CN102005723A - IEEE1588-based data synchronization method for fiber differential protection device - Google Patents

Abstract

The invention discloses an IEEE1588-based data synchronization method for a fiber differential protection device, which comprises the following steps that: one of two bilateral devices, namely precision time protocol (PTP) clocks which are connected with a fiber optic Ethernet is automatically determined as a PTP master clock, and the other one is determined as a PTP slave clock through best master clock (BMC) algorithm; the PTP slave clock carries out fine adjustment on the PTP clocks at the same side of the PTP slave clock according to the IEEE1588 protocol, so that the PTP master clock and the PTP slave clock are synchronous; and the PTP master clock and the PTP slave clock capture the PPS input, adjust the sampling interval and start the A/D sampling, so that the synchronized sampling at the two sides of the fiber differential protection device can be guaranteed. The method of the invention has the advantages that: the synchronization precision is high; the time deviations of pulse per second (PPS) at the two sides of the fiber differential protection device and the time deviation of each sampling pulse are all less than 1 mu s; the methods for adjusting sample data by complex algorithms are abandoned, and the data synchronization method is totally independent of differential protection and has nothing to do with the sampled data.

Description

Method of data synchronization based on the fiber differential protection device of IEEE1588

Technical field

The present invention relates to a kind of communication of power system method, particularly a kind of method of data synchronization of the fiber differential protection device based on IEEE1588.

Background technology

Optical fiber differential protective in protecting electrical power system in occupation of critical role.Though the differential protection principle is simple, it also will solve the synchronous problem of both sides protective device sampled data except facing the common problem of protective device exploitation.The method of data synchronization that traditional fiber differential protection device is commonly used has following several: method, clock correction method, the same footwork of GPS, the same footwork of reference vector, sampling sequence number adjustment method etc. are adjusted in sampled data revised law, sampling instant.There is following problem at present in these methods: the both sides crystal oscillator is required height, and the sampling interval is inhomogeneous, to the hardware requirement height.GPS is subjected to the influence of factors such as natural environment and social environment with footwork, and needs relevant hardware support etc.Since the promulgation of IEEE1588 standard, IEEE1588 more and more payes attention in the application in automatic measure control field, supports that the hardware of IEEE1588 is also more and more, therefore IEEE1588 is applied to the protecting electrical power system field and has great importance.

Summary of the invention

In order to solve above-mentioned technical problem, the purpose of this invention is to provide a kind of method of data synchronization that can be applicable to the fiber differential protection device both sides simply, accurately based on the fiber differential protection device of IEEE1588.

The technical scheme that the present invention is adopted for its technical problem of solution is:

Method of data synchronization based on the fiber differential protection device of IEEE1588 may further comprise the steps:

A. the both sides device that links to each other with optical-fibre channel moves the IEEE1588 agreement respectively, sends, receives the PTP message packet;

B. the both sides device moves the best master clock BMC algorithm in the IEEE1588 agreement respectively, determines that the side in the device of both sides is the PTP master clock, and opposite side is that PTP is from clock;

C.PTP according to IEEE1588 agreement calculated data communication channel delay and this side clock synchronization compliant with precision time protocol deviation with respect to the PTP master clock, and finely tunes this side clock synchronization compliant with precision time protocol according to result of calculation from the clock lateral root;

D. judge that whether PTP is synchronous with the PTP master clock from clock, then returns step C if not; If the clock synchronization sign then is set;

E. principal and subordinate's clock is caught the PPS input, adjusts sampling timing at interval, and starts the A/D sampling.

The invention has the beneficial effects as follows: the inventive method synchronization accuracy height; the time deviation of both sides PPS pulse per second (PPS) time deviation and each sampling pulse is all less than 1us; abandoned the method for adjusting sampled data by complicated algorithm; method of data synchronization is totally independent of differential protection, and is irrelevant with sampled data.

Description of drawings

The invention will be further described below in conjunction with drawings and Examples:

Fig. 1 is the flow chart of method of data synchronization of the present invention;

Fig. 2 is the connection diagram of fiber differential protection device of the present invention.

