CN103311953A - System and method for controlling distributed power and energy storage system-containing power distribution network - Google Patents

Abstract

The invention discloses a system and a method for controlling a distributed power and energy storage system-containing power distribution network. The system and the method are used for controlling the optimized operation of the distributed power and the energy storage system, which are accessed in a synchronization way, in a power distribution network. The system and the method are used for computing the difference between a measured value of the exchange power of the power distribution network and an external power network and the optimum value or a planed target value obtained by means of optimal computation and defining into the running error of the power distribution network, and are applicable to the closed-loop control on the energy storage system and the distributed power, so that the power distribution network can be kept to be consistent with the actual value of the external power exchange power and the optimum value or the planed target value computed in an optimizing way.

Description

The control system and the method that contain the power distribution network of distributed power source and energy-storage system

Technical field

The present invention relates to a kind of control system of power distribution network, what especially relate to a kind of power distribution network that contains distributed power source and energy-storage system decides the exchange power control system.The invention still further relates to and adopt described system to the exchange power control method of deciding of the power distribution network that contains distributed power source and energy-storage system.

Background technology

Behind access distributed power source (DG), energy-storage system, power distribution network has possessed certain active adjustment, has optimized the ability of load.But the renewable energy resources have the characteristics such as intermittence or fluctuation, have limited being incorporated into the power networks of DG, need to control, the scheduling of DG be optimized.Active management to power distribution network and the DG that is incorporated into the power networks, energy-storage system can improve be incorporated into the power networks quantity and the on-road efficiency of DG.Power distribution network with active management ability is power distribution network (Active Distribution Network, ADN) initiatively, is characterized in can be on one's own initiative the operation of the equipment such as the DG that is incorporated into the power networks, energy storage, reactive power compensation being optimized and controlling.

The ADN optimal control generally is divided into real-time control two parts of global optimization computation and DG, energy storage, microgrid.Aspect global optimization and in real time control, more research is all arranged, coordinate control with in real time controls such as inhibition DG power fluctuations such as improved control strategy based on P-f and Q-V droop control, energy storage and the batch (-type) energy; And based on the economical operation optimization of energy storage peak load shifting function and energy storage optimal scheduling, supply of cooling, heating and electrical powers optimization of operation strategy, consider that the active power distribution network operation of the factors such as line loss, the cost of electric energy, reactive power compensation cost optimizes.

Realize active optimization and the control of ADN, must take into account simultaneously the requirement of global optimization and partial autonomy control.Existing active power distribution network global optimization system and method calculates each DG, energy-storage system and power distribution network optimized operation state according to the electrical network global information.According to the complexity of optimized algorithm, the size of deal with data amount, generally calculate take length sometime as the cycle, like this just can't satisfy DG, energy storage control system to the requirement of response speed; In addition, initiatively the power distribution network global optimization computation generally adopts load prediction, batch (-type) energy power prediction or historical data, has certain difference with measured data in the actual motion, brings adverse effect for the effect of optimization of DG, energy-storage system.

Summary of the invention

First technical problem to be solved by this invention just provides a kind of control system that contains the power distribution network of distributed power source and energy-storage system.

Second technical problem to be solved by this invention just provides and adopts said system to the control method of the power distribution network that contains distributed power source and energy-storage system.

System and method of the present invention, calculate take whole time span as the cycle, can satisfy DG, energy storage control system to the requirement of response speed, power distribution network kinematic error (Distribution network Operation Error is proposed, DOE) definition and computation model, the difference of active power distribution network actual motion state and optimized operation state is described in real time, propose to decide the Optimized-control Technique of the active power distribution network under the exchange power control pattern based on DOE, further reduced the difference between electrical network global optimization state and the actual motion state.

Solve above-mentioned first technical problem, the present invention adopts following technical scheme:

A kind of control system that contains the power distribution network of distributed power source and energy-storage system is characterized in that: comprising: in power distribution network outlet breaker position, dispose power-measuring device, be used for actual measurement power distribution network exchange power; At each distributed power source and energy-storage system place, the exchange power control device is decided in configuration, is used for calculating the power distribution network kinematic error, and calculates the power adjustments amount of corresponding distributed power source and energy-storage system according to the exchange power error; At the configuring distributed power supply of distribution main website, energy-storage system optimization operation computing system, calculate optimum distribution line exchange power; Optimizing has between operation computing system and power-measuring device and the Ge Ding exchange power control device that data wire is two-way to be connected, and optimizes the operation computing system and accepts measured data and transmit control signal.

