CN105356481A - Multi-infeed-short-circuit-ratio-based dynamic reactive compensation point selection method - Google Patents

Abstract

The invention provides a multi-infeed-short-circuit-ratio-based dynamic reactive compensation point selection method. The method comprises the following steps: establishing a jacobian matrix and solving a voltage impact factor; determining a multi-infeed short circuit ratio according to the voltage impact factor; establishing effect evaluation objective functions of dynamic reactive compensation apparatus installation at all stations and corresponding constraint conditions; and selecting an optimal dynamic reactive compensation apparatus installation point by using a genetic algorithm. According to the invention, with consideration of the interactive influence between multi-loop direct-current lines, an effective method and an effective technical support are provided for selection of a dynamic reactive compensation apparatus installation point at a direct-current multi-infeed area of the country; and because the influences on the system stability by response characteristics of all elements during the dynamic process are taken into consideration, the point selection method is practical and has the engineering application value. Dynamic point selection optimization is carried out by using the genetic algorithm, so that the calculation efficiency is high.

Description

A kind of dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio

Technical field

The invention belongs to technical field of power systems, be specifically related to a kind of dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio.

Background technology

The load center areas such as China's East China Yangtze River Delta are by the restriction of local normal power supplies development, and will present many direct currents future concentrates feed-in structure, and the system failure may cause multiple-circuit line chain-react, cause Voltage-stabilizing Problems.Domestic and international operation of power networks experience shows, every REACTIVE POWER/VOLTAGE CONTROL problem of relating to, dynamic reactive compensation device is more satisfactory solution, dynamic reactive compensation device control strategy is flexible, fast response time, the Voltage-stabilizing Problems of multi-infeed DC receiving end electrical network can be considered to adopt dynamic reactive compensation device, improves the voltage support ability of extra-high voltage grid, particularly after system malfunctions disturbance, help the fast quick-recovery realizing system weak spot voltage.

Consider that receiving end Net Frame of Electric Network is intensive, land resource scarcity, the restriction that dynamic reactive compensation device is easily subject to site is installed in transformer station, so, its dynamic passive compensation allocation plan can when reaching effect same, the scheme that capacity is minimum or configuration site is minimum should being selected, needing to determine by optimizing.

Many feed-ins short circuit ratio is more common for the index of DC support ability for measurement interchange in multi-infeed DC electrical network, be widely used, but it is defined as static index, only can reflects network topology structure, cannot take into account dynamic element model.And stability of power system focuses on the system performance in dynamic process under each element responds, various dynamic element is as larger on the impact of voltage stability in generator model, load model, DC control model, dynamic passive compensation model etc.At present, domestic and international existing dynamic reactive compensation device collocation method generally carries out reconnaissance based on the weakness zone of static voltage stability, not yet considers multi-infeed DC system performance and dynamic element model characteristics.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the invention provides a kind of dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio, reconnaissance method more gears to actual circumstances, and possesses engineer applied and is worth.

In order to realize foregoing invention object, the present invention takes following technical scheme:

The invention provides a kind of dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio, said method comprising the steps of:

Step 1: set up Jacobian matrix and solve the voltage influence factor;

Step 2: determine many feed-ins short circuit ratio according to the voltage influence factor;

Step 3: set up each website and install dynamic reactive compensation device effect assessment target function and corresponding constraints;

Step 4: adopt the preferred dynamic reactive compensation device mounting points of genetic algorithm.

Described step 1 comprises the following steps:

Step 1-1: consider dynamic element model, set up power balance equation;

Step 1-2: set up Jacobian matrix, and solve the voltage influence factor.

In described step 1-1, dynamic element model comprises generator model, load model, DC control model and dynamic reactive compensation device model.

In described step 1-1, set up following power balance equation:

$\{\begin{array}{c}{\mathrm{\ΔP}}_i=P_{Gi}-P_{Li}\±P_{Di}-U_i\underset{j\∈i}{\Σ}{U}_j(G_{ij}{\mathrm{cos\θ}}_{ij}+B_{ij}{\mathrm{sin\θ}}_{ij})\\ {\mathrm{\ΔQ}}_i=Q_{Gi}-Q_{Li}-Q_{Di}+Q_{Si}-U_i\underset{j\∈i}{\Σ}{U}_j(G_{ij}{\mathrm{sin\θ}}_{ij}-B_{ij}{\mathrm{cos\θ}}_{ij})\end{array}---\left(1\right)$

Wherein, Δ P _i, Δ Q _irepresent the active power variable quantity that node i is injected and reactive power variable quantity respectively, P _gi, Q _girepresent that generator injects node i meritorious and exerts oneself and idlely to exert oneself, P respectively _li, Q _lirepresent burden with power and the load or burden without work of node i respectively, P _direpresent the direct current power of node i, Q _direpresent that DC filter capacitor injects the reactive power of node i, U _i, U _jrepresent the voltage of node i, j respectively, Q _sirepresent that dynamic reactive compensation device injects the idle of node i and exerts oneself, G _ij, B _ijrepresent the conductance between node i, j and susceptance respectively, θ _ijrepresent the phase difference of voltage between node i, j, i=1,2 ..., n, j=1,2 ..., n, n are node total number.

In described step 1-2, set up following Jacobian matrix equation:

$\begin{array}{c}\left[\begin{array}{c}0\\ 0\\ .\\ .\\ .\\ 0\\ \∂{\mathrm{\ΔQ}}_l/\∂U_l\\ .\\ .\\ .\\ 0\\ 0\end{array}\right]=\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& \mathrm{...}& H_{1k}& N_{1k}& \mathrm{...}& H_{1n}& N_{1n}\\ M_{11}& L_{11}& \mathrm{...}& M_{1k}& L_{1k}& \mathrm{...}& M_{1n}& L_{1n}\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{l1}& N_{l1}& \mathrm{...}& H_{lk}& N_{lk}& \mathrm{...}& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& \mathrm{...}& M_{lk}& L_{lk}& \mathrm{...}& M_{\ln }& L_{\ln }\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{n1}& N_{n1}& \mathrm{...}& H_{nk}& N_{nk}& \mathrm{...}& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& \mathrm{...}& M_{nk}& L_{nk}& \mathrm{...}& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\∂{\mathrm{\θ}}_1/\∂U_k\\ \∂U_1/\∂U_k\\ .\\ .\\ .\\ \∂{\mathrm{\θ}}_l/\∂U_k\\ \∂U_l/\∂U_k\\ .\\ .\\ .\\ \∂{\mathrm{\θ}}_n/\∂U_k\\ \∂U_n/\∂U_k\end{array}\right]\\ =\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& \mathrm{...}& H_{1k}& N_{1k}& \mathrm{...}& H_{1n}& N_{1n}\\ M_{11}& L_{11}& \mathrm{...}& M_{1k}& L_{1k}& \mathrm{...}& M_{1n}& L_{1n}\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{l1}& N_{l1}& \mathrm{...}& H_{lk}& N_{lk}& \mathrm{...}& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& \mathrm{...}& M_{lk}& L_{lk}& \mathrm{...}& M_{\ln }& L_{\ln }\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{n1}& N_{n1}& \mathrm{...}& H_{nk}& N_{nk}& \mathrm{...}& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& \mathrm{...}& M_{nk}& L_{nk}& \mathrm{...}& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\∂{\mathrm{\θ}}_1/\∂U_k\\ {\mathrm{MIIF}}_{1k}\\ .\\ .\\ .\\ \∂{\mathrm{\θ}}_l/\∂U_k\\ {\mathrm{MIIF}}_{lk}\\ .\\ .\\ .\\ \∂{\mathrm{\θ}}_n/\∂U_k\\ {\mathrm{MIIF}}_{nk}\end{array}\right]\end{array}---\left(2\right)$

