Summary of the invention
Poor to the inhibition of low-frequency oscillation for above-mentioned oscillation suppression method, cause the stability of power system
The problem that safety with generating set is low, it is to avoid turbine regulating system provides negative damping to deteriorate system
The generation of low-frequency oscillation, it is an object of the invention to provide a kind of generating set primary frequency regulation non-linear speed governing side electricity
Force system stabilizer control method.To this end, the technical scheme used is as follows.
A kind of generating set primary frequency regulation non-linear governor-side PSS control method, to electromotor
Group primary frequency modulation controls the output instruction signal in loop and carries out non-linear speed limit calculating process, will process gained
The control output order that the former generating set primary frequency regulation of signal substituting controls in loop carries out primary frequency modulation control,
The described output instruction signal controlled generating set primary frequency regulation in loop carries out non-linear speed limit meter
Calculation processes, and step is as follows:
Step 1, controls generating set primary frequency regulation the output instruction signal in loop and delivers to calculate treatment loop
IN input, be D by computing by IN signal decomposition1And DfThe signal of two components, as follows
Carry out:
D1=(1-Kr)·IN
Df=Kr·IN
In formula, KrFor damping action intensive parameter constant;
Step 2, to the D obtained in step 1fSignal carries out calculating process, is split as positive component signal
DfPWith negative value component signal DfN, calculate and carry out as follows:
Step 3, to the D obtained in step 2fPAnd DfNSignal carries out non-linear speed limit calculation process respectively,
Obtain D2Signal and D3Signal,
The speed limit operation function of non-linear speed limit calculation process has 3 input signals, respectively input signals Rin、
Upper cycle operation result Rout(n-1)Arranging parameter R with rate limit, speed limit operation function has 1 output signal
Rout, speed limit operation function carries out computing according to following 2 kinds of situations:
1st kind of situation:
T is execution cycle time constant, and engineering unit is s, when meetingTime, then this
Computing RoutOutput is pressed formula and is calculated:
Rout=RL (Rin,Rout(n-1), R) and=Rin
Obtain RoutAfter, its value is assigned to Rout(n-1), in order to called when next execution cycle:
Rout(n-1)=Rout
2nd kind of situation:
WhenTime, then this computing RoutOutput is pressed formula and is calculated:
Obtain RoutAfter, its value is assigned to Rout(n-1), in order to called when next execution cycle:
Rout(n-1)=Rout
Step 3.1: positive component signal DfPNon-linear speed limit calculation process, if rise computing,
Then select higher speed limit parameter value;If the computing declined, then select slower speed limit parameter value.By with
Lower formula carries out speed limit parameter value RPSelection calculate:
In formula, RfFor higher rate constraining parameters constant, RsFor slower rate constraining parameters constant,
Obtain RPAfter, to DfPCarry out RL speed limit functional operation, obtain D2Signal, is calculated as follows:
D2=RL (DfP,D2(n-1),RP)
Obtain D2After, its value is assigned to D2(n-1), in order to called when next execution cycle:
D2(n-1)=D2
Step 3.2: negative value component signal DfNNon-linear speed limit calculation process, if the computing risen, then
Select slower speed limit parameter value;If the computing declined, then select higher speed limit parameter value.Press public affairs
Formula carries out speed limit parameter value RNSelection calculate:
Obtain RNAfter, to DfNCarry out RL speed limit functional operation, obtain D3Signal, is calculated as follows:
D3=RL (DfN,D3(n-1),RN)
Obtain D3After, its value is assigned to D3(n-1), in order to called when next execution cycle:
D3(n-1)=D3
Step 4: by D calculated in step 11, calculated D in step 32And D3Add up mutually,
Obtain calculate treatment loop output signal OUT:
OUT=D1+D2+D3
Calculated calculating treatment loop OUT signal is substituted former generating set primary frequency regulation control in loop
Control output order carry out primary frequency modulation control.
Use the generating set primary frequency regulation non-linear governor-side PSS control method of the present invention,
During mains frequency fluctuation offrating, it is possible to more efficiently increase generating set reality and once adjust
When there is big load disturbance in the load compensation amount of action frequently, especially network load, the increasing of load compensation amount
Add and will be apparent from;During mains frequency returns to rated value, using the teaching of the invention it is possible to provide a stronger damping is made
With, prevent the generation of low frequency oscillations;During the fierce fluctuation of mains frequency offrating, at it
Under the effect of damping, in addition to the load compensation amount of bigger primary frequency modulation action can be provided, moreover it is possible to effectively
Avoid the occurrence of the regulation fluctuation repeatedly of steam turbine pitch, prevent steam turbine pitch from vibrating;Occur at electrical network
During low frequency oscillations, under its effect damped, unit primary frequency modulation will not participate in system oscillation process
Regulation, prevents governing system and resonates with network system, is conducive to suppressing the low-frequency oscillation of network system,
Improve network system security and stability.
