CN109143143B - Intelligent detection device and method for secondary side polarity of current transformer of transformer substation - Google Patents
Intelligent detection device and method for secondary side polarity of current transformer of transformer substation Download PDFInfo
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Abstract
The invention discloses a device and a method for intelligently detecting secondary side polarity of a current transformer of a transformer substation, wherein the device comprises a checking host and a plurality of acquisition terminals; the checking host comprises a first human-computer interaction module, a supervisor module, a wave collecting and recording module, an alternating current source, an internal CT (computed tomography) and a wireless transceiving module; the management machine module is respectively connected with the first human-computer interaction module, the alternating current source, the wireless transceiver module and the acquisition and recording module; the output current of the alternating current source passes through the primary side of the internal CT and then is connected with the tested CT in parallel; the internal CT secondary side is connected with a collecting and recording module. The invention can test the correctness of the secondary side loop and has high efficiency.
Description
Technical Field
The invention belongs to the technical field of primary tests of transformer substations, and particularly relates to a secondary side polarity intelligent detection device and method of a transformer substation current transformer.
Background
In a traditional substation, secondary current and voltage loops play an important role. As a signal source of a transformer substation protection and measurement and control system, the secondary current and voltage loop provides measurement and protection current and voltage signals for the transformer substation protection and measurement system, and the functions of monitoring and protecting the operation of the power system are realized. Therefore, the wiring correctness of each current and voltage secondary circuit in the transformer substation has direct influence on the reliable operation of the transformer substation. When the secondary current and voltage loops have wiring errors or defects, the misoperation or the failure of the transformer substation protection equipment is easily caused, and the power supply reliability of the transformer substation is reduced. In addition, once the open circuit phenomenon of the CT (current transformer) occurs, equipment damage and personal accidents are easily caused. Therefore, in a conventional substation, before a new or modified substation is put into operation or when a change of the CT secondary circuit is involved, each set of current secondary circuits in the substation must be carefully checked and tested before power transmission to ensure that each current circuit is connected correctly. The polarity of the current transformer means that the current directions of the current on the primary side and the secondary side are positive or negative at the same time at a certain moment, and in this case, the polarity is called as a homonymous terminal or a homopolar terminal.
The alternating current source required by the primary through-current method generally adopts the principles of station power consumption, a current booster, a switching power supply and the like, wherein the station power consumption is 220V single-phase alternating current or 380V three-phase alternating current in a station, the voltage is not adjustable, the voltage can only be generally used for CT polarity verification of a transformer, and the working current is determined by the impedance of the transformer and is not adjustable, so the application range is limited.
The current booster and the switching power supply have the advantage of adjustable current, the former adopts the principle of an auto-coupling voltage regulator to convert high-voltage and low-current input into low-voltage and high-current output, but the output current of the auto-coupling voltage regulator is greatly influenced by the voltage change of a power grid and the load change, and once an abnormal phenomenon is found in the test process, the current can be changed rapidly to damage the safety of the power grid; the latter is composed of a large number of semiconductor elements, mainly composed of a main power supply circuit, a switching circuit (a switching circuit is composed of multiple field effect tubes to complete rectification and current regulation functions), a trigger circuit and a control power supply circuit, and has the characteristics of high energy efficiency ratio, small volume, light weight, stable output voltage and the like.
In addition, the above methods all have a common disadvantage that all the methods work in a steady-state mode, and only the mutual relationship of the polarities of a plurality of CTs can be checked, and the correctness of the polarity of a single CT cannot be judged, which can be realized only by synchronously acquiring and comparing primary and secondary currents. At present, two methods for realizing synchronous acquisition exist, the first method is to connect primary and secondary currents into the same measuring equipment, but the first method is limited by distance, the test wiring is too long, and the difficulty of field application is increased; the second one adopts time synchronization technologies such as GPS and B code, but the GPS technology is limited by signal strength and can hardly be used indoors, and the B code technology needs to be wired from a station time synchronization device, so that the wiring process is still complicated.
Therefore, it is necessary to develop an apparatus and a method for intelligently detecting the secondary side polarity of a transformer substation current transformer.
Disclosure of Invention
The invention aims to provide a secondary side polarity intelligent detection device and method for a transformer substation current transformer, which can quickly test the correctness of a secondary side loop.
