High-voltage circuit breaker spring operating mechanism multi-parameter state monitoring system and state feature extraction method

Abstract

The invention provides a high-voltage circuit breaker spring operating mechanism multi-parameter state monitoring system and state feature extraction method.The system comprises a data acquisition system located on site and a remote inspection system located in a control center, and the data acquisition system comprises a sensor unit, a signal conditioning circuit, a lower computer and an RS232 / RS485 converter which are connected in sequence; the sensor unit is used for realizing comprehensive monitoring of stroke-current-vibration-force multi-state parameters, the RS232 / RS485 converter is used for converting an RS232 signal into an RS485 signal and realizing remote transmission, the remote inspection system comprises an RS485 / RS232 converter, an upper computer and a mobile phone APP which are connected in sequence, and the RS485 / RS232 converter is connected with the RS232 / RS485 converter. According to the invention, the fault features of the spring operating mechanism of the high-voltage circuit breaker are effectively extracted.

Description

Technical Field

[0001] The invention relates to a multi-parameter state monitoring system and a state feature extraction method, in particular to a multi-parameter state monitoring system and a state feature extraction method suitable for a spring operating mechanism of a high-voltage circuit breaker. Background Art

[0002] High-voltage circuit breakers are important equipment in the power system and play a vital role in the stability of the power grid. High-voltage circuit breakers play two roles in the power grid: (1) Control. According to the needs of the power grid operation, some electrical equipment or lines are put into or out of operation; (2) Protection. When an electrical equipment or line fails, the relay protection or automatic device sends a tripping signal, and the high-voltage circuit breaker quickly cuts off the faulty electrical equipment or line from the power grid to ensure the normal operation of the fault-free area of ​​the power grid. Regardless of the state of the power equipment or line (no load, load or short circuit), once the closing or opening command is received, the high-voltage circuit breaker is required to complete the closing or opening action quickly and efficiently.

[0003] The closing or opening action of the high-voltage circuit breaker is completed by the operating mechanism. At present, the operating mechanism of the high-voltage circuit breaker is mainly divided into three types, namely the spring operating mechanism, the hydraulic operating mechanism and the pneumatic operating structure. The main components of the spring operating mechanism: cam, pawl, crank arm, ratchet, opening spring, closing spring, opening holding latch, closing holding latch, opening trigger, closing trigger, opening coil, closing coil, arc extinguishing chamber. The opening action is completed by the opening trigger, opening coil, opening holding latch, opening spring, crank arm and other components; the closing action is completed by the closing trigger, closing coil, closing holding latch, closing spring, crank arm, ratchet, cam and other components; the closing spring energy storage action is completed by the energy storage motor reduction mechanism, closing spring, ratchet, cam, pawl, closing holding latch and other components. When the spring operating mechanism fails, it will cause serious power grid safety accidents.

[0004] At present, most of the online monitoring systems for circuit breaker operating mechanisms monitor single state parameters such as the current of the opening and closing coils, and lack the application of multi-parameter state comprehensive monitoring systems. In addition, there is a lack of effective feature extraction methods for the collected state parameters. Summary of the invention

[0005] In view of this, the present invention aims to overcome the shortcomings of the above-mentioned problems in the prior art, and proposes a multi-parameter state monitoring system for a spring operating mechanism of a high-voltage circuit breaker and a state feature extraction method, thereby realizing a multi-parameter state monitoring system for a spring operating mechanism of a high-voltage circuit breaker, and adopting different filtering, time domain and frequency domain analysis methods for the monitored contact travel signals, opening and closing coil currents, vibration signals and pressure signals, so as to more effectively extract the fault characteristics of the spring operating mechanism of the high-voltage circuit breaker, so as to facilitate the diagnosis of the mechanical state of the high-voltage circuit breaker, and provide a powerful tool for the safe operation of the power grid.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A multi-parameter state monitoring system for a spring operating mechanism of a high-voltage circuit breaker and a state feature extraction method, comprising a data acquisition system located on site and a remote inspection system located in a control center, wherein the data acquisition system comprises a sensor unit, a signal conditioning circuit, a lower computer and an RS232 / RS485 converter connected in sequence, the sensor unit is used to realize comprehensive monitoring of multiple state parameters such as stroke, current, vibration and force, the RS232 / RS485 converter is used to convert RS232 signals into RS485 signals to realize long-distance transmission, and the remote inspection system comprises an RS485 / RS232 converter, a host computer and a mobile phone APP connected in sequence, and the RS485 / RS232 converter is connected to the RS232 / RS485 converter.

