CN103236916A - Dynamic compensation method for access network delay in SV (Sampled Value) networking of digitalized relay protection device - Google Patents

Abstract

The invention discloses a method for accurately calculating SV (Sampled Value) network delay. The method overcomes the uncertainty of network delay caused after SV data are transmitted through a switch. By using the accurate clock synchronization protocol of an IEEE1588 network measurement and control system or optical fiber B code signals, the actual delay caused after the SV data are transmitted through a network can be rapidly and accurately calculated in real time. The compensated SV data meet the demand of matching different SV access methods for optical fiber differential protection between two substations, including multiple combinations such as SV networking to SV networking, SV networking to SV point-to-point and SV networking to conventional sampling. Therefore, the engineering demands of reconstructing intelligent substations and constructing new intelligent substations at different stages can be met.

Description

Digital relay protection device SV networking access network time-delay dynamic compensation method

Technical field

The invention belongs to relaying protection and automatic field in the intelligent substation; be specifically related to the network delay uncertain problem that a kind of solution causes when sampled value SV signal transmits by network, realize that real-time, accurate detection goes out the actual time delay method that SV causes after the network transmission.

Background technology

Since carrying out the intelligent station pilot from State Grid Corporation of China in 2008, passed through nearly 4 years time, finished covering full voltage grade (the intelligent station pilot of 110kV～500kV), intelligent substation work has entered into bidding phase in batches, has set up the comparatively perfect intelligent substation system of a cover substantially.

The process layer network can transmit SV (sampled data value) message, can adopt point-to-point, independent networking or realize message transmissions with the common network's mode of GOOSE.State Grid Corporation of China has put into effect a series of company standard with Southern Power Grid Company is continuous mutually, and process layer SV transmission means has been carried out standard.For 220kV and above electric pressure intelligent station, SV adopts point-to-point mode to transmit substantially; For 110kV electric pressure intelligent station, state net company substantially also regulation adopts point-to-point mode to transmit, but has stipulated still that for some provinces and regions digitizing technique standards and the standard of south electric network SV adopts the network transmission.

Process layer SV network construction form has following several: share two nets (as shown in Figure 1), two cover separate double nets (as shown in Figure 2) or two single net (as shown in Figure 3).

Which kind of networking mode SV no matter adopt, passed through switch after, cause the transmission delay of SV to have uncertainty, principal element have following some:

(1) the different network delay that causes of the switch quantity of cascade is inconsistent, and standard code switch cascade progression can not be above 4 grades at present;

(2) the SV transfer of data that causes of exchange fault is uncertain;

(3) network data increases unusually, as: the data that network storm causes are stopped up.

In view of top some, " the normal delay time " of IEC61850-9-2 message ASDU data centralization is insincere, can not adopt this value to carry out compensation of delay again.For transformer and bus differential protection; the nondeterministic network transmission delay may cause protecting responsiveness slack-off; can not cause malfunction; and for the circuit optical fiber differential protection, relate to matching problem between the station; if the time-delay of both sides can not truly reflect actual conditions; then can cause analog quantity phase angle difference to occur, serious situation can cause malfunction.

Summary of the invention

In order to address the above problem, the application discloses a kind of method fast and accurately, correctly detects each sampled point actual transmissions time-delay, the dynamic compensation of delaying time.

The present invention specifically by the following technical solutions.

SV networking access network time-delay dynamic compensation method in the intelligent substation is characterized in that described compensation method may further comprise the steps:

(1) when merge cells MU receives the pps pulse per second signal PPS of optical fiber B sign indicating number or IEEE1588 generation, with the Sample Counter smpCnt zero setting in the IEC61850-9-2 message of output;

(2) when protective device is received the PPS signal of optical fiber B sign indicating number or IEEE1588 generation, minute book apparatus system time T 0;

(3) when protective device receives that Sample Counter smpCnt is zero message, minute book apparatus system time T 0 ';

(4) Sample Counter smpCnt is that the actual transmissions time-delay of zero message is: T0 '-T0;

(5) the Sample Counter smpCnt that sends for merge cells MU is at the theoretical time of the message of n:

Tn=T0+n×250us；

(6) when protective device receives that Sample Counter smpCnt is the message of n, minute book apparatus system time T n ';

(7) Sample Counter smpCnt is that the actual transmissions time-delay of the message of n is:

Tn’-Tn=Tn’-(T0+n×250us)。

(8) this side protective device is the time-delay dTn-n ' of n according to Sample Counter smpCnt, reduces this data true markers when producing, and is used for finishing the data sync with the offside GPF (General Protection False.

Another innovative point of the present invention is: the uncertainty that has overcome the network delay that the SV data cause after the switch transmission.Utilize the accurate clock synchronization protocol of optical fiber B coded signal or IEEE1588 network TT﹠C system, calculate the actual time delay that the SV data cause in real time, fast and accurately after the network transmission.

SV data after the compensation satisfy the cooperation demand of the different SV access waies of optical fiber differential protective between the station, comprising:

(1) the SV networking is to the SV networking;

(2) the SV networking is point-to-point to SV;

(3) the SV networking is to routine sampling.

Thereby can satisfy the intelligent substation transformation of different phase and the application demand of newly-built intelligent substation.