Solve above-mentioned second technical problem, the present invention adopts following control method:

Based on above-mentioned control system, adopt the exchange power control method of deciding based on the power distribution network that contains distributed power source and energy-storage system of power distribution network kinematic error, may further comprise the steps:

S1 proposes power distribution network kinematic error computation model

Definition power distribution network kinematic error (DOE) is power distribution network and dispatch from foreign news agency exchange power P _EActual value and the planned value of optimal value or global optimization poor, that is:

DOE=P _E.C-P _E.S （1）

P wherein _E.CFor exchanging power P in the actual motion _EMeasured value, P _E.SBe P _EThe planned value of optimal value or global optimization, operational plan calculates according to existing technology for global optimization or according to power distribution network;

Global optimization is with load and regenerative resource prediction, power network topology parameter, and energy-storage system (Energy Storage System, ESS) information such as state-of-charge is initial data, calculates the optimum power output of ESS, adjustable DG and exchange power P in following one day or one hour _EOptimal value, i.e. P _E.S

P _E.C, P _E.SAll to inject ADN for just;

The DOE product moment control of S2 DG/ energy-storage system

Based on the DG/ energy-storage system governing equation of DOE shown in (2) formula:

${\∫}_0^t(P_{E.C}-P_{E.S})\·\mathrm{dt}+\frac{1}{{\mathrm{\α}}_i}\·{\mathrm{\ΔP}}_i=0---\left(2\right)$

Constant alpha in the formula _iBe i ^ThThe regulationing factor of power of DG/ energy-storage system; P _i, △ P _iBe the i that accesses in the active power distribution network ^ThDG/ energy-storage system power and regulated quantity thereof are all to flow out feeder line as positive direction.

The exchange power optimized value P that obtains according to step S1 _E.SAnd measured value P _E.CCalculate the power distribution network kinematic error, according to governing equation (2) formula DOE is carried out integration, calculate the power control value of each DG/ energy-storage system under the DOE control system;

Decide exchange power control with the exchange power P _EActual value is all the control target mutually with the planned value of global optimization, and each DG, energy-storage system are according to predetermined power adjustments distribution coefficient regulation output power.

Deciding under the exchange power control pattern i ^ThThe power adjustments amount of DG/ energy-storage system is:

${\mathrm{\ΔP}}_i=\frac{{\mathrm{\α}}_i}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\α}}_i}\·\mathrm{\ΔP};$

Constant alpha wherein _iBe the power adjustments distribution coefficient, be i ^ThThe power adjustments amount of DG/ energy-storage system accounts for the ratio of the total regulated quantity of all DG/ energy-storage systems; △ P is all DG, energy-storage system power adjustments amount sum.

Beneficial effect: power distribution network kinematic error proposed by the invention has been described initiatively power distribution network actual motion state on the whole and the difference of optimized operation state in real time, the optimum state of having considered that global optimization computation obtains based on the exchange power control method of deciding of DOE and the difference between electrical network actual motion state, and on this basis DG, energy-storage system are carried out closed-loop control, further improve the effect of DG, energy-storage system optimization operation, further reduced the impact that the difference of predicted value and measured value is brought.

Description of drawings

Fig. 1 is composition and the annexation schematic diagram of deciding the exchange power control system based on the power distribution network of power distribution network kinematic error;

Fig. 2 decides exchange power control method schematic diagram based on the power distribution network of power distribution network kinematic error.

Embodiment

Below in conjunction with the drawings and specific embodiments the present invention is made detailed explanation.

The power distribution network that contains distributed power source and energy-storage system based on the power distribution network kinematic error of the present invention is decided the exchange power control system as shown in Figure 1.

Comprise: in power distribution network outlet breaker position, dispose power-measuring device, be used for actual measurement power distribution network exchange power; At each distributed power source and energy-storage system place, the exchange power control device is decided in configuration, is used for calculating the power distribution network kinematic error, and calculates the power adjustments amount of corresponding distributed power source and energy-storage system according to the exchange power error; At the configuring distributed power supply of distribution main website, energy-storage system optimization operation computing system, calculate optimum distribution line exchange power; Optimizing has between operation computing system and power-measuring device and the Ge Ding exchange power control device that data wire is two-way to be connected, and optimizes the operation computing system and accepts measured data and transmit control signal.

Optimize computing system, according to load and regenerative resource prediction, power network topology, DG and ESS parameter, and the measured data of actual motion, the optimum power output of ESS, adjustable DG in following a period of time of calculating and the exchange power of ADN and external power grid.

The DOE control system, the exchange power optimization value that calculates according to optimization and the measured value of Real-time Collection calculate the power distribution network kinematic error; According to governing equation, error is carried out integration, calculate ESS, the DG performance number under the DOE control system.

