CN104037805B - A kind of photovoltaic plant taking into account power system security constraints can power generation margin distribution method - Google Patents

Abstract

The present invention relates to a kind of photovoltaic plant taking into account power system security constraints can power generation margin distribution method, belongs to the operation and control technical field of new forms of energy access electric power system.This method is according to equity dispatching principle, after photovoltaic plant freedom of entry hair-like state, the space of photovoltaic generation is received by electrical network to be evenly distributed to each photovoltaic plant according to the method that load factor deviation is minimum, avoid on the one hand because photovoltaic plant set point of gaining merit is too small and produce unnecessary light of abandoning, avoid causing meritorious set point excessive owing to issuing photovoltaic plant capacity on the other hand, photovoltaic plant is exerted oneself and exceedes electrical network ability to bear.This method is integrated in the photovoltaic generation real power control main station system run control centre, make this system in real time according to photovoltaic generation running status and operation of power networks state, implement optimum control strategy, ensure that electrical network has enough backspins for safe space, and the active power safety of photovoltaic plant and electrical network connection line section, and take into account the equity dispatching between each photovoltaic plant.

Description

A kind of photovoltaic plant taking into account power system security constraints can power generation margin distribution method

Technical field

The present invention relates to a kind of photovoltaic plant taking into account power system security constraints can power generation margin distribution method, belongs to the operation and control technical field of new forms of energy access electric power system.

Background technology

The feature such as strong randomness, prediction difficulty, anti-peak regulation of light resources makes electric network active scheduling controlling further difficult.How under the prerequisite ensureing power grid security, at utmost utilize photovoltaic generation resource, photovoltaic generation of dissolving as much as possible has become one of common challenge that each place, photovoltaic generation base electrical network at present faces.At present, industry has carried out large quantity research to the active power scheduling controlling after photovoltaic generation access, and obtains a series of investigation and application achievement.Actual field operating experience shows, the quick photovoltaic power generation dispatching introducing minute level in active power scheduling controlling system controls in real time, and to guarantee power grid security, minimizing is abandoned light loss and can be played remarkable effect.

At present, engineering site mainly adopts heuristic Artificial Control method to control photovoltaic plant active power, namely when electrical network exists safety problem, when needing to reduce photovoltaic plant active power, operations staff relies on operating experience directly to excise 1 or multiple photovoltaic plant or will abandon light quantity to be evenly distributed to each photovoltaic plant, when electrical network has photoelectricity receiving space, each photovoltaic plant freedom of entry hair-like state, does not go to limit exerting oneself of photovoltaic generation.This method subject matter is: (1) depends on the experience of operations staff, is difficult to the fairness ensureing scheduling; (2) when power grid security is not limited, when there is photovoltaic generation receiving space, Artificial Control mode cannot recover photovoltaic plant active power in time, and causes unnecessary light of abandoning; (3) in a free state, if the flash-up of photovoltaic plant is very fast, simultaneously during electrical network receiving limited space, electrical network is easily caused to occur safety problem.

Summary of the invention

The object of the invention is to propose a kind of photovoltaic plant taking into account power system security constraints can power generation margin distribution method, overcome the deficiencies in the prior art part, to adapt to rapid fluctuations and power grid security, the minimum multiple control demand of abandoning light and equity dispatching of current photovoltaic generation.

The photovoltaic plant taking into account power system security constraints that the present invention proposes can power generation margin distribution method, comprises the following steps:

(1) gather from the data acquisition of electrical network and supervisor control that the real-time backspin of current electric grid automatic-generation-control unit is standby, connection line active power deviation between photovoltaic plant and electrical network, obtain the admissible photovoltaic plant active power of electrical network from grid dispatching center from the real-time active power p of each photovoltaic plant that the data acquisition of electrical network is connected with electrical network with supervisor control collection ^wand the real-time active power p of connection line section between each photovoltaic plant and electrical network ^s, obtain active power lower limit from grid dispatching center p ^w, estimate maximum active power with the active power upper limit ;

(2) if above-mentioned photovoltaic plant active power the regulated quantity that freely generates electricity of each photovoltaic plant then will be connected with electrical network be set to 0, and carry out step (6);

(3) the active power sensitivity S of each photovoltaic plant to connection line section between photovoltaic plant and electrical network is obtained from grid dispatching center ^sW;

(4) setting up the photovoltaic plant taking into account power system security constraints can the target function of power generation margin distribution method, as follows:

$\underset{\mathrm{\Δ}{p}_i^{w,f}}{\min }(W^p\·(\mathrm{\Δ}{p}_{\mathrm{wind}}^{\mathrm{cap}}-\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}\mathrm{\Δ}{p}_i^{w,f})+W^r\·\underset{i{\mathrm{\Ω}}^w}{\mathrm{\Σ}}{\left({r_i}^w\right)}^2)$

Wherein: Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity that freely generates electricity of i-th photovoltaic plant, be the load deviation rate of i-th photovoltaic plant, W ^p, W ^rbe respectively weight coefficient, W ^pvalue is 10.0, W ^rvalue is 0.01;

(5) setting take into account the photovoltaic plant of power system security constraints can the constraints of power generation margin distribution method, comprising:

(5-1) the real-time active power of i-th photovoltaic plant active power lower limit freely generate electricity regulated quantity with photovoltaic plant capacity p ^w,mbetween meet following relational expression:

${\underset{\‾}{p}}_i^w\≤p_i^w+\mathrm{\Δ}{p}_i^{w,f}\≤p^{w,m}$

(5-2) the real-time active power of i-th section of connection line between photovoltaic plant and electrical network the active power upper limit sensitivity S ^sWwith the regulated quantity Δ p that freely generates electricity ^w,fbetween meet following relation:

$p_i^s+S^{\mathrm{SW}}\mathrm{\Δ}{p}^{w,f}\≤{\stackrel{\‾}{p}}_i^s,$

(5-3) in electrical network, the regulated quantity that freely generates electricity of all photovoltaic plants meets following relational expression:

$\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}\mathrm{\Δ}{p}_i^{w,f}\≤\max \{\mathrm{\Δ}{p}_{\mathrm{wind}}^{\mathrm{cap}},-\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}(p_i^w-{\underset{\‾}{p}}_i^w)\},$

Wherein, Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the real-time active power of i-th photovoltaic plant, be i-th photovoltaic plant active power lower limit;

(5-4) set the direction constrain of photovoltaic generation active power regulation, make

(6) adopt interior point method to solve the quadratic programming Mathematical Modeling of above-mentioned steps (4) and step (5), obtain photovoltaic plant and freely to generate electricity regulated quantity

(7) freely to generate electricity regulated quantity with above-mentioned photovoltaic plant photovoltaic plant is controlled, realizes the free Generation Control of electric power system photovoltaic plant considering power grid security.

The photovoltaic plant taking into account power system security constraints that the present invention proposes can power generation margin distribution method, its feature and effect are: this method is according to equity dispatching principle, after photovoltaic plant freedom of entry hair-like state, the space of photovoltaic generation is received by electrical network to be evenly distributed to each photovoltaic plant according to the method that load factor deviation is minimum, avoid on the one hand because photovoltaic plant set point of gaining merit is too small and produce unnecessary light of abandoning, avoid causing meritorious set point excessive owing to issuing photovoltaic plant capacity on the other hand, photovoltaic plant is exerted oneself and exceedes electrical network ability to bear.In the photovoltaic generation real power control main station system that this method accessible site runs in control centre, enable this system in real time according to photovoltaic generation running status and operation of power networks state, implement optimum control strategy, ensure that electrical network has enough backspins for safe space, and the active power safety of photovoltaic plant and electrical network connection line section, and take into account the equity dispatching between each photovoltaic plant.

Embodiment

The photovoltaic plant taking into account power system security constraints that the present invention proposes can power generation margin distribution method, comprises the following steps:

(1) gather from the data acquisition of electrical network and supervisor control that the real-time backspin of current electric grid automatic-generation-control unit is standby, connection line active power deviation between photovoltaic plant and electrical network, obtain the admissible photovoltaic plant active power of electrical network from grid dispatching center from the real-time active power p of each photovoltaic plant that the data acquisition of electrical network is connected with electrical network with supervisor control collection ^wand the real-time active power p of connection line section between each photovoltaic plant and electrical network ^s, obtain active power lower limit from grid dispatching center p ^w, estimate maximum active power with the active power upper limit ;

(2) if above-mentioned photovoltaic plant active power then show that current electric grid does not possess to continue to receive the space of photovoltaic generation, by the regulated quantity that freely generates electricity of each photovoltaic plant be connected with electrical network be set to 0, and carry out step (6);

(3) the active power sensitivity S of each photovoltaic plant to connection line section between photovoltaic plant and electrical network is obtained from grid dispatching center ^sW;

(4) setting up the photovoltaic plant taking into account power system security constraints can the target function of power generation margin distribution method, as follows:

$\underset{\mathrm{\Δ}{p}_i^{w,f}}{\min }(W^p\·(\mathrm{\Δ}{p}_{\mathrm{wind}}^{\mathrm{cap}}-\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}\mathrm{\Δ}{p}_i^{w,f})+W^r\·\underset{i{\mathrm{\Ω}}^w}{\mathrm{\Σ}}{\left({r_i}^w\right)}^2)$

Wherein: Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity that freely generates electricity of i-th photovoltaic plant, be the load deviation rate of i-th photovoltaic plant, for the deviation of the load factor and Rate of average load that characterize each photovoltaic plant, in above-mentioned target function impel during free Generation Control and farthest utilize electrical network digestion capability, avoid photovoltaic generation total amount to exceed electrical network digestion capability simultaneously, in formula (3) target function impel each photovoltaic plant to the more balanced future development of its active power, namely load factor deviation is close to zero, W ^p, W ^rbe respectively weight coefficient, in order to optimize, guarantee is minimum abandons light, generally has W ^p>W ^r.In actual applications, W ^pvalue 10.0, W ^rvalue 0.01;

(5) setting take into account the photovoltaic plant of power system security constraints can the constraints of power generation margin distribution method, comprising:

(5-1) the real-time active power of i-th photovoltaic plant active power lower limit freely generate electricity regulated quantity with photovoltaic plant capacity p ^w,mbetween meet following relational expression: ensure that photovoltaic plant active power is between its minimum load and its maximum output:

${\underset{\‾}{p}}_i^w\≤p_i^w+\mathrm{\Δ}{p}_i^{w,f}\≤p^{w,m}$

(5-2) the real-time active power of i-th section of connection line between photovoltaic plant and electrical network the active power upper limit sensitivity S ^sWwith the regulated quantity Δ p that freely generates electricity ^w,fbetween meet following relation: with after ensureing out-of-limit Corrective control between each photovoltaic plant and electrical network the active power of connection line section be less than the active power upper limit, wherein the maximum active power of connection line section between the main photovoltaic plant by electrical network scleronomic constraint restriction and electrical network,

$p_i^s+S^{\mathrm{SW}}\mathrm{\Δ}{p}^{w,f}\≤{\stackrel{\‾}{p}}_i^s.$

(5-3) in electrical network, the regulated quantity that freely generates electricity of all photovoltaic plants meets following relational expression: the regulated quantity that always freely generates electricity is less than photovoltaic generation capacity-constrained of can dissolving, avoid because photovoltaic generation active power is excessive, cause the frequency security problem of electrical network, namely the standby deficiency of AGC unit backspin or interconnection real-time active power value diasporometer streak many

$\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}\mathrm{\Δ}{p}_i^{w,f}\≤\max \{\mathrm{\Δ}{p}_{\mathrm{wind}}^{\mathrm{cap}},-\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}(p_i^w-{\underset{\‾}{p}}_i^w)\}.$

Wherein, Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the real-time active power of i-th photovoltaic plant, be i-th photovoltaic plant active power lower limit;

(5-4) set photovoltaic generation freely to generate electricity the direction constrain of regulated quantity, make this constraint is avoided under freely controlling, and produces the unreasonable instruction that restriction photovoltaic plant is exerted oneself.

(6) adopt interior point method to solve the quadratic programming Mathematical Modeling of above-mentioned steps (4) and step (5), the photovoltaic plant obtaining the free Generation Control of electric power system photovoltaic plant of consideration power grid security freely generates electricity regulated quantity

(7) freely to generate electricity regulated quantity with above-mentioned photovoltaic plant photovoltaic plant is controlled, realizes the free Generation Control of electric power system photovoltaic plant considering power grid security.

The photovoltaic plant taking into account power system security constraints of the present invention can in power generation margin distribution method, and the automatic-generation-control unit related to, refers in electrical network the generating set participating in automatic generation control.Automatic generation control (AutomaticGenerationControl, AGC) be the adjustment of electric power system active power and the one of FREQUENCY CONTROL, AGC is one of main contents of dispatching automation of electric power systems, utilize the closed-loop control system of the compositions such as side, control centre supervisory control comuter, telecontrol channel, generating set automation device, the frequency of monitoring, adjustment electric power system, to control generator output.