Description of drawings

Fig. 1 is that process layer SV shares two net schematic diagrames in the prior art;

Fig. 2 is the two cover of process layer SV separate double net schematic diagram in the prior art;

Fig. 3 is the two single net schematic diagrames of process layer SV in the prior art;

Fig. 4 is that function of the present invention is used connection diagram;

Fig. 5 be the present invention to the time system schematic;

Fig. 6 is that B sign indicating number of the present invention inserts the hardware handles schematic diagram;

Fig. 7 transmits and time-delay calculating schematic diagram the time of the present invention.

Embodiment

Below in conjunction with Figure of description technical scheme of the present invention is described in further detail.

Accompanying drawing 4 is that function of the present invention is used connection diagram, and M, N are that CSC-103 high-voltage line protection device is all installed at two ends among the figure, adopts optical cable to be connected between protection and communication terminal device.Protection sidelight terminal is contained on the backboard of protective device.Be that digitized sampling, M cover is that routine sampling is the example explanation with the N cover; M cover protection is owing to be sampled as the routine sampling mode, and AD is sampled as does not have time-delay, and N cover protection SV data through MU and switch after; produce network delay, therefore must adopt method of the present invention to realize the both sides data sync.

Accompanying drawing 5 be the inventive method to the time system schematic; to the time device from satellite obtain GPS or dipper system to the time information; and output to protective device in the mode of optical fiber B sign indicating number, guarantee the synchronism between wall protection, measure and control device and the process layer equipment at full station.

Accompanying drawing 6 is hardware module schematic diagrames that optical fiber B sign indicating number of the present invention inserts protective device; the hardware configuration that optical fiber B sign indicating number inserts protective device comprises Ethernet physical interface PHY, on-site programmable gate array FPGA, SV plug-in unit, is used for 485 chips of direction control; please the inventor write annexation and functional relationship between the above element exactly, write exactly by this hardware configuration and realize the course of work that the B sign indicating number inserts.This hardware module realized the IRIGB sign indicating number receive, resolve, to the time function and pps pulse per second signal PPS interrupt control, the key step of hardware module that the B sign indicating number inserts protective device is as follows:

Ethernet physical layer interface PHY realizes the access of B coded signal and the control function of pps pulse per second signal PPS, and ethernet physical layer interface PHY sends the data to the SV plug-in unit after stamping time stab information for the B coded signal.

Programmable gate array FPGA realizes data link layer functions, finishes the data transmit-receive of Ethernet data and the direction control that pps pulse per second signal PPS is exported.

The SV plug-in unit is finished decoding and the logical process of B coded signal, and the B coded signal is converted to absolute time information: the date Hour Minute Second, and obtain the B sign indicating number and export the PPS pulse per second (PPS) along also passing through Ethernet physical interface PHY second.

When the SV plug-in unit is received the PPS pulse signal, the current markers T0 of the system that obtains, the time among Fig. 3 transmits all based on this time.

Accompanying drawing 7 is to transmit the time of the present invention and time-delay calculating schematic diagram, with Sample Counter SampCnt=0, SampCnt=1

For example is calculated the real network time-delay.

(1) T0: device is received markers when PPS interrupts;

(2) T0 ': device is received the markers of the message of SampCnt=0;

(3) T1: the theoretical markers of the message of the SampCnt=1 of device conversion, T1=T0+1*250us;

(4) T1 ': device is received the markers of the message of sample counter SampCnt=1;

(5) the real network transmission delay of SampCnt=0 is: dT0-0 '=T0 ’ – T0;

(6) the real network transmission delay of SampCnt=1 is: dT1-1 '=T1 ’ – T1=T1 '-(T0+1*250us);

(7) the real network transmission delay of SampCnt=n is: dTn-n '=Tn ’ – Tn=Tn '-(T0+n*250us);

(8) with Fig. 4 be example, N side digitized sampling protection is the time-delay dTn-n ' of n by Sample Counter smpCnt, reduces the true markers of these data when producing, and is used for finishing the data sync with M side GPF (General Protection False.

Claims (1)

1. SV networking access network time-delay dynamic compensation method in the intelligent substation is characterized in that described compensation method may further comprise the steps:

(1) when merge cells MU receives the pps pulse per second signal PPS of optical fiber B sign indicating number or IEEE1588 generation, with the Sample Counter smpCnt zero setting in the IEC61850-9-2 message of output;

(2) when protective device is received the pps pulse per second signal PPS of optical fiber B sign indicating number or IEEE1588 generation, minute book apparatus system time T 0;

(3) when protective device receives that Sample Counter smpCnt is zero message, minute book apparatus system time T 0 ';

(4) Sample Counter smpCnt is that the actual transmissions time-delay of zero message is: T0 '-T0;

(5) the Sample Counter smpCnt that sends for merge cells MU is at the theoretical time of the message of n:

Tn=T0+n×250us；

(6) when protective device receives that Sample Counter smpCnt is the message of n, minute book apparatus system time T n ';

(7) Sample Counter smpCnt is that the actual transmissions time-delay of the message of n is:

dTn-n’=Tn’-Tn=Tn’-(T0+n×250us)。

(8) this side protective device is the time-delay dTn-n ' of n according to Sample Counter smpCnt, reduces this data true markers when producing, and is used for finishing the data sync with the offside GPF (General Protection False.

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