CN113985213B - Correction method for errors of Beidou time service module during power distribution network fault distance measurement - Google Patents
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- 238000012937 correction Methods 0.000 title claims abstract description 65
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R35/005—Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
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- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
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Abstract
The invention discloses a correction method of errors of a Beidou time service module during power distribution network fault ranging, which is used for realizing accurate positioning of fault points in a power distribution network; the method comprises the steps that an antenna receives radio frequency signals transmitted by satellites, and a baseband signal is obtained through down-conversion; capturing and tracking the baseband, then carrying out data decoding to obtain a navigation message and a pseudo range, wherein the navigation message contains parameters such as clock error, ionosphere troposphere delay and the like, carrying out parameter correction to obtain a corrected pseudo range, listing a positioning equation set by using the corrected pseudo range, and solving the equation set to calculate the position of a user; the time delay of signal space transmission can be calculated by dividing the distance between the satellite and the receiver by the speed of light, the time delay of the receiver is tested, and the real 1PPS can be obtained after the time delay correction is carried out on the original 1PPS; the method can eliminate time delay errors during signal propagation, and then the fault point is accurately positioned by using the fault ranging and positioning device.
Description
Technical Field
The invention belongs to the technical field of communication, and particularly relates to a correction method for errors of a Beidou time service module in power distribution network fault distance measurement.
Background
The power distribution network has the problems that the fault distance measurement is difficult due to factors such as short circuit, more branches, the mixed laying phenomenon of overhead lines and cable lines, various loads distributed along the line and the like; particularly, in a small-current grounding system, fault current is weak, the influence of transition resistance and measurement error of a fault point is extremely large, and the traditional impedance ranging principle is utilized for error-beating application; the traveling wave can be adopted to measure the distance of the small-current ground fault aiming at the medium-voltage distribution network line with longer line and fewer branches.
The current double-end traveling wave ranging method based on GPS time synchronization has the time synchronization precision of the double-end device of about 1 mu s, the generated actual ranging error is about 300m, the multiple surface of a line point of a distribution network is wide, the region is complex, the site fault positioning requirement can be prepared as far as possible, the time synchronization error of the double-end device is required to be within 100ns (1 mu s=1000ns) as accurate as possible between two electric poles (within 30 m), the time service precision of a synchronous time synchronization module is required to be kept within 100ns, the generated errors comprise satellite time service errors and time synchronization module hardware errors, and the hardware errors need to be controlled within 50 ns.
Disclosure of Invention
The invention provides a correction method for errors of the Beidou time service module during power distribution network fault distance measurement, which aims to solve the problems; correcting the clock error effect by using the obtained clock error and other parameters; performing troposphere effect correction by using the obtained troposphere correction parameters; performing ionosphere effect correction by using the acquired ionosphere parameters; and (3) obtaining corrected pseudo-ranges, establishing a positioning equation by using a plurality of corrected pseudo-ranges, and measuring the distances between the receiver and four satellites to position the receiver, thereby obtaining the GPS system.
And (3) performing receiver time delay calculation by using the corrected pseudo range, and performing time delay correction on the original 1PPS by using the receiver time delay to obtain accurate time service.
When the fault transient current traveling wave signal of the power distribution network appears, the fault point is accurately positioned by using the fault ranging and positioning device.
