CN102315644B - Self-adaptive delay feedback static bifurcation control system and control method thereof - Google Patents

Abstract

The invention discloses a self-adaptive delay feedback static bifurcation control system, which comprises a voltage measuring module, a delay module, a self-adaptive module, an addition module and an amplifying module. The control method of the self-adaptive delay feedback static bifurcation control system comprises the steps of equivalent calculation, voltage measurement, delay calculation, addition calculation, signal amplification and control signal output. The self-adaptive delay feedback static bifurcation control system and the control method thereof have the advantages that: (1) the static bifurcation of a simple power system specified by the invention can be eliminated and no new bifurcation is introduced while the bifurcation of an original system is eliminated; (2) a saddle node bifurcation controller is designed by adopting a linear feedback control law, the change range of parameters is not needed to be determined, favorable control effect is achieved, and the circuit design and the method are simple and are easy to realize; and (3) a control algorithm is easy for realization of the circuit.

Description

A kind of adaptive delay feedback static BIFURCATION CONTROL system and control method thereof

(1) technical field:

The present invention relates to field of power system control, especially a kind of adaptive delay feedback static BIFURCATION CONTROL system and control method thereof.

(2) background technology:

The conventional electric power system is a nonlinear dynamical system, in recent years, due to the impact that is subject to the many factors such as environment and relieving control, the running status of electric power system is increasingly severe, nonlinear problem causes people's attention gradually, therefore in order to ensure the fail safe of electric power system, must searching can analyze and control the new method of nonlinear problem, so some research workers target diversion bifurcation theory.

The external manifestation of Voltage Instability is significantly to fall vibration unstability or the moment of amplitude, unstability can be thought the nonlinear dynamic system of containing parameter, when continuous parameters changes and pass through a certain critical value, when the qualitative condition of system (number of balance point, stability etc.) occurs to change suddenly, the inevitable outcome that dynamical system occurs, the main Study system of bifurcation theory changes the change procedure of the Structure and stability of the solution that causes with parameter, can better disclose Voltage Instability mechanism.The final purpose of carrying out Bifurcation is the Bifurcation Characteristics that controller of design and corresponding algorithm thereof are revised electric power system, enlarges the safe and stable operation territory of electric power system, remains the stability of electric power system.Typical electric power system BIFURCATION CONTROL target comprises: the intrinsic fork that postpones or eliminate electric power system; Under parameter value given in advance, introduce new fork to eliminate original fork; Change the parameter of existing bifurcation point to increase the stability margin of system; Revise shape and the type of fork chain, obtain the chance of effective control measure; Calm Bifurcation Solutions and fork branch are with the good dynamic stability quality of keeping system; Supervision enters the possibility of chaos state by amplitude, frequency and the tuple of the limit cycle that fork causes with the elimination system; Near the operation characteristic of optimization system bifurcation point and the combination of above-mentioned each target.

BIFURCATION CONTROL method commonly used mainly contains at present: by linearity or Based on Nonlinear State Feedback, at the system parameter values place of expectation, produce fork, thereby postpone the appearance of bifurcation, or produce new fork; Utilize the wash-out filter at the system parameter values place of expectation, to produce fork in conjunction with Linear State Feedback, utilize Based on Nonlinear State Feedback to change the type of fork.These BIFURCATION CONTROL methods can postpone the appearance of fork, enlarge the scope of system stable operation, might not eliminate bifurcation, design with Time Controller is also relevant with system parameter values, therefore only have and determine when the excursion of parameter, and when parameter was known, these controllers just can be guaranteed the stability of system.

(3) summary of the invention:

The object of the present invention is to provide a kind of adaptive delay feedback static BIFURCATION CONTROL system and control method thereof, it can overcome the deficiencies in the prior art, it is a kind of simple in structure, control method convenience, the system of easy operating, not only the control time can be reduced, can also effectively to the parameter of system state variables and system, control, eliminate bifurcation and not introducing on new bifurcation basis.

Technical scheme of the present invention: a kind of adaptive delay feedback static BIFURCATION CONTROL system, comprise by two generator bus, the electric power system that load bus and excitation generator form, it is characterized in that it comprises voltage measurement module, time delay module, adaptation module, addition module and amplification module; Wherein, the input of described voltage measurement module gathers the load bus nodes voltage signal in electric power system, and its output connects respectively the input of addition module and the input of time delay module; Described time delay module is two-way with adaptation module and is connected, and its output is connected with the input of addition module; The input of described adaptation module gathers the load bus nodes voltage signal in electric power system; The output of described addition module is connected with the input of amplification module; Described amplification module is two-way with adaptation module and is connected, and its output is connected with the input that the generator excitation in electric power system is controlled.

