CN121483897A - 10KV pole-mounted contact switch with intelligent locking function - Google Patents

Abstract

The invention provides a 10kV pole connection switch with an intelligent locking function, which comprises a switch body, a voltage transformer for 10kV connection, a secondary and a main control system, wherein two sides of the switch body are connected with a power supply side voltage transformer and a load side voltage transformer, signals of the power supply side voltage transformer and the load side voltage transformer are input to the secondary and the main control system, the secondary and the main control system process the signals of the power supply side voltage transformer and the load side voltage transformer, and when the phase angle difference of the two sides is calculated and is larger than a set value, a control signal is sent to the switch body, and the switch body is intelligently locked and does not allow closing. The invention can accurately identify the phase and the phase sequence at the two sides of the switch without timing based on GPS or other communication.

Description

10KV pole-mounted contact switch with intelligent locking function

Technical Field

The invention relates to the field of switches, in particular to a 10kV pole-mounted contact switch with an intelligent locking function.

Background

The power supply reliability of the power system is required to be higher and higher, in order to avoid power failure in the field, the 10kV line is in thermal reverse load in most cases, but the phase sequences of the two sides are required to be verified to be consistent before thermal reverse load, and if the phase angle difference is too large, the condition of closing the loop thermal reverse load is not provided.

The nuclear phase operation before the current 10kV line thermal conduction load is performed manually by using a nuclear phase instrument, so that the phase sequences at two sides are consistent. Nuclear phase work not only needs nuclear phase instrument auxiliary operation, and most circumstances need to step on pole auxiliary hanging wire moreover, and is loaded down with trivial details and has the potential safety hazard.

In the thermal conduction nuclear phase process, part of operators save trouble, and have the condition of no nuclear phase, namely thermal conduction, the conventional switch lacks the technical measure of inconsistent locking and closing of the phases at two sides of the switch, and only relies on the management technology to require nuclear phase rear thermal conduction, so that great potential safety hazards are left for thermal conduction work.

The nuclear phase work before the current 10kV line thermal conduction load has the following defects:

Firstly, nuclear phase operation of a nuclear phase instrument not only needs to rely on manual operation, and the nuclear phase operation needs to be carried at any time and has complicated field operation, but also has the principle that a base station is needed as a reference based on a GPS (global positioning system) time setting technology, and the problem of disconnection exists.

Secondly, partial operators save trouble, have the condition of no nuclear phase, namely heat conduction, the conventional switch lacks the technical measure of inconsistent locking and closing of phase positions at two sides of the switch, and only relies on the management technology to require nuclear phase rear heat conduction, so that great potential safety hazards are left for heat conduction work.

Disclosure of Invention

The invention aims to provide a 10kV pole-mounted interconnection switch with an intelligent locking function, which solves the phase sequence checking problem before heat sealing of a loop without being based on GPS or other communication timing, accurately identifies the phase and the phase sequence at two sides of the switch, and can be used for intelligently locking two lines with overlarge phase angle gap and without loop closing conditions.

The technical solution for realizing the purpose of the invention is as follows:

the utility model provides a contact switch on 10kV post with intelligence shutting function, includes the switch body, is used for voltage transformer, secondary and the master control system of 10kV contact, power side voltage transformer and load side voltage transformer are connected to switch body both sides, and power side voltage transformer and load side voltage transformer's signal input is to secondary and master control system, and secondary and master control system handle power side voltage transformer and load side voltage transformer's signal, calculate the both sides phase angle difference, when the phase angle difference is greater than the setting value, send control signal to the switch body, and switch body intelligence shutting does not allow the combined floodgate.

Further, the secondary and main control system comprises an analog quantity acquisition module, a filtering module, a digital-to-analog conversion module, a CPU and decision control module, a communication module and a man-machine interaction module, wherein,

The analog quantity acquisition module is used for acquiring signals of the power supply side voltage transformer and the load side voltage transformer;

The filtering module is used for filtering out high-frequency harmonic waves in the acquired signals;

the digital-to-analog conversion module is used for converting the filtered analog quantity signal into a digital quantity signal and inputting the digital quantity signal to the CPU and decision control module;

the CPU and the decision control module calculate the phase angle difference of the two sides, and when the phase angle difference is larger than a set value, a control signal is sent to the switch body;

The communication module is used for communication between the man-machine interaction module and the CPU and decision control module;

The man-machine interaction module is used for monitoring and remote operation of the background.