The invention relates to an intelligent secondary side polarity detection device of a current transformer of a unit transformer substation, which comprises a calibration host and a plurality of acquisition terminals;
the checking host comprises a first human-computer interaction module, a supervisor module, a wave collecting and recording module, an alternating current source, an internal CT (computed tomography) and a wireless transceiving module; the management machine module is respectively connected with the first human-computer interaction module, the alternating current source, the wireless transceiver module and the acquisition and recording module; the output current of the alternating current source passes through the primary side of the internal CT and then is connected with the tested CT in parallel; the internal CT secondary side is connected with an acquisition wave recording module;
the first human-computer interaction module is used for configuring a test scheme, inputting parameters, monitoring a test process, viewing a waveform and viewing a test report;
the alternating current source is used for outputting 0A-200A alternating current;
the wireless transceiver module is used for realizing communication between the manager module and the acquisition terminal;
the acquisition terminal is used for acquiring the secondary loop current of the tested CT, generating a first recording file and transmitting the first recording file to the supervisor module;
the acquisition wave recording module is used for acquiring the primary loop current of the tested CT, generating a second wave recording file and transmitting the second wave recording file to the supervisor module;
the supervisor module is used for analyzing the first wave recording file and the second wave recording file in the same test and judging the correctness of the CT polarity.
Further, the acquisition terminal comprises a pincer-shaped mutual inductor module, a processing module, a communication module, a second human-computer interaction module and an acquisition module; the pincerlike mutual inductor module is electrically connected with the acquisition module; the acquisition module, the communication module and the second human-computer interaction module are respectively electrically connected with the processing module.
Furthermore, the acquisition module comprises an aviation plug, a 5-time attenuation circuit, a two-stage amplification circuit and an analog-to-digital conversion chip;
the 5-time attenuation circuit comprises a resistor R3, a resistor R4, a resistor R7, a resistor R8 and an analog switch U1, wherein the resistor R8 and the analog switch U1 are connected in series, then are connected in parallel with the resistor R7, and then are connected in series with the resistor R3 and the resistor R4;
the two-stage amplifying circuit comprises a first-stage amplifying circuit and a second-stage amplifying circuit, wherein:
the first-stage amplifying circuit comprises a resistor R5, a resistor R6, a resistor R9, a capacitor C1 and an operational amplifier U2; one end of the resistor R5 is grounded, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2 through a resistor R6; one end of the capacitor C1 is connected with the inverting input end of the operational amplifier U2, the other end of the capacitor C1 is connected with the output end of the operational amplifier U2, and the resistor R9 is connected with the capacitor C1 in parallel;
the second-stage amplifying circuit comprises a resistor R10, a resistor R11, a resistor R12, a capacitor C2 and an operational amplifier U3; one end of the resistor R10 is grounded, and the other end of the resistor R10 is connected with the inverting input end of the operational amplifier U3 through a resistor R11; one end of the capacitor C2 is connected with the inverting input end of the operational amplifier U3, the other end of the capacitor C2 is connected with the output end of the operational amplifier U3, and the resistor R12 is connected with the capacitor C2 in parallel.
The invention relates to an intelligent secondary side polarity detection method of a transformer substation current transformer, which adopts the intelligent secondary side polarity detection device of the transformer substation current transformer, and comprises the following steps:
the checking host outputs a primary current to pass through a primary loop of the tested CT, and a secondary loop current of the tested CT is collected on the secondary side of the tested CT by using the collecting terminal to generate a first recording file and transmit the first recording file to the supervisor module;
the primary loop current of the tested CT is sent to the acquisition wave recording module through the internal CT of the checking host computer, and a second wave recording file is generated and transmitted to the supervisor module;
the supervisor module analyzes the first recording file and the second recording file and automatically judges the correctness of the polarity of the tested CT.
Further, a primary current of aA is introduced into the tested CT through an alternating current source, and the initial phase is b degrees;
sampling the secondary loop current of the tested CT by utilizing an acquisition terminal at a preset sampling frequency, taking k sampling points forward from a current sampling point every millisecond to calculate a secondary current effective value, converting the sampling points to primary current according to the transformation ratio of the tested CT, taking k sampling points backward from the current sampling point when a primary current mutation quantity is a preset threshold value, calculating the phase of the primary current of the current sampling point, judging the polarity of a primary loop and a secondary loop of the tested CT to be positive polarity if the phase is in a preset interval, and otherwise judging the polarity of the primary loop and the secondary loop of the tested CT to be negative polarity.