Described addition module adopts 32 addition module ADDER32B.Vhd.

Described amplification module adopts high input impedance operational amplifier CA3130.

Described adaptation module adopts the dsp chip TMS320F2812 of TI company.

A kind of control method of adaptive delay feedback static BIFURCATION CONTROL system is characterized in that it comprises the following steps:

1. according to electric power system equivalent calculation method, the bus of a generator in electric power system is processed into to lax bus, this moment, system equation was:

$\left\{\begin{array}{c}{\stackrel{.}{\mathrm{\δ}}}_m=\mathrm{\ω}\\ M\stackrel{.}{\mathrm{\ω}}=-\mathrm{D\ω}+P_m+V_{m}V{Y}_m\sin (\mathrm{\δ}-{\mathrm{\δ}}_m-{\mathrm{\θ}}_m)+{V_m}^2{Y}_m\sin {\mathrm{\θ}}_m\\ k_{\mathrm{q\ω}}\stackrel{.}{\mathrm{\δ}}=-k_{\mathrm{qV}}V-k_{\mathrm{qV}2}{V}^2+Q-Q_0-Q_1\\ T{K}_{\mathrm{q\ω}}{k}_{\mathrm{pV}}\stackrel{.}{V}=k_{\mathrm{p\ω}}{k}_{\mathrm{qV}2}{V}^2+(k_{\mathrm{p\ω}}{k}_{\mathrm{qV}}-k_{\mathrm{q\ω}}{k}_{\mathrm{pV}})V\\ {+k}_{\mathrm{p\ω}}(Q_0+Q_1-Q)-k_{\mathrm{q\ω}}(P_0+P_1-P)\end{array}\right.$

In formula, M, D and P _mBe respectively inertia constant, damping coefficient and the mechanical output of generator, δ _m, ω is respectively angle and the angular speed of generator, δ, V are respectively angle and the amplitude of load voltage, the capacitor on the load bus belongs to the part of constant-impedance load, P ₀, Q ₀Permanent active power and the reactive power of motor; P ₁And Q ₁It is permanent P-Q load;

2. by voltage measurement module, measured the voltage V (t) of load bus in electric power system;

3. by adaptation module, gather the load bus nodes voltage signal signal in electric power system, utilize the adaptive delay feedback control law to calculate delay time T to time delay module, by time delay module, obtain the voltage quantities V that the delayed time is τ (t-τ);

The voltage quantities V that 4. will be recorded by addition module (t) and the voltage quantities V after time delay (t-τ) superpose, and the voltage after superposeing flows to amplification module;

5. the Time-delayed Feedback signal of amplification module output in 4. by step amplifies, and obtains:

F(t)＝K(V(t-τ)-V(t))＝KD(t)

Wherein K is the adaptive gain coefficient, and τ is the adaptive delay time;

6. the voltage signal after amplifying flows to the input that the generators in power systems excitation is controlled again.

The described step 3. acquiring method of middle delay time T is:

(1) choosing delay time τ is the time interval between the individual peak value of arbitrary neighborhood (k-1) on measured state variable time history curve

τ＝Δt ⁽ⁿ⁾ _max＝t ⁽ⁿ⁾ _max-t ^(n-k) _max

(2) along with constantly applying of controlling, this time interval also equals a constant, the i.e. cycle of periodic orbit gradually.

The described step 5. acquiring method of middle adaptive gain coefficient is:

(1) definition moment t _nThe localized variation rate of Time-delayed Feedback time be,

$\mathrm{\λ}\left(t_n\right)=\log \left|\frac{\mathrm{\Δ}{t^{\left(n\right)}}_{\max }}{\mathrm{\Δ}{t^{(n-1)}}_{\max }}\right|$

The delayed feedback signal of the adaptive gain coefficient in this moment and amplification is:

$K\left(t_n\right)=\frac{K\left(t_{n-1}\right)}{1-\tanh \left(\mathrm{\σ\λ}\left(t_n\right)\right)}$

F(t _n)＝K(t _n)(x(t _n-Δt ⁽ⁿ⁾ _max)-(x(t _n))

Wherein, K (t _N-1) be the gain coefficient of a upper time period, when σ → 0, the adaptive delay feedback just degenerates to the form in original Time-delayed Feedback method, and σ>0 is a decimal, to all time, σ λ drops in the range of linearity of function tanh.