The technical scheme of the invention for realizing the purpose is as follows:
a correction method for errors of a Beidou time service module during power distribution network fault distance measurement comprises the following steps:
step one, a receiver receives radio frequency signals transmitted by satellites, digital baseband signals are obtained through down conversion, the baseband captures and tracks the digital baseband signals, and then data decoding is carried out to obtain data of two aspects: on the one hand, the navigation message comprises a clock error parameter, an ionosphere delay parameter and a troposphere delay parameter; on the other hand, a pseudo range is obtained in the tracking process, wherein the pseudo range is the distance between a satellite and a receiver;
step two, correcting the clock error parameter by using a clock error effect to obtain a clock error correction value; performing tropospheric effect correction on the tropospheric delay parameter to obtain a tropospheric correction value; performing ionospheric effect correction on the ionospheric delay parameter to obtain an ionospheric correction value;
substituting the clock difference correction value, the troposphere correction value, the ionosphere correction value and the pseudo range into a pseudo range correction calculation formula to obtain a corrected pseudo range;
fourth, repeating the first step to the third step to obtain 4 corrected pseudo ranges, and establishing a positioning equation set by using the corrected pseudo ranges to obtain clock differences of the receiver and the satellite; correcting the local clock through the clock difference between the receiver and the satellite to obtain satellite system time;
step five, after the baseband captures and tracks, generating an original 1PPS when encountering a synchronous head of a whole second, and deducting the signal transmission delay generated by the original 1PPS, wherein the calculation process of the signal transmission delay is as follows: dividing the corrected pseudo range by the speed of light to obtain the time delay of signal space transmission; performing receiver time delay calculation, wherein the receiver time delay is obtained through testing; after the signal transmission delay generated by the original 1PPS is subtracted, the receiver delay is subtracted, and finally the true 1PPS is obtained;
step six, receiving fault transient current traveling wave signals generated when the internal fault of the distribution network line occurs by a fault ranging and positioning device, wherein the fault ranging and positioning device comprises a Beidou time service module, a transient voltage traveling wave head measuring sensor module and a main MCU; the transient voltage traveling wave head measuring sensor module is used for receiving fault transient current traveling wave signals; a clock formed by a high-stability crystal oscillator synchronized with a real 1PPS pulse is arranged in the Beidou time service module; the main MCU accurately records the arrival time of the fault transient current traveling wave signal; the positioning principle of the fault ranging and positioning device is as follows:
the fault transient current traveling wave signals generated during internal faults of the distribution network line reach buses at two ends of the line at the same propagation speed v, the buses at two ends of the line are respectively M-end and N-end, and the time when the fault transient current traveling wave signals reach the buses at the M-end and the N-end is respectively T M And T N The accurate calculation formula of the distances from the M-terminal bus and the N-terminal bus to the fault point is as follows:
wherein: d (D) MK Is the distance from the M-end bus to the fault point, D NK The distance from the N-end bus to the fault point is L, the length of the line MN is the length of the line, and the line is an overhead line or a cable line.
Further, the specific steps of the second step are as follows:
s1, correcting the clock error effect in the following way:
the clock error effect correction adopts a GNSS time difference monitoring receiver clock error correction method to obtain a clock error correction value;
s2, the ionospheric effect correction mode is as follows:
establishing an ionospheric delay single frequency correction model, wherein the ionospheric delay single frequency correction model is as follows:
wherein: d=5ns, night value for ionospheric delay, P period, a amplitude, T local, initial phase T p = 50400s, Δt3 is ionospheric correction value, MF is projection function; the projection function converts the ionospheric delay in the zenith direction of the puncture point into the ionospheric delay in the signal propagation direction; the calculation formula of the projection function is as follows:
wherein: z is the zenith distance of the receiver, R E Is the average radius of the earth, which is generally 6371km and h ion The average height of the ionosphere is generally taken as 350km, and SinZ is a trigonometric function of Z;
the calculation formula of the amplitude A and the period P is as follows:
in phi m Geomagnetic latitude of the ionosphere penetration point; alpha i And beta i (i=1, 2,3, 4) is an ionosphere parameter of satellite broadcast, which is a constant derived from the observation date and the solar average radiation flux;
the ionospheric delay single-frequency correction model can also be written as a practical formula:
wherein: />
S3, the troposphere effect correction mode is as follows: establishing a total atmospheric delay calculation model:
wherein: h T ＝40136+148.72(T 0 -273.15)、H W ＝11000；
Wherein: h T The unit of the top height of the dry atmosphere is m and H W The unit of the top height of the wet atmosphere is m and P 0 Is the unit of ground air pressure is mbar, T 0 Is the unit of ground humidity is T, e 0 The unit of water pressure is mbar, the unit of height is meter and the parameter k is relative to the ground level 1 ＝77.6K 2 /mbar、k 2 ＝71.6K 2 /mbar、k 3 ＝3.747×10 5 K 2 /mbar。
Further, the specific steps of the third step are as follows:
the pseudo-range correction calculation formula is as follows: ρ n ＝ρ′ n -c·(Δt1+Δt2+Δt3)
Wherein: Δt1 is the clock correction value, Δt2 is the tropospheric correction value, ρ' n And c is the speed of light for measuring the n-th satellite pseudo range.