Detailed description of the invention
The present invention can be at DCS (Distributed Control System, DCS), PLC (Programmable
Logic Controller, PLC), programming realization on single-chip microcomputer or computer.For making this patent easier to understand,
Below in conjunction with the accompanying drawings this patent is further elaborated, but the embodiment in accompanying drawing does not constitute and appoints this patent
What limits.
As it is shown in figure 1, as follows 1~step 4 calculating process, to generating set primary frequency regulation control
Output instruction signal in loop carries out non-linear speed limit calculating and processes, and step is as follows:
Step 1, controls generating set primary frequency regulation the output instruction signal in loop and delivers to calculate treatment loop
IN input, be D by computing by IN signal decomposition1And DfThe signal of two components, as follows
Carry out:
D1=(1-Kr)·IN
Df=Kr·IN
In formula, KrFor damping action intensive parameter constant, this constant is adjustable parameter, its span 0~1,
Representative value is 0.8.
Step 2, to the D obtained in step 1fSignal carries out calculating process, is split as positive component signal
DfPWith negative value component signal DfN, calculate and carry out as follows:
In DCS configuration loop, it is possible to use the export-restriction block of DCS or piecewise linear interpolation functional blocks f (x)
Realize positive component signal DfPWith negative value component signal DfNCalculating.
Such as, piecewise linear interpolation functional blocks f (x) is used to realize, then:
DfPF (x) calculate calculated by piecewise linear interpolation by following function point:
F (x) inputs % |
-100 |
0 |
100 |
F (x) exports % |
0 |
0 |
100 |
DfNF (x) calculate calculated by piecewise linear interpolation by following function point:
F (x) inputs % |
-100 |
0 |
100 |
F (x) exports % |
-100 |
0 |
0 |
Step 3, to the D obtained in step 2fPAnd DfNSignal carry out respectively linear R L speed limit (Rate Limit,
RL) calculation process obtains D2Signal and D3Signal,
The RL speed limit operation function of non-linear speed limit calculation process has 3 input signals, respectively input signals
Rin, upper cycle operation result Rout(n-1)Arranging parameter R with rate limit, RL speed limit operation function has 1
Output signal Rout, RL speed limit operation function carries out computing according to following 2 kinds of situations:
1st kind of situation:
T is execution cycle time constant, and engineering unit is s, and general selection range is 0.05s~1s, when meetingTime, then this computing RoutOutput is pressed formula and is calculated:
Rout=RL (Rin,Rout(n-1), R) and=Rin
Obtain RoutAfter, its value is assigned to Rout(n-1), in order to called when next execution cycle:
Rout(n-1)=Rout
2nd kind of situation:
WhenTime, then this computing RoutOutput is pressed formula and is calculated:
Obtain RoutAfter, its value is assigned to Rout(n-1), in order to called when next execution cycle:
Rout(n-1)=Rout
In DCS configuration loop, can directly use the rate limit block RL of DCS to realize RL speed limit
Computing.
Step 3.1: positive component signal DfPNon-linear speed limit calculation process, if rise computing,
Then select bigger speed limit parameter value;If the computing declined, then select slower speed limit parameter value.By with
Lower formula carries out speed limit parameter value RPSelection calculate:
In formula, RfFor higher rate constraining parameters constant, this constant is adjustable parameter, and unit is %/s, allusion quotation
Offset is 1000%/s;RsFor slower rate constraining parameters constant, this constant is adjustable parameter, according to specifically
The Characteristics of Low Frequency Oscillations frequency of electrical network and generating set capacity adjust, and representative value is 0.25%/s.