Wherein, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k;

Jacobian matrix element H _ii, N _ii, M _ii, L _iicalculate according to the following formula:

$\left\{\begin{array}{c}{H}_{ii}=\frac{\∂{\mathrm{\ΔP}}_i}{\∂{\mathrm{\θ}}_i}=U_i\underset{j\≠i}{\underset{j\∈i}{\Σ}}{U}_j(G_{ij}{\mathrm{sin\θ}}_{ij}-B_{ij}{\mathrm{cos\θ}}_{ij})+\frac{\∂P_{Gi}}{\∂{\mathrm{\θ}}_i}\\ N_{ii}=\frac{\∂{\mathrm{\ΔP}}_i}{\∂U_i}=-\underset{j\≠i}{\underset{j\∈i}{\Σ}}{U}_j(G_{ij}{\mathrm{cos\θ}}_{ij}+B_{ij}{\mathrm{sin\θ}}_{ij})-2U_i{G}_{ii}+\frac{\∂P_{Gi}}{\∂U_i}-\frac{\∂P_{Li}}{\∂U_i}\±\frac{\∂P_{Di}}{\∂U_i}\\ M_{ii}=\frac{\∂{\mathrm{\ΔQ}}_i}{\∂{\mathrm{\θ}}_j}=-U_i\underset{j\≠i}{\underset{j\∈i}{\Σ}}{U}_j(G_{ij}{\mathrm{cos\θ}}_{ij}+B_{ij}{\mathrm{sin\θ}}_{ij})+\frac{\∂Q_{Gi}}{\∂{\mathrm{\θ}}_i}\\ L_{ii}=\frac{\∂{\mathrm{\ΔQ}}_i}{\∂U_j}=-\underset{j\≠i}{\underset{j\∈i}{\Σ}}{U}_j(G_{ij}{\mathrm{sin\θ}}_{ij}-B_{ij}{\mathrm{cos\θ}}_{ij})+2U_i{B}_{ii}+\frac{\∂Q_{Gi}}{\∂U_i}-\frac{\∂Q_{Li}}{\∂U_i}-\frac{\∂Q_{Di}}{\∂U_i}+\frac{\∂Q_{Si}}{\∂U_i}\end{array}\right.---\left(3\right)$

Wherein, G _iirepresent the conductance of node i, B _iirepresent the susceptance of node i;

be expressed as:

$\{\begin{array}{c}\frac{\∂P_{Gi}}{\∂{\mathrm{\θ}}_i}=\frac{\∂(E_i^{\′\′}{U}_i{\mathrm{sin\θ}}_{\mathrm{\δ}i}/X_{di}^{\′\′})}{\∂{\mathrm{\θ}}_i}=-E_i^{\′\′}{U}_i{\mathrm{cos\θ}}_{\mathrm{\δ}i}/X_{di}^{\′\′}\\ \frac{\∂P_{Gi}}{\∂U_i}=\frac{\∂(E_i^{\′\′}{U}_i{\mathrm{sin\θ}}_{\mathrm{\δ}i}/X_{di}^{\′\′})}{\∂U_i}=E_i^{\′\′}{\mathrm{sin\θ}}_{\mathrm{\δ}i}/X_{di}^{\′\′}\\ \frac{\∂Q_{Gi}}{\∂{\mathrm{\θ}}_i}=\frac{\∂\left(\right(E_i^{\′\′}{U}_i{\mathrm{cos\θ}}_{\mathrm{\δ}i}-U_i^2)/X_{di}^{\′\′})}{\∂{\mathrm{\θ}}_i}=-E_i^{\′\′}{U}_i{\mathrm{sin\θ}}_{\mathrm{\δ}i}/X_{di}^{\′\′}\\ \frac{\∂Q_{Gi}}{\∂U_i}=\frac{\∂\left(\right(E_i^{\′\′}{U}_i{\mathrm{cos\θ}}_{\mathrm{\δ}i}-U_i^2)/X_{di}^{\′\′})}{\∂U_i}=(E_i^{\′\′}{\mathrm{cos\θ}}_{\mathrm{\δ}i}-2U_i)/X_{di}^{\′\′}\end{array}---\left(4\right)$

Wherein, E _i" represent generator electromotive force, θ _{δ i}represent E _i" and U _iphase angle difference, X " _direpresent that generator d axle surpasses transient state reactance; If node i is constant current load bus, be expressed as:

$\{\begin{array}{c}\frac{\∂P_{Li}}{\∂U_i}=\frac{\∂\left(U_i{I}_{Pi}\right)}{\∂U_i}=I_{Pi}\\ \frac{\∂Q_{Li}}{\∂U_i}=\frac{\∂\left(U_i{I}_{Qi}\right)}{\∂U_i}=I_{Qi}\end{array}---\left(5\right)$

Wherein, I _pi, I _qirepresent active current and the reactive current of constant current load bus respectively;

If node i is constant impedance load bus, be expressed as:

$\{\begin{array}{c}\frac{\∂P_{Li}}{\∂U_i}=\frac{\∂\left(U_i^2{G}_i\right)}{\∂U_i}=2U_i{G}_i\\ \frac{\∂Q_{Li}}{\∂U_i}=\frac{\∂\left(U_i^2{B}_i\right)}{\∂U_i}=2U_i{B}_i\end{array}---\left(6\right)$

Wherein, G _i, B _irepresent conductance and the susceptance of constant impedance load bus respectively;

If node i is DC line access node, be expressed as:

Wherein, I _drepresent direct current, n _trepresent six pulse conversion device series connection numbers, k _trepresent converter transformer no-load voltage ratio, k _γrepresent converter transformer equivalence no-load voltage ratio, θ _drepresent the direct current angle of overlap of rectification side or the extinguish angle of inverter side, X _crepresent equivalent commutating reactance; represent Equivalent Power Factor angle, and

If node i is dynamic reactive compensation device install node, be expressed as:

$\frac{\∂Q_{Si}}{\∂U_i}=\frac{\∂\left(U_i^2{B}_i\right)}{\∂U_i}=-{\mathrm{KU}}_i^2---\left(8\right)$

Wherein, B _irepresent that dynamic passive compensation installs the susceptance of node, and B _i=-K Δ U _i=-K (U _i-U _i0), Δ U _irepresent the voltage deviation installed before and after dynamic reactive compensation device, U _i0represent that dynamic reactive compensation device installs the initial voltage of node, K represents proportionality coefficient.