Operation principle of the present invention:

If non linear system is

$\stackrel{.}{x}=f(x,\mathrm{\μ})$

In formula, x ∈ R ⁿFor state variable, For variable system parameters,

F:R ⁿ* J → R ⁿUnique smooth Nonlinear Mapping.

By it at balance point x ₀Place's linearisation, obtain its approximately linear system and be

$\stackrel{.}{x}=A\left(\mathrm{\μ}\right)x$

A in formula (μ) is that f (x, μ) is at (x ₀, the Jacobian matrix of μ) locating.

This linearized system is carried out to the adaptive delay FEEDBACK CONTROL, and controlled system is:

$\stackrel{.}{x}=A\left(\mathrm{\μ}\right)x+F\left(t\right)$

F(t)＝K(x(t-τ)-x(t))＝KD(t)

Wherein K is the adaptive gain coefficient, and τ is the adaptive delay time, but x is an examining system state variable,

In whole control procedure, Time-delayed Feedback time and feedback gain are all automatically to select according to the Transient Dynamics behavior of system, have the characteristics of adaptivity.

Superiority of the present invention is: (1) can eliminate the quiet fork of the specific simple power system of the present invention, and does not introduce new fork when eliminating the original system fork; (2) adopt linear Feedback Control to restrain to design the Saddle-Node Bifurcation Control device, need not determine the excursion of parameter, controls effectively, circuit design and method are simple and be easy to realization; (3) control algolithm is easy to the circuit realization.

(4) accompanying drawing explanation:

Fig. 1 is the overall structure block diagram of the related a kind of adaptive delay feedback static BIFURCATION CONTROL system of the present invention;

Fig. 2 is the equivalent circuit diagram of electric power system in the related a kind of adaptive delay feedback static BIFURCATION CONTROL system of the present invention;

Fig. 3 is the control principle drawing of adaptation module in the related a kind of adaptive delay feedback static BIFURCATION CONTROL system of the present invention.

(5) embodiment:

Embodiment: a kind of adaptive delay feedback static BIFURCATION CONTROL system (seeing Fig. 1), comprise by two generator bus, the electric power system that load bus and excitation generator form, it is characterized in that it comprises voltage measurement module, time delay module, adaptation module, addition module and amplification module; Wherein, the input of described voltage measurement module gathers the load bus nodes voltage signal in electric power system, and its output connects respectively the input of addition module and the input of time delay module; Described time delay module is two-way with adaptation module and is connected, and its output is connected with the input of addition module; The input of described adaptation module gathers the load bus nodes voltage signal in electric power system; The output of described addition module is connected with the input of amplification module; Described amplification module is two-way with adaptation module and is connected, and its output is connected with the input that the generator excitation in electric power system is controlled.

Described addition module adopts 32 addition module ADDER32B.Vhd (seeing Fig. 1).

Described amplification module adopts high input impedance operational amplifier CA3130 (seeing Fig. 1).

Described adaptation module adopts the dsp chip TMS320F2812 (seeing Fig. 1) of TI company.

A kind of control method of adaptive delay feedback static BIFURCATION CONTROL system is characterized in that it comprises the following steps:

1. according to electric power system equivalent calculation method, the bus of a generator in electric power system (seeing Fig. 2) is processed into to lax bus, this moment, system equation was:

$\left\{\begin{array}{c}{\stackrel{.}{\mathrm{\δ}}}_m=\mathrm{\ω}\\ M\stackrel{.}{\mathrm{\ω}}=-\mathrm{D\ω}+P_m+V_{m}V{Y}_m\sin (\mathrm{\δ}-{\mathrm{\δ}}_m-{\mathrm{\θ}}_m)+{V_m}^2{Y}_m\sin {\mathrm{\θ}}_m\\ k_{\mathrm{q\ω}}\stackrel{.}{\mathrm{\δ}}=-k_{\mathrm{qV}}V-k_{\mathrm{qV}2}{V}^2+Q-Q_0-Q_1\\ T{K}_{\mathrm{q\ω}}{k}_{\mathrm{pV}}\stackrel{.}{V}=k_{\mathrm{p\ω}}{k}_{\mathrm{qV}2}{V}^2+(k_{\mathrm{p\ω}}{k}_{\mathrm{qV}}-k_{\mathrm{q\ω}}{k}_{\mathrm{pV}})V\\ {+k}_{\mathrm{p\ω}}(Q_0+Q_1-Q)-k_{\mathrm{q\ω}}(P_0+P_1-P)\end{array}\right.$