In DCS configuration loop, it is possible to use the deviation computing block △ of DCS, ceiling value alarming block H/,
Signal handoff block T realizes RPCalculating.As it is shown in figure 1, work as D2-Dfp> 0 time, then signal handoff block
T selects RfAs output signal, and output valve is assigned to RP;Work as D2-DfpWhen≤0, then signal handoff block
T selects RsFor output signal, and output valve is assigned to RP。
Obtain RPAfter, to DfPCarry out RL speed limit functional operation, obtain D2Signal, is calculated as follows:
D2=RL (DfP,D2(n-1),RP)
Obtain D2After, its value is assigned to D2(n-1), in order to called when next execution cycle:
D2(n-1)=D2
Step 3.2: negative value component signal DfNNon-linear speed limit calculation process, if the computing risen, then
Select slower speed limit parameter value;If the computing declined, then select higher speed limit parameter value.Press public affairs
Formula carries out speed limit parameter value RNSelection calculate:
In DCS configuration loop, it is possible to use the deviation computing block △ of DCS, ceiling value alarming block H/,
Signal handoff block T realizes RNCalculating.As it is shown in figure 1, work as D3-DfN> 0 time, then signal handoff block
T selects RsAs output signal, and output valve is assigned to RN;Work as D3-DfNWhen≤0, then signal handoff block
T selects RfFor output signal, and output valve is assigned to RN。
Obtain RNAfter, to DfNCarry out RL speed limit functional operation, obtain D3Signal, is calculated as follows:
D3=RL (DfN,D3(n-1),RN)
Obtain D3After, its value is assigned to D3(n-1), in order to called when next execution cycle:
D3(n-1)=D3
Step 4: by D calculated in step 11, calculated D in step 32And D3Add up mutually,
Obtain calculate treatment loop output signal OUT:
OUT=D1+D2+D3
Calculated calculating treatment loop OUT signal is substituted former generating set primary frequency regulation control in loop
Control output order carry out primary frequency modulation control.
Fig. 2 is a 600MW generating set primary frequency regulation control drawing being typically made up of DCS,
WS in figure is turbine speed signal, and unit is r/min;WSrFor specified turn, for constant value 3000r/min;
DEH_X151 is the primary frequency modulation command signal with % dimension, and unit is %, and this signal delivers to DEH (Digital
Electro-Hydraulic Control System, DEH) pitch command drcuit, be directly superimposed to DEH pitch
In instruction;DEH_X is the primary frequency modulation command signal after being converted to dimension MW, and unit is MW, this letter
Number deliver to CCS (Coordinated Control System, CCS) power instruction loop, as CCS system
Primary frequency modulation command signal.
In fig. 2, frequency difference (WS is calculated first with deviation computing block △rWS), one point is then utilized
Section linear interpolation function block f (x) realizes 5% speed governor droop, 2r/min Regulation dead-band and 6% frequency modulation instruction limit
The functions such as width, are calculated by piecewise linear interpolation by following function point and realize:
F (x) inputs r/min |
-150 |
-11 |
-2 |
0 |
2 |
11 |
150 |
F (x) exports % |
6 |
6 |
0 |
0 |
0 |
-6 |
-6 |
In fig. 2, when primary frequency modulation puts into, by signal handoff block T, select piecewise linear interpolation function
The output of block f (x) is as DEH_X151 primary frequency modulation command signal;When exiting primary frequency modulation, once adjust
Frequently command signal DEH_X151 is 0%.This unit rated power is 600MW, then from the dimension of % to MW
Dimension conversion coefficient be 3.6, DEH_X151 × 3.6 just obtain the primary frequency modulation command signal that dimension is MW
DEH_X。
Piecewise linear interpolation function in this units present invention, the access present invention that only need to connect to Fig. 2
The outfan of block f (x), as shown in Figure 3.
In figure 3, in order to make control drawing succinct, clear, present invention DCS configuration is packaged into one
Individual grand computing module, and it is named as NLGPSS.Damping action partition coefficient KrParameter value is 0.8;Speed
Limit parameter RfValue is 1000%/s;Rate constraining parameters RsValue is 0.25%/s.
In order to realize the input of GPSS function/exit operation, in figure 3, also add a signal switching
Block T, when putting into GPSS function, selects the OUT output as signal handoff block T of the present invention;When
When exiting GPSS function, select the output of original piecewise linear interpolation functional blocks f (x) as signal handoff block
The output of T.
Embodiment described above only have expressed the several embodiments of the present invention, and it describes more concrete and detailed,
But therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that, for this area
Those of ordinary skill for, without departing from the inventive concept of the premise, it is also possible to make some deformation and
Improving, these broadly fall into protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be with appended
Claim is as the criterion.