Further, a current of 200A is introduced into the tested CT through an alternating current source, and the initial phase is 0 degree;
sampling the secondary loop current of the tested CT by using an acquisition terminal at a sampling frequency of 10kHz, calculating the effective value of the secondary current by taking 200 sampling points forward from the current sampling point every millisecond, converting the effective value into the primary current according to the transformation ratio of the tested CT, and when the abrupt change of the primary current is
And then, 200 sampling points are backwards taken from the current sampling point, the phase of the primary current of the current sampling point is calculated, if the phase is in a (90 DEG and 270 DEG) interval, the polarity of the primary loop and the secondary loop of the tested CT is judged to be positive, and if not, the polarity of the primary loop and the secondary loop of the tested CT is judged to be negative.
Further, still include: the method for judging the tested CT transformation ratio specifically comprises the following steps:
collecting the secondary loop current of the tested CT by using a collecting terminal;
the transformation ratio of the tested CT is equal to the ratio of the output current value of the alternating current source and the secondary loop current.
The invention has the beneficial effects that: the method can test the correctness of the secondary side loop and can also provide a final rectification scheme, so that the whole detection is more intelligent and convenient, the test efficiency is effectively improved, and the test time is greatly saved.
Drawings
FIG. 1 is a functional block diagram of the present invention;
FIG. 2 is a schematic block diagram of an acquisition terminal of the present invention;
FIG. 3 is a circuit diagram of an acquisition module of the present invention;
fig. 4 is a schematic diagram of a delay measurement time synchronization algorithm according to the present invention.
In the figure: 1. the checking system comprises a checking host computer, a first human-computer interaction module, a management machine module, a collecting and wave recording module, a 1d alternating current source, a 1e internal CT, a 1f wireless transceiving module, a 2 measured CT, a3 collecting terminal, a 3a pincerlike mutual inductor module, a 3b processing module, a 3c communication module, a 3d second human-computer interaction module, a 3e collecting module.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Fig. 1 shows an intelligent secondary side polarity detection device for a current transformer of a unit substation, which comprises a checking host 1 and a plurality of acquisition terminals 3. The acquisition terminal 3 is configured to acquire a secondary loop current of the CT2 to be detected, generate a first recording file, and transmit the first recording file to the supervisor module 1 b.
As shown in fig. 2, the verification host 1 includes a first human-computer interaction module 1a, a supervisor module 1b, a collection and recording module 1c, an ac current source 1d, an internal CT1e, and a wireless transceiver module 1 f; the supervisor module 1b is respectively connected with the first human-computer interaction module 1a, the alternating current source 1d, the wireless transceiver module 1f and the acquisition and recording module 1 c; the output current of the alternating current source 1d passes through the primary side of the internal CT1e and then is connected in parallel with the tested CT 2; the secondary side of the internal CT1e is connected with a collecting and recording module 1 c.
The following describes each module of the verification host 1 in detail:
(1) first human-computer interaction module
And the operation interface of the user is used for configuring a test scheme, inputting parameters, monitoring a test process, checking waveforms, checking test reports and the like. In this embodiment, the first human-computer interaction module 1a includes a liquid crystal display, a keyboard and a single-key shuttle; the model of the liquid crystal screen is JLT10001A of Shenzhen Jing Li Tai science and technology Limited, the model of the keyboard is M160HP of Shenzhen Shen Jing Ji special electronics Limited, and the model of the single-bond flying shuttle is LUYEE5000D of Shenzhen Yilong electronics Limited.
(2) Alternating current source
For outputting 0-200A AC current, in the present embodiment, the AC current source 1d is MF111D manufactured by APEX corporation.
(3) Wireless transceiver module
Conversion and control of wired data and wireless data for communication between the supervisor module 1b and the external environment. In this embodiment, the model of the wireless transceiver module 1f is hua shi ME 909S-821.
(4) Collection and wave recording module
The primary loop current of the tested CT2 is collected through the internal CT1e (namely, a current transformer), and a second recording file is generated and transmitted to the supervisor module 1 b. In this embodiment, the type of the wave collecting and recording module 1c is AD7606 of ADI corporation.
(5) Internal CT
The internal CT1e is a type of TBD-200A/3.53 from ADI, in this embodiment, and is used to convert the current output by the ac current source 1d into a small voltage that can be processed by the acquisition and recording module 1 c.
(6) Supervisor module
The system is used for completing all background functions including data communication, data analysis, data storage and the like. The supervisor module 1b is used for analyzing the first recording file and the second recording file during the same test and judging the correctness of the polarity of the CT.
In this embodiment, the model of the supervisor module 1b is QA3/N2807 of congou technologies ltd.
(1) The manager module 1b communicates with the acquisition terminal 3 through the wireless transceiver module 1f, and is used for downloading the current start setting value of the secondary loop of the tested CT2, receiving a first recording file and the like.
