CN86108436A - Large power system strongly-adaptive stable control method and device - Google Patents

Abstract

The present invention relates to a kind of method and device of the optimum stable control of strongly-adaptive decentralized integrated of large power system in parallel.It adopts reaction system non-linear, and the quantity of state of correlation and disturbance type can be measured in real time between unit, sets up decoupling zero compressive state spatial model, obtains easily measuring as the optimal control rule of importing with this unit.This controlled function is to guarantee that any network structure system all has best stabilized control effect when being in any operating point and being subjected to any interference.

Description

The present invention relates to a kind of method for designing and Project Realization means that can increase substantially the optimum stability controller of self adaptation decentralized integrated of multi-machine power system maintenance level.

It is constant that the conventional automatic voltage regulator (AVR) of tradition adopts classic control principle to realize that set end voltage is effectively kept in the PID adjusting of electric power system set end voltage, and large disturbance in the system had some inhibition abilities, but the effect of negative damping that it provides often produces or increases the weight of the low-frequency oscillation of system.(particularly big unit and quick-response excitation situation); The electric power system subduer (PSS) that proposes the end of the sixties is to introduce an additional stability signal (must carry out leading sometimes or correction or lag) coming feed system additional damping moment by regulating excitation in former excitation system, clump and reach the purpose that suppresses low-frequency oscillation.But its frequency range is narrower, is difficult to coordinate configuration and carry out parameter tuning in multimachine system, and its design depends on running status and network configuration; The linear optimal stabilizer (LOS) of Ti Chuing designs by linearized system according to optimal control theory in recent years, can effectively suppress the multimodal high and low frequency vibration of multimachine, but powerless aspect the large disturbance nonlinear stability.And controller parameter changes with operating point, needs remote message transmission in multimachine system, intersects to feed back, so the difficulty of realization, reliability more be cannot say for sure to demonstrate,prove.The measure that can increase substantially multi-machine power system transient state and dynamic dispatching comprehensive stability level is not arranged so far as yet.

Task of the present invention provide a kind of effectively easily row, can the optimum stabilizer of decentralized integrated supporting at random, that have the strongly-adaptive ability.Be installed on each unit in the multi-machine power system.To appointing the multi-machine power system close network knot Xun to be in any operating point and all having the optimum efficiency that recovers stable when standing the interference of any kind.

The present invention is based upon on the design basis of following initiative:

1) visible each machine end electric current I of each quantitative change situation and power P (or other is measured accordingly) have been reacted the correlation between concrete network configuration, operating point and fault type and unit well behind the analysis electric power system fault.And these quantity of states relevance non-linear by the embodiment system can be measured in real time, without any simplification and the approximate decoupling zero compressive state space equation formula that can be fit to the multimachine system optimal control from the most original system equation formula derivation.When adopting suitable model, each element of system can set up following equation of state:

Brief note is:

_i=A _iX _i+ B _iU _i+ C _i(t)

2) give newspaper thought according to the association of large system decomposing coordination, derive with Pang De lia king maximum principle and disperse the optimal control rule, derive the computing formula of these feedback oscillators:

U _i＝F _iX _i+G _iC _i（t）……（2）

Wherein: F _i=-R ^-1 _iB ^-1 _iK _i(3)

G _i＝R ^-1 _iB ^-1 _i（A ^-1 _i-K _iB _iR ^-1 _iB ^-1 _i） ^-1K _i……（4）

K _iBe separating of algebraic riccati equation formula:

K _iA _i+A ^-1 _iK _i-K _iB _iR ^-1 _iB ^-1 _iK _i+Q _i＝0……（5）

3) because I _dAnd E ^' _gIn actual engineering, be difficult for to measure, utilize the fundamental formular of synchronous machine to derive them and modern science and technology are easily measured P _e, I _t, V _t, the relation of cos φ:

$E^{\text{'}}{}_q=\sqrt{\frac{\mathrm{P\; e(}\frac{{\mathrm{(V}}_t{\mathrm{/I}}_t{)}^2{\cos }^2\phi }{V_t{\mathrm{/I}}_t{\mathrm{sin\; \phi \; +X}}_q}{\mathrm{+V}}_t{\mathrm{/I}}_t{\mathrm{sin\; \phi +X}}^{\text{'}}{}_d{\mathrm{)\; (V}}_t{\mathrm{/I}}_t{\mathrm{sin\; \phi +X}}_q)}{\frac{{\mathrm{(V}}_t{\mathrm{/I}}_t{)}^2{\cos }^2\phi }{V_t{\mathrm{/\; I}}_t\mathrm{sin\; \phi \; +X\; q}}{\mathrm{+V}}_t{\mathrm{/I}}_t{\mathrm{sin\; \phi \; )(V}}_t{\mathrm{/\; I}}_t\mathrm{cos\; \phi )}}}$ (6)

$I_d=\frac{E^{\text{'}}{}_q}{\frac{{\mathrm{(V}}^2{}_t{\mathrm{/\; I}}^2{}_t{\cos }^2\mathrm{\phi )}}{{\mathrm{(V}}_t{\mathrm{/\; I}}_t{\mathrm{sin\; \phi \; +\; X}}_q)}{\mathrm{+(V}}_t{\mathrm{/\; I}}_t{\mathrm{s\; in\; \phi \; +X}}^{\text{'}}{}_d)}\mathrm{\dots \dots }$ (7)

According to modern surveying technology P, the cos amount can be by I in digital processing, and V obtains:

P=1/L $\underset{\mathrm{k\; =\; 1}}{\overset{L}{\mathrm{\Σ}}}$ U _kI _K……（8）

P=IVcos $\sqrt{\mathrm{V\; =\; 1/L}\underset{\mathrm{k\; =1}}{\overset{L}{\mathrm{\Σ}}}{U}^2{}_k}$

cosφ=P/IV $\sqrt{\mathrm{I\; =\; 1/L}\underset{\mathrm{k\; =\; 1}}{\overset{L}{\mathrm{\Σ}}}{I}^2{}_k}$ ……（9）

E ^' _GiThe transient potential of-Di i platform machine

P _RiThe mechanical output of-Di i platform machine

P _EiThe electromagnetic power of-Di i platform machine

μ _iThe steam turbine aperture of-Di i platform machine

T ^' _DoiThe excitation winding time constant of-Di i platform machine

T _Bi, T _{μ i}The steam turbine link time constant of-Di i platform machine

C _iThe steam turbine link constant of-Di i platform machine

T _Ji-Di i platform unit set inertia time constant

W _iThe rotor velocity of-Di i platform machine

W _n-rotor rated angular velocity

V _AiThe excitation control voltage of-Di i platform machine

V _GiThe steam turbine controlled quentity controlled variable of-Di i platform unit

P _m-brake resistance capacity

The D-damping coefficient

X _d, X ^' _d-d axle synchronous reactance, the transient state reactance

X _g-q axle synchronous reactance

I _d-stator d shaft current

V _t, I _t-set end voltage, electric current

φ-power-factor angle

Q _i, R _i-Quan Zhen

The L-sampling period

The present invention compared with prior art has following advantage and good effect:

1) controller parameter of the present invention is only relevant with generator 's parameter, and is all irrelevant with network configuration and running status and disturbed condition, thereby has adaptive ability and recover stable optimum efficiency.

2) system model keeps former non-linear relation in the present invention's design, can adapt to the large disturbance situation, effectively raises electrical power system transient and dynamic stability level.

3) the present invention adopts this unit easily to measure as the controller input, does not need remote message transmission and intersection feedback, be easy to realize, and also simple in structure.

