CN106340893A - Distributed photovoltaic power generation power control method based on virtual power plant - Google Patents

Abstract

The invention provides a distributed photovoltaic power generation power control method based on a virtual power plant. The distributed photovoltaic power generation power control method comprises the steps of: applying an active power optimized dispatching method to a virtual power plant control center, performing optimized distribution on an active power dispatching command of the virtual power plant issued by a power grid regulation and control center, and issuing the active power dispatching command after optimized distribution to distributed photovoltaic power generation units in the virtual power plant; and issuing node voltage reference values to the distributed photovoltaic power generation units in the virtual power plant by the virtual power plant according to the node voltage reference values issued by the power grid regulation and control center, wherein each distributed photovoltaic power generation unit automatically sets a sagging slope for carrying out reactive/voltage control according to the voltage reference value and a reactive power adjustable range thereof. The distributed photovoltaic power generation power control method provided by the invention realizes information management of distributed photovoltaic power generation, reduces the light discarding cost of the whole virtual power plant, and improves the operation efficiency; moreover, the distributed photovoltaic power generation power control method realizes the self-adaptive control of distributed photovoltaic power generation on grid-connected point voltage, reduces the influence of distributed photovoltaic power generation on power grid voltage, and ensures the normal operation of the power grid.

Description

A kind of distributed photovoltaic power generation Poewr control method based on virtual power plant

Technical field

The present invention relates to the operation control technology field of distributed photovoltaic power generation and in particular to a kind of based on virtual power plant Distributed photovoltaic power generation Poewr control method.

Background technology

In recent years, with distributed photovoltaic power generation, energy-storage system, miniature gas turbine distributed power supply (distributed Generator, dg) permeability in electrical network improves constantly, its to the monitoring of electrical network, operations, control and management carries Carry out lot of challenges.The proposition of the virtual power plant (virtual power plant, vpp) based on distributed power generation is regarded For solving a kind of new thinking of these problems, and become the focus of domestic and international research and engineering mimoir.

With the quick increase of China's distributed photovoltaic power generation grid connection capacity, the sending out of " exploitation, multiple spot dispersion access in flakes " Exhibition trend increasingly manifests, and it brings new challenge to operation, control and the management of electrical network, becomes restriction distributed photovoltaic The limiting factor developing further.First, photovoltaic generation intermittent, randomness active go out fluctuation, electrical network can be caused Power flow changing increases, thus leading to electrical network the problems such as voltage deviation is out-of-limit, voltage pulsation increases.And, photovoltaic is simultaneously The voltage deviation of site and fluctuating range are higher than all distribution net side, only rely on power distribution network and adjust load tap changer and switching simultaneously The conventional measures such as connection capacitor will be unable to meet reactive voltage regulatory demand of overall importance.Secondly, rely on existing power grid regulation Pattern, will be unable to meet following multi-point and wide-ranging distributed photovoltaic access.Distributed photovoltaic power based on virtual power plant Control technology will become the powerful measure solving the above problems.

At present existing virtual power plant power control techniques have the disadvantage that only consider virtual power plant within active Power dispatching, does not form the integral traffic control of active power and Reactive Power Control；Do not account for virtual power plant to be respectively distributed The voltage of formula generator unit access point controls and does not account for the safe transmission means of information in virtual power plant；Therefore, existing There is technology cannot meet reactive voltage regulatory demand of overall importance and the requirement of following multi-point and wide-ranging distributed photovoltaic access, It is easily caused electrical network and the problems such as voltage deviation is out-of-limit, voltage pulsation increases occurs.

Content of the invention

In view of this, a kind of distributed photovoltaic power generation Poewr control method based on virtual power plant that the present invention provides, should The monitoring and control difficult problem that method is led to by distributed photovoltaic power generation " point is many, wide " access electrical network provides a kind of effective Technological approaches；Make distributed photovoltaic power generation participate in active power scheduling and the REACTIVE POWER/VOLTAGE CONTROL of system, and realize The information management of distributed photovoltaic power generation；Decrease whole virtual power plant abandons light cost, improves on-road efficiency； It is simultaneously achieved the Self Adaptive Control to grid-connected point voltage for the distributed photovoltaic power generation, reduce distributed photovoltaic power generation to electrical network The impact of voltage is it is ensured that the normal operation of electrical network.

The purpose of the present invention is achieved through the following technical solutions:

A kind of distributed photovoltaic power generation Poewr control method based on virtual power plant, methods described is sent out by distributed photovoltaic Electric power control system is realized, and described control system includes virtual power plant control centre and distributed photovoltaic power generation unit basis Ground controls；Described virtual power plant control centre and power grid regulation center interconnect, and with each distributed photovoltaic power generation list Unit carries out data transmission in wireless public network；

Methods described comprises the steps:

Step 1. is in a scheduling slot；Described virtual power plant control centre receives each described distributed photovoltaic power generation The real-time traffic information that unit sends, described real-time traffic information includes active power output, reactive power exports, active Power adjustable adjusting range, active power regulation scope and node voltage；

What described in step 2., the described power grid regulation center of virtual power plant control centre reception was assigned has to virtual power plant The instruction of work(power dispatching and the node voltage reference value of each distributed photovoltaic access point；