(2) The supervisor module 1b communicates with the acquisition and recording module 1c, and is used for downloading a primary loop current starting fixed value of the tested CT2, receiving a second recording file, and the like.
(3) The supervisor module 1b communicates with the alternating current source 1d for starting/stopping output, setting output current, and the like.
(4) The supervisor module 1b communicates with the first human-computer interaction module 1a, and a user sets a wiring mode, starts a fixed value and a transformation ratio through the first human-computer interaction module 1a, and checks a wave recording file, a test report and the like.
As shown in fig. 2, the acquisition terminal 3 includes a pincer-shaped mutual inductor module 3a, a processing module 3b, a communication module 3c, a second human-computer interaction module 3d and an acquisition module 3 e; the pincerlike mutual inductor module 3a is electrically connected with the acquisition module 3 e; the acquisition module 3e, the communication module 3c and the second human-computer interaction module 3d are respectively electrically connected with the processing module 3 b.
The following describes each module in detail:
(1) pincerlike mutual inductor module
The current transformer secondary circuit is used for converting the current of the current transformer secondary circuit into small voltage which can be processed by the acquisition module 3e under the condition of not disconnecting the original circuit.
In this embodiment, the pincer-shaped transformer module 3a has a model number of Q8B-5, a measuring range of 5A, and a transformation ratio of 2000: 1.
(2) Acquisition module
The processing module is used for collecting the current of the secondary loop of the current transformer, generating a first wave-forming recording file and transmitting the first wave-forming recording file to the processing module 3 b.
In this embodiment, since the secondary side signal is relatively small, the acquisition module 3e needs to amplify the acquired data first. However, after the secondary side signal is amplified, there are many interference high frequency signals in the signal, and there are many interferences to the data processing, which may cause the detecting device to be unable to correctly determine whether the polarity is correct, so it is necessary to perform filtering processing on the data. The filter can be divided into a low-pass filter, a band-pass filter and a high-pass filter from the aspect of working frequency, the filter can be continuously divided into a Butterworth filter, a Chebyshev filter, a Bessel filter and the like from the aspect of performance, power frequency 50Hz alternating current is led in at the primary side of the detection device, the low frequency is achieved, the field interference of a transformer substation is mainly high-frequency interference, and therefore the low-pass filter is adopted. Meanwhile, the butterworth filter has good amplitude-frequency characteristics, and is used most in practice, in the present embodiment, the filtering portion of the acquisition module 3e adopts a second-order butterworth low-pass filter. After the acquisition module 3e performs amplification filtering processing on the acquired data, high-frequency signals in the signals are basically filtered.
The primary side of the current transformer is provided with a power frequency 50Hz signal, but the signal frequency is not fixed and unchanged and can float to a certain extent, so that the self-adaptive frequency tracking algorithm is designed for the signal frequency change, and when the frequency changes, data can be accurately acquired, and the accuracy of data acquisition is ensured. The self-adaptive frequency tracking algorithm specifically comprises the following steps: firstly, processing the signal by fast Fourier transform to calculate the frequency f of the input signalcAssuming that the number of sampling points per cycle of the signal is n, the frequency interval f of each sampling point isc＝fcN when the input frequency changes to fc1The number of sampling points per time is changed to fc1＝fc1And/n, adjusting the A/D sampling interval according to the changed sampling interval frequency, thereby ensuring the same number of sampling points in each period, ensuring the sampling precision, and avoiding the influence on the accuracy of final data due to insufficient number of sampling points in one period caused by frequency change.
As shown in fig. 3, in this embodiment, a specific circuit of the acquisition module 3e is as follows: the acquisition module 3e comprises an aviation plug, a 5-time attenuation circuit, a two-stage amplification circuit and an analog-to-digital conversion chip, wherein the model of the analog-to-digital conversion chip is AD7606 BSTZ. The 5-time attenuation circuit comprises a resistor R3, a resistor R4, a resistor R7, a resistor R8 and an analog switch U1, wherein the resistor R8 and the analog switch U1 are connected in series and then connected in parallel with the resistor R7, and then connected in series with the resistor R3 and the resistor R4, the resistor R3 is grounded through the resistor R2, and the resistor R3 is grounded through the resistor R1. The two-stage amplifying circuit comprises a first-stage amplifying circuit and a second-stage amplifying circuit, wherein: the first-stage amplifying circuit comprises a resistor R5, a resistor R6, a resistor R9, a capacitor C1 and an operational amplifier U2; one end of the resistor R5 is grounded, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2 through a resistor R6; one end of the capacitor C1 is connected with the inverting input end of the operational amplifier U2, the other end of the capacitor C1 is connected with the output end of the operational amplifier U2, and the resistor R9 is connected with the capacitor C1 in parallel. The second-stage amplifying circuit comprises a resistor R10, a resistor R11, a resistor R12, a capacitor C2 and an operational amplifier U3; one end of the resistor R10 is grounded, and the other end of the resistor R10 is connected with the inverting input end of the operational amplifier U3 through a resistor R11; one end of the capacitor C2 is connected with the inverting input end of the operational amplifier U3, the other end of the capacitor C2 is connected with the output end of the operational amplifier U3, and the resistor R12 is connected with the capacitor C2 in parallel. In this embodiment, the resistances of the resistor R3 and the resistor R4 are 2.2k Ω, the resistance of the resistor R7 is 200k Ω, and the resistance of the resistor R8 is 1.1k Ω. The resistances of the resistor R5, the resistor R6, the resistor R10 and the resistor R11 are all 10 omega, the resistances of the resistor R9 and the resistor R12 are all 15k omega, and the capacitance values of the capacitor C1 and the capacitor C2 are all 3.3 pF.
