Resonance detection system and detection method thereof

Abstract

The invention discloses a resonance detection system and a resonance detection method, and the system comprises a power management unit which is electrically connected with a signal conditioning unit, an A / D sampling unit, a microprocessor unit, a remote communication unit, and a man-machine interaction unit. The signal conditioning unit is externally connected with a three-phase voltage signal line and a three-phase current signal line; a built-in chip of the microprocessor unit is electrically connected with the timer. Periodically and synchronously sampling three-phase voltage and current to generate original data; carrying out normalization processing and filtering processing on the original data; constructing a network node admittance matrix for eigenvalue analysis and overall model analysis, and determining a resonant frequency; and based on singular value decomposition, analyzing an abnormal rule of harmonic voltage and branch current in the network. Dynamic modeling of various harmonic sources, an interaction mechanism between wave sources and quantitative analysis are realized, corresponding measures are given to improve power supply reliability, and safe and stable operation of a power grid is maintained.

Description

Technical Field

[0001] The present invention relates to the field of electric power monitoring, and in particular to a resonance detection system and a resonance detection method. Background Art

[0002] With the large number of photovoltaic and wind power connected to the grid, the risk of grid resonance has increased. Therefore, each grid-connected power plant must conduct resonance analysis before grid connection. If a resonance point is found, the corresponding suppression equipment must be installed. To ensure the safety of the grid, a lot of analysis has been done on both the photovoltaic side and the system side, and relevant rectification and optimization have been carried out. On the other hand, when resonance occurs in the traditional medium and low voltage distribution network, overvoltage and impact current are caused, resulting in PT burning. Such accidents are common and have occurred in power grids in various regions.

[0003] However, the mechanism of resonance is relatively complex. Since there is no effective monitoring method at present, it is difficult to effectively grasp the information of its occurrence process. Therefore, the source tracing is often started after the event occurs. In this mode, the loss caused by the resonance has already occurred, the information is seriously missing, and the source tracing analysis is difficult. Therefore, it is necessary to establish an integrated system with complete resonance online monitoring and analysis capabilities, establish the resonance monitoring and evaluation methods carried by the system, and meet the implementation method to rely on the logical model to form a resonance inertia analysis, and establish rules for future resonance risk avoidance. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the title of the invention of this application to avoid blurring the purpose of this section, the abstract of the specification and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above-mentioned problems and / or the problems existing in the prior art due to the lack of effective monitoring means, the present invention is proposed.

[0006] Therefore, the technical problem to be solved by the present invention is to establish an integrated system with complete resonance online monitoring and analysis capabilities.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a resonance detection system, comprising a power management unit, electrically connected to include,

[0008] Signal conditioning unit, A / D sampling unit, microprocessor unit, remote communication unit, human-computer interaction unit;

[0009] The signal conditioning unit is externally connected to a three-phase voltage signal line and a three-phase current signal line;

[0010] The built-in chip of the microprocessor unit is electrically connected to the timer.

[0011] The beneficial effects of this part of the invention are: an effective basic system with monitoring logic is formed.

[0012] Given that the resonance mechanism is relatively complex and it is difficult to effectively grasp the information about its occurrence process, the source tracing often begins after the event occurs. In this mode, the losses caused by the resonance have already occurred, and there is a serious lack of information, making source tracing difficult.

[0013] Therefore, the technical problem to be solved by the present invention is to establish a resonance monitoring and evaluation method carried by the system, and to meet the implementation method that can rely on a logical model to form a resonance inertia analysis and establish rules for future resonance risk avoidance.

[0014] In order to solve the above technical problems, the present invention also provides the following technical solutions: a resonance detection method, comprising the above resonance detection system, and periodically synchronously sampling three-phase voltage and current to generate original data;

[0015] Normalize and filter the original data;

[0016] Construct the network node admittance matrix to perform eigenvalue analysis and overall model analysis to determine the resonant frequency;

[0017] Based on singular value decomposition, analyze the abnormal laws of harmonic voltage and branch current in the network. Construct node injection current and node voltage to form the network node admittance matrix;

[0018] Through mathematical models and physical characteristics, the dynamic characteristics of the system are obtained;

[0019] By analyzing the network harmonic amplification rules, the harmonic amplification path and mode are obtained.