Further, calculating the two-side phase angle difference specifically comprises the steps of collecting instantaneous values of 24 points of the power supply side voltage transformer and the load side voltage transformer according to each cycle, determining detection correction values of the power supply side voltage transformer and the load side voltage transformer through a detection algorithm, and taking the detection correction values of the two sides as the difference to obtain the two-side phase angle difference, wherein the step of determining the detection correction values of the power supply side voltage transformer and the load side voltage transformer through the detection algorithm specifically comprises the following steps:

the collected signals on two sides are respectively expressed as cosine functions:

;

Wherein: is the signal effective value; Is the initial phase angle; Is angular frequency; the frequency is 50Hz power frequency; is the frequency offset;

Setting the sampling frequency to be set as 24 points in each period At this time, discrete signals are obtained:

;

And adopting an Euler formula and carrying out Fourier transformation to obtain a signal error:

;

Wherein: Is an initial error, related to the input only; is a dynamic error, and is related to the input offset and the initial phase angle;

frequency tracking is realized through frequency measurement, initial errors in a compensation algorithm are realized, and then phase angles at two sides are detected.

Further, frequency tracking is realized through frequency measurement, initial errors in a compensation algorithm are realized, and then phase angles at two sides are detected, and the method specifically comprises the following steps:

Propose movement Is to build up phase differencesIs used to attenuate signal amplitude using a balanced relationshipThe method comprises the following steps of:

;

;

;

Wherein: Is the initial error coefficient; for the dynamic error coefficient, the sampling range is shifted to the left and right by 4 points, and fourier transformation is performed to obtain:

;

;

Will be 、Phasor synthesis, obtaining:

;

When (when) When the measuring error is completely eliminated, whenWhen in use, for、The correction is carried out as follows:

;

;

will be corrected 、Phasor synthesis, and the correction signal is obtained by simplifying the Taylor series expansion:

。

Further, the CPU and the decision control module adopt a clock signal sampling synchronization adjustment algorithm to determine the signal difference of the synchronous clock between the power supply side voltage transformer and the load side voltage transformer.

Further, the CPU and the decision control module adopt a clock signal sampling synchronization adjustment algorithm specifically comprising:

SA and SB are set as clock synchronous signals of a power supply side and a load side respectively, For the time difference of the transmission signals between SA and SB, at a certain moment, the power supply side transmits a synchronizing signal SA to the load side, and when the load side receives the SA signal transmitted by the power supply side, the load side adds a frame time difference in the synchronizing signal data frame and transmits the synchronizing signal data frame to the power supply side, wherein the time interval is that;

At a certain moment, the load side sends a synchronous signal SB to the power side, and when the power side receives the synchronous signal SB sent by the load side, the power side also adds a frame time difference in the data frame of the reply synchronous signal, and the time interval is equal to the time interval;

Combining time intervals of transmission of load side through each other、Calculating the clock signal difference at both sides, i.eWhen (when)Timing of occurrence indicates that the clock information of the transmitting signal end is advanced to the clock synchronization information of the receiving end whenWhen negative occurs, the clock information representing the transmitting signal end lags behind the clock synchronization information of the receiving end.

Further, the secondary and main control system collects control clock pulses of the voltage transformers at the power supply side and the load side through an A/D chip of the same clock pulse control digital-to-analog conversion module, generates a unique serial number, combines the serial number with a clock signal sampling synchronization adjustment algorithm calculated value, generates fixed time mark information, and beats the fixed time mark information at the front end of a sampling value.

Further, isolation measures are adopted between the secondary and main control systems and the switch body.

Further, the isolation measures adopted between the secondary and main control systems and the switch body specifically comprise the steps of isolating strong and weak current through the TLP181 optocoupler when the voltages at the power supply side and the load side are collected, and isolating by using the TLP127 when the switch body is controlled to operate.

Further, when the phase angle difference is larger than 10 degrees, the two sides are reminded that the phase angle is too large, the switch is closed carefully, and when the phase angle difference is larger than 20 degrees, the switch body is closed intelligently and the switch is not allowed to be closed.