[0008] Furthermore, the sensor unit includes a travel sensor, a current sensor, a vibration sensor and a pressure sensor.

[0009] Furthermore, the lower computer is configured with a PCI-6220 acquisition card, the RS-232 serial port is set to a half-duplex communication mode, the bit rate is set to 9600 bit / s, and the read-write cache is set to 10 kbit.

[0010] Furthermore, the stroke sensor includes a displacement sensor for measuring the contact stroke-time characteristics, including an arc extinguishing chamber, an oil buffer, a copper connecting rod, a linear displacement sensor, and a crank arm and a piston rod connection point. The copper connecting rod is fixed to the end of the insulating pull rod connected to the moving contact, and the linear displacement sensor is fixed to the copper connecting rod. The differential transformer part of the linear displacement sensor is fixed to the oil buffer with two copper sheets.

[0011] Furthermore, the current sensor is used to measure the current of the opening and closing coil, and a Hall current sensor is selected. During installation, the circuit wires of the opening and closing coil are vertical and the axis passes through the Hall current sensor.

[0012] Furthermore, the vibration sensor is used to measure vibration signals of the operating mechanism, near the oil buffer, and the arc extinguishing chamber. The vibration sensor is installed at four positions: above the closing electromagnet, above the opening electromagnet, on the top of the closing spring, and on the top of the opening spring.

[0013] Furthermore, the pressure sensor is used to measure the pressure of the opening and closing spring, including a closing spring cylinder, a closing spring, a closing spring pressure plate, a first pressure sensor, and a closing spring pull rod. One end of the closing spring is supported by the closing spring cylinder, and the other end is in a compressed state under the joint action of the closing spring pressure plate, the first pressure sensor and the closing spring pull rod; the opening spring pressure sensor includes an opening spring cylinder, an opening spring, an opening spring pressure plate, a second pressure sensor, and an opening spring pressure rod. One end of the opening spring is supported by the opening spring cylinder and the second pressure sensor, and the other end is in a compressed state under the joint action of the opening spring pressure plate and the opening spring pressure rod.

[0014] Furthermore, the working process of the lower computer is as follows: after the lower computer is started, the lower computer program enters initialization, and the initialization work includes registering the data acquisition card, setting the sampling channel, setting the sampling frequency, and initializing the RS-232 serial port communication. When the circuit breaker operating mechanism is actuated, the operating mechanism action signal triggers the acquisition card to start the contact travel signal to separate the closing coil current, vibration signal and pressure signal. The sampling frequency is set to 40kHz. After the communication handshake between the lower computer and the upper computer is successful, the collected signal is uploaded, and the bit rate is set to 9600bit / s.

[0015] Furthermore, the working process of the host computer is as follows: when the host computer is started, the host computer program enters initialization and starts the inspection system homepage. After the communication handshake between the lower computer and the upper computer is successful, the upper computer receives the signal collected by the lower computer, and performs signal filtering, time domain analysis and frequency domain analysis, stores the analysis results in the historical database, and performs analysis and display according to the operation instructions.

[0016] Furthermore, in the host computer, analyzing the collected signals includes:

[0017] The contact travel signal uses Daubechies4 as the wavelet basis function, and performs three-layer wavelet packet decomposition and reconstruction to achieve contact travel signal denoising. The denoised travel signal is smoothed using the FFT smoothing filter algorithm; the contact opening time t is calculated using the contact travel-time waveform. 分 , Closing time t 合 , Different periods of gate separation 分同 , Closing at different times 合同 , Contact travel S 1 , Overtravel S 2 , opening speed V 刚分 , just closing speed V 刚合, Maximum opening speed V 分m , Maximum closing speed V 合m , average opening speed V 分a , average closing speed V 合a , extract 12 time domain features [t 分 , t 合 , t 分同 , t 合同 , S 1 , S 2 , V 刚分 , V 刚合 , V 分m , V 合m , V 分a , V 合a ];