Further, the specific steps of the fourth step are as follows:
the set of positioning equations is:
in (x) u ,y u ,z u ) Is the location of the receiver; (x) u ,y u ,z u ) (n=1, 2, …) is the position of a known satellite; ρ n The corrected n satellite pseudo-range; Δt (delta t) u Clock difference between the receiver and the satellite; if the exact location of the receiver is known, then there are:
namely, receiving the data of 1 satellite to calculate deltat u And obtaining a GPS system.
Further, the receiver delay includes delay Deltat 4 of an antenna head, delay Deltat 5 of a feeder line, delay Deltat 6 of a radio frequency channel and signal processing delay which are defined as Deltat 7, and the receiver delay can be obtained by testing Deltat 4 < + > Deltat 5 < + > Deltat 6 < + > Deltat 7.
Further, the Beidou time service module consists of a traveling wave detection module, a time receiving and timing module and a Beidou module.
Compared with the prior art, the technical scheme of the invention has the advantages that:
after the signal is successfully captured, obtaining a text signal through data processing such as decoding, performing clock error effect correction, troposphere effect correction and ionosphere effect correction by using parameters in the text signal, obtaining corrected pseudo-ranges by using the corrected parameters, and obtaining a GPS (global positioning system) by using a plurality of corrected pseudo-ranges; the corrected pseudo range is used for carrying out time delay calculation of a receiver, the time delay of the original 1PPS is corrected by using the time delay of the receiver, accurate time service is obtained, and the reliability and the accuracy of timing can be improved; when a power distribution network fault transient current traveling wave signal appears, a fault location device is utilized to accurately locate a fault point, so that the average time synchronization error of devices at two ends of a line is not more than 100ns, and the absolute distance measurement error generated by the time synchronization error is not more than 30m.
Drawings
FIG. 1 is a flow chart of time delay calculation and correction;
FIG. 2 is a schematic diagram of a fault line model;
FIG. 3 is a timing diagram of a second signal versus a message;
fig. 4 is a schematic delay diagram of an antenna and a feed line;
FIG. 5 is a schematic diagram of the time delay of the RF channel and signal processing;
fig. 6 is a block diagram of the beidou time service module.
The specific embodiment is as follows:
the invention will be further described with reference to the accompanying drawings and preferred examples.
Example 1
The invention provides a correction method for errors of a Beidou time service module in power distribution network fault distance measurement, which comprises the following specific embodiments:
as shown in fig. 1, the navigation satellite signal is received by an antenna, and a digital baseband signal is obtained after down-conversion and a/D sampling; the code generator of the local receiver generates code slices consistent with the satellite C/A codes and carries out correlation processing on the digital baseband signals; when acquisition and tracking are achieved, correlation peak pulses will be generated locally; setting the synchronous code time of the telemetry word TLW of the detected subframe 1 as tacq; assuming that the delays of the antenna and the radio frequency channel are fixed, the delay between the tacq moment and the moment when the satellite signal containing the synchronous code enters the antenna is fixed due to the flow of the flow operation of the receiver; correcting the clock error effect by using parameters such as clock error in the message signal; performing troposphere effect correction by using the obtained troposphere correction parameters; performing ionosphere effect correction by using the acquired ionosphere parameters; and finally obtaining the corrected pseudo range.
The receiver can receive a plurality of satellite signals simultaneously to obtain a plurality of corrected pseudo ranges, and a positioning equation is established; the self position can be obtained by solving the positioning equation, and the local clock difference can be calculated by the positioning equation; because the navigation message has ephemeris parameters, the satellite position can be calculated, so that the accurate distance between the satellite and the receiver can be obtained, the time correction value of the signal propagation distance can be calculated, and the local time can be corrected, so that the GPS system can be recovered.
