Data synchronization method of digital optical fiber differential protective clock by relay method
Technical field
The present invention relates to a kind of method of data synchronization of transmission line digital optical fiber differential protective, belong to field of relay protection in power.
Background technology
Along with the digital transformer substation technology in progressively pilot and popularization of electric power system; the various digital protection devices that insert based on electronic mutual inductor (ET) progressively are developed; in these protective devices; the circuit optical fiber differential protection is a kind of of comparatively complexity; because it is except will also solving the synchronous problem of both sides protective device sampled data in the face of the common problem of digital protection device development.Compare with the traditional fiber differential protection, there is following difficulty in the optical fiber differential protective data sync that ET inserts:
(1) according to the electronic mutual inductor and the merge cells (MU) thereof of IEC60044-7/8 standard manufacture; the interface that does not possess the control command (as sampling instant adjustment) of reception from protective device to the MU direction, thus present widely used method by adjustment sampling instant realization both sides data sync can not be suitable in the fiber differential protection device that ET inserts.
(2) circuit primary current and voltage is through the ET conversion, and there is apparent in view time-delay in the process that is sent to protective device through MU again, generally more than the hundreds of microsecond, even above 1 millisecond.
(3) the circuit offside instrument transformer in the digital transformer substation that puts into operation in advance remains traditional instrument transformer, and it is that ET inserts the situation that opposite side is traditional instrument transformer access that fiber differential protection device wants to adapt to a this side.
(4) electronic mutual inductor that adopts the IEC61850-9 interface protocol to export when the process layer network transmits sampled data, is subjected to the influence of network operating mode, and the secondary transmission delay may be unstable, and amplitude of fluctuation is bigger.Maximum amplitude of fluctuation may be nearly 4 milliseconds.
Because the difficulty of above several aspects, application good data method for synchronous can not maybe can not directly apply in the fiber differential protection device of ET access in the traditional fiber differential protection.
Use global position system GPS (Global Position System) to provide the reference clock of a unified high stable for whole differential protective system, what realize sampled data is a simple directly method synchronously.IEC61850 still be IEC60044-8 all clear and definite mentioned this method.In engineering, GPS also is the standard configuration of factory's substation automation system already, and Equipment Foundations are to satisfy easily.Adopt the GPS pulse per second (PPS) to come the method for synchronous both sides ET sampling instant no doubt simple and convenient, but method itself depend on external equipment, GPS particularly, one has reduced the protective device reliability to being thought by the relaying protection specialty.In addition, use other country's control gps system, may be subjected to the influence of International Politics, military relations.
The relaying protection specialty is paid attention to reliability, and the design of protective device is always wished to finish required function with the least possible equipment, device, external condition.Minimizing has reduced possible fault point to the dependence of external equipment from architecture, and the reliability that guarantees protection is had meaning of overall importance.The present invention is based on the design of this principle and be applicable to the data sync new method of digital optical fiber differential protective.
Below be the exterior technology condition and basis that solves digitlization circuit optical fiber differential protection data synchronization problems:
(1) is installed on vertical optical fiber communication passage between the protective device in two transformer stations respectively; the promotion and application because of the digital transformer substation technology do not have too many variation; self-built or the optical-fibre channel of renting of operation power department; offering passage and the two-way time-delay of route thereof that line differential protection uses equates; this prerequisite with the method for data synchronization of traditional fiber differential protection is identical, also is can guarantee fully in engineering.
(2) in the station of digital transformer substation, the sampling pulse signal of all bay devices such as protective device and process layer equipment such as MU device is accepted the pps pulse per second signal 1pps (1 Pulse Per Second) synchronously once (phase locking) of the same reference clock in full station each second.Full station reference clock (master clock) receives day time signal of aerial gps satellite by the GPS receiver, and the synchronous error of the rising edge of this this pulse signal of signal and universal time UTC (Universal Time Coordinated Universal Time Coordinated) is no more than 1us.Master clock self has the punctual clock of high accuracy in standing, if with gps clock synchronously after step-out again, in the long period thereafter, still can keep synchronous with UTC.