In formula, M, D and P _mBe respectively inertia constant, damping coefficient and the mechanical output of generator, δ _m, ω is respectively angle and the angular speed of generator, δ, V are respectively angle and the amplitude of load voltage, the capacitor on the load bus belongs to the part of constant-impedance load, P ₀, Q ₀Permanent active power and the reactive power of motor; P ₁And Q ₁It is permanent P-Q load;

2. by voltage measurement module, measured the voltage V (t) of load bus in electric power system;

3. by adaptation module (seeing Fig. 3), gather the load bus nodes voltage signal signal in electric power system, utilize the adaptive delay feedback control law to calculate delay time T to time delay module, by time delay module, obtain the voltage quantities V that the delayed time is τ (t-τ);

The voltage quantities V that 4. will be recorded by addition module (t) and the voltage quantities V after time delay (t-τ) superpose, and the voltage after superposeing flows to amplification module;

5. the Time-delayed Feedback signal of amplification module output in 4. by step amplifies, and obtains:

F(t)＝K(V(t-τ)-V(t))＝KD(t)

Wherein K is the adaptive gain coefficient, and τ is the adaptive delay time;

6. the voltage signal after amplifying flows to the input that the generators in power systems excitation is controlled again.

The described step 3. acquiring method of middle delay time T is:

(1) choosing delay time τ is the time interval between the individual peak value of arbitrary neighborhood (k-1) on measured state variable time history curve

τ＝Δt ⁽ⁿ⁾ _max＝t ⁽ⁿ⁾ _max-t ^(n-k) _max

(2) along with constantly applying of controlling, this time interval also equals a constant, the i.e. cycle of periodic orbit gradually.

The described step 5. acquiring method of middle adaptive gain coefficient is:

(1) definition moment t _nThe localized variation rate of Time-delayed Feedback time be,

$\mathrm{\λ}\left(t_n\right)=\log \left|\frac{\mathrm{\Δ}{t^{\left(n\right)}}_{\max }}{\mathrm{\Δ}{t^{(n-1)}}_{\max }}\right|$

The delayed feedback signal of the adaptive gain coefficient in this moment and amplification is:

$K\left(t_n\right)=\frac{K\left(t_{n-1}\right)}{1-\tanh \left(\mathrm{\σ\λ}\left(t_n\right)\right)}$

F(t _n)＝K(t _n)(x(t _n-Δt ⁽ⁿ⁾ _max)-(x(t _n))

Wherein, K (t _N-1) be the gain coefficient of a upper time period, when σ → 0, the adaptive delay feedback just degenerates to the form in original Time-delayed Feedback method, and σ>0 is a decimal, to all time, σ λ drops in the range of linearity of function tanh.

Claims (7)

1. adaptive delay feedback static BIFURCATION CONTROL system, comprise by two generator bus, the electric power system that load bus and excitation generator form, it is characterized in that it comprises voltage measurement module, time delay module, adaptation module, addition module and amplification module; Wherein, the input of described voltage measurement module gathers the load bus nodes voltage signal in electric power system, and its output connects respectively the input of addition module and the input of time delay module; Described time delay module is two-way with adaptation module and is connected, and its output is connected with the input of addition module; The input of described adaptation module gathers the load bus nodes voltage signal in electric power system; The output of described addition module is connected with the input of amplification module; Described amplification module is two-way with adaptation module and is connected, and its output is connected with the input that the generator excitation in electric power system is controlled.

According to claim 1 described in a kind of adaptive delay feedback static BIFURCATION CONTROL system, it is characterized in that described addition module adopts 32 addition module ADDER32B.Vhd.

According to claim 1 described in a kind of adaptive delay feedback static BIFURCATION CONTROL system, it is characterized in that described amplification module adopts high input impedance operational amplifier CA3130.

According to claim 1 described in a kind of adaptive delay feedback static BIFURCATION CONTROL system, it is characterized in that described adaptation module adopts the dsp chip TMS320F2812 of TI company.