In the fixed point time service mode of the shielding environment, a user can manually input position coordinates after positioning accurately, and a receiver performs time service calculation according to the coordinates, so that positioning is not performed any more; the receiver can also automatically locate, optimize the locating result according to the PDOP factor, adopt the result after optimizing as the basis of the time service algorithm; therefore, after successful positioning, positioning calculation is not performed any more, and only delay correction is performed; the method can reduce the large change of the positioning position caused by insufficient satellite quantity in the shielding environment, and improve the reliability and accuracy of timing.
The fault location device is used for accurately locating fault points in the power distribution network and consists of a transient voltage traveling wave head measuring sensor module, a Beidou time service module and a main MCU; the Beidou time service module consists of a traveling wave detection module, a time receiving and timing module and a Beidou module; the Beidou time service module synchronizes the 1PPS pulses received by the Beidou time service module through a clock formed by the internal high-stability crystal oscillator, so that the travel time error is controlled within 1 us; when the fault transient current traveling wave signal of the power distribution network appears, the signal triggers the main MCU to accurately record the arrival time of the traveling wave pulse signal.
The response speed of the transient voltage traveling wave head measuring sensor module can be within 10ns, the transient abrupt change signal of the traveling wave head can be rapidly captured, the ranging error is 50m, and the transient voltage traveling wave head measuring sensor module can be widely applied to power distribution network fault processing terminals (such as a station terminal DTU, a feeder terminal FTU and a distribution transformer monitoring terminal TTU);
as shown in FIG. 2, the time (time tag) when the fault initial traveling wave surge arrives at the M-end and N-end buses (forming the first reverse traveling wave surge at each end) at the same propagation velocity v (the overhead line approaches the speed of light, about 294km/ms, and the cable line about 160 km/ms) is set to be T M And T N The accurate calculation formula of the distances from the M-terminal bus and the N-terminal bus to the fault point is as follows:
wherein D is MK And D NK The distance between the bus at the M end and the bus at the N end and the fault point is respectively, L is the length of a line MN, and the line is an overhead line or a cable line.
The pin definition of the Beidou time service module is shown in table 1.
TABLE 1
| Pin | Signal definition | Function of |
| 1 | Antenna power supply | +5.0V DC power supply |
| 2 | +3.3V DC | +3.3V DC power supply |
| 3 | TXD | Transmission, LVCMOS logic level |
| 4 | Reserved | Reservation of |
| 5 | RXD | Receiving, LVCMOS logic level |
| 6 | TIMEPULSE | Second pulse, LVCMOS logic level |
| 7 | Reserved | Reservation of |
| 8 | GND | Ground (floor) |
The 6 th pin of the Beidou time service module outputs timing pulses, and the time sequence relation between the timing pulses and the messages is shown as figure 3; the message is transmitted by an asynchronous serial port, the baud rate is 9600bps, the start bit is 1, the stop bit is 1, and the parity check bit is not available.
Example 2
Receiver delay calculations are further described in connection with example 1.
The receiver recovers the system time from receiving the satellite signal, during which there is a delay; the delay can be divided into two main aspects: firstly, delaying the antenna and the feeder line; and secondly, after the signals enter the radio frequency channel, the delay of 1PPS is recovered after the signals are processed by down-conversion. As shown in fig. 4, the delays of the antenna and the feeder line include delay Δt4 of the antenna head and delay Δt5 of the feeder line; the processing flow in the antenna head comprises amplification and filtering, wherein the delay of the amplifier is obtained by calculating the length of signal transmission, and the delay of the filter is obtained by calculating the length of signal transmission and the phase shift of the filter; the transmission of the feeder line is by precisely calculating the length of the signal transmission.