Automatic-generation-control unit backspin in this method is standby, is used for characterizing maximum the lowered space of unit active power.If the active power currency of unit i is active power lower limit is then the active power backspin of unit i is standby be defined as: $p_i^{\mathrm{cap}}=p_i^{\mathrm{curr}}-p_i^{\min }.$

Photovoltaic plant load deviation rate in this method for the deviation of the load factor and Rate of average load that characterize each photovoltaic plant, meet following relation:

${r_i}^w=\frac{p_i^w}{c_i^w\·{\stackrel{\‾}{p}}_i^w}-\stackrel{\‾}{r^w}$

Wherein for photovoltaic plant Rate of average load, be enthusiasm in order to give full play to each photovoltaic plant tracking and control center dispatch command and introduce photovoltaic plant, and as the foundation of photovoltaic generation equity dispatching, meeting following relation:

$\stackrel{\‾}{r^w}=\frac{\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}{p}_i^w}{\underset{i\∈{\mathrm{\Ω}}^w}{\mathrm{\Σ}}(c_i^w\·{\stackrel{\‾}{p}}_i^w)}$

Wherein, Ω ^wfor all controlled light overhead utility set, for the maximum output predicted value of i-th photovoltaic plant that photovoltaic plant send.C ^wfor photovoltaic plant examination marking index, for quantitative description photovoltaic plant, the close friend to electrical network accesses degree, manually determines and cycle renewal (monthly/weekly), meet 0≤c primarily of management and running personnel ^w≤ 1.

Claims (1)

1. the photovoltaic plant taking into account power system security constraints can a power generation margin distribution method, it is characterized in that the method comprises the following steps:

(1) gather the connection line active power deviation between photovoltaic plant and electrical network from the data acquisition of electrical network and supervisor control, obtain the admissible photovoltaic plant active power of electrical network from grid dispatching center from the real-time active power p of each photovoltaic plant that the data acquisition of electrical network is connected with electrical network with supervisor control collection ^wand the real-time active power p of connection line section between each photovoltaic plant and electrical network ^s, obtain active power lower limit from grid dispatching center p ^w, estimate maximum active power with the active power upper limit

(2) if above-mentioned photovoltaic plant active power the regulated quantity that freely generates electricity of each photovoltaic plant then will be connected with electrical network be set to 0, and carry out step (6);

(3) the active power sensitivity S of each photovoltaic plant to connection line section between photovoltaic plant and electrical network is obtained from grid dispatching center ^sW;

(4) setting up the photovoltaic plant taking into account power system security constraints can the target function of power generation margin distribution method, as follows:

$\underset{{\mathrm{\Δp}}_i^{w,f}}{\min }(W^p\·({\mathrm{\Δp}}_{wind}^{cap}-\underset{i\∈{\mathrm{\Ω}}^w}{\Σ}{\mathrm{\Δp}}_i^{w,f})+W^r\·\underset{i\∈{\mathrm{\Ω}}^w}{\Σ}{\left(r_i^w\right)}^2)$

Wherein: Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity that freely generates electricity of i-th photovoltaic plant, be the load deviation rate of i-th photovoltaic plant, W ^p, W ^rbe respectively weight coefficient, W ^pvalue is 10.0, W ^rvalue is 0.01;

(5) setting take into account the photovoltaic plant of power system security constraints can the constraints of power generation margin distribution method, comprising:

(5-1) the real-time active power of i-th photovoltaic plant active power lower limit freely generate electricity regulated quantity with photovoltaic plant capacity p ^w,mbetween meet following relational expression:

(5-2) the real-time active power of i-th section of connection line between photovoltaic plant and electrical network the active power upper limit sensitivity S ^sWwith the regulated quantity Δ p that freely generates electricity ^w,fbetween meet following relation:

$p_i^s+S^{SW}{\mathrm{\Δp}}^{w,f}\≤{\stackrel{\‾}{p}}_i^s,$

(5-3) in electrical network, the regulated quantity that freely generates electricity of all photovoltaic plants meets following relational expression:

$\underset{i\∈{\mathrm{\Ω}}^w}{\Σ}{\mathrm{\Δp}}_i^{w,f}\≤max\{{\mathrm{\Δp}}_{wind}^{cap},-\underset{i\∈{\mathrm{\Ω}}^w}{\Σ}(p_i^w-{\underset{\‾}{p}}_i^w)\},$

Wherein, Ω ^wfor all photovoltaic plant set be connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the real-time active power of i-th photovoltaic plant, be i-th photovoltaic plant active power lower limit;

(5-4) set photo-voltaic power generation station freely to generate electricity the direction constrain of regulated quantity, make

(6) adopt interior point method to solve the quadratic programming Mathematical Modeling of above-mentioned steps (4) and step (5), obtain photovoltaic plant and freely to generate electricity regulated quantity

(7) freely to generate electricity regulated quantity with above-mentioned photovoltaic plant photovoltaic plant is controlled, realizes the free Generation Control of electric power system photovoltaic plant considering power grid security.