[0020] As a preferred solution of the resonance detection method described in the present invention, wherein: an impedance matrix is ​​generated according to a network node admittance matrix;

[0021] Identify specific frequencies through eigenvector analysis and modal impedance curve visualization.

[0022] As a preferred solution of the resonance detection method described in the present invention, wherein: using matrix decomposition, the network node admittance matrix is ​​subjected to participation factor analysis and modal sensitivity analysis, including:

[0023] Participation factor analysis, including quantitative analysis of the participation of each component in the network in the resonance, and obtaining the range of resonance factors;

[0024] Based on the results of modal sensitivity analysis, the changes of the impedance matrix under different sensitive parameters are observed, and the visualization results of the modal impedance curve are obtained.

[0025] As a preferred solution of the resonance detection method described in the present invention, wherein: an impedance matrix is ​​generated according to a network node admittance matrix;

[0026] Through singular value analysis, singular values ​​and corresponding singular vectors are obtained to confirm the harmonic position and degree of change.

[0027] As a preferred solution of the resonance detection method described in the present invention, wherein: a transfer function matrix between branch current and node voltage is generated according to a network node admittance matrix;

[0028] By taking advantage of the fact that singular value analysis is not constrained by matrix form, by observing the singular vector components of branch current, it is determined whether the branch current belongs to the corresponding node voltage and the branch current amplification law is confirmed.

[0029] As a preferred solution of the resonance detection method described in the present invention, extracting the original data includes:

[0030] The signal conditioning unit converts the electrical signals outputted from the secondary sides of the voltage sensor and the current sensor into a suitable range and sends them to the A / D sampling unit;

[0031] Through the microprocessor unit, the digital signal in the A / D sampling unit is read at a high frequency with the assistance of a timer.

[0032] As a preferred solution of the resonance detection method described in the present invention, the original voltage signal Ua is sent to the sensor TV1, and the abnormal data is removed by the low-pass filter circuit to change the signal, and the secondary electrical signal A1 enters the A / D sampling unit;

[0033] The low-pass filter circuit is an RC circuit.

[0034] As a preferred solution of the resonance detection method described in the present invention, wherein: the power management unit controls the voltage levels including DC 1.8V, 3.3V, 5V, 12V, and AC 220V;

[0035] The 5V voltage is used as the reference voltage of the A / D sampling unit;

[0036] 1.8V and 3.3V are used for the microprocessor unit and built-in chips;

[0037] 12V is used for remote communication unit.

[0038] The beneficial effects of this part of the invention are: to realize dynamic modeling of multiple types of harmonic sources, interaction mechanism and quantitative analysis between harmonic sources, and to provide corresponding measures to improve power supply reliability and maintain safe and stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative labor. Among them:

[0040] Figure 1 A schematic structural diagram of a resonance detection system according to an embodiment of the present invention;

[0041] Figure 2 A resonance frequency extraction block diagram of a resonance detection method provided by the present invention;

[0042] Figure 3 A resonance or amplification law analysis block diagram of a resonance detection method provided by the present invention;

[0043] Figure 4 A schematic diagram of the structure of a voltage signal conditioning unit of a resonance detection system according to an embodiment of the present invention;

[0044] Figure 5 A detailed monitoring flow diagram of a resonance detection method according to an embodiment of the present invention; DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0048] Furthermore, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0049] Example 1

[0050] Reference Figure 1-5 This embodiment provides a resonance detection system, including

[0051] The power management unit 100 is electrically connected to include:

[0052] Signal conditioning unit 200, A / D sampling unit 300, microprocessor unit 400, remote communication unit 500, human-computer interaction unit 600;

[0053] The signal conditioning unit 200 is externally connected to a three-phase voltage signal line and a three-phase current signal line;

[0054] The built-in chip of the microprocessor unit 400 is electrically connected to the timer.