(3) ADC of the sensing head of ET part or the remote end module sampling starting sampled signal starting of being sent by MU, the sampled signal of MU becomes the sample frequency of ET by 1pps after frequency multiplication, send to the ADC conversion portion of ET, starts the AD sampling.So the sampling instant of ET is by having kept a kind of fixing relation between public 1pps and the protective device.
(4) each phase ET of circuit merges the packing framing through MU earlier through the data that synchronized sampling obtains, and gives protective device then.In the MU output communication message of IEC60044-8 and IEC61850-9 regulation, include one 16 sample counting, these 16 countings add 1 in order to check the frame number of continuous renewal when new frame of every appearance, and the zero setting when occurring with each lock-out pulse 1pps of this counting.Therefore we can say that in fact the sample counting value has the meaning of relative time.
(5) in the standard frame format of MU output, including the specified delay time of ET, can be 2Ts, 3Ts (Ts is the sampling period), to adopting the MU of lock-out pulse, also can for 3ms (+10%-100%).This delay time has provided primary current or voltage transmission is delayed time to the process of MU.
Summary of the invention
Technical problem to be solved by this invention provides a kind of two ends method of data synchronization that directly applies to the line numbers fiber differential protection device.
For solving the problems of the technologies described above, the invention provides a kind of and ET secondary become sending time-delay irrelevant, based on clock by relay with improve the method for data synchronization of interpolation method.
The technical solution adopted in the present invention is as follows: data synchronization method of digital optical fiber differential protective clock by relay method, implementation process relates to following four table apparatus: this side protective device, this side electronic mutual inductor merge cells, the offside protective device, offside electronic mutual inductor merge cells, be respectively equipped with timer tm in the processor of described four table apparatus, tM, tn, tN, synchronous between this side electronic mutual inductor merge cells and this side protective device by this side pps pulse per second signal 1pps/M, forward position in each 1pps/M pulse, with timer tM, timer tm puts 0 simultaneously, subsequently timer tM, timer tm self-clocking; Synchronous between offside electronic mutual inductor merge cells and the offside protective device by offside pps pulse per second signal 1pps/N, in the forward position of each 1pps/N pulse, timer tN, timer tn are put 0 simultaneously, subsequently timer tN, timer tn self-clocking;
After this side electronic mutual inductor merge cells is received this side pps pulse per second signal 1pps/M, send the sampled signal that the sampling period is Ts to the ADC of electronic mutual inductor, receive the sampled data that electronic mutual inductor is passed back simultaneously, and this sampled data put on sample counting M, the moment zero setting that this sample counting M occurs at this side pps pulse per second signal 1pps/M, described sample counting M adds 1 at every turn when receiving sampled data; This side electronic mutual inductor merge cells sends to this side protective device with the up-to-date primary voltage current sampling data of receiving and sample counting thereof, the specified time-delay Tpm of this side electronic mutual inductor by standard frame format in each sampling interval;
Accordingly, after offside electronic mutual inductor merge cells is received offside pps pulse per second signal 1pps/N, send the sampled signal that the sampling period is Ts to the ADC of electronic mutual inductor, receive the sampled data that electronic mutual inductor is passed back simultaneously, and this sampled data put on sample counting N, the moment zero setting that this sample counting N occurs at offside pps pulse per second signal 1pps/N, described sample counting N adds 1 at every turn when receiving sampled data; Offside electronic mutual inductor merge cells sends to the offside protective device with the up-to-date primary voltage current sampling data of receiving and sample counting thereof, the specified time-delay Tpn of offside electronic mutual inductor by standard frame format in each sampling interval;
The concrete steps of method of data synchronization are as follows:
(a); this side protective device is that the cycle is by timer interrupt mode work with Ts; starting point in each cycle sends a frame message to the offside protective device; write down the reading tm1 of timer tm when sending simultaneously; when the offside protective device is received this message; write down the reading tn2 of timer tn; the offside protective device is to this side protective device loopback one frame message subsequently; the reading tn3 of timer tn when writing down loopback simultaneously; comprise sampled data and sample counting thereof that the up-to-date homonymy electronic mutual inductor merge cells of receiving is sent here in the message of loopback; the reading tn2 of timer tn; the specified time-delay Tpn of tn3 and homonymy electronic mutual inductor; write down the reading tm4 of timer tm when this side protective device is received the message of loopback, calculate the difference of reading Δ tmn of timer tm and timer tn according to formula (1):
Δtmn=(tm4+tm1)/2-(tn3+tn2)/2 (1)
Because tn and tN, respectively hang oneself 1pps/N and 1pps/M of tm and tM is synchronous, then protective device also as can be known the difference of reading Δ tMN of the timer of both sides MU equal the difference of reading Δ tmn of the timer of both sides protective device, Δ tMN=tM-tN wherein promptly has following formula:
ΔtMN=Δtmn (2)
(b), after this side protective device calculates Δ tMN, calculating with the offside sample counting is the markers tmd of synchronous this side sampled data of the sampled data of N1 again:
tmd=N1*Ts-Tpn+ΔtMN+Tpm (3)
Tpm, Tpn are respectively this side and the specified time-delay of offside ET in the formula;
(c), this side protective device calculates this side sample counting M1, M2 and time difference Ta, Tb according to formula (4), (5), (6), (7);
M1=Mod(tmd,Ts) (4)
M2=M1+1 (5)
Ta=tmd-M1*Ts (6)
Tb=M2*Ts-tmd (7)
In the formula (4), and Mod (tmd, Ts) expression is that modulus is made rounding operation to tmd with Ts;
(d), to calculate with the offside sample counting according to formula (8) be synchronous each phase sampler value A (md) of this side electric current and voltage of each phase sampler value of electric current and voltage of N1 to this side protective device:
A(md)=Tb*A(M1)/Ts+Ta*A(M2)/Ts (8)
It is each phase sampler value of electric current and voltage of M1, M2 that formula (8) middle A (M1), A (M2) represent this side sample counting respectively, and so far, a complete data synchronization process is finished.
Beneficial effect of the present invention is as follows: the condition of data synchronization process of the present invention institute foundation is all in the framework of correlation technique standard, without any expansion or change; Notice not require between 1pps/M and the 1pps/N synchronously, thus synchronized algorithm not rely on the 1pps that GPS or other wide area navigation positioning systems do between the station synchronous, improved the reliability of relaying protection greatly; Data synchronization process is not adjusted sampling instant, is adapted to the MU functional structure condition of ET standard code; Both can solve MU by the data synchronization problems of IEC61850-9 standard interface when the process layer network inserts, also can solve the data synchronization problems of MU by both sides protective device under the IEC60044-8 standard interface access situation; For circuit one side is ET, and opposite side is the situation that traditional instrument transformer inserts protective device, and the specified time-delay that needs only traditional instrument transformer in the data synchronization process is considered as null value.
Description of drawings
Fig. 1 is a clock by relay method data synchronization process schematic diagram of the present invention.
Embodiment
With reference to the accompanying drawings and in conjunction with the embodiments the present invention is described in further detail.But the invention is not restricted to given example.
Figure 1 shows that clock by relay method data synchronization process schematic diagram of the present invention, data synchronization method of digital optical fiber differential protective clock by relay method of the present invention, implementation process relates to following four table apparatus: this side protective device, this side electronic mutual inductor merge cells, the offside protective device, offside electronic mutual inductor merge cells, be respectively equipped with timer tm in the processor of described four table apparatus, tM, tn, tN, synchronous between this side electronic mutual inductor merge cells and this side protective device by this side pps pulse per second signal 1pps/M, forward position in each 1pps/M pulse, with timer tM, timer tm puts 0 simultaneously, subsequently timer tM, timer tm self-clocking; Synchronous between offside electronic mutual inductor merge cells and the offside protective device by offside pps pulse per second signal 1pps/N, in the forward position of each 1pps/N pulse, timer tN, timer tn are put 0 simultaneously, subsequently timer tN, timer tn self-clocking;
After this side electronic mutual inductor merge cells is received this side pps pulse per second signal 1pps/M, send the sampled signal that sampling period Ts is 0.417ms to the ADC of electronic mutual inductor, receive the sampled data that electronic mutual inductor is passed back simultaneously, and this sampled data put on sample counting M, the moment zero setting that this sample counting M occurs at this side pps pulse per second signal 1pps/M, described sample counting M adds 1 at every turn when receiving sampled data; This side electronic mutual inductor merge cells sends to this side protective device with the up-to-date primary voltage current sampling data of receiving and sample counting thereof, the specified time-delay 0.833ms of this side electronic mutual inductor (Tpm) by standard frame format in each sampling interval;
Accordingly, after offside electronic mutual inductor merge cells is received offside pps pulse per second signal 1pps/N, send the sampled signal that sampling period Ts is 0.417ms to the ADC of electronic mutual inductor, receive the sampled data that electronic mutual inductor is passed back simultaneously, and this sampled data put on sample counting N, the moment zero setting that this sample counting N occurs at offside pps pulse per second signal 1pps/N, described sample counting N adds 1 at every turn when receiving sampled data; Offside electronic mutual inductor merge cells sends to the offside protective device with the up-to-date primary voltage current sampling data of receiving and sample counting thereof, the specified time-delay 1.250ms of offside electronic mutual inductor (Tpn) by standard frame format in each sampling interval;
The concrete steps of method of data synchronization are as follows:
(a), this side protective device with 0.417ms be the cycle by timer interrupt mode work, the starting point in each cycle sends a frame message to the offside protective device, is that example describes with certain cycle in the present embodiment.