In this embodiment, the analog switch is the model ADG541BCPZ-RL7, the 7 pins of which are grounded through the capacitor C14, the 6 pins of which are grounded through the resistor R13, and the 4 pins of which are grounded through the capacitor C3.
In this embodiment, the analog-to-digital conversion chip is AD7606BSTZ, pin 3 of the analog-to-digital conversion chip is grounded via a resistor R14, pin 4 is grounded via a resistor R15, pin 5 is grounded via a resistor R16, pin 6 is grounded via a resistor R17, pin 23 is grounded via a capacitor C12, pin 42 is grounded via a capacitor C13, the connection point of pin 44 and pin 45 is grounded via a capacitor C11, pin 39 is grounded via a capacitor C10, pin 36 is grounded via a capacitor C9, the connection point of pin 1, pin 37, pin 38 and pin 48 is grounded via a capacitor C4, the capacitor C5 is connected in parallel with the capacitor C4, the capacitor C6 is connected in parallel with the capacitor C5, the capacitor C7 is connected in parallel with the capacitor C6, and the capacitor C8 is connected in parallel with the capacitor C7. The pin 33 of the analog-to-digital conversion chip is grounded after passing through the resistor R18, the pin 25 thereof is connected with the resistor R19, and the pin 24 thereof is connected with the resistor R20.
(3) Processing module
For performing phase calculation and polarity determination functions.
In this embodiment, the model of the processing module 3b is XC7Z20-L1CLG484I from Series.
(4) Second human-computer interaction module
And the operation interface of the user is used for configuring a test scheme, inputting parameters, monitoring a test process, checking waveforms, checking test reports and the like.
In this embodiment, the second human-computer interaction module 3d includes a key and a 5-inch display screen.
(5) Communication module
For communication between the processing module 3b and external devices, including conversion and control of wired data and wireless data.
In this embodiment, the communication module 3c adopts a wired communication module 3c of an RS485 interface chip MAX3442 and a wireless communication module with a model number of F8L 10D-E-433.
The invention relates to an intelligent secondary side polarity detection method of a transformer substation current transformer, which adopts the intelligent secondary side polarity detection device of the transformer substation current transformer, and comprises the following steps:
the checking host 1 outputs a primary current to pass through a primary loop of the tested CT2, and the acquisition terminal 3 is utilized to acquire a secondary loop current of the tested CT2 on the secondary side of the tested CT2 to generate a first wave recording file and transmit the first wave recording file to the supervisor module 1 b;
the primary loop current of the tested CT2 is sent to the acquisition wave recording module 1c through the internal CT1e of the checking host 1, and a second wave recording file is generated and transmitted to the supervisor module 1 b;
the supervisor module 1b analyzes the first recording file and the second recording file, and automatically determines the correctness of the polarity of the CT2 to be tested.
In this embodiment, a primary current of aA (hereinafter, 200A is described as an example) is supplied to the CT2 to be measured by the ac current source 1d, and the initial phase is b ° (hereinafter, the initial phase is 0 °);
sampling the secondary loop current of the tested CT2 by using the acquisition terminal 3 at a preset sampling frequency (hereinafter, taking 10kHz as an example), taking k sampling points (hereinafter, taking 200 as an example and including the current point) forward from the current sampling point every millisecond, calculating the effective value of the secondary current, converting the effective value to the primary current according to the transformation ratio of the tested CT2, and when the primary current mutation is 10kHz, calculating the effective value of the secondary current
And then, 200 sampling points are backwards taken from the current sampling point, the phase of the primary current of the current sampling point is calculated, if the phase is in a (90 DEG and 270 DEG) interval, the polarities of the primary loop and the secondary loop of the tested CT2 are judged to be positive, and if not, the polarities of the primary loop and the secondary loop of the tested CT2 are judged to be negative.