[0018] Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve denoising of the closing and opening coil current signal; the closing and opening coil current signal is analyzed in the time domain to extract 8 time domain features [t 0 , t 1 , t 2 , t 3 , t 4 , I 1 , I 2 , I 3 ]: Current starting time t 0 , Current first peak time t 1 and the first peak current I 1 , current valley time t 2 and valley current I 2 , Second wave peak current time t 3 and the second peak current I 3 , current end time t 4 ;

[0019] Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve vibration signal denoising; local mean decomposition is performed on the vibration signal;

[0020] Perform time domain analysis on the pressure signal and extract four time domain features [F max , F min , t s , t l ]: Maximum pressure F max , minimum pressure F min , spring energy storage time t s , spring energy release time t l .

[0021] Compared with the prior art, the multi-parameter state monitoring system and state feature extraction method of the spring operating mechanism of a high-voltage circuit breaker described in the present invention have the following advantages:

[0022] (1) The multi-parameter status monitoring system of the spring operating mechanism of high-voltage circuit breakers consists of two parts: a data acquisition system located on site and a remote inspection system located in the control center, which facilitates the status monitoring of circuit breakers.

[0023] (2) The field data acquisition system consists of a variety of sensors, signal conditioning circuits, a lower computer and an RS232 / RS485 converter. The sensors consist of travel sensors, current sensors, vibration sensors and pressure sensors to achieve comprehensive monitoring of multiple state parameters such as travel-current-vibration-force. The RS232 / RS485 converter converts RS232 signals into RS485 signals to achieve long-distance transmission.

[0024] (3) The linear displacement sensor is fixed on the copper connecting rod, and the differential transformer part of the linear displacement sensor is fixed on the oil buffer to achieve accurate measurement of the contact travel-time parameters.

[0025] (4) The Hall current sensor is used to measure the current of the opening and closing coil without changing the structure of the circuit breaker operating mechanism. The closing and opening coil loop wire is required to be vertical and the axis passes through the Hall current sensor to achieve accurate measurement of the closing and opening coil current.

[0026] (5) Install acceleration sensors at four locations: above the closing electromagnet, above the opening electromagnet, at the top of the closing spring, and at the top of the opening spring to measure the multi-point vibration characteristics of the circuit breaker spring operating mechanism.

[0027] (6) A resistive pressure sensor is designed to measure the pressure of the closing and opening springs. One end of the closing spring is supported by the closing spring cylinder, and the other end is in a compressed state under the joint action of the closing spring pressure plate, the pressure sensor and the closing spring pull rod; one end of the opening spring is supported by the opening spring cylinder and the pressure sensor, and the other end is in a compressed state under the joint action of the opening spring pressure plate and the opening spring pressure rod.

[0028] (7) Different filtering, time domain and frequency domain analysis methods are used for the 9 different sensor signals. The contact travel signal uses Daubechies4 as the wavelet basis function, performs 3-layer wavelet packet decomposition and reconstruction, realizes the denoising of the contact travel signal, and uses the FFT smoothing filter algorithm to smooth the denoised travel signal, extracting 12 time domain features of the contact travel signal [t 分 , t 合 , t 分同 , t 合同 , S 1 , S2 , V 刚分 , V 刚合 , V 分m , V 合m , V 分a , V 合a ]; The closing coil current signal uses Daubechies4 as the wavelet basis function, performs three-layer wavelet packet decomposition and reconstruction, realizes closing coil current signal denoising, performs time domain analysis on the closing coil current signal, and extracts 8 time domain features [t 0 , t 1 , t 2 , t 3 , t 4 , I 1 , I 2 , I 3 ]; The vibration signal uses Daubechies4 as the wavelet basis function, performs three-layer wavelet packet decomposition and reconstruction, realizes vibration signal denoising, performs local mean decomposition on the vibration signal, calculates the box dimension of each PF component, and extracts five time-frequency features of the vibration signal [D 1 , D 2 , D 3 , D 4 , D 5 ]; The pressure signal is not subjected to noise reduction processing, and the pressure signal is analyzed in the time domain to extract four time domain features [F max , F min , t s , t l ]. Using different filtering, time domain and frequency domain analysis methods for different sensor signals can more effectively extract the fault characteristics of the spring operating mechanism of the high-voltage circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a schematic diagram of a multi-parameter state monitoring system for a spring operating mechanism of a high-voltage circuit breaker of the present invention;