Compared with the prior art, the contact switch has the beneficial effects that the contact switch can be provided with the phase sequence detection function on two sides on the basis of not needing GPS or other communication timing, can forcedly lock the heat conducting rings on two sides for overlarge phase sequence difference on two sides, and improves the safety and the working efficiency of the ring closing, and when the voltage on two sides is acquired, the contact switch isolates strong and weak current through the TLP181 optical coupler. When the switch body is controlled to operate, TLP127 is used for isolation. The invention collects control clock pulses at two sides, so that the clock information of voltage signals collected at a power supply side and a load side is more consistent, and provides a clock signal sampling synchronous adjustment algorithm based on local time delay, which accurately calculates phase angle differences at two sides.

Drawings

Fig. 1 is a system configuration diagram.

Fig. 2 is a schematic diagram of a local delayed clock signal sampling synchronization adjustment algorithm.

Fig. 3 is an isolated circuit diagram.

Detailed Description

Referring to fig. 1, this embodiment provides a 10kV pole-mounted tie switch with intelligent locking function, which mainly includes a switch body, 10kV tie two-side voltage transformers (PT), a secondary and a main control system. The secondary and main control system mainly comprises an analog quantity acquisition module, a filtering module, a digital-to-analog conversion module, a CPU and decision control module, a communication module and a man-machine interaction module.

The analog quantity acquisition module is used for acquiring signals of the power supply side voltage transformer and the load side voltage transformer;

the filtering module is used for filtering out high-frequency harmonic waves and reserving 50Hz power frequency signals.

The digital-to-analog conversion module is used for converting the filtered analog quantity signal into a digital quantity signal and inputting the digital quantity signal to the CPU and decision control module.

The CPU and the decision control module are used for calculating the phase angle difference of two sides, and when the phase angle difference is larger than a set value, a control signal is sent to the switch body.

The communication module is used for communication with a man-machine interaction background, and mainly adopts a wireless communication mode.

The man-machine interaction module is used for the functions of background monitoring, remote operation and the like.

The automatic check of the phase sequence of the two sides of the circuit can be realized, when the phase angle difference is greater than 10 degrees, the two sides of the circuit can be reminded that the phase angle is overlarge, the circuit is closed carefully, when the phase angle difference is greater than 20 degrees, the switch body can be closed intelligently, the circuit is not allowed to be closed, and the safe operation of the power grid when the circuit on the two sides is closed by heat is ensured.

The tie switch can detect whether the phase sequences of the two sides are consistent through a power supply side PT and a load side PT, and judge the phase angle difference of the two sides in real time according to the instantaneous values of 24 points acquired by each cycle. The specific detection algorithm is as follows.

The signal collected by the method can be expressed as a cosine function as formula (1).

(1)

Wherein: Is a valid value; Is the initial phase angle; Is angular frequency; the frequency is 50Hz power frequency; is the frequency offset.

Setting 24 points for each period, and setting the sampling frequency of the device to beWhen formula (1) can be expressed as:

(2)

applying the Euler formula and performing Fourier transform.

(3)

Wherein: Is an initial error, related to the input only; Is a dynamic error, and is related to the input offset and the initial phase angle. As can be seen from equation (3), the initial error is Frequency tracking can be achieved through frequency measurement, enabling compensation of initial errors in the algorithm. Due to dynamic errorsIs not easy to compensate and correct, and proposes a movementBy constructing phase differencesIs used to attenuate signal amplitude using a balanced relationshipAnd the accuracy of phase angle detection is improved.

(4)

(5)

(6)

Wherein: Is the initial error coefficient; is a dynamic error coefficient. The sampling range is shifted to the left and right by 4 points, and fourier transformation is performed to obtain the sample range.

(7)

(8)

The phasors in the formulas (7) and (8) are synthesized, so that dynamic errors are eliminated.

(9)

As can be seen from formula (9), whenIn this case, the dynamic error and the initial error can be eliminated, and the measurement error is completely eliminated. When (when)In this case, the formulas (7) and (8) should be modified.

(10)

(11)

The phasors in the formula (10) and the formula (11) are synthesized, and the taylor series expansion is simplified.

(12)

As can be seen from equation (12), the dynamic error is increased by a set of coefficientsThe algorithm is called weakening coefficient, and can effectively improve the phase angle detection precision as can be seen from the above formula.