In described step 2, the drop point that p returns DC line is bus l, and the drop point that q returns DC line is bus k, determines many feed-ins short circuit ratio, have according to the voltage influence factor:

${\mathrm{MISCR}}_p^{\′}=\frac{S_l}{P_p+\underset{q=1,q\≠p}{\overset{m}{\Σ}}{\mathrm{MIF}}_{lk}{P}_q}=\frac{S_l}{P_p+\underset{q=1,q\≠p}{\overset{m}{\Σ}}\frac{{\mathrm{\ΔU}}_k}{{\mathrm{\ΔU}}_l}{P}_q}---\left(9\right)$

Wherein, MISCR ' _prepresent that p returns many feed-ins short circuit ratio of DC line, S _lrepresent the system short circuit capacity of bus l, P _prepresent that p returns the power of DC line, P _qrepresent that q returns the power of DC line, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k, m represents that in direct current many feed-ins electrical network, returning of DC line counts.

In described step 3, set up each website and dynamic reactive compensation device effect assessment target function be installed, have:

$\max f=\underset{p=1}{\overset{m}{\Σ}}{\widehat{\mathrm{\ω}}}_p{\mathrm{MISCR}}_p^{\′}---\left(10\right)$

Wherein, f represents that each website installs dynamic reactive compensation device effect assessment target function, represent that p returns the equivalent weight coefficient of DC line, have:

${\widehat{\mathrm{\ω}}}_p=\frac{{\mathrm{\ω}}_p}{\underset{q=1}{\overset{m}{\Σ}}{\mathrm{\ω}}_q}---\left(11\right)$

Wherein, ω _prepresent that p returns the weight coefficient of DC line, ω _qrepresent that q returns the weight coefficient of DC line, ω _p, ω _qreflect that p, q return the impact of DC line on other direct currents in direct current many feed-ins electrical network respectively, have:

${\mathrm{\ω}}_p=\underset{q\≠p}{\overset{m}{\underset{q=1}{\Σ}}}\frac{\left|Z_{pq}\right|P_p}{\left|Z_{qq}\right|P_q}---\left(12\right)$

${\mathrm{\ω}}_q=\underset{p\≠q}{\overset{m}{\underset{p=1}{\Σ}}}\frac{\left|Z_{pq}\right|P_q}{\left|Z_{pp}\right|P_p}---\left(13\right)$

Wherein, Z _pqrepresent that p returns DC line change of current bus and q and returns equiva lent impedance between DC line change of current bus, Z _pprepresent that p returns the equiva lent impedance of DC line change of current bus, Z _qqrepresent that q returns the equiva lent impedance of DC line change of current bus;

The constraints that each website installs dynamic reactive compensation device effect assessment target function additional corresponding is as follows:

$\{\begin{array}{c}{P}_l=U_l\underset{k=1}{\overset{n}{\Σ}}{U}_k(G_{lk}{\mathrm{cos\θ}}_{lk}+B_{lk}{\mathrm{sin\θ}}_{lk})\\ Q_l=U_l\underset{j=1}{\overset{n}{\Σ}}{U}_j(G_{lk}{\mathrm{sin\θ}}_{lk}-B_{lk}{\mathrm{cos\θ}}_{lk})\\ I_k\≤I_k^{\max }\\ S_r\≤S_r^{\max }\\ U_k^{\min }\≤U_k\≤U_k^{\max }\end{array}---\left(13\right)$

Wherein, P _l, Q _lrepresent active power and the reactive power of bus l respectively, U _l, U _krepresent the voltage of bus l, k respectively, with represent upper voltage limit and the lower limit of bus k respectively, G _lk, B _lkrepresent the conductance between bus l, k and susceptance respectively, θ _lkrepresent the phase difference of voltage between bus l, k, I _krepresent the short circuit current of bus k, represent the short circuit current upper limit of bus k, S _rrepresent the power of branch road r, represent the power upper limit of branch road r.

In described step 4, adopt the preferred dynamic reactive compensation device mounting points of genetic algorithm, comprising:

(1) arranging evolutionary generation t is 0, and arranges maximum evolutionary generation T and individual in population number M;

(2) in n node, select s node as dynamic reactive compensation device mounting points, then have the individual dynamic reactive compensation device reconnaissance strategy that may exist, and gene code is carried out to reactive power compensator reconnaissance strategy, gene code length L meets the value of each bit of gene code length is 0 or 1;

(3) stochastic generation M individuality is as initial population P ₀, each dynamic reactive compensation device reconnaissance strategy is as body one by one;

(4) calculate the fitness of each individuality, namely each website installs dynamic reactive compensation device effect assessment target function value;

(5) for each parent individuality distributes a random number, and according to corresponding random number, parent individuality is sorted according to order from big to small, adjacent two parent individualities are hybridized, certain bit in Stochastic choice gene order, 0 of bit or 1 exchange by two parent individualities, produce offspring individual, calculate the fitness of offspring individual, and offspring individual is joined in parent individuality composition parent colony;

(6) parent colony is screened, M individuality before retaining according to ideal adaptation degree size;

(7) certain individuality of Stochastic choice, and a bit in this genes of individuals sequence of Stochastic choice, overturn, obtain colony of future generation;

(8) if t=T, then the individuality in evolutionary process with maximum adaptation degree exports as optimal solution, namely completes the preferred of dynamic reactive compensation device mounting points; If t<T, then repeat (4) ~ (8).

Compared with immediate prior art, technical scheme provided by the invention has following beneficial effect:

1. the present invention utilizes many feed-ins short circuit ratio as the measurement index of idle input, carry out preferably for dynamic reactive compensation device mounting points in direct current many feed-ins electrical network, consider the reciprocal effect between multiple-circuit line circuit, the choosing of dynamic reactive compensation device mounting points for China's direct current many feed-ins area provides effective ways and technical support;

2. the present invention considers multi-infeed DC system performance and dynamic element model characteristics, the dynamic element models such as generator, load, direct current, dynamic reactive compensation device are brought in the measurement index of many feed-ins short circuit ratio, to consider in dynamic process each element responds characteristic to the impact of the stability of a system, reconnaissance method more gears to actual circumstances, and possesses engineer applied and is worth;

3. the present invention utilizes genetic algorithm to carry out dynamic reconnaissance optimization, and not based on time-domain-simulation, computational efficiency is high.

Accompanying drawing explanation

Fig. 1 is the dynamic passive compensation reconnaissance method flow diagram based on many feed-ins short circuit ratio in the embodiment of the present invention;

Fig. 2 is the geographical wiring schematic diagram of the year two thousand twenty East China direct current many feed-ins electrical network in the embodiment of the present invention 2.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

The invention provides a kind of dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio, as Fig. 1, said method comprising the steps of:

Step 1: set up Jacobian matrix and solve the voltage influence factor;

Step 2: determine many feed-ins short circuit ratio according to the voltage influence factor;

Step 3: set up each website and install dynamic reactive compensation device effect assessment target function and corresponding constraints;

Step 4: adopt the preferred dynamic reactive compensation device mounting points of genetic algorithm.