When the polarity is judged to be inaccurate, a rectification scheme can be given, such as: in practice, the polarity of the CT2 to be tested is positive, but the polarity to be detected is negative, so that the wires of the terminal S1 and the terminal S2 on the secondary side of the CT2 to be tested need to be exchanged. On the contrary, when the polarity of the CT2 to be tested is negative, but the detected polarity is positive, the wires of the terminal S1 and the terminal S2 on the secondary side of the CT2 to be tested are exchanged.
In this embodiment, the method further includes: the method for detecting the tested CT2 transformation ratio specifically comprises the following steps: collecting the secondary loop current of the tested CT2 by using a collecting terminal 3; the transformation ratio of the CT2 to be measured is equal to the ratio of the output current value of the ac current source 1d to the secondary loop current. When the output current value of the ac current source 1d is 200A and the secondary circuit current of the CT2 to be measured acquired by the acquisition terminal 3 is 1A, it can be detected that the transformation ratio of the CT2 to be measured is 200. In this embodiment, the internal CT1e can also be used to monitor the current value output by the ac current source 1 d.
In this embodiment, the primary side calibration host 1 and the secondary side acquisition terminal 3 are connected by a wireless sensor network, and the phase of the primary side sinusoidal signal and the phase of the secondary side sinusoidal signal need to be compared in the determination method, so that time synchronization of data acquisition on both sides is required to be achieved, and the comparison is meaningful.
There are two main reasons for affecting WSN time dyssynchrony: (1) the crystal oscillators of the respective timers have frequency difference and instability; and (2) delay in the WSN message transmission process. The crystal oscillator mainly affects the time synchronization: firstly, crystal oscillator manufacturing processes of different devices are different, although the frequencies of the crystal oscillators are the same, different crystal oscillators work in different environments, actual conditions are different, time deviation occurs, and finally time asynchronism is caused. Secondly, the generally adopted crystal oscillator is low in price and not very high in stability, and the clock frequency of the crystal oscillator changes along with the change of time, the environment, the temperature and the like, and further the time is asynchronous.
The delay in the process of transmitting the WSN message mainly comprises sending delay, receiving delay, transmission delay, propagation delay, physical layer receiving delay and upper layer receiving delay. For the WSN time synchronization of different places, several algorithms are mainly adopted at present, including (1) RBS algorithm, (2) TPSN algorithm, (3) DMTS algorithm and the like, the RBS algorithm has high synchronization precision, but the calculation is too complex and the energy consumption is too high, the TPSN algorithm is a hierarchical bidirectional synchronization mode, the synchronization precision is higher than that of the RBS, but the algorithm is also too complex, the DMTS algorithm adopts a hierarchical broadcast type synchronization mode, the algorithm precision is a little lower than that of the RBS, the calculation is relatively simple and the energy consumption is relatively low, and the synchronization algorithm in the embodiment mainly adopts the DMTS algorithm.
The DMTS algorithm is called as a delay measurement time synchronization algorithm, and mainly comprises the steps that local time is embedded into a sending end and sent out together with a message, a receiving end calculates transmission time delay after receiving the message, and finally the local time of the receiving end is changed into the sum of the transmission delay time and sending time. The algorithm is simple in calculation, WSN time synchronization can be completed only by broadcasting a message with time, the energy consumption is low, the application range is wide, and a schematic diagram is shown in FIG. 4.