In combination with fig. 2, in order to accurately calculate the phase angle difference at two sides, a clock signal sampling synchronization adjustment algorithm based on local delay is provided. The specific real-time steps are as follows:

the first step is to set SA and SB as the clock synchronization signals of the power supply side and the load side respectively, For the time difference of the transmission signals between SA and SB, at a certain moment, the power supply side transmits a synchronizing signal SA to the load side, and when the load side receives the SA signal transmitted by the power supply side, the load side adds a frame time difference in the synchronizing signal data frame and transmits the frame time difference to the power supply side. I.e. the time intervals in fig. 2

The second step, the load side sends the synchronous signal SB to the power side at a certain time, when the power side receives the synchronous signal SB sent by the load side, the power side adds a frame time difference in the data frame of the recovered synchronous signal, namely the time interval in figure 2。

Third, it can be seen from the schematic diagram that the time interval of the transmission of the opposite side is combined with the load side、The clock signal difference on both sides can be calculated, i.e。

The fourth step, the power side can calculate the time difference of the synchronous clock between the current side and the load side after one round:

The fifth step, the load side can also obtain the time difference of the synchronous clock between the local side and the power supply side:

Sixth step: can be positive and negative when Timing of occurrence indicates that the clock information of the transmitting signal end is advanced to the clock synchronization information of the receiving end whenWhen negative occurs, the clock information representing the transmitting signal end lags behind the clock synchronization information of the receiving end.

In order to make the clock information of the voltage signals collected by the power supply side and the load side more consistent, the control clock pulses are collected at two sides, in the control system, the same clock pulse is used for controlling the analog-digital conversion chip to collect, and a unique serial number is generated, the serial number is combined with a local clock synchronization algorithm calculation value to generate fixed time mark information, the fixed time mark information is beaten at the front end of a sampling value, operation information under accurate time synchronization is obtained, and the accuracy of phase sequence calculation at two sides is ensured.

In order to prevent electromagnetic interference, the device designs an isolation measure of a signal acquisition and switch body control circuit, and as shown in fig. 3, when voltages at two sides are acquired, strong and weak currents are isolated through the TLP181 optocoupler. When the switch body is controlled to operate, TLP127 is used for isolation. The stability of a secondary switch signal acquisition and control system is ensured.

The invention mainly solves the phase sequence checking problem before thermal inversion ring closing, and for two lines with overlarge phase angle gap and without ring closing conditions, the switch can intelligently close to remind operators without ring closing conditions, and mainly solves the problem that the phase and phase sequence at two sides of the switch are accurately identified on the basis of not needing GPS or other communication timing.

It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims (10)

1. The 10kV pole connection switch with the intelligent locking function is characterized by comprising a switch body, a voltage transformer for 10kV connection, a secondary and a main control system, wherein two sides of the switch body are connected with a power supply side voltage transformer and a load side voltage transformer, signals of the power supply side voltage transformer and the load side voltage transformer are input to the secondary and the main control system, the secondary and the main control system process the signals of the power supply side voltage transformer and the load side voltage transformer, and when the phase angle difference of the two sides is calculated and is larger than a set value, a control signal is sent to the switch body, and the switch body is intelligently locked and does not allow closing.

2. The 10kV pole-mounted tie switch with an intelligent locking function according to claim 1, wherein the secondary and main control system comprises an analog quantity acquisition module, a filtering module, a digital-to-analog conversion module, a CPU and decision control module, a communication module and a man-machine interaction module,

The analog quantity acquisition module is used for acquiring signals of the power supply side voltage transformer and the load side voltage transformer;

The filtering module is used for filtering out high-frequency harmonic waves in the acquired signals;

the digital-to-analog conversion module is used for converting the filtered analog quantity signal into a digital quantity signal and inputting the digital quantity signal to the CPU and decision control module;

the CPU and the decision control module calculate the phase angle difference of the two sides, and when the phase angle difference is larger than a set value, a control signal is sent to the switch body;

The communication module is used for communication between the man-machine interaction module and the CPU and decision control module;

The man-machine interaction module is used for monitoring and remote operation of the background.