In described step 1, dynamic element model comprises generator model, load model, DC control model and dynamic reactive compensation device model.

Described step 1 comprises the following steps:

Step 1-1: consider dynamic element model, set up power balance equation;

Step 1-2: set up Jacobian matrix, and solve the voltage influence factor.

In described step 1-1, set up following power balance equation:

$\{\begin{array}{c}{\mathrm{\&Delta;P}}_i=P_{Gi}-P_{Li}\&PlusMinus;P_{Di}-U_i\underset{j\&Element;i}{\&Sigma;}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})\\ {\mathrm{\&Delta;Q}}_i=Q_{Gi}-Q_{Li}-Q_{Di}+Q_{Si}-U_i\underset{j\&Element;i}{\&Sigma;}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})\end{array}---\left(1\right)$

Wherein, Δ P _i, Δ Q _irepresent the active power variable quantity that node i is injected and reactive power variable quantity respectively, P _gi, Q _girepresent that generator injects node i meritorious and exerts oneself and idlely to exert oneself, P respectively _li, Q _lirepresent burden with power and the load or burden without work of node i respectively, P _direpresent the direct current power of node i, Q _direpresent that DC filter capacitor injects the reactive power of node i, U _i, U _jrepresent the voltage of node i, j respectively, Q _sirepresent that dynamic reactive compensation device injects the idle of node i and exerts oneself, G _ij, B _ijrepresent the conductance between node i, j and susceptance respectively, θ _ijrepresent the phase difference of voltage between node i, j, i=1,2 ..., n, j=1,2 ..., n, n are node total number.

In described step 1-2, set up following Jacobian matrix equation:

$\begin{array}{c}\left[\begin{array}{c}0\\ 0\\ .\\ .\\ .\\ 0\\ \&part;{\mathrm{\&Delta;Q}}_l/\&part;U_l\\ .\\ .\\ .\\ 0\\ 0\end{array}\right]=\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& \mathrm{...}& H_{1k}& N_{1k}& \mathrm{...}& H_{1n}& N_{1n}\\ M_{11}& L_{11}& \mathrm{...}& M_{1k}& L_{1k}& \mathrm{...}& M_{1n}& L_{1n}\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{l1}& N_{l1}& \mathrm{...}& H_{lk}& N_{lk}& \mathrm{...}& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& \mathrm{...}& M_{lk}& L_{lk}& \mathrm{...}& M_{\ln }& L_{\ln }\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{n1}& N_{n1}& \mathrm{...}& H_{nk}& N_{nk}& \mathrm{...}& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& \mathrm{...}& M_{nk}& L_{nk}& \mathrm{...}& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\&part;{\mathrm{\&theta;}}_1/\&part;U_k\\ \&part;U_1/\&part;U_k\\ .\\ .\\ .\\ \&part;{\mathrm{\&theta;}}_l/\&part;U_k\\ \&part;U_l/\&part;U_k\\ .\\ .\\ .\\ \&part;{\mathrm{\&theta;}}_n/\&part;U_k\\ \&part;U_n/\&part;U_k\end{array}\right]\\ =\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& \mathrm{...}& H_{1k}& N_{1k}& \mathrm{...}& H_{1n}& N_{1n}\\ M_{11}& L_{11}& \mathrm{...}& M_{1k}& L_{1k}& \mathrm{...}& M_{1n}& L_{1n}\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{l1}& N_{l1}& \mathrm{...}& H_{lk}& N_{lk}& \mathrm{...}& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& \mathrm{...}& M_{lk}& L_{lk}& \mathrm{...}& M_{\ln }& L_{\ln }\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ .& .& .& .& .& .& .& .\\ H_{n1}& N_{n1}& \mathrm{...}& H_{nk}& N_{nk}& \mathrm{...}& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& \mathrm{...}& M_{nk}& L_{nk}& \mathrm{...}& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\&part;{\mathrm{\&theta;}}_1/\&part;U_k\\ {\mathrm{MIIF}}_{1k}\\ .\\ .\\ .\\ \&part;{\mathrm{\&theta;}}_l/\&part;U_k\\ {\mathrm{MIIF}}_{lk}\\ .\\ .\\ .\\ \&part;{\mathrm{\&theta;}}_n/\&part;U_k\\ {\mathrm{MIIF}}_{nk}\end{array}\right]\end{array}---\left(2\right)$

Wherein, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k;

Jacobian matrix element H _ii, N _ii, M _ii, L _iicalculate according to the following formula:

$\left\{\begin{array}{c}{H}_{ii}=\frac{\&part;{\mathrm{\&Delta;P}}_i}{\&part;{\mathrm{\&theta;}}_i}=U_i\underset{j\&NotEqual;i}{\underset{j\&Element;i}{\&Sigma;}}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})+\frac{\&part;P_{Gi}}{\&part;{\mathrm{\&theta;}}_i}\\ N_{ii}=\frac{\&part;{\mathrm{\&Delta;P}}_i}{\&part;U_i}=-\underset{j\&NotEqual;i}{\underset{j\&Element;i}{\&Sigma;}}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})-2U_i{G}_{ii}+\frac{\&part;P_{Gi}}{\&part;U_i}-\frac{\&part;P_{Li}}{\&part;U_i}\&PlusMinus;\frac{\&part;P_{Di}}{\&part;U_i}\\ M_{ii}=\frac{\&part;{\mathrm{\&Delta;Q}}_i}{\&part;{\mathrm{\&theta;}}_j}=-U_i\underset{j\&NotEqual;i}{\underset{j\&Element;i}{\&Sigma;}}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})+\frac{\&part;Q_{Gi}}{\&part;{\mathrm{\&theta;}}_i}\\ L_{ii}=\frac{\&part;{\mathrm{\&Delta;Q}}_i}{\&part;U_j}=-\underset{j\&NotEqual;i}{\underset{j\&Element;i}{\&Sigma;}}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})+2U_i{B}_{ii}+\frac{\&part;Q_{Gi}}{\&part;U_i}-\frac{\&part;Q_{Li}}{\&part;U_i}-\frac{\&part;Q_{Di}}{\&part;U_i}+\frac{\&part;Q_{Si}}{\&part;U_i}\end{array}\right.---\left(3\right)$

Wherein, G _iirepresent the conductance of node i, B _iirepresent the susceptance of node i;

be expressed as:

$\{\begin{array}{c}\frac{\&part;P_{Gi}}{\&part;{\mathrm{\&theta;}}_i}=\frac{\&part;(E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;})}{\&part;{\mathrm{\&theta;}}_i}=-E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;P_{Gi}}{\&part;U_i}=\frac{\&part;(E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;})}{\&part;U_i}=E_i^{\&prime;\&prime;}{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;Q_{Gi}}{\&part;{\mathrm{\&theta;}}_i}=\frac{\&part;\left(\right(E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}-U_i^2)/X_{di}^{\&prime;\&prime;})}{\&part;{\mathrm{\&theta;}}_i}=-E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;Q_{Gi}}{\&part;U_i}=\frac{\&part;\left(\right(E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}-U_i^2)/X_{di}^{\&prime;\&prime;})}{\&part;U_i}=(E_i^{\&prime;\&prime;}{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}-2U_i)/X_{di}^{\&prime;\&prime;}\end{array}---\left(4\right)$