Claims (6)
1. The utility model provides a transformer substation's current transformer secondary side polarity intellectual detection system device which characterized in that: the system comprises a checking host (1) and a plurality of acquisition terminals (3);
the checking host (1) comprises a first human-computer interaction module (1a), a supervisor module (1b), a wave collecting and recording module (1c), an alternating current source (1d), an internal CT (1e) and a wireless transceiving module (1 f); the supervisor module (1b) is respectively connected with the first human-computer interaction module (1a), the alternating current source (1d), the wireless transceiver module (1f) and the wave collecting and recording module (1 c); the output current of the alternating current source (1d) passes through the primary side of the internal CT (1e) and then is connected with the tested CT (2) in parallel; the secondary side of the internal CT (1e) is connected with an acquisition and wave recording module (1 c);
wherein the first human-computer interaction module (1a) is used for configuring a test scheme, inputting parameters, monitoring a test process, viewing a waveform and viewing a test report;
the alternating current source (1d) is used for outputting 0A-200A alternating current;
the wireless transceiver module (1f) is used for realizing communication between the manager module (1b) and the acquisition terminal (3);
the acquisition terminal (3) is used for acquiring the secondary loop current of the tested CT (2), generating a first recording file and transmitting the first recording file to the supervisor module (1 b);
the acquisition wave recording module (1c) is used for acquiring the primary loop current of the tested CT (2), generating a second wave recording file and transmitting the second wave recording file to the supervisor module (1 b);
the supervisor module (1b) is used for analyzing a first recording file and a second recording file during the same test and judging the correctness of the CT polarity;
the acquisition terminal (3) comprises a pincer-shaped mutual inductor module (3a), a processing module (3b), a communication module (3c), a second human-computer interaction module (3d) and an acquisition module (3 e); the pincerlike mutual inductor module (3a) is electrically connected with the acquisition module (3 e); the acquisition module (3e), the communication module (3c) and the second human-computer interaction module (3d) are electrically connected with the processing module (3b) respectively.
2. The intelligent secondary side polarity detection device of the transformer substation current transformer according to claim 1, characterized in that: the acquisition module (3e) comprises an aviation plug, a 5-time attenuation circuit, a two-stage amplification circuit and an analog-to-digital conversion chip;
the 5-time attenuation circuit comprises a resistor R3, a resistor R4, a resistor R7, a resistor R8 and an analog switch U1, wherein the resistor R8 and the analog switch U1 are connected in series, then are connected in parallel with the resistor R7, and then are connected in series with the resistor R3 and the resistor R4;
the two-stage amplifying circuit comprises a first-stage amplifying circuit and a second-stage amplifying circuit, wherein:
the first-stage amplifying circuit comprises a resistor R5, a resistor R6, a resistor R9, a capacitor C1 and an operational amplifier U2; one end of the resistor R5 is grounded, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2 through a resistor R6; one end of the capacitor C1 is connected with the inverting input end of the operational amplifier U2, the other end of the capacitor C1 is connected with the output end of the operational amplifier U2, and the resistor R9 is connected with the capacitor C1 in parallel;
the second-stage amplifying circuit comprises a resistor R10, a resistor R11, a resistor R12, a capacitor C2 and an operational amplifier U3; one end of the resistor R10 is grounded, and the other end of the resistor R10 is connected with the inverting input end of the operational amplifier U3 through a resistor R11; one end of the capacitor C2 is connected with the inverting input end of the operational amplifier U3, the other end of the capacitor C2 is connected with the output end of the operational amplifier U3, and the resistor R12 is connected with the capacitor C2 in parallel.
3. A secondary side polarity intelligent detection method of a transformer substation current transformer is characterized by comprising the following steps: the intelligent secondary side polarity detection device of the transformer substation current transformer according to claim 1 or 2 is adopted, and the detection method comprises the following steps:
the checking host (1) outputs a primary current to pass through a primary loop of the tested CT (2), and the acquisition terminal (3) is utilized to acquire a secondary loop current of the tested CT (2) on the secondary side of the tested CT (2) to generate a first recording file and transmit the first recording file to the supervisor module (1 b);
a primary loop circuit of the tested CT (2) is sent to the acquisition wave recording module (1c) through the internal CT (1e) of the checking host (1) to generate a second wave recording file and transmit the second wave recording file to the supervisor module (1 b);
the supervisor module (1b) analyzes the first wave recording file and the second wave recording file and automatically judges the correctness of the polarity of the tested CT (2).
4. The intelligent secondary side polarity detection method for the transformer substation current transformer according to claim 3, characterized in that: introducing primary current of aA to the CT (2) to be detected through an alternating current source (1d), wherein the initial phase is b degrees;
sampling the secondary loop current of the tested CT (2) by utilizing an acquisition terminal (3) at a preset sampling frequency, taking k sampling points forward from a current sampling point every millisecond to calculate the effective value of the secondary current, converting the effective value into the primary current according to the transformation ratio of the tested CT (2), taking k sampling points backward from the current sampling point when the primary current mutation is a preset threshold value, calculating the phase of the primary current of the current sampling point, judging the polarity of a primary loop and a secondary loop of the tested CT (2) to be positive if the phase is in a preset interval, and otherwise judging the polarity of the primary loop and the secondary loop of the tested CT (2) to be negative.