Optimize and calculate and according to the complexity of optimized algorithm or according to optimizing needs, to calculate take the set time as the cycle.And DOE control system Real-time Collection operation of power networks state calculates kinematic error, and according to the governing equation that (2) formula is determined, energy-storage system, adjustable DG is carried out real-time product moment control.

Adopt said system to the exchange power control method of deciding of the power distribution network that contains distributed power source and energy-storage system, may further comprise the steps:

S1 proposes power distribution network kinematic error computation model

For active power distribution network (ADN), external power grid can equivalence be infinitely great power supply, keeps the ADN power-balance.DG power output and determination of power load if be incorporated into the power networks, according to trend calculate can unique definite ADN and the exchange power of external power grid (hereinafter all use P _EExpression).When unplanned variation occurs load, or DG, energy-storage system and optimized operation state be when variant, P _EAlso change thereupon, so P _ECan reflect ADN overall operation state.And in the ADN global optimization computation, P _EAn also Optimized model aspect needing emphasis to consider often.

Definition power distribution network kinematic error (DOE) is P _EThe planned value of actual value and optimal value or global optimization poor:

DOE=P _E.C-P _E.S (1)

P wherein _E.SBe P _EThe planned value of optimal value or global optimization obtains according to global optimization computation; P _E.CBe P in the actual motion _EMeasured value.P _E.C, P _E.SAll injecting ADN for just,, if load power and DG, energy storage actual power are identical with global optimization, DOE=0 so; DOE〉0 item show that load power increase or DG, energy storage power output reduce; Otherwise DOE＜0 shows that load power reduces or DG, energy storage power output increase.

The proposition of DOE, quantificational description the difference between the overall operation state of the actual overall operation state of ADN and global optimization.

In the actual motion, if load power and DG, energy storage actual power are identical with global optimization, DOE=0 so; DOE〉0 item show that load power increase or DG, energy storage power output reduce; Otherwise DOE＜0 shows that load power reduces or DG, energy storage power output increase.To the integrated value of time, control each DG and energy-storage system according to the size of the symbol of DOE and absolute value or DOE, make the actual motion state level off to running status in the global optimization.

S2 optimizes the operation computing system according to load and regenerative resource prediction, power network topology parameter, and energy-storage system state-of-charge, adjustable DG exported electric weight actual motion information, calculates the optimum power output of ESS, adjustable DG and exchange power optimized value in following 24 hours or one hour.

Decide the exchange power control method with the exchange power P _EActual value is all the control target mutually with the planned value of global optimization, and each DG, energy-storage system are according to predetermined power adjustments distribution coefficient regulation output power.

DG, energy-storage system governing equation are shown below:

${\∫}_0^t\mathrm{DOE}\·\mathrm{dt}+\frac{1}{{\mathrm{\α}}_i}\·{\mathrm{\ΔP}}_i=0---\left(3\right)$

Constant alpha in the formula _iBe the DGi regulationing factor of power; P _i, △ P _iBe DGi power and regulated quantity thereof in the active power distribution network, to flow out feeder line as positive direction.

Controllable burden or equivalence are adjustable equipment or the equivalent node of microgrid constant power of individual node, also can adopt the DOE integral control.

First take the ADN of single DG as example, the load power predicted value is P among the ADN _LoadExternal power grid is P to active power distribution network injecting power _EAccording to the ADN global optimization, DG power is P _DG, P _EThe planned value of global optimization is P _E.S=P _Load+ P _DGIf ignore loss, DOE=0.If a certain moment feeder line load plan other places increases △ P _Load, this moment DOE=△ P _Load0.According to the DG governing equation as can be known

△ P _DG＜0, the DG node that is incorporated into the power networks flows out the power reduction of feeder line, and namely DG injects the feeder line the increase of output power, and DOE is reduced.When DOE was decreased to 0, power adjustment procedure finished.Have this moment:

${\mathrm{\ΔP}}_i=\frac{{\mathrm{\α}}_i}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\α}}_j}\·\mathrm{\ΔP},---\left(4\right)$

In following formula, definition α _iBe the power adjustments distribution coefficient, for DGi power adjustments amount accounts for the ratio of total regulated quantity, and have When unplanned load, power injection occurring, DG determines the variable quantity of power output according to DOE and power adjustments distribution coefficient.Can consider the information such as each DG type, capacity, whether adjustable, cost of electricity-generating, according to different Optimal Control Strategy, set the power adjustments distribution coefficient of each DG.