Wherein, E _i" represent generator electromotive force, θ _{δ i}represent E _i" and U _iphase angle difference, X " _direpresent that generator d axle surpasses transient state reactance;

If node i is constant current load bus, be expressed as:

$\{\begin{array}{c}\frac{\&part;P_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i{I}_{Pi}\right)}{\&part;U_i}=I_{Pi}\\ \frac{\&part;Q_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i{I}_{Qi}\right)}{\&part;U_i}=I_{Qi}\end{array}---\left(5\right)$

Wherein, I _pi, I _qirepresent active current and the reactive current of constant current load bus respectively;

If node i is constant impedance load bus, be expressed as:

$\{\begin{array}{c}\frac{\&part;P_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i^2{G}_i\right)}{\&part;U_i}=2U_i{G}_i\\ \frac{\&part;Q_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i^2{B}_i\right)}{\&part;U_i}=2U_i{B}_i\end{array}---\left(6\right)$

Wherein, G _i, B _irepresent conductance and the susceptance of constant impedance load bus respectively;

If node i is DC line power node, be expressed as:

Wherein, I _drepresent direct current, n _trepresent six pulse conversion device series connection numbers, k _trepresent converter transformer no-load voltage ratio, k _γrepresent converter transformer equivalence no-load voltage ratio, θ _drepresent the direct current angle of overlap of rectification side or the extinguish angle of inverter side, X _crepresent equivalent commutating reactance; represent Equivalent Power Factor angle, and

If node i is dynamic reactive compensation device install node, be expressed as:

$\frac{\&part;Q_{Si}}{\&part;U_i}=\frac{\&part;\left(U_i^2{B}_i\right)}{\&part;U_i}=-{\mathrm{KU}}_i^2---\left(8\right)$

Wherein, B _irepresent that dynamic passive compensation installs the susceptance of node, and B _i=-K Δ U _i=-K (U _i-U _i0), Δ U _irepresent the voltage deviation installed before and after dynamic reactive compensation device, U _i0represent that dynamic reactive compensation device installs the initial voltage of node, K represents proportionality coefficient.

In described step 2, the drop point that p returns DC line is bus l, and the drop point that q returns DC line is bus k, determines many feed-ins short circuit ratio, have according to the voltage influence factor:

${\mathrm{MISCR}}_p^{\&prime;}=\frac{S_l}{P_p+\underset{q=1,q\&NotEqual;p}{\overset{m}{\&Sigma;}}{\mathrm{MIF}}_{lk}{P}_q}=\frac{S_l}{P_p+\underset{q=1,q\&NotEqual;p}{\overset{m}{\&Sigma;}}\frac{{\mathrm{\&Delta;U}}_k}{{\mathrm{\&Delta;U}}_l}{P}_q}---\left(9\right)$

Wherein, MISCR ' _prepresent that p returns many feed-ins short circuit ratio of DC line, S _lrepresent the system short circuit capacity of bus l, P _prepresent that p returns the power of DC line, P _qrepresent that q returns the power of DC line, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k, m represents that in direct current many feed-ins electrical network, returning of DC line counts.

In described step 3, set up each website and dynamic reactive compensation device effect assessment target function be installed, have:

$\max f=\underset{p=1}{\overset{m}{\&Sigma;}}{\widehat{\mathrm{\&omega;}}}_p{\mathrm{MISCR}}_p^{\&prime;}---\left(10\right)$

Wherein, f represents that each website installs dynamic reactive compensation device effect assessment target function, represent that p returns the equivalent weight coefficient of DC line, have:

${\widehat{\mathrm{\&omega;}}}_p=\frac{{\mathrm{\&omega;}}_p}{\underset{q=1}{\overset{m}{\&Sigma;}}{\mathrm{\&omega;}}_q}---\left(11\right)$

Wherein, ω _prepresent that p returns the weight coefficient of DC line, ω _qrepresent that q returns the weight coefficient of DC line, ω _p, ω _qreflect that p, q return the impact of DC line on other direct currents in direct current many feed-ins electrical network respectively, have:

${\mathrm{\&omega;}}_p=\underset{q\&NotEqual;p}{\overset{m}{\underset{q=1}{\&Sigma;}}}\frac{\left|Z_{pq}\right|P_p}{\left|Z_{qq}\right|P_q}---\left(12\right)$

${\mathrm{\&omega;}}_q=\underset{p\&NotEqual;q}{\overset{m}{\underset{p=1}{\&Sigma;}}}\frac{\left|Z_{pq}\right|P_q}{\left|Z_{pp}\right|P_p}---\left(13\right)$

Wherein, Z _pqrepresent that p returns DC line change of current bus and q and returns equiva lent impedance between DC line change of current bus, Z _pprepresent that p returns the equiva lent impedance of DC line change of current bus, Z _qqrepresent that q returns the equiva lent impedance of DC line change of current bus;

The constraints that each website installs dynamic reactive compensation device effect assessment target function additional corresponding is as follows:

$\{\begin{array}{c}{P}_l=U_l\underset{k=1}{\overset{n}{\&Sigma;}}{U}_k(G_{lk}{\mathrm{cos\&theta;}}_{lk}+B_{lk}{\mathrm{sin\&theta;}}_{lk})\\ Q_l=U_l\underset{j=1}{\overset{n}{\&Sigma;}}{U}_j(G_{lk}{\mathrm{sin\&theta;}}_{lk}-B_{lk}{\mathrm{cos\&theta;}}_{lk})\\ I_k\&le;I_k^{\max }\\ S_r\&le;S_r^{\max }\\ U_k^{\min }\&le;U_k\&le;U_k^{\max }\end{array}---\left(13\right)$

Wherein, P _l, Q _lrepresent active power and the reactive power of bus l respectively, U _l, U _krepresent the voltage of bus l, k respectively, with represent upper voltage limit and the lower limit of bus k respectively, G _lk, B _lkrepresent the conductance between bus l, k and susceptance respectively, θ _lkrepresent the phase difference of voltage between bus l, k, I _krepresent the short circuit current of bus k, represent the short circuit current upper limit of bus k, S _rrepresent the power of branch road r, represent the power upper limit of branch road r.