[0031] Figure 2 It is a schematic diagram of the installation of the displacement sensor of the present invention;

[0032] Figure 3 It is a schematic diagram of the installation of the current sensor of the present invention;

[0033] Figure 4 It is a schematic diagram of the installation of the closing spring pressure sensor of the present invention;

[0034] Figure 5This is a schematic diagram of the installation of the opening spring pressure sensor of the present invention;

[0035] Figure 6 It is the lower computer program flow chart of the present invention;

[0036] Figure 7 It is the upper computer program flow chart of the present invention;

[0037] Figure 8 This is a schematic diagram of the startup interface of the remote monitoring system of the present invention;

[0038] Fig. 9 It is a schematic diagram of the opening coil current display interface of the present invention.

[0039] Description of reference numerals:

[0040] 1-arc extinguishing chamber; 2-oil buffer; 3-copper connecting rod; 4-linear displacement sensor; 5-connection point of crank arm and piston rod; 6-closing spring cylinder; 7-closing spring; 8-closing spring pressure plate; 9-first pressure sensor; 10-closing spring pull rod; 11-opening spring cylinder; 12-opening spring; 13-opening spring pressure plate; 14-second pressure sensor; 15-opening spring pressure rod. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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 limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0044] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0045] In order to accurately monitor the operating state of the spring operating mechanism of the high-voltage circuit breaker, the state parameters of the spring operating mechanism should be monitored as much as possible, and the practicality and cost basis of the state parameters should be comprehensively considered. The state parameters detected by the multi-parameter state monitoring system of the spring operating mechanism of the high-voltage circuit breaker provided by the present invention are: contact travel signal, opening and closing coil current, vibration signal and pressure signal. For these four state parameter signals, the installation methods of the displacement sensor, current sensor, vibration sensor and pressure sensor are respectively given.

[0046] Schematic diagram of multi-parameter state monitoring system for spring operating mechanism of high voltage circuit breaker Figure 1 As shown, it includes two parts: the field data acquisition system and the remote inspection system. The field data acquisition system consists of a variety of sensors, signal conditioning circuits, a lower computer and an RS232 / RS485 converter. Among them, the multiple sensors are composed of travel sensors, current sensors, vibration sensors and pressure sensors to achieve comprehensive monitoring of travel-current-vibration-force multi-state parameters. The lower computer is equipped with a PCI-6220 acquisition card (16-bit A / D conversion, 250kHz sampling rate), the RS-232 serial port is set to half-duplex communication mode, the bit rate is set to 9600bit / s, and the read and write cache is set to 10kbit. The RS232 / RS485 converter converts RS232 signals into RS485 signals to achieve long-distance transmission.

[0047] The installation method of various sensors of the present invention includes:

[0048] (1) Installation of displacement sensor. The displacement sensor is used to measure the contact travel-time characteristics. A linear displacement sensor is selected. The installation diagram of the displacement sensor is as follows: Figure 2As shown, it includes an arc extinguishing chamber 1, an oil buffer 2, a copper connecting rod 3, a linear displacement sensor 4, a crank arm and a piston rod connection point 5. During installation, the copper connecting rod 3 is fixed to the end of the insulating pull rod connected to the moving contact, the linear displacement sensor 4 is fixed to the copper connecting rod 3, and the differential transformer part of the linear displacement sensor 4 is fixed to the oil buffer 2 with two copper sheets. The travel-time curve measured by the displacement sensor can be used to calculate the average speed of opening and closing.

[0049] (2) Current sensor installation. The current sensor is used to measure the current of the opening and closing coils. Hall current sensors are used. The installation specifications of Hall current sensors are as follows: Figure 3 As shown, the closing and opening coil loop wires are required to be vertical and the axis to pass through the Hall current sensor.

[0050] (3) Installation of vibration sensors. The vibration sensors are used to measure the vibration signals of the operating mechanism, near the oil buffer, and in the arc extinguishing chamber. Acceleration sensors are used. The vibration sensors are installed at four locations: above the closing electromagnet, above the opening electromagnet, at the top of the closing spring, and at the top of the opening spring.