[0055] Example 2

[0056] Reference Figure 1-4 , which is the second embodiment of the present invention, and this embodiment provides a resonance detection method. This embodiment is based on the previous embodiment, and is different from the previous embodiment in that:

[0057] Periodically synchronously sample three-phase voltage and current to generate raw data;

[0058] Normalize and filter the original data;

[0059] Construct the network node admittance matrix to perform eigenvalue analysis and overall model analysis to determine the resonant frequency;

[0060] Based on singular value decomposition, the abnormal patterns of harmonic voltage and branch current in the network are analyzed.

[0061] Example 3

[0062] Reference Figure 1-3 , which is the third embodiment of the present invention, is based on the previous embodiment, and is different from the previous embodiment in that:

[0063] Construct node injection current and node voltage to form network node admittance matrix;

[0064] Through mathematical models and physical characteristics, the dynamic characteristics of the system are obtained;

[0065] By analyzing the network harmonic amplification rules, the harmonic amplification path and mode are obtained.

[0066] Example 4

[0067] Reference Figure 1-3 , which is the fourth embodiment of the present invention, and is based on the previous embodiment, and is different from the previous embodiment in that: a power matrix equation is formed by constructing node injection current and node voltage;

[0068] The number of special frequencies is confirmed through left and right eigenvector analysis and modal impedance amplitude.

[0069] Using matrix decomposition, the network node admittance matrix is ​​subjected to participation factor analysis and modal sensitivity analysis, including:

[0070] Participation factor analysis, including quantitative analysis of the participation of each component in the network in the resonance and confirmation of the resonance factors;

[0071] Based on the results of modal sensitivity analysis, the changes of the impedance matrix under different sensitive parameters are observed, the visualization results of the modal impedance curve are obtained, and the resonance range is confirmed.

[0072] In detail, the resonant frequency extraction is a qualitative and quantitative analysis method of network resonant frequency based on modal analysis. First, on the basis of accurately establishing the electrical model of various harmonic sources, a power matrix equation between the injected current and the node voltage of each node of the network is formed. The modal analysis theory is used to carry out a qualitative study on the resonant frequency of the network.

[0073] Modal analysis can effectively analyze all resonant frequencies in the network by performing eigenvalue analysis on the formed network matrix equation, visualizing the output of the modal impedance curve, and analyzing the eigenvectors. By using matrix decomposition, participating factor analysis and modal sensitivity analysis of network resonance can be carried out, and the participation of each component in the network in the resonance can be quantitatively analyzed, and then the main components causing the resonance and the influence range of the resonance can be obtained.

[0074] Example 5

[0075] Reference Figure 1-3 , which is the fifth embodiment of the present invention, and is based on the previous embodiment, and is different from the previous embodiment in that: branch currents and node voltages are constructed to form an impedance matrix;

[0076] Through singular value decomposition, the singular eigenvalues ​​are obtained, the harmonic positions and the degree of change are obtained, and the voltage amplification law of each node is confirmed.

[0077] Construct branch current and node voltage to form a transfer function matrix;

[0078] By judging whether the branch current has components at each voltage node, the harmonic position and degree of change are obtained, and the amplification law of each branch current is confirmed.

[0079] In detail, the resonance or amplification law analysis is a network harmonic amplification law analysis method based on the singular value decomposition theory. Since the singular values ​​obtained by the singular value decomposition of the matrix have important properties such as rotation invariance, displacement invariance and mirror invariance, these properties make the matrix singular value decomposition technology as an effective algebraic feature extraction method suitable for the analysis of any non-zero matrix, so the singular value analysis is not constrained by the transfer function matrix form between the excitation source and the response.

[0080] It is theoretically feasible to explore the amplification characteristics of each branch current and node voltage in the network. Research on the amplification law of harmonic voltage is carried out. From constructing the impedance matrix formed by the node injection current and the node voltage, using singular value decomposition, proposing singular eigenvectors, obtaining the maximum singular eigenvalue, etc., the amplification law of each node voltage in the network can be analyzed.