In described step 4, adopt the preferred dynamic reactive compensation device mounting points of genetic algorithm, comprising:

(1) arranging evolutionary generation t is 0, and arranges maximum evolutionary generation T and individual in population number M;

(2) in n node, select s node as dynamic reactive compensation device mounting points, then have the individual dynamic reactive compensation device reconnaissance strategy that may exist, and gene code is carried out to reactive power compensator reconnaissance strategy, gene code length L meets the value of each bit of gene code length is 0 or 1;

(3) stochastic generation M individuality is as initial population P ₀, each dynamic reactive compensation device reconnaissance strategy is as body one by one;

(4) calculate the fitness of each individuality, namely each website installs dynamic reactive compensation device effect assessment target function value;

(5) for each parent individuality distributes a random number, and according to corresponding random number, parent individuality is sorted according to order from big to small, adjacent two parent individualities are hybridized, certain bit in Stochastic choice gene order, 0 of bit or 1 exchange by two parent individualities, produce offspring individual, calculate the fitness of offspring individual, and offspring individual is joined in parent individuality composition parent colony;

(6) parent colony is screened, M individuality before retaining according to ideal adaptation degree size;

(7) certain individuality of Stochastic choice, and a bit in this genes of individuals sequence of Stochastic choice, overturn, obtain colony of future generation;

(8) if t=T, then the individuality in evolutionary process with maximum adaptation degree exports as optimal solution, namely completes the preferred of dynamic reactive compensation device mounting points; If t<T, then repeat (4) ~ (8).

Embodiment 1

Reconnaissance method provided by the invention is applied to present East China Power Grid, carries out many feed-ins short circuit ratio and calculate.If be MISCR with traditional reconnaissance method acquired results _p, reconnaissance method acquired results provided by the invention is MISCR _p'.East China Power Grid feed-in direct current 9 times, shown in East China Power Grid direct current many feed-ins short circuit ratio result of calculations 1 in 2016:

Table 1

In table 1, MISCR' does not consider hvdc control mode, and load model is " 40% constant impedance+60% firm power ".

Result as can be seen from table, two class methods result of calculations have different, but substantially do not change according to the sequence of many feed-ins short circuit ratio size.

To same 9 times direct currents, the many feed-ins short circuit ratio calculated under different DC control strategy calculates, and under the different control strategies of East China Power Grid direct current in 2016, many feed-ins short circuit ratio result of calculation is as table 2:

Table 2

Table 2 result of calculation shows: under most cases, bigger when the many feed-ins short circuit ratio ratio under Given current controller mode ignores DC control; Constant dc power control mode many feed-ins short circuit ratio is little.This be due to, the reason that constant dc power control mode makes reactive voltage support situation variation is: when on inverter side change of current bus, voltage drop is low, converter makes extinguish angle remain unchanged by regulating Trigger Angle, and inverter side direct voltage reduces, thus causes direct current to raise; Due to the impact of commutating reactance, inverter side direct voltage reduces further, causes inverter side converter power factor to reduce, and reactive requirement raises.For rectification side, because direct current raises, in order to keep power invariability, must direct voltage be reduced, thus also make reactive requirement raise.

Illustrated by above-mentioned result of calculation, the many feed-ins short circuit ratio result of calculation adopting the inventive method to derive and former short circuit ratio result of calculation are consistent sexual intercourse, reflect, the model of all kinds of dynamic element is different, will produce certain influence to the result of calculation of index and stability thereof simultaneously.

Embodiment 2

Reconnaissance method provided by the invention is applied to the year two thousand twenty Jiangsu planning electrical network, as shown in Figure 2, total political affairs are put down, with inner, Liyang, Taizhou, Nanjing, Changshu, 7, Changzhou direct current drop point, are formed typical multi-infeed DC electrical network, the powered ratio 40% of Jiangsu Power Grid.Because feed-in direct current scale is excessive, when not installing dynamic reactive compensation device, Jiangsu has the 14 Flow Line generation three-phase permanent short faults that backcross to cause Voltage Instability.

Choose 25, southern area of Jiangsu Province 500kV transformer station as alternative point, as shown in table 3, select 5 websites that the SVC of 2 × 240Mvar capacity is installed by optimizer;

Table 3

Set different evolutionary generation T, colony individual amount M, and be optimized calculating, southern Jiangsu dynamic passive compensation reconnaissance scenario outcomes is as shown in table 4, from result of calculation, adopt different evolutionary generations and individual amount on result of calculation impact not quite, result of calculation substantially can be stabilized in one and compare the scheme determined.Work as T=30, during M=30, its result and all the other schemes slightly difference, but from target function value, both differences are very little.

Table 4

From result in table, adopt genetic algorithm to solve the problem, good convergence can be reached.Carry out analysis safety and stability to above-mentioned two different reactive power compensation allocation plans to check, result shows, and under two class schemes, N-1 causes the circuit of system unstability to be 7 times, to the lifting successful of the stability of a system.

As can be seen here, the dynamic reactive compensation device optimization reconnaissance method computational efficiency in the direct current many feed-ins area carried herein is high, and effect of optimization is good, has very strong engineer applied and is worth.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; those of ordinary skill in the field still can modify to the specific embodiment of the present invention with reference to above-described embodiment or equivalent replacement; these do not depart from any amendment of spirit and scope of the invention or equivalent replacement, are all applying within the claims of the present invention awaited the reply.

Claims (8)

1., based on a dynamic passive compensation reconnaissance method for many feed-ins short circuit ratio, it is characterized in that: said method comprising the steps of:

Step 1: set up Jacobian matrix and solve the voltage influence factor;

Step 2: determine many feed-ins short circuit ratio according to the voltage influence factor;

Step 3: set up each website and install dynamic reactive compensation device effect assessment target function and corresponding constraints;

Step 4: adopt the preferred dynamic reactive compensation device mounting points of genetic algorithm.

2. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 1, is characterized in that: described step 1 comprises the following steps:

Step 1-1: consider dynamic element model, set up power balance equation;

Step 1-2: set up Jacobian matrix, and solve the voltage influence factor.

3. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 2, it is characterized in that: in described step 1-1, dynamic element model comprises generator model, load model, DC control model and dynamic reactive compensation device model.

4. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 2, is characterized in that: in described step 1-1, sets up following power balance equation:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_i=P_{Gi}-P_{Li}\&PlusMinus;P_{Di}-U_i\underset{j\&Element;i}{\&Sigma;}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})\\ {\mathrm{\&Delta;Q}}_i=Q_{Gi}-Q_{Li}-Q_{Di}+Q_{Si}-U_i\underset{j\&Element;i}{\&Sigma;}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})\end{array}\right.---\left(1\right)$

Wherein, Δ P _i, Δ Q _irepresent the active power variable quantity that node i is injected and reactive power variable quantity respectively, P _gi, Q _girepresent that generator injects node i meritorious and exerts oneself and idlely to exert oneself, P respectively _li, Q _lirepresent burden with power and the load or burden without work of node i respectively, P _direpresent the direct current power of node i, Q _direpresent that DC filter capacitor injects the reactive power of node i, U _i, U _jrepresent the voltage of node i, j respectively, Q _sirepresent that dynamic reactive compensation device injects the idle of node i and exerts oneself, G _ij, B _ijrepresent the conductance between node i, j and susceptance respectively, θ _ijrepresent the phase difference of voltage between node i, j, i=1,2 ..., n, j=1,2 ..., n, n are node total number.

5. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 4, is characterized in that: in described step 1-2, sets up following Jacobian matrix equation:

$\begin{array}{c}\left[\begin{array}{c}0\\ 0\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ 0\\ \&part;{\mathrm{\&Delta;Q}}_l/\&part;U_l\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ 0\\ 0\end{array}\right]=\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& ...& H_{1k}& N_{1k}& ...& H_{1n}& N_{1n}\\ M_{11}& L_{11}& ...& M_{1k}& L_{1k}& ...& M_{1n}& L_{1n}\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ H_{l1}& N_{l1}& ...& H_{lk}& N_{lk}& ...& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& ...& M_{lk}& L_{lk}& ...& M_{\ln }& L_{\ln }\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ H_{n1}& N_{n1}& ...& H_{nk}& N_{nk}& ...& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& ...& M_{nk}& L_{nk}& ...& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\&part;{\mathrm{\&theta;}}_1/\&part;U_k\\ \&part;U_1/\&part;U_k\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ \&part;{\mathrm{\&theta;}}_l/\&part;U_k\\ \&part;U_l/\&part;U_k\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ \&part;{\mathrm{\&theta;}}_n/\&part;U_k\\ \&part;U_n/\&part;U_k\end{array}\right]\\ =\left[\begin{array}{cccccccc}{H}_{11}& N_{11}& ...& H_{1k}& N_{1k}& ...& H_{1n}& N_{1n}\\ M_{11}& L_{11}& ...& M_{1k}& L_{1k}& ...& M_{1n}& L_{1n}\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ H_{l1}& N_{l1}& ...& H_{lk}& N_{lk}& ...& H_{\ln }& N_{\ln }\\ M_{l1}& L_{l1}& ...& M_{lk}& L_{lk}& ...& M_{\ln }& L_{\ln }\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;& \&CenterDot;\\ H_{n1}& N_{n1}& ...& H_{nk}& N_{nk}& ...& H_{nn}& N_{nn}\\ M_{n1}& L_{n1}& ...& M_{nk}& L_{nk}& ...& M_{nn}& L_{nn}\end{array}\right]\left[\begin{array}{c}\&part;{\mathrm{\&theta;}}_1/\&part;U_k\\ \&part;U_1/\&part;U_k\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ \&part;{\mathrm{\&theta;}}_l/\&part;U_k\\ {\mathrm{MIIF}}_{lk}\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ \&part;{\mathrm{\&theta;}}_n/\&part;U_k\\ {\mathrm{MIIF}}_{nk}\end{array}\right]\end{array}---\left(2\right)$

Wherein, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k;

Jacobian matrix element H _ii, N _ii, M _ii, L _iicalculate according to the following formula:

$\{\begin{array}{c}{H}_{ii}=\frac{\&part;{\mathrm{\&Delta;P}}_i}{\&part;{\mathrm{\&theta;}}_i}=U_i\underset{\underset{j\&NotEqual;i}{j\&Element;i}}{\mathrm{\&Sigma;}}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})+\frac{\&part;P_{Gi}}{\&part;{\mathrm{\&theta;}}_i}\\ N_{ii}=\frac{\&part;{\mathrm{\&Delta;P}}_i}{\&part;U_i}=-\underset{\underset{j\&NotEqual;i}{j\&Element;i}}{\mathrm{\&Sigma;}}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})-2U_i{G}_{ii}\frac{\&part;P_{Gi}}{\&part;U_i}+\frac{\&part;P_{Li}}{\&part;U_i}\&PlusMinus;\frac{\&part;P_{Di}}{\&part;U_i}\\ M_{ii}=\frac{\&part;{\mathrm{\&Delta;Q}}_i}{\&part;{\mathrm{\&theta;}}_j}=-U_i\underset{\underset{j\&NotEqual;i}{j\&Element;i}}{\mathrm{\&Sigma;}}{U}_j(G_{ij}{\mathrm{cos\&theta;}}_{ij}+B_{ij}{\mathrm{sin\&theta;}}_{ij})+\frac{\&part;Q_{Gi}}{\&part;{\mathrm{\&theta;}}_i}\\ L_{ii}=\frac{\&part;{\mathrm{\&Delta;Q}}_i}{\&part;U_i}=-\underset{\underset{j\&NotEqual;i}{j\&Element;i}}{\mathrm{\&Sigma;}}{U}_j(G_{ij}{\mathrm{sin\&theta;}}_{ij}-B_{ij}{\mathrm{cos\&theta;}}_{ij})+2U_i{B}_{ii}\frac{\&part;Q_{Gi}}{\&part;U_i}+\frac{\&part;Q_{Li}}{\&part;U_i}-\frac{\&part;Q_{Di}}{\&part;U_i}+\frac{\&part;Q_{Si}}{\&part;U_i}\end{array}---\left(3\right)$

Wherein, G _iirepresent the conductance of node i, B _iirepresent the susceptance of node i;

be expressed as:

$\left\{\begin{array}{c}\frac{\&part;P_{Gi}}{\&part;{\mathrm{\&theta;}}_i}=\frac{\&part;(E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;})}{\&part;{\mathrm{\&theta;}}_i}=-E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;P_{Gi}}{\&part;U_i}=\frac{\&part;(E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;})}{\&part;U_i}=E_i^{\&prime;\&prime;}{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;Q_{Gi}}{\&part;{\mathrm{\&theta;}}_i}=\frac{\&part;\left(\right(E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}/U_i^2)X_{di}^{\&prime;\&prime;})}{\&part;{\mathrm{\&theta;}}_i}=-E_i^{\&prime;\&prime;}{U}_i{\mathrm{sin\&theta;}}_{\mathrm{\&delta;}i}/X_{di}^{\&prime;\&prime;}\\ \frac{\&part;Q_{Gi}}{\&part;U_i}=\frac{\&part;\left(\right(E_i^{\&prime;\&prime;}{U}_i{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}/U_i^2)X_{di}^{\&prime;\&prime;})}{\&part;U_i}=(E_i^{\&prime;\&prime;}{\mathrm{cos\&theta;}}_{\mathrm{\&delta;}i}-2U_i)/X_{di}^{\&prime;\&prime;}\end{array}\right.---\left(4\right)$

Wherein, E " _irepresent generator electromotive force, θ _{δ i}represent E " _iwith U _iphase angle difference, X " _direpresent that generator d axle surpasses transient state reactance;

If node i is constant current load bus, be expressed as:

$\left\{\begin{array}{c}\frac{\&part;Q_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i{I}_{Pi}\right)}{\&part;U_i}=I_{Pi}\\ \frac{\&part;Q_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i{I}_{Qi}\right)}{\&part;U_i}=I_{Qi}\end{array}\right.---\left(5\right)$

Wherein, I _pi, I _qirepresent active current and the reactive current of constant current load bus respectively;

If node i is constant impedance load bus, be expressed as:

$\left\{\begin{array}{c}\frac{\&part;P_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i^2{G}_i\right)}{\&part;U_i}=2U_i{G}_i\\ \frac{\&part;Q_{Li}}{\&part;U_i}=\frac{\&part;\left(U_i^2{B}_i\right)}{\&part;U_i}=2U_i{B}_i\end{array}\right.---\left(6\right)$