5. The intelligent secondary side polarity detection method for the transformer substation current transformer according to claim 4, characterized in that: introducing a primary current of 200A to the tested CT (2) through an alternating current source (1d), wherein the initial phase is 0 degree;
sampling the secondary loop current of the tested CT (2) by using an acquisition terminal (3) at a sampling frequency of 10kHz, calculating a secondary current effective value by taking 200 sampling points forward from a current sampling point every millisecond, converting the secondary current effective value into a primary current according to the transformation ratio of the tested CT (2), and when the primary current abrupt change is
And then, 200 sampling points are backwards taken from the current sampling point, the phase of the primary current of the current sampling point is calculated, if the phase is in a (90 DEG and 270 DEG) interval, the polarities of the primary loop and the secondary loop of the tested CT (2) are judged to be positive, and if not, the polarities of the primary loop and the secondary loop of the tested CT (2) are judged to be negative.
6. The intelligent secondary side polarity detection method for the substation current transformer according to any one of claims 3 to 5, characterized by further comprising: the method for judging the transformation ratio of the tested CT (2) specifically comprises the following steps:
collecting the secondary loop current of the CT (2) to be detected by using a collecting terminal (3);
the transformation ratio of the tested CT (2) is equal to the ratio of the output current value of the alternating current source (1d) to the secondary loop current.
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| CN110763882B (en) * | 2019-10-30 | 2021-11-09 | 国网宁夏电力有限公司检修公司 | Transient phase-controlled large-current generator and simulation measurement method before commissioning of secondary equipment |
| CN111736108A (en) * | 2020-06-19 | 2020-10-02 | 国网河南省电力公司鹤壁供电公司 | Device for rapidly measuring polarity of current transformer |
| CN112039033B (en) * | 2020-07-28 | 2022-05-31 | 积成软件有限公司 | Method for resisting power frequency magnetic field interference for line protection device |
| CN112083372B (en) * | 2020-08-21 | 2023-12-15 | 深圳供电局有限公司 | Polarity identification method and system for current transformer |
| CN112147549A (en) * | 2020-09-28 | 2020-12-29 | 广东电网有限责任公司肇庆供电局 | Transformer substation current transformer polarity testing device based on single chip microcomputer |
| CN112485504A (en) * | 2020-10-29 | 2021-03-12 | 国网湖北省电力有限公司电力科学研究院 | Multi-machine-assistant-slave power grid secondary loop volt-ampere phase monitoring method and platform |
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| CN112684381A (en) * | 2020-12-03 | 2021-04-20 | 广东电网有限责任公司中山供电局 | CT polarity tester of hand-held type wireless transmission sampling |
| CN112834798B (en) * | 2020-12-21 | 2022-08-30 | 深圳供电局有限公司 | Transformation ratio testing method, transformation ratio testing device, testing equipment and storage medium |
| CN112946553B (en) * | 2021-01-29 | 2023-04-28 | 南方电网科学研究院有限责任公司 | Online checking method and device for same name end of distribution network |
| CN113933758A (en) * | 2021-09-23 | 2022-01-14 | 国网浙江新昌县供电有限公司 | Portable digital current transformer polarity detection device and method |
| CN114137469A (en) * | 2021-11-25 | 2022-03-04 | 国网陕西省电力公司西咸新区供电公司 | Method and system for realizing intelligent calibration of multi-tap current transformer |
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| CN103123389A (en) * | 2011-11-21 | 2013-05-29 | 甘肃省电力公司定西供电公司 | Method for verifying polarity of zero-sequence current transformer |
| CN205080251U (en) * | 2015-10-14 | 2016-03-09 | 大唐碧口水力发电厂 | Through -flow calibration system of current transformer secondary circuit |
| CN105891664B (en) * | 2016-06-14 | 2018-09-11 | 李彦吉 | Multi-analog loop polarity tester |
| CN107121614B (en) * | 2017-03-29 | 2019-10-25 | 国家电网公司 | A kind of duplex configuration of bus protection transformation current loop polarity measurement method |
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Effective date of registration: 20240108 Address after: 562400 No.1 Beijing Road, Xingyi City, Qianxinan Buyi and Miao Autonomous Prefecture, Guizhou Province Patentee after: TIANSHENGQIAO HYDROPOWER GENERATION Co.,Ltd. Patentee after: HYDROELECTRIC POWER GENERATION FACTORY, TIANSHENGQIAO FIRST-STAGE HYDROPOWER DEVELOPMENT Co.,Ltd. Address before: 562400 No.1, Beijing Road, Xingyi City, Guizhou Province Patentee before: TIANSHENGQIAO HYDROPOWER GENERATION Co.,Ltd. |