[0081] Conduct research on the amplification law of harmonic currents. Construct the transfer function matrix between the branch currents and node voltages of the network, and use the characteristic that matrix singular value analysis is not constrained by the matrix form to analyze the amplification law of branch currents in the network by analyzing the two situations of branch currents belonging to nodes and not belonging to nodes.

[0082] Example 6

[0083] Reference Figure 1-5 , which is the sixth embodiment of the present invention, is based on the previous embodiment, and is different from the previous embodiment in that: extracting the original data includes,

[0084] The signal conditioning unit 200 converts the electrical signals outputted from the secondary side of the voltage sensor and the current sensor into a suitable range and sends them to the A / D sampling unit 300;

[0085] Through the microprocessor unit, the digital signal in the A / D sampling unit 300 is read at a high frequency with the assistance of a timer.

[0086] In detail, the microprocessing unit needs high-frequency multi-interface processing capabilities, and can use the STM32F103VGT6 microprocessor based on the CORTEX-M3 32-bit RISC core, with an operating frequency of 72MHz, high-speed embedded memory (FLASH up to 1MB, SRAM up to 96KB), and various enhanced I / O and peripherals connected to two APB buses. The processor provides three 12-bit ADC converters (up to 21 channel inputs), ten general-purpose 16-bit timers and two PWM timers, as well as standard and advanced communication interfaces: up to two I2Cs, three SPIs, two I2Ss, one SDIO, five USARTs, one USB and one CAN. The human-computer interaction unit and the remote communication unit are connected to the microprocessing unit through USART, and the A / D sampling unit is connected to the microprocessing unit through SPI. The microprocessing unit includes raw data processing, resonance frequency extraction, and resonance or amplification law analysis.

[0087] Example 7

[0088] Reference Figure 1-5 , which is the seventh embodiment of the present invention, is based on the previous embodiment, and is different from the previous embodiment in that: the original voltage signal U a It is sent to the sensor TV1, and the abnormal data is removed through the low-pass filter circuit to change the signal, and becomes the secondary electrical signal A1 and enters the A / D sampling unit 300;

[0089] The low-pass filter circuit is an RC circuit.

[0090] The power management unit 100 controls voltage levels including DC 1.8V, 3.3V, 5V, 12V, and AC 220V;

[0091] The 5V voltage is used as the reference voltage of the A / D sampling unit 300;

[0092] 1.8V and 3.3V are used for the microprocessor unit 400 and the built-in chip;

[0093] 12V is used by the remote communication unit 500 .

[0094] Specifically, the power management unit manages the working power of the entire device and needs to manage multiple voltage levels. The external AC 220V voltage is converted into 12V and 5V for the device through the switching power module. The AMS1117-3.3 chip is used to convert 5V to 3.3V, and the XC6206-1.8V chip is used to convert 5V to 1.8V. In addition, the device has a built-in battery to power the microprocessor unit and the remote communication unit to ensure that the device can still send and receive data for a short time after power failure.

[0095] Example 8

[0096] Reference Figure 1-5 , which is the eighth embodiment of the present invention. This embodiment is based on the previous embodiment, and is different from the previous embodiment in that: the remote communication unit realizes RS485 and GPRS functions. Among them, the RS485 function is used to network with other devices or systems. Based on the needs of increasing efficiency and reducing consumption, it can adopt a +3.3V low-power half-duplex transceiver SP3485EN, which complies with the RS-485 serial protocol and is isolated with an optocoupler chip TLP785; the GPRS function is connected to the remote background through 2G / 3G / 4G remote communication to realize remote viewing of data. The low-power wide-area Internet of Things technology wireless communication ML5510 module can realize 2GGPRS / NB-IOT / 4G LET multiple communication methods to meet the Internet of Things application requirements of this device.