Wherein, G _i, B _irepresent conductance and the susceptance of constant impedance load bus respectively;

If node i is DC line access node, be expressed as:

Wherein, I _drepresent direct current, n _trepresent six pulse conversion device series connection numbers, k _trepresent converter transformer no-load voltage ratio, k _γrepresent converter transformer equivalence no-load voltage ratio, θ _drepresent the direct current angle of overlap of rectification side or the extinguish angle of inverter side, X _crepresent equivalent commutating reactance; represent Equivalent Power Factor angle, and

If node i is dynamic reactive compensation device install node, be expressed as:

$\frac{\&part;Q_{Si}}{\&part;U_i}=\frac{\&part;\left(U_i^2{B}_i\right)}{\&part;U_i}=-{\mathrm{KU}}_i^2---\left(8\right)$

Wherein, B _irepresent that dynamic passive compensation installs the susceptance of node, and B _i=-K Δ U _i=-K (U _i-U _i0), Δ U _irepresent the voltage deviation installed before and after dynamic reactive compensation device, U _i0represent that dynamic reactive compensation device installs the initial voltage of node, K represents proportionality coefficient.

6. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 5, it is characterized in that: in described step 2, the drop point that p returns DC line is bus l, and the drop point that q returns DC line is bus k, determine many feed-ins short circuit ratio according to the voltage influence factor, have:

${\mathrm{MISCR}}_p^{\&prime;}=\frac{S_l}{P_p+\underset{q=1,q\&NotEqual;p}{\overset{m}{\&Sigma;}}{\mathrm{MIIF}}_{lk}{P}_q}=\frac{S_l}{P_p+\underset{q=1,q\&NotEqual;p}{\overset{m}{\&Sigma;}}\frac{{\mathrm{\&Delta;U}}_k}{{\mathrm{\&Delta;U}}_l}{P}_q}---\left(9\right)$

Wherein, MISCR ' _prepresent that p returns many feed-ins short circuit ratio of DC line, S _lrepresent the system short circuit capacity of bus l, P _prepresent that p returns the power of DC line, P _qrepresent that q returns the power of DC line, MIIF _lkrepresent the voltage influence factor of bus l opposing busbars k, and MIIF _lk=Δ U _l/ Δ U _k, Δ U _lrepresent the voltage variety of bus l, Δ U _krepresent the voltage variety of bus k, m represents that in direct current many feed-ins electrical network, returning of DC line counts.

7. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 6, is characterized in that: in described step 3, sets up each website and installs dynamic reactive compensation device effect assessment target function, have:

$\max f=\underset{p=1}{\overset{m}{\&Sigma;}}{\widehat{\mathrm{\&omega;}}}_p{\mathrm{MISCR}}_p^{\&prime;}---\left(10\right)$

Wherein, f represents that each website installs dynamic reactive compensation device effect assessment target function, represent that p returns the equivalent weight coefficient of DC line, have:

${\widehat{\mathrm{\&omega;}}}_p=\frac{{\mathrm{\&omega;}}_p}{\underset{q=1}{\overset{m}{\&Sigma;}}{\mathrm{\&omega;}}_q}---\left(11\right)$

Wherein, ω _prepresent that p returns the weight coefficient of DC line, ω _qrepresent that q returns the weight coefficient of DC line, ω _p, ω _qreflect that p, q return the impact of DC line on other direct currents in direct current many feed-ins electrical network respectively, have:

${\mathrm{\&omega;}}_p=\underset{\underset{q\&NotEqual;p}{q=1}}{\overset{m}{\&Sigma;}}\frac{\left|Z_{pq}\right|P_p}{\left|Z_{qq}\right|P_q}---\left(12\right)$

${\mathrm{\&omega;}}_q=\underset{\underset{p\&NotEqual;q}{p=1}}{\overset{m}{\&Sigma;}}\frac{\left|Z_{pq}\right|P_q}{\left|Z_{pp}\right|P_p}---\left(13\right)$

Wherein, Z _pqrepresent that p returns DC line change of current bus and q and returns equiva lent impedance between DC line change of current bus, Z _pprepresent that p returns the equiva lent impedance of DC line change of current bus, Z _qqrepresent that q returns the equiva lent impedance of DC line change of current bus;

The constraints that each website installs dynamic reactive compensation device effect assessment target function additional corresponding is as follows:

$\left\{\begin{array}{c}{P}_l=U_l\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{U}_k(G_{lk}{\mathrm{cos\&theta;}}_{lk}+B_{lk}{\mathrm{sin\&theta;}}_{lk})\\ Q_l=U_l\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{U}_J(G_{lk}{\mathrm{sin\&theta;}}_{lk}-B_{lk}{\mathrm{cos\&theta;}}_{lk})\\ I_K\&le;I_k^{\max }\\ S_r\&le;S_r^{\max }\\ U_k^{\max }\&le;U_k\&le;U_k^{\max }\end{array}\right.---\left(13\right)$

Wherein, P _l, Q _lrepresent active power and the reactive power of bus l respectively, U _l, U _krepresent the voltage of bus l, k respectively, with represent upper voltage limit and the lower limit of bus k respectively, G _lk, B _lkrepresent the conductance between bus l, k and susceptance respectively, θ _lkrepresent the phase difference of voltage between bus l, k, I _krepresent the short circuit current of bus k, represent the short circuit current upper limit of bus k, S _rrepresent the power of branch road r, represent the power upper limit of branch road r.

8. the dynamic passive compensation reconnaissance method based on many feed-ins short circuit ratio according to claim 1, is characterized in that: in described step 4, adopts the preferred dynamic reactive compensation device mounting points of genetic algorithm, comprising:

(1) arranging evolutionary generation t is 0, and arranges maximum evolutionary generation T and individual in population number M;

(2) in n node, select s node as dynamic reactive compensation device mounting points, then have the individual dynamic reactive compensation device reconnaissance strategy that may exist, and gene code is carried out to reactive power compensator reconnaissance strategy, gene code length L meets the value of each bit of gene code length is 0 or 1;

(3) stochastic generation M individuality is as initial population P ₀, each dynamic reactive compensation device reconnaissance strategy is as body one by one;

(4) calculate the fitness of each individuality, namely each website installs dynamic reactive compensation device effect assessment target function value;

(5) for each parent individuality distributes a random number, and according to corresponding random number, parent individuality is sorted according to order from big to small, adjacent two parent individualities are hybridized, certain bit in Stochastic choice gene order, 0 of bit or 1 exchange by two parent individualities, produce offspring individual, calculate the fitness of offspring individual, and offspring individual is joined in parent individuality composition parent colony;

(6) parent colony is screened, M individuality before retaining according to ideal adaptation degree size;

(7) certain individuality of Stochastic choice, and a bit in this genes of individuals sequence of Stochastic choice, overturn, obtain colony of future generation;

(8) if t=T, then the individuality in evolutionary process with maximum adaptation degree exports as optimal solution, namely completes the preferred of dynamic reactive compensation device mounting points; If t<T, then repeat (4) ~ (8).