[0051] (4) Installation of pressure sensor. The pressure sensor is used to measure the pressure of the closing and opening springs. A resistive pressure sensor is used. The installation diagram of the closing spring pressure sensor is as follows: Figure 4 As shown, it includes a closing spring cylinder 6, a closing spring 7, a closing spring pressure plate 8, a first pressure sensor 9, and a closing spring pull rod 10. One end of the closing spring 7 is supported by the closing spring cylinder 6, and the other end is in a compressed state under the joint action of the closing spring pressure plate 8, the pressure sensor 9 and the closing spring pull rod 10; the schematic diagram of the installation of the opening spring pressure sensor is shown in Figure 5 As shown, it includes a breaking spring cylinder 11, a breaking spring 12, a breaking spring pressure plate 13, a second pressure sensor 14, and a breaking spring pressure rod 15. One end of the breaking spring 12 is supported by the breaking spring cylinder 11 and the second pressure sensor 14, and the other end is in a compressed state under the joint action of the breaking spring pressure plate 13 and the breaking spring pressure rod 15.

[0052] The lower computer program flow chart of the present invention is as follows Figure 6 As shown. When the lower computer is started, the lower computer program enters initialization, and the initialization work includes registering the data acquisition card, setting the sampling channel, setting the sampling frequency, and initializing the RS-232 serial port communication. When the circuit breaker operating mechanism is activated, the operating mechanism action signal triggers the PCI-6220 acquisition card to start data acquisition of 9 signals, including 1 contact travel signal, 2 opening and closing coil currents, 4 vibration signals, and 2 pressure signals. The sampling frequency is set to 40kHz. After the communication handshake between the lower computer and the upper computer is successful, the 9 collected signals are uploaded, and the bit rate is set to 9600bit / s, that is, 1200Byte / s.

[0053] The upper computer program flow chart of the present invention is as follows Figure 7 As shown. When the host computer is started, the host computer program enters initialization and starts the monitoring system homepage. When the lower computer and the host computer successfully communicate and shake hands, the upper computer receives the 9-channel signals collected by the lower computer, and performs signal filtering, time domain analysis and frequency domain analysis, stores the analysis results in the historical database, and analyzes and displays them according to the operation instructions.

[0054] The steps of analyzing the 9-channel sensor signal data in the host computer of the present invention are as follows:

[0055] (1) Contact travel signal. The contact travel signal uses Daubechies4 as the wavelet basis function, performs three-layer wavelet packet decomposition and reconstruction, realizes contact travel signal denoising, and uses FFT smoothing filter algorithm to smooth the denoised travel signal; uses the contact travel-time waveform to calculate the contact opening time t 分 , Closing time t 合 , Different periods of gate separation 分同 , Closing at different times 合同 , Contact travel S 1 , Overtravel S 2 , opening speed V 刚分 , just closing speed V 刚合 , Maximum opening speed V 分m , Maximum closing speed V 合m , average opening speed V 分a , average closing speed V 合a , extract 12 time domain features [t 分 , t 合 , t 分同 , t 合同 , S 1 , S 2 , V 刚分 , V 刚合 , V 分m , V 合m , V 分a , V 合a ].

[0056] (2) Switching coil current signal. Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve the denoising of the switching coil current signal. The switching coil current signal is analyzed in the time domain to extract 8 time domain features [t 0 , t 1 , t 2 , t 3 , t 4 , I 1 , I 2 , I 3 ]: Current starting time t 0, Current first peak time t 1 and the first peak current I 1 , current valley time t 2 and valley current I 2 , Second wave peak current time t 3 and the second peak current I 3 , current end time t 4 .

[0057] (3) Vibration signal. Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve vibration signal denoising. Local mean decomposition is performed on the vibration signal. The steps of local mean decomposition are as follows:

[0058] (a) Determine the vibration signal x(t) = {x 1 , x 2 , …, x N All local extreme points n of} i , and calculate the average value m of all adjacent local extreme points i and the envelope estimate a i :

[0059] m i =0.5(n i +n i+1 ) (1)

[0060] a i =0.5n i -n i+1 | (2)

[0061] (b) Use a broken line to connect all adjacent mean values ​​m i and the envelope estimate a i , use the sliding average method to get the local mean function m 11 (t) and envelope estimation function a 11 (t).