3. The 10kV pole-mounted tie switch with an intelligent locking function according to claim 2, wherein the calculation of the phase angle difference at two sides is specifically carried out by collecting instantaneous values of 24 points of a power side voltage transformer and a load side voltage transformer according to each cycle, determining detection correction values of the power side voltage transformer and the load side voltage transformer through a detection algorithm, and taking the detection correction values at two sides as a difference to obtain the phase angle difference at two sides, wherein the determination of the detection correction values of the power side voltage transformer and the load side voltage transformer through the detection algorithm specifically comprises the following steps:

the collected signals on two sides are respectively expressed as cosine functions:

;

Wherein: is the signal effective value; Is the initial phase angle; Is angular frequency; the frequency is 50Hz power frequency; is the frequency offset;

Setting the sampling frequency to be set as 24 points in each period At this time, discrete signals are obtained:

;

And adopting an Euler formula and carrying out Fourier transformation to obtain a signal error:

;

Wherein: Is an initial error, related to the input only; is a dynamic error, and is related to the input offset and the initial phase angle;

frequency tracking is realized through frequency measurement, initial errors in a compensation algorithm are realized, and then phase angles at two sides are detected.

4. The 10kV pole-mounted tie switch with intelligent locking function according to claim 3, wherein the method is characterized in that frequency tracking is realized through frequency measurement, initial errors in a compensation algorithm are realized, and then phase angles at two sides are detected, and the method specifically comprises the following steps:

Propose movement Is to build up phase differencesIs used to attenuate signal amplitude using a balanced relationshipThe method comprises the following steps of:

;

;

;

Wherein: Is the initial error coefficient; for the dynamic error coefficient, the sampling range is shifted to the left and right by 4 points, and fourier transformation is performed to obtain:

;

;

Will be 、Phasor synthesis, obtaining:

;

When (when) When the measuring error is completely eliminated, whenWhen in use, for、The correction is carried out as follows:

;

;

will be corrected 、Phasor synthesis, and the correction signal is obtained by simplifying the Taylor series expansion:

。

5. The 10kV pole-mounted tie switch with intelligent locking function according to claim 2, wherein the CPU and the decision control module adopt a clock signal sampling synchronization adjustment algorithm to determine the signal difference of a synchronous clock between the power supply side voltage transformer and the load side voltage transformer.

6. The 10kV column contact switch with intelligent locking function according to claim 5, wherein the CPU and the decision control module adopt a clock signal sampling synchronization adjustment algorithm, and the method specifically comprises the following steps:

SA and SB are set as clock synchronous signals of a power supply side and a load side respectively, For the time difference of the transmission signals between SA and SB, at a certain moment, the power supply side transmits a synchronizing signal SA to the load side, and when the load side receives the SA signal transmitted by the power supply side, the load side adds a frame time difference in the synchronizing signal data frame and transmits the synchronizing signal data frame to the power supply side, wherein the time interval is that;

At a certain moment, the load side sends a synchronous signal SB to the power side, and when the power side receives the synchronous signal SB sent by the load side, the power side also adds a frame time difference in the data frame of the reply synchronous signal, and the time interval is equal to the time interval;

Combining time intervals of transmission of load side through each other、Calculating the clock signal difference at both sides, i.eWhen (when)Timing of occurrence indicates that the clock information of the transmitting signal end is advanced to the clock synchronization information of the receiving end whenWhen negative occurs, the clock information representing the transmitting signal end lags behind the clock synchronization information of the receiving end.

7. The 10kV pole-mounted tie switch with intelligent locking function according to claim 5, wherein the secondary and main control system collects control clock pulses of the power side voltage transformer and the load side voltage transformer through an A/D chip of the same clock pulse control digital-to-analog conversion module, generates a unique serial number, combines the serial number with a clock signal sampling synchronization adjustment algorithm calculated value, generates fixed time scale information, and is arranged at the front end of a sampling value.

8. The 10kV pole-mounted tie switch with intelligent locking function according to claim 1, wherein isolation measures are adopted between the secondary and main control systems and the switch body.

9. The 10kV pole-mounted contact switch with intelligent locking function according to claim 8, wherein the secondary and main control system and the switch body take isolation measures, specifically, when voltages on the power side and the load side are collected, strong current and weak current are isolated through the TLP181 optocoupler, and when the switch body is controlled to operate, TLP127 is used for isolation.

10. The 10kV pole-mounted tie switch with intelligent locking function according to claim 1, wherein when the phase angle difference is larger than 10 degrees, the two sides are reminded of overlarge phase angle, and when the phase angle difference is larger than 20 degrees, the switch body is intelligently locked and does not allow to be closed.