4) the present invention is suitable for the multimachine system of any number, and the selection of each component models of electric power system is decided by needs fully.Control device adopts exciting voltage, quick closing valve, brake resistance etc. also can determine on request.All do not need method for designing is made any change.

Embodiments of the invention:.(referring to accompanying drawing)

Because versatility of the present invention; so think and to control from single exciting voltage according to the electric power system existing level; brake resistances etc. progressively reach comprehensive optimal control, its circuit can adopt analog circuit or digital circuit to realize, and shared microcomputer such as employing and relaying protection is realized more favourable.

Accompanying drawing 1: dynamic model experiment winding diagram." external system " is meant other part of system except that this generator.G-generator, T-transformer, PT-voltage transformer, CT-current transformer, U ₁-excitation control voltage, U ₂-porthole controlled quentity controlled variable, U ₃-brake resistance controlled quentity controlled variable.

Accompanying drawing 2: with the theory diagram of microcomputer realization.The conversion of its control law and measurement is all finished by microcomputer software.

Accompanying drawing 3: with the theory diagram of analog circuit realization.Its control law and measurement conversion are to finish by analog operational circuit.

Hardware design :-

1) the unit measurement links comprises the measurement mechanism of CT, PT, μ, Pt etc.

2) input transducer comprises inner PT, CT etc. and adjustment member, and inner PTCT etc. are that adjustment member is to be used for eliminating each PT, the incomplete same caused error of CT no-load voltage ratio with voltage, the current signal circuit allowed band of remapping.Inner CT back also is connected to pressure limiting partly, damages the A/D modular converter when electric current is too big when preventing fault.

3) analog filter is eliminated Harmonious Waves in Power Systems, reduces because of the caused error of aliasing in spectra.

4) sampling holder and analog-to-digital conversion are original analog signal is converted to the digital signal of MICROCOMPUTER PROCESSING.

5) microcomputer mainly is to finish control law with a cover software, measures calculating such as conversion.(this software provides when substantive examination, enforcement permission)

6) parallel interface adapter and digital-to-analogue conversion revert to analog signal to the digital controlled signal that calculates gained.

7) amplitude limiter is that requirement according to each element of system is limited in control signal in the allowed band.

When 8) adopting analog operational circuit to realize, the part of wherein above-mentioned (4) to (7) can directly wait with squarer, square root extractor, multiplier and divider and finish control law, measures the calculating of conversion.

Claims (8)

1, the method for a kind of transient state that is used for large power system in parallel and dynamic stability control is characterized in that it adopts the reflection system non-linear, the quantity of state I of correlation and interference type between unit _d, P _e(being convertible into easy measurement) measures in real time, sets up decoupling zero compression linear state space model.(referring to specification formula 1)

2, stable control method as claimed in claim 1 is characterized in that it will be difficult for measuring electric parameters I _d, E ^' _gConvert easy survey electric parameters I to _t, V _tDeng.(referring to specification formula 6,7,8,9)

3, stable control method as claimed in claim 1 is characterized in that it provides one group of optimal control rule.(referring to specification formula 2,3,4,5)

4, a kind of by measuring transducer, transmitter, transducer, microcomputer, the transient state of the large power system in parallel that analog operating unit etc. are formed and dynamic stability control device is characterized in that it has microcomputer or analog circuit and the software that can finish above-mentioned measurement conversion, control law calculating.(this software provides when implementing permission in substantive examination)

5, stabilization control device as claimed in claim 4 is characterized in that it has the measurement component that control input parameter can be provided: ω, μ, P _r, P _eDeng transducer, transmitter.

6, stabilization control device as claimed in claim 4 is characterized in that it has the filter of eliminating system harmonics.

7, stabilizing arrangement as claimed in claim 4 is characterized in that it has A/D, the D/A plate that digital and analog signaling is changed mutually, sampling holder and PIA when adopting microcomputer.

8, stabilization control device as claimed in claim 4 other levy and be that it has control signal is limited in amplitude limiter in the allowed band.

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