The signals are transmitted through an antenna and a feeder line, reach the entrance of a radio frequency channel of the equipment, and are converted into analog intermediate frequency through frequency mixing, filtering and automatic gain adjustment; this delay is commonly referred to as the radio frequency channel delay Deltat 6; the radio frequency channel consists of frequency synthesis, down-conversion treatment and numerical control attenuator control; the frequency synthesis completes phase locking and frequency multiplication of the reference frequency and provides local oscillation frequency synthesis of down-conversion processing; the down-conversion processing adopts a two-stage frequency conversion scheme to finish the conversion from an input radio frequency signal to an intermediate frequency signal, the numerical control attenuation realizes the variable gain control of the intermediate frequency signal according to the power of the input signal, and the effective quantization range of the intermediate frequency signal in the A/D sampling processing is ensured.
As shown in fig. 5, the analog intermediate frequency output by the radio frequency module is converted into a digital intermediate frequency after a/D conversion, and carrier synchronization, pseudo code capturing and tracking, demodulation, despreading and frame synchronization are mainly completed in the signal processing unit. Once the frames are synchronized, a time stamp is generated, which is typically recovered 1PPS; the delay of the signal processing section is defined as Δt7; therefore, compared with the original 1PPS for tracing the satellite signals, the 1PPS not only experiences the time delay, but also comprises the time delay for transmitting the signals from the central station to the satellite and then from the satellite to the ground; the time delay of the section needs to calculate the position of the satellite so as to obtain the time delay of signal transmission; the delay of signal transmission is subtracted to recover the original 1PPS.
The present invention is not limited to the preferred embodiments, and any simple modification, equivalent variation and modification of the above embodiments according to the technical principles of the present invention will fall within the scope of the technical principles of the present invention, as will be apparent to those skilled in the art without departing from the scope of the technical principles of the present invention.
Claims (5)
1. A correction method for errors of a Beidou time service module during power distribution network fault distance measurement is characterized by comprising the following steps:
step one, a receiver receives radio frequency signals transmitted by satellites, digital baseband signals are obtained through down conversion, the baseband captures and tracks the digital baseband signals, and then data decoding is carried out to obtain data of two aspects: on the one hand, the navigation message comprises a clock error parameter, an ionosphere delay parameter and a troposphere delay parameter; on the other hand, a pseudo range is obtained in the tracking process, wherein the pseudo range is the distance between a satellite and a receiver;
step two, correcting the clock error parameter by using a clock error effect to obtain a clock error correction value; performing tropospheric effect correction on the tropospheric delay parameter to obtain a tropospheric correction value; performing ionospheric effect correction on the ionospheric delay parameter to obtain an ionospheric correction value;
s1, correcting the clock error effect in the following way:
the clock error effect correction adopts a GNSS time difference monitoring receiver clock error correction method to obtain a clock error correction value;
s2, the ionospheric effect correction mode is as follows:
establishing an ionospheric delay single frequency correction model, wherein the ionospheric delay single frequency correction model is as follows:wherein: d=5ns, night value for ionospheric delay, P period, a amplitude, T local, initial phase T p = 50400s, Δt3 is ionospheric correction value, MF is projection function; the projection function converts the ionospheric delay in the zenith direction of the puncture point into the ionospheric delay in the signal propagation direction; the calculation formula of the projection function is as follows:
wherein: z is the zenith distance of the receiver, R E Is the average radius of the earth, which is 6371km, h ion Taking the average height of the ionosphere as 350km, and SinZ as a trigonometric function of Z;
the calculation formula of the amplitude A and the period P is as follows:
in phi m Geomagnetic latitude of the ionosphere penetration point; alpha i And beta i i=1, 2,3,4, is an ionosphere parameter of satellite broadcast, which is a constant derived from the observation date and the solar average radiant flux;
the ionospheric delay single-frequency correction model is written as a practical formula:
wherein: />
S3, the troposphere effect correction mode is as follows: establishing a total atmospheric delay calculation model:
wherein: h T ＝40136+148.72(T 0 -273.15)、H W ＝11000；