The reading of timer tm was 417.00ms (tm1) when this side protective device sent certain frame data to the offside protective device; when the offside protective device is received this message; the reading of timer tn is 217.88ms (tn2); offside protection dress is when this side protective device loopback one frame message; the reading of timer tn is 218.09ms (tn3); comprising the sampled data that the up-to-date homonymy electronic mutual inductor merge cells of receiving sends here in the message of loopback (is that example describes with A phase current sampling value only in this example; A phase current sampling value is 3276) and sample counting be 523 (N1); the reading 217.88ms (tn2) of timer tn; 218.09ms (tn3) and the specified time-delay 1.250ms (Tpn) of homonymy electronic mutual inductor; when receiving the message of loopback, this side protective device writes down the reading 419.21ms (tm4) of timer tm; can calculate the difference of reading Δ tmn of timer tn and timer tm according to formula (1) and (2); the difference of reading Δ tMN of timer tM and timer tN
Δtmn=(tm4+tm1)/2-(tn3+tn2)/2 (1)
ΔtMN=Δtmn (2)
ΔtMN=Δtmn=(419.21+417.00ms)/2-(218.09ms+217.88ms)/2=200.12ms。
(b), the offside sample counting is the sampled data of N1 and this side timer tM reading data sync when being tmd, tmd can calculate according to formula (3) and obtain,
tmd=N1*Ts-Tpn+ΔtMN+Tpm (3)
tmd=523*0.417-1.250+200.12+0.833=417.793ms。
(c), calculate this side sample counting M1, M2 and time difference Ta, Tb according to formula (4), (5), (6), (7);
M1=Mod(tmd,Ts) (4)
M2==M1+1 (5)
Ta=tmd-M1*Ts (6)
Tb=M2*Ts-tmd (7)
M1=1001,M2=1002,Ta=0.376ms,Tb=0.041ms。
In the formula (4), and Mod (tmd, Ts) expression is that modulus is made rounding operation to tmd with Ts;
(d), to calculate with the offside sample counting according to formula (7) be synchronous each phase sampler value A (md) of this side electric current and voltage of each phase sampler value of electric current and voltage of N1, is that example describes with A phase sampler electric current only in this example
A(md)=Tb*A(M1)/Ts+Ta*A(M2)/Ts (8)
A(md)=0.041*2701/0.417+0.376*3338/0.417=3275。
It is each phase sampler value of electric current and voltage of M1, M2 that formula (8) middle A (M1), A (M2) represent this side sample counting respectively, the numerical value of A in this example (M1), A (M2) substitution is A phase sampler electric current, and this side sample counting is that 1001 A phase current sampling value is 2701, this side sample counting is 1002 A phase current values 3338.
With the offside sample counting be that synchronous this side A phase current values of 523 A phase current is 3275.
So far, a complete data synchronization process is finished.
In addition to the implementation, the present invention can also have other execution modes.All employings are equal to the technical scheme of replacement or equivalent transformation form, all drop on the protection range of requirement of the present invention.