5. the control method of an adaptive delay feedback static BIFURCATION CONTROL system is characterized in that it comprises the following steps:

1. according to electric power system equivalent calculation method, the bus of a generator in electric power system is processed into to lax bus, this moment, system equation was:

$\left\{\begin{array}{c}{\stackrel{.}{\mathrm{\δ}}}_m=\mathrm{\ω}\\ M\stackrel{.}{\mathrm{\ω}}=-\mathrm{D\ω}+P_m+V_{m}V{Y}_m\sin (\mathrm{\δ}-{\mathrm{\δ}}_m-{\mathrm{\θ}}_m)+{V_m}^2{Y}_m\sin {\mathrm{\θ}}_m\\ k_{\mathrm{q\ω}}\stackrel{.}{\mathrm{\δ}}=-k_{\mathrm{qV}}V-k_{\mathrm{qV}2}{V}^2+Q-Q_0-Q_1\\ T{K}_{\mathrm{q\ω}}{k}_{\mathrm{pV}}\stackrel{.}{V}=k_{\mathrm{p\ω}}{k}_{\mathrm{qV}2}{V}^2+(k_{\mathrm{p\ω}}{k}_{\mathrm{qV}}-k_{\mathrm{q\ω}}{k}_{\mathrm{pV}})V\\ {+k}_{\mathrm{p\ω}}(Q_0+Q_1-Q)-k_{\mathrm{q\ω}}(P_0+P_1-P)\end{array}\right.$

In formula, M, D and P _mBe respectively inertia constant, damping coefficient and the mechanical output of generator, δ _m, ω is respectively angle and the angular speed of generator, δ, V are respectively angle and the amplitude of load voltage, the capacitor on the load bus belongs to the part of constant-impedance load, P ₀, Q ₀Permanent active power and the reactive power of motor; P ₁And Q ₁It is permanent P-Q load;

2. by voltage measurement module, measured the voltage V (t) of load bus in electric power system;

3. by adaptation module, gather the load bus nodes voltage signal signal in electric power system, utilize the adaptive delay feedback control law to calculate delay time T to time delay module, by time delay module, obtain the voltage quantities V that the delayed time is τ (t-τ);

The voltage quantities V that 4. will be recorded by addition module (t) and the voltage quantities V after time delay (t-τ) superpose, and the voltage after superposeing flows to amplification module;

5. the Time-delayed Feedback signal of amplification module output in 4. by step amplifies, and obtains:

F(t)＝K(V(t-τ)-V(t))＝KD(t)

Wherein K is the adaptive gain coefficient, and τ is the adaptive delay time;

6. the voltage signal after amplifying flows to the input that the generators in power systems excitation is controlled again.

According to claim 5 described in a kind of control method of adaptive delay feedback static BIFURCATION CONTROL system, it is characterized in that during described step was 3., the acquiring method of delay time T was:

(1) choosing delay time τ is the time interval between the individual peak value of arbitrary neighborhood (k-1) on measured state variable time history curve

τ＝Δt ⁽ⁿ⁾ _max＝t ⁽ⁿ⁾ _max-t ^(n-k) _max

(2) along with constantly applying of controlling, this time interval also equals a constant, the i.e. cycle of periodic orbit gradually.

According to claim 5 described in a kind of control method of adaptive delay feedback static BIFURCATION CONTROL system, it is characterized in that during described step was 5., the acquiring method of adaptive gain coefficient was:

(1) definition moment t _nThe localized variation rate of Time-delayed Feedback time be,

$\mathrm{\λ}\left(t_n\right)=\log \left|\frac{\mathrm{\Δ}{t^{\left(n\right)}}_{\max }}{\mathrm{\Δ}{t^{(n-1)}}_{\max }}\right|$

The delayed feedback signal of the adaptive gain coefficient in this moment and amplification is:

$K\left(t_n\right)=\frac{K\left(t_{n-1}\right)}{1-\tanh \left(\mathrm{\σ\λ}\left(t_n\right)\right)}$

F(t _n)＝K(t _n)(x(t _n-Δt ⁽ⁿ⁾ _max)-(x(t _n))

Wherein, K (t _N-1) be the gain coefficient of a upper time period, when σ → 0, the adaptive delay feedback just degenerates to the form in original Time-delayed Feedback method, and σ>0 is a decimal, to all time, σ λ drops in the range of linearity of function tanh.

Images