[0062] (c) Separating the local mean function m from the vibration signal x(t) 11 (t) get h 11 (t), and divided by the envelope estimation function a 11 (t) get the frequency modulated signal s 11 (t):

[0063] h 11 (t) = x(t) - m 11 (t) (3)

[0064] s 11 (t) = h 11 (t) / a 11 (t) (4)

[0065] (d) Calculate s 11 (t)'s envelope estimation function a 12 (t). If a 12 (t) is not equal to 1, then s 11 (t) is not a pure frequency modulation signal. Repeat the iteration n times until s 1n (t) is a pure frequency modulation signal.

[0066] The iteration termination condition is

[0067]

[0068] In practical applications, a number ε greater than 0 can be set. When |a 1n (t) - 1| ≤ ε, the iteration terminates.

[0069] (e) Multiply the envelope estimation functions generated during the iteration process to obtain the envelope signal a 1 (t), and multiply it with the pure frequency modulation function s 1n (t) to obtain the PF of the signal x(t) 1 (t):

[0070] a 1 (t) = a 11 (t)a 12 (t)…a 1n (t) (6)

[0071] PF 1 (t) = a 1 (t)s 1n (t) (7)

[0072] (f) Separate PF 1 (t) from the vibration signal x(t) to obtain the signal y 1 (t). Take y 1 (t) as the original data and repeat the above steps k times until y k (t) is a monotonic function.

[0073] (g) The vibration signal x(t) is equivalent to the sum of all PF components and y k (t)

[0074]

[0075] Calculate the box dimension of each PF component. The calculation process is as follows: Divide the spectrogram of size M×M into sub-blocks of L×L (1 < L ≤ M / 2, L is an integer). Let r = L / M, then each grid is a column of L×L×L 1 of boxes, L 1=L×G / M, G is the grayscale. Assume that the minimum and maximum values ​​of the image grayscale in the (i, j)th grid fall in the kth and lth boxes respectively, then the number of boxes required for the (i, j)th grid image is

[0076] n r (i,j)=k-l+1 (9)

[0077] The number of boxes needed to cover the entire image

[0078] N r =∑n r (i,j) (10)

[0079] The box dimension can be calculated by formula (11):

[0080]

[0081] Extracting five time-frequency features of vibration signals[D 1 , D 2 , D 3 , D 4 , D 5 ].

[0082] (4) Pressure signal. No noise reduction is performed on the pressure signal. The pressure signal is analyzed in the time domain to extract four time domain features [F max , F min , t s , t l ]: Maximum pressure F max , minimum pressure F min , spring energy storage time t s , spring energy release time t l .

[0083] Figure 8 It is the interface for the host computer to remotely monitor the system, and can set the acquisition card and serial port communication parameters. Fig. 9 It is the opening coil current display interface, which can perform time domain analysis on the opening coil current and extract 8 time domain features of the opening coil current [t 0 , t 1 , t 2 , t 3 , t 4 , I 1 , I 2 , I 3 ].

[0084] All matters not mentioned above are prior art.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker, characterized in that: It includes a data acquisition system located on site and a remote inspection system located in a control center. The data acquisition system includes a sensor unit, a signal conditioning circuit, a lower computer and an RS232 / RS485 converter connected in sequence. The sensor unit is used to realize comprehensive monitoring of multiple state parameters such as stroke, current, vibration and force. The RS232 / RS485 converter is used to convert RS232 signals into RS485 signals to realize long-distance transmission. The remote inspection system includes an RS485 / RS232 converter, a host computer and a mobile phone APP connected in sequence. The RS485 / RS232 converter is connected to the RS232 / RS485 converter.

2. A multi-parameter state monitoring system and state feature extraction method for a high-voltage circuit breaker spring operating mechanism according to claim 1, characterized in that: The sensor unit includes a travel sensor, a current sensor, a vibration sensor and a pressure sensor.

3. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 1, characterized in that: The lower computer is equipped with a PCI-6220 acquisition card, the RS-232 serial port is set to a half-duplex communication mode, the bit rate is set to 9600 bit / s, and the read and write cache is set to 10 kbit.

4. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 2, characterized in that: The stroke sensor includes a displacement sensor for measuring the contact stroke-time characteristics, including an arc extinguishing chamber, an oil buffer, a copper connecting rod, a linear displacement sensor, and a crank arm and a piston rod connection point. The copper connecting rod is fixed to the end of an insulating pull rod connected to the moving contact, and the linear displacement sensor is fixed to the copper connecting rod. The differential transformer part of the linear displacement sensor is fixed to the oil buffer using two copper sheets.

5. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 2, characterized in that: The current sensor is used to measure the current of the opening and closing coil. A Hall current sensor is selected. During installation, the circuit wires of the opening and closing coil are vertical and the axis passes through the Hall current sensor.

6. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 2, characterized in that: The vibration sensor is used to measure the vibration signals of the operating mechanism, the vicinity of the oil buffer, and the arc extinguishing chamber. The vibration sensor is installed at four positions: above the closing electromagnet, above the opening electromagnet, on the top of the closing spring, and on the top of the opening spring.

7. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 2, characterized in that: The pressure sensor is used to measure the pressure of the opening and closing spring, and includes a closing spring cylinder, a closing spring, a closing spring pressure plate, a first pressure sensor, and a closing spring pull rod. One end of the closing spring is supported by the closing spring cylinder, and the other end is in a compressed state under the joint action of the closing spring pressure plate, the first pressure sensor, and the closing spring pull rod; the opening spring pressure sensor includes an opening spring cylinder, an opening spring, an opening spring pressure plate, a second pressure sensor, and an opening spring pressure rod. One end of the opening spring is supported by the opening spring cylinder and the second pressure sensor, and the other end is in a compressed state under the joint action of the opening spring pressure plate and the opening spring pressure rod.

8. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 1, characterized in that: The working process of the lower computer is as follows: after the lower computer is started, the lower computer program enters initialization, and the initialization work includes registering the data acquisition card, setting the sampling channel, setting the sampling frequency, and initializing the RS-232 serial port communication. When the circuit breaker operating mechanism is actuated, the operating mechanism action signal triggers the acquisition card to start the contact travel signal to separate the closing coil current, vibration signal and pressure signal. The sampling frequency is set to 40kHz. After the communication handshake between the lower computer and the upper computer is successful, the collected signal is uploaded, and the bit rate is set to 9600bit / s.

9. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 1, characterized in that: The working process of the host computer is as follows: when the host computer is started, the host computer program enters initialization and starts the inspection system homepage. After the communication handshake between the lower computer and the upper computer is successful, the upper computer receives the signal collected by the lower computer, and performs signal filtering, time domain analysis and frequency domain analysis, stores the analysis results in the historical database, and performs analysis and display according to the operation instructions.

10. A multi-parameter state monitoring system and state feature extraction method for a spring operating mechanism of a high-voltage circuit breaker according to claim 9, characterized in that: In the host computer, analyzing the collected signals includes: The contact travel signal uses Daubechies4 as the wavelet basis function, and performs three-layer wavelet packet decomposition and reconstruction to achieve contact travel signal denoising. The denoised travel signal is smoothed using the FFT smoothing filter algorithm; the contact opening time t is calculated using the contact travel-time waveform. 分 , Closing time t 合 , Different periods of gate opening 分同 , Closing at different times 合同 , contact travel S1, overtravel S2, opening speed V 刚分 , just closing speed V 刚合 , Maximum opening speed V 分m , Maximum closing speed V 合m , average opening speed V 分a , average closing speed V 合a , extract 12 time domain features [t 分 , t 合 , t 分同 , t 合同 , S1, S2, V 刚分 , V 刚合 , V 分m , V 合m , V 分a , V 合a ]; Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve denoising of the closing and opening coil current signal; the closing and opening coil current signal is analyzed in the time domain to extract 8 time domain features [t0, t1, t2, t3, t4, I1, I2, I3]: current start time t0, current first peak time t1 and first peak current I1, current valley time t2 and valley current I2, second peak current time t3 and second peak current I3, current end time t4; Daubechies4 is used as the wavelet basis function to perform three-layer wavelet packet decomposition and reconstruction to achieve vibration signal denoising; local mean decomposition is performed on the vibration signal; Perform time domain analysis on the pressure signal and extract four time domain features [F max , F min , t s , t l ]: Maximum pressure F max , minimum pressure F min , spring energy storage time t s , spring energy release time t l。

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