requirements, and is conducive to large-scale promotion.

[0070] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0071] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0072] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0073] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps for the functions specified in one or more boxes.

[0074] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for identifying a non-intrusive load, the method comprising: The current and voltage data of electrical appliances of high-voltage industrial users are sampled at a preset sampling frequency to obtain sampling data; According to the sampling data, the total load power and power characteristics of the electrical appliances are determined, the total load power is decomposed, the status of the electrical appliances is monitored according to the decomposed total load power, and the actual current curve of typical equipment in the electrical appliances is obtained; The relationship between industrial industry types and typical equipment in the high-voltage industrial user load type database is called, and the actual current curve of the typical equipment is decomposed to obtain the number of typical equipment put into operation at a certain moment included in the high-voltage industrial user, that is, to complete the identification of the non-intrusive load of the high-voltage industrial user and obtain the identification result; The identification result is verified by comparing the rated current of the typical equipment in a steady state with the total current amplitude of the electrical appliances of the high-voltage industrial users. If the verification error is within the preset empirical value, the verification is passed, and the verification result is obtained. The operation status of the typical equipment of the high-voltage industrial users is analyzed through the verification result. When calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, the current waveform within the preset time period is imported, and it is verified whether there is a non-periodic transient component in the current waveform. If so, the non-periodic transient component is determined to be a startup process, a shutdown process or a periodic transition process, and is substituted into the load type database for matching to identify the typical equipment.

2. According to the method of claim 1, the preset sampling frequency is >10k / s.

3. A system for identifying non-intrusive loads, the system comprising: The sampling unit samples the current and voltage data of the electrical appliances of the high-voltage industrial users at a preset sampling frequency to obtain sampling data; The monitoring unit determines the total load power and power characteristics of the electrical appliances based on the sampled data, decomposes the total load power, monitors the state of the electrical appliances based on the decomposed total load power, and obtains the actual current curve of typical equipment in the electrical appliances; The identification unit calls the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, decomposes the actual current curve of the typical equipment, obtains the number of typical equipment put into operation at a certain moment, that is, completes the identification of the non-intrusive load of the high-voltage industrial user, and obtains the identification result; The identification result is verified by comparing the rated current of the typical equipment in a steady state with the total current amplitude of the electrical appliances of the high-voltage industrial users. If the verification error is within the preset empirical value, the verification is passed, and the verification result is obtained. The operation status of the typical equipment of the high-voltage industrial users is analyzed through the verification result. When calling the relationship between the industrial industry type and the typical equipment in the high-voltage industrial user load type database, the current waveform within the preset time period is imported, and it is verified whether there is a non-periodic transient component in the current waveform. If so, the non-periodic transient component is determined to be a startup process, a shutdown process or a periodic transition process, and is substituted into the load type database for matching to identify the typical equipment.

4. According to the system of claim 3, the preset sampling frequency is >10k / s.

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