CN104037805A - Power generation margin distribution method for photovoltaic power station based on power grid security constraints - Google Patents

Abstract

The invention relates to a power generation margin distribution method for a photovoltaic power station based on power grid security constraints and belongs to the field of running and control technologies of new energy electric power systems. The power generation margin distribution method for the photovoltaic power station based on power grid security constraints includes that according to a fair scheduling principle, after the photovoltaic power station enters a free power generation state, the space of a power grid for performing photovoltaic power generation is uniformly distributed for each photovoltaic power station according to a minimum load rate deviation method, on the one hand, unnecessary photovoltaic power discarding due to a too small active set value of the photovoltaic power generation is avoided, and on the other hand, the problem that the power output by the photovoltaic power generation surpasses the power grid bearing capacity due to a too large active set value due to distributing the photovoltaic power generation capacity is avoided. The power generation margin distribution method for the photovoltaic power station based on power grid security constraints is integrated in a photovoltaic power generation active control master station run by a dispatching center to enable the system to implement an optimal control strategy in real time according to the photovoltaic power generation running state and the power grid running state, maintain enough backspin security space for the power grid, guarantee the active power security of the section of a connecting wire of the photovoltaic power station and the power grid and guarantee the fair scheduling among the photovoltaic power stations.

Description

A kind of photovoltaic plant of taking into account power system security constraints nargin distribution method of can generating electricity

Technical field

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

Background technology

The strong randomness of light resources, the features such as difficulty, anti-peak regulation of predicting make electric network active scheduling controlling difficulty further.How ensureing, under the prerequisite of power grid security, at utmost utilizing photovoltaic generation resource, the photovoltaic generation of dissolving as much as possible has become one of common challenge that each place, photovoltaic generation base electrical network faces at present.At present, industry has been carried out large quantity research to the active power scheduling controlling after photovoltaic generation access, and obtains a series of research and application achievements.Actual field operating experience shows, introduces the quick photovoltaic power generation dispatching of minute level and controls in real time, to ensureing power grid security, reduce that abandoning light loss can play remarkable effect in active power scheduling controlling system.

At present, engineering site mainly adopts heuristic Artificial Control method to control photovoltaic plant active power, when electrical network exists safety problem, need to reduce photovoltaic plant active power time, operations staff relies on 1 of the direct excision of operating experience or multiple photovoltaic plant or will abandon light quantity mean allocation to each photovoltaic plant, in the time that electrical network has photoelectricity to receive space, each photovoltaic plant freedom of entry is sent out state, does not go to limit exerting oneself of photovoltaic generation.This method subject matter is: (1) depends on operations staff's experience, is difficult to ensure the fairness of scheduling; (2) not limited when power grid security, while existing photovoltaic generation to receive space, Artificial Control mode cannot be recovered photovoltaic plant active power in time, and causes the unnecessary light of abandoning; (3), under free state, if the flash-up of photovoltaic plant is very fast, when electrical network is received limited space simultaneously, easily cause electrical network to occur safety problem.

Summary of the invention

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

The photovoltaic plant of the taking into account power system security constraints nargin distribution method of can generating electricity that the present invention proposes, comprises the following steps:

(1) from the data acquisition of electrical network and supervisor control gather that the real-time backspin of current electrical network 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 the real-time active power p of the each photovoltaic plant being connected with electrical network with supervisor control collection from the data acquisition of electrical network ^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 by the regulated quantity of freely generating electricity of the each photovoltaic plant being connected with electrical network be made as 0, and carry out step (6);

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

(4) set up can the generate electricity target function of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, 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 that are connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity of freely generating electricity of i photovoltaic plant, be the load deviation ratio of i photovoltaic plant, W ^p, W ^rbe respectively weight coefficient, W ^pvalue is 10.0, W ^rvalue is 0.01;

(5) set can the generate electricity constraints of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, comprising:

(5-1) the real-time active power of i photovoltaic plant active power lower limit the regulated quantity of freely generating electricity 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 connection line section between i 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 of freely generating 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 that are connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the real-time active power of i photovoltaic plant, be i photovoltaic plant active power lower limit;

(5-4) direction constrain of setting photovoltaic generation active power regulation, makes

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

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

The photovoltaic plant of the taking into account power system security constraints nargin distribution method of can generating electricity that the present invention proposes, its feature and effect are: this method is according to equity dispatching principle, send out after state in photovoltaic plant freedom of entry, electrical network is received the space of photovoltaic generation arrive each photovoltaic plant according to the method mean allocation of load factor deviation minimum, avoid on the one hand producing because the meritorious set point of photovoltaic plant is too small the unnecessary light of abandoning, avoid on the other hand causing meritorious set point excessive owing to issuing photovoltaic plant capacity, photovoltaic plant is exerted oneself and exceed electrical network ability to bear.This method can be integrated in the photovoltaic generation real power control main station system of control centre's operation, make this system can be 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 of the taking into account power system security constraints nargin distribution method of can generating electricity that the present invention proposes, comprises the following steps:

(1) from the data acquisition of electrical network and supervisor control gather that the real-time backspin of current electrical network 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 the real-time active power p of the each photovoltaic plant being connected with electrical network with supervisor control collection from the data acquisition of electrical network ^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 show that current electrical network does not possess the space of continuing to receive photovoltaic generation, by the regulated quantity of freely generating electricity of the each photovoltaic plant being connected with electrical network be made as 0, and carry out step (6);

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

(4) set up can the generate electricity target function of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, 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 that are connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity of freely generating electricity of i photovoltaic plant, be the load deviation ratio of i photovoltaic plant, for characterizing the load factor of each photovoltaic plant and the deviation of Rate of average load, in above-mentioned target function while impelling free Generation Control, farthest utilize the electrical network ability of dissolving, avoid photovoltaic generation total amount to exceed the electrical network ability of dissolving simultaneously, in formula (3) target function impel each photovoltaic plant to the more balanced future development of its active power, load factor deviation is close to zero, W ^p, W ^rto be respectively weight coefficient, to ensure that in order optimizing minimum abandons light, generally have W ^p>W ^r.In actual applications, W ^pvalue 10.0, W ^rvalue 0.01;

(5) set can the generate electricity constraints of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, comprising:

(5-1) the real-time active power of i photovoltaic plant active power lower limit the regulated quantity of freely generating electricity 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 connection line section between i 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: to ensure after out-of-limit correction control between each photovoltaic plant and electrical network that the active power of connection line section is less than the active power upper limit, wherein mainly be subject to the maximum active power of connection line section between the photovoltaic plant of stabilization of power grids constrained 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 of freely generating electricity of all photovoltaic plants meets following relational expression: the regulated quantity of always freely generating electricity is less than the photovoltaic generation capacity-constrained of can dissolving, avoid because photovoltaic generation active power is excessive, cause the frequency security problem of electrical network, be that AGC unit backspin streaks many for deficiency or the real-time active power value of interconnection diasporometer

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

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

(5-4) set freely the generate electricity direction constrain of regulated quantity of photovoltaic generation, 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 that obtains the free Generation Control of electric power system photovoltaic plant of the considering power grid security regulated quantity of freely generating electricity

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

The photovoltaic plant of taking into account power system security constraints of the present invention can generate electricity in nargin distribution method, and the automatic-generation-control unit relating to, refers to the generating set that participates in automatic generation control in electrical network.Automatic generation control (Automatic Generation Control, AGC) be the one of the adjustment of electric power system active power and 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 control centre's side 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 the lowered space of unit active power maximum.If the active power currency of unit i is under active power, be limited to 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 ratio in this method for characterizing the load factor of each photovoltaic plant and the deviation of Rate of average load, 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 the 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, meet 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 photovoltaic plant sending on photovoltaic plant.C ^wfor photovoltaic plant examination marking index, for quantitative description photovoltaic plant, the close friend of electrical network is accessed to degree, mainly manually determine that by management and running personnel also the cycle is upgraded (monthly/weekly), meet 0≤c ^w≤ 1.

Claims (1)

1. the photovoltaic plant of the taking into account power system security constraints nargin distribution method of can generating electricity, is characterized in that the method comprises the following steps:

(1) from the data acquisition of electrical network and supervisor control gather that the real-time backspin of current electrical network 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 the real-time active power p of the each photovoltaic plant being connected with electrical network with supervisor control collection from the data acquisition of electrical network ^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 by the regulated quantity of freely generating electricity of the each photovoltaic plant being connected with electrical network be made as 0, and carry out step (6);

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

(4) set up can the generate electricity target function of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, 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 that are connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the regulated quantity of freely generating electricity of i photovoltaic plant, be the load deviation ratio of i photovoltaic plant, W ^p, W ^rbe respectively weight coefficient, W ^pvalue is 10.0, W ^rvalue is 0.01;

(5) set can the generate electricity constraints of nargin distribution method of the photovoltaic plant of taking into account power system security constraints, comprising:

(5-1) the real-time active power of i photovoltaic plant active power lower limit the regulated quantity of freely generating electricity 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 connection line section between i 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 of freely generating 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 that are connected with electrical network, for the admissible photovoltaic plant active power of electrical network, be the real-time active power of i photovoltaic plant, be i photovoltaic plant active power lower limit;

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

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

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