Wherein: h T The unit of the top height of the dry atmosphere is m and H W The unit of the top height of the wet atmosphere is m and P 0 Is the unit of ground air pressure is mbar, T 0 Is the unit of ground humidity is T, e 0 The unit of water pressure is mbar, the unit of height is meter and the parameter k is relative to the ground level 1 ＝77.6K 2 /mbar、k 2 ＝71.6K 2 /mbar、k 3 ＝3.747×10 5 K 2 /mbar；
Substituting the clock difference correction value, the troposphere correction value, the ionosphere correction value and the pseudo range into a pseudo range correction calculation formula to obtain a corrected pseudo range;
fourth, repeating the first step to the third step to obtain 4 corrected pseudo ranges, and establishing a positioning equation set by using the corrected pseudo ranges to obtain clock differences of the receiver and the satellite; correcting the local clock through the clock difference between the receiver and the satellite to obtain satellite system time;
step five, after the baseband captures and tracks, generating an original 1PPS when encountering a synchronous head of a whole second, and deducting the signal transmission delay generated by the original 1PPS, wherein the calculation process of the signal transmission delay is as follows: dividing the corrected pseudo range by the speed of light to obtain the time delay of signal space transmission; performing receiver time delay calculation, wherein the receiver time delay is obtained through testing; after the signal transmission delay generated by the original 1PPS is subtracted, the receiver delay is subtracted, and finally the true 1PPS is obtained;
step six, receiving fault transient current traveling wave signals generated when the internal fault of the distribution network line occurs by a fault ranging and positioning device, wherein the fault ranging and positioning device comprises a Beidou time service module, a transient voltage traveling wave head measuring sensor module and a main MCU; the transient voltage traveling wave head measuring sensor module is used for receiving fault transient current traveling wave signals; a clock formed by a high-stability crystal oscillator synchronized with a real 1PPS pulse is arranged in the Beidou time service module; the main MCU accurately records the arrival time of the fault transient current traveling wave signal; the positioning principle of the fault ranging and positioning device is as follows:
the fault transient current traveling wave signals generated during internal faults of the distribution network line reach buses at two ends of the line at the same propagation speed v, the buses at two ends of the line are respectively M-end and N-end, and the time when the fault transient current traveling wave signals reach the buses at the M-end and the N-end is respectively T M And T N The accurate calculation formula of the distances from the M-terminal bus and the N-terminal bus to the fault point is as follows:
wherein: d (D) MK Is the distance from the M-end bus to the fault point, D NK The distance from the N-end bus to the fault point is L, the length of the line MN is the length of the line, and the line is an overhead line or a cable line.
2. The method for correcting the error of the Beidou time service module during the fault distance measurement of the power distribution network as set forth in claim 1, wherein the specific steps of the third step are as follows:
the pseudo-range correction calculation formula is as follows: ρ n ＝ρ’ n -c·(Δt1+Δt2+Δt3)
Wherein: Δt1 is the clock correction value, Δt2 is the tropospheric correction value, ρ' n And c is the speed of light for measuring the n-th satellite pseudo range.
3. The method for correcting the error of the Beidou time service module during the fault distance measurement of the power distribution network as set forth in claim 1, wherein the specific steps of the fourth step are as follows:
the set of positioning equations is:
in (x) u ,y u ,z u ) Is the location of the receiver; (x) u ,y u ,z u ) (n=1, 2, …) is the position of a known satellite; ρ n The corrected n satellite pseudo-range; Δt (delta t) u Clock difference between the receiver and the satellite; if the exact location of the receiver is known, then there are:
namely, receiving the data of 1 satellite to calculate deltat u And obtaining a GPS system.
4. The method for correcting errors of the Beidou time service module during power distribution network fault distance measurement according to claim 1, wherein the receiver time delay comprises time delay delta t4 of an antenna head, time delay delta t5 of a feeder line, radio frequency channel time delay delta t6 and signal processing time delay which are defined as delta t7, and the receiver time delay can be obtained by testing delta t4 < + > delta t5 < + > delta t6 < + > delta t 7.
5. The method for correcting errors of the Beidou time service module during power distribution network fault location according to claim 1, wherein the Beidou time service module consists of a traveling wave detection module, a time receiving and timing module and a Beidou module.
Priority Applications (1)
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