Embodiment

With reference to Fig. 1, the method for data synchronization based on the fiber differential protection device of IEEE1588 may further comprise the steps:

A. the both sides device that links to each other with optical-fibre channel moves the IEEE1588 agreement respectively, sends, receives the PTP message packet; The model of the PHY chip of Ethernet is DP83640 in the device of both sides, the adjustable high accuracy PTP of a 125MHZ of inner sustain (precision time protocol) clock, and exportable pulse per second (PPS) PPS (pulse per second);

B. the both sides device moves the best master clock BMC algorithm in the IEEE1588 agreement respectively, determines that the side in the device of both sides is the PTP master clock, and opposite side is that PTP is from clock;

C.PTP according to IEEE1588 agreement calculated data communication channel delay and this side clock synchronization compliant with precision time protocol deviation with respect to the PTP master clock, and finely tunes this side clock synchronization compliant with precision time protocol according to result of calculation from the clock lateral root;

D. judge that whether PTP is synchronous with the PTP master clock from clock, then returns step C if not; If the clock synchronization sign then is set; When PTP from clock then can be considered during with respect to the deviation of PTP master clock less than 1us PTP from clock synchronization in the PTP master clock.

E. principal and subordinate's clock is caught the PPS input, adjusts the sampling interval, and starts the A/D sampling; When both sides PPS is synchronous; every two adjacent PPS inputs were 1 second blanking time; the sample rate of setting device is N time/second; then sampling timing is spaced apart 1/N second; each side is from capturing the current PPS input time of this side; go to trigger the A/D sampling at interval according to sampling timing, can guarantee fiber differential protection device both sides sample-synchronous.

If a side device re-powers or optical-fibre channel disconnects the back and reappears when connecting abnormal conditions and occurring, the free-running operation respectively of the clock of both sides device, the PPS of both sides device not necessarily keeps synchronously, repeats above-mentioned steps A-E process and then can make a side device be synchronized with the opposite side device once more.

With reference to Fig. 2, fiber optic Ethernet passage both sides device is connected with MAC on being integrated in CPU by PHY, the PHY chip adopts DP83640, the adjustable high accuracy PTP of a 125MHZ of inner sustain, and the exportable pulse per second (PPS) PPS that samples with triggering A/D that catches for the both sides device.CPU passes through the deviation of PTP protocol engine computable number according to communication channel delay and principal and subordinate's clock synchronization compliant with precision time protocol, and finely tunes local clock synchronization compliant with precision time protocol according to result of calculation; CPU can also catch local PPS pulse per second (PPS) from PHY, and goes to trigger the A/D sampling by preset sampling frequency at interval with timing sampling.

More than be that preferable enforcement of the present invention is specified, but the invention is not limited to described embodiment, those of ordinary skill in the art also can make all equivalent variations or replacement under the prerequisite of spirit of the present invention, modification that these are equal to or replacement all are included in the application's claim institute restricted portion.

Claims (1)

1. based on the method for data synchronization of the fiber differential protection device of IEEE1588, it is characterized in that: may further comprise the steps:

A. the both sides device that links to each other with optical-fibre channel moves the IEEE1588 agreement respectively, sends, receives the PTP message packet;

B. the both sides device moves the best master clock BMC algorithm in the IEEE1588 agreement respectively, determines that the side in the device of both sides is the PTP master clock, and opposite side is that PTP is from clock;

C.PTP according to IEEE1588 agreement calculated data communication channel delay and this side clock synchronization compliant with precision time protocol deviation with respect to the PTP master clock, and finely tunes this side clock synchronization compliant with precision time protocol according to result of calculation from the clock lateral root;

D. judge that whether PTP is synchronous with the PTP master clock from clock, then returns step C if not; If the clock synchronization sign then is set;

E. principal and subordinate's clock is caught the PPS input, adjusts the sampling interval, and starts the A/D sampling.

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