In the control model of being determined by (3) formula, when unplanned load fluctuation or DG power fluctuation occurring, the terminal point of DG power adjustment procedure is DOE=0, i.e. P _E.C=P _E.S, P _EActual value consistent with planned value (unless all DG power all are adjusted to the upper limit) therefore is called and decides the exchange power control pattern.Under this control model, each DG controls according to the power adjustments distribution coefficient.

Fig. 2 decides exchange power control method schematic diagram based on the power distribution network of power distribution network kinematic error, comprises the electrical network primary system among Fig. 2, optimizes computing system and DOE control system three parts.

As shown in Figure 2, for optimization system, loop (A) is the running status of Real-time Collection energy-storage system, DG, comprises energy storage SOC, the information such as the issued electric energy of DG; Loop (B) is the data such as load prediction, regenerative resource prediction, grid equipment parameter, as optimizing the initial data of calculating; Loop (C) is the output of optimization system, is the optimal value of active power distribution network and dispatch from foreign news agency exchange power.

For the control system based on DOE, loop (1) is the exchange performance number of Real-time Collection; Loop (2) is the power distribution network kinematic error that calculates according to exchanging power measured value and optimal value; Loop (3) (4) is control circuit, builds according to governing equation (2); Loop (5) (6) is the control system output loop based on DOE, and output content is the power control signal of energy-storage system, DG.

Claims (2)

1. a control system that contains the power distribution network of distributed power source and energy-storage system is characterized in that comprising: in power distribution network outlet breaker position, dispose power-measuring device, be used for actual measurement power distribution network exchange power; At each distributed power source and energy-storage system place, the exchange power control device is decided in configuration, is used for calculating the power distribution network kinematic error, and calculates the power adjustments amount of corresponding distributed power source and energy-storage system according to the exchange power error; At the configuring distributed power supply of distribution main website, energy-storage system optimization operation computing system, calculate optimum distribution line exchange power; Optimizing has between operation computing system and power-measuring device and the Ge Ding exchange power control device that data wire is two-way to be connected, and optimizes the operation computing system and accepts measured data and transmit control signal.

2. one kind is adopted the exchange power control method of deciding based on the power distribution network that contains distributed power source and energy-storage system of power distribution network kinematic error based on control system claimed in claim 1, may further comprise the steps:

S1 proposes power distribution network kinematic error computation model

Definition power distribution network kinematic error (DOE) is power distribution network and dispatch from foreign news agency exchange power P _EActual value and the planned value of optimal value or global optimization poor, that is:

DOE=P _E.C-P _E.S （1）

P wherein _E.CFor exchanging power P in the actual motion _EMeasured value, P _E.SBe P _EThe planned value of optimal value or global optimization, operational plan calculates according to existing global optimization or according to power distribution network;

Global optimization is with load and regenerative resource prediction, power network topology parameter, and energy-storage system (Energy Storage System, ESS) information such as state-of-charge is initial data, calculates the optimum power output of ESS, adjustable DG and exchange power P in following one day or one hour _EOptimal value, i.e. P _E.S

P _E.C, P _E.SAll to inject ADN for just;

The DOE product moment control of S2DG/ energy-storage system

Based on the DG/ energy-storage system governing equation of DOE shown in (2) formula:

${\∫}_0^t(P_{E.C}-P_{E.S})\·\mathrm{dt}+\frac{1}{{\mathrm{\α}}_i}\·{\mathrm{\ΔP}}_i=0---\left(2\right)$

Constant alpha in the formula _iBe i ^ThThe regulationing factor of power of DG/ energy-storage system; P _i, △ P _iBe the i that accesses in the active power distribution network ^ThDG/ energy-storage system power and regulated quantity thereof are all to flow out feeder line as positive direction;

The exchange power optimized value P that obtains according to step S1 _E.SAnd measured value P _E.CCalculate the power distribution network kinematic error, according to governing equation (2) formula DOE is carried out integration, calculate the power control value of each DG/ energy-storage system under the DOE control system;

Decide exchange power control with the exchange power P _EActual value is all the control target mutually with the planned value of global optimization, and each DG, energy-storage system are according to predetermined power adjustments distribution coefficient regulation output power;

Deciding under the exchange power control pattern i ^ThThe power adjustments amount of DG/ energy-storage system is:

${\mathrm{\ΔP}}_i=\frac{{\mathrm{\α}}_i}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\α}}_i}\·\mathrm{\ΔP};$

Constant alpha wherein _iBe the power adjustments distribution coefficient, be i ^ThThe power adjustments amount of DG/ energy-storage system accounts for the ratio of the total regulated quantity of all DG/ energy-storage systems; △ P is all DG, energy-storage system power adjustments amount sum.

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