[0097] Example 9

[0098] Reference Figure 1-5 , which is the ninth embodiment of the present invention. This embodiment is based on the previous embodiment, and is different from the previous embodiment in that: the human-computer interaction unit is connected to the device through WIFI, and does not set a display screen and keyboard for display and input, so as to avoid the impact of the on-site environment on the device and improve the operating reliability of the device. The WIFI function allows a handheld dedicated PDA, mobile phone or tablet to connect to the device, browse the device operating status and historical data, view real-time data and current status display, information statistics, event browsing, historical data query, parameter setting and other functions. The E103-W01 module is developed using the ESP8266EX chip. The module integrates the transparent transmission function, plug-and-play, supports the serial port AT instruction set, the server AT instruction set, and the user can use the network access function through the serial port. It also supports the AirKiss function.

[0099] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0100] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0101] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A resonance detection system, characterized in that: include, The power management unit (100) is electrically connected to include: A signal conditioning unit (200), an A / D sampling unit (300), a microprocessor unit (400), a remote communication unit (500), and a human-computer interaction unit (600); The signal conditioning unit (200) is externally connected to a three-phase voltage signal line and a three-phase current signal line; The built-in chip of the microprocessor unit (400) is electrically connected to the timer.

2. A resonance detection method, characterized in that: include, Periodically synchronously sample three-phase voltage and current to generate raw data; Normalize and filter the original data; Construct the network node admittance matrix to perform eigenvalue analysis and overall model analysis to determine the resonant frequency; Based on singular value decomposition, the abnormal patterns of harmonic voltage and branch current in the network are analyzed.

3. A resonance detection method according to claim 2, characterized in that: Constructing node injection current and node voltage to form the network node admittance matrix; Through mathematical models and physical characteristics, the dynamic characteristics of the system are obtained; By analyzing the network harmonic amplification rules, the harmonic amplification path and mode are obtained.

4. A resonance detection method according to claim 3, characterized in that: Construct node injection current and node voltage to form a power matrix equation; The number of special frequencies is confirmed through left and right eigenvector analysis and modal impedance amplitude.

5. A resonance detection method according to claim 4, characterized in that: Using matrix decomposition, the network node admittance matrix is ​​subjected to participation factor analysis and modal sensitivity analysis, including: Participation factor analysis, including quantitative analysis of the participation of each component in the network in the resonance and confirmation of the resonance factors; Based on the results of modal sensitivity analysis, the changes of the impedance matrix under different sensitive parameters are observed, the visualization results of the modal impedance curve are obtained, and the resonance range is confirmed.

6. A resonance detection method according to claim 3 or 5, characterized in that: Construct branch current and node voltage to form an impedance matrix; Through singular value decomposition, the singular eigenvalues ​​are obtained, the harmonic positions and the degree of change are obtained, and the voltage amplification law of each node is confirmed.

7. A resonance detection method according to claim 3 or 5, characterized in that: Construct branch current and node voltage to form a transfer function matrix; By judging whether the branch current has components at each voltage node, the harmonic position and degree of change are obtained, and the amplification law of each branch current is confirmed.

8. A resonance detection method according to claim 2, characterized in that: Extracting raw data includes: The signal conditioning unit (200) converts the electrical signals outputted from the secondary sides of the voltage sensor and the current sensor into a suitable range and sends them to the A / D sampling unit (300); Through the microprocessor unit, the digital signal in the A / D sampling unit (300) is read at a high frequency with the assistance of a timer.

9. A resonance detection method according to claim 2, characterized in that: Original voltage signal U a The signal is sent to the sensor TV1, and the abnormal data is removed through a low-pass filter circuit to change the signal, and the secondary electrical signal A1 is input into the A / D sampling unit (300); The low-pass filter circuit is an RC circuit.

10. A resonance detection method according to claim 2, characterized in that: The power management unit (100) controls voltage levels including DC 1.8V, 3.3V, 5V, 12V, and AC 220V; The 5V voltage is used as a reference voltage of the A / D sampling unit (300); 1.8V and 3.3V are used for the microprocessing unit (400) and built-in chips; 12V is used by the remote communication unit (500).

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