Virtual power plant control centre described in step 3. abandons light cost minimization as target according to entirely described virtual power plant Active power Optimal Operation Model, obtain the active power dispatch command of each described distributed photovoltaic power generation unit；

Virtual power plant control centre described in step 4. sends described active power to each described distributed photovoltaic power generation unit Dispatch command and described node voltage reference value；

The each described distributed photovoltaic power generation unit of step 5. is according to the described active power dispatch command receiving to its own Carry out active power controller；

Reactive power adjustable extent and the described node receiving that step 6. calculates distributed photovoltaic power generation unit in real time Voltage reference value, carries out self adaptation reactive power/voltage control；

Each distributed photovoltaic power generation unit described in step 7. sends described real-time after controlling to virtual power plant control centre Operation information；

Described in the next scheduling slot of virtual power plant control centre assessment described in step 8., virtual power plant is described active Power regulating range, and assessment result is sent to power grid regulation center, assign next scheduling for described power grid regulation center The described active power dispatch command of period.

Preferably, described step 3 includes:

3-1. sets up and described abandons the active power Optimal Operation Model as target for the light cost minimization with described virtual power plant；

The object function of described scheduling model is:

$\min \underset{i=1}{\overset{n_p}{\σ}}{c}_{pv}^i(p_{pv,max}^i-p_{pv,ed}^i);$

3-2., under the constraints of described scheduling model, solves described scheduling model, obtains each described distributed photovoltaic and send out The active power dispatch command of electric unit, i.e. the disaggregation of described object function；

Wherein, described constraints is:

$\underset{i=1}{\overset{n_p}{\σ}}{p}_{pv,ed}^i=p_{vpp};$

$p_{pv,\min }^i\≤p_{pv,ed}^i\≤p_{pv,max}^i,i=1,2,...,n_p;$

In formula,Represent the active power dispatch command of distributed photovoltaic power generation unit i, the optimization for this model becomes Amount；p_vppThe active power dispatch command of the whole virtual power plant assigned for power grid regulation center；n_pRepresent virtual Distributed photovoltaic power generation unit number in power plant；Represent that distributed photovoltaic power generation unit i's abandons light cost； Maximum power generation for described distributed photovoltaic power generation unit i；Minimum for distributed photovoltaic power generation unit i Generated output, wherein,0 ＜ α ＜ 1.

Preferably, described step 5 includes:

The described active power dispatch command that each described distributed photovoltaic power generation unit of 5-1. receives；

5-2. measures active power output valve p of each described distributed photovoltaic power generation unit in real time_pv；

The each described distributed photovoltaic power generation unit of 5-3. carries out active power controller, will described active power output valve p_pv With active power dispatch command p_pv,edConstitute difference power, and make described difference power obtain parallel network reverse through pi controller Dutycycle d of device boost circuit, described pi controlling unit is provided with output upper limit d_maxWith bottoming d_min.

Preferably, described output upper limit d in described 5-3_maxWith bottoming d_minValue be:

$d_{max}=\frac{v_o-v_{pv,\min }}{v_o};$

$d_{\min }=\frac{v_o-v_{pv,max}}{v_o};$

In formula, v_oVoltage for combining inverter dc bus；v_pv,maxFor the photovoltaic battery array DC voltage upper limit； v_pv,minFor photovoltaic battery array DC voltage lower limit.

Preferably, described photovoltaic battery array DC voltage upper limit v_pv,maxAnd described photovoltaic battery array DC voltage lower limit v_pv,minProcess of asking for be:

A. the intensity of illumination in real-time measure environment variables and temperature；

B. according to described intensity of illumination and temperature, obtain the p-v curve of described distributed photovoltaic power generation unit；

C. on described p-v curve, obtain the maximum power point p of described distributed photovoltaic power generation unit_pv,maxAnd and its Corresponding described photovoltaic battery array DC voltage upper limit v_pv,max；

D. basisAnd 0 ＜ α ＜ 1, obtain the minimum power point p of distributed photovoltaic power generation unit_pv,min And corresponding described photovoltaic battery array DC voltage lower limit v_pv,min.

Preferably, described step 6, comprising:

6-1. calculates distributed photovoltaic power generation unit reactive power adjustable extent in real time, that is, be calculated described distributed light The reactive power output maximum of volt generator unit iAnd minimum of a value

6-2. is according to reactive power adjustable extent and the described node voltage reference value receiving and the described section receiving Point voltage reference value v_pv,ref, the sagging slope k of calculating:

$k=\frac{{\mathrm{\βv}}_{pv,ref}-{\mathrm{\θv}}_{pv,ref}}{q_{pv,min}-q_{pv,max}};$

6-3. calculates described reactive power and instructs q_pv:

Work as v_pv≤min(v_pcc,max,βv_pv,ref) and v_pv≥max(v_pcc,min,θv_pv,ref) when,

$q_{pv}=\frac{1}{k}{v}_{pv}-v_{pv,ref};$

Work as v_pv≥min(v_pcc,max,βv_pv,ref) when,

q_pv=q_pv,min；

Work as v_pv≤max(v_pcc,min,θv_pv,ref) when,

q_pv=q_pv,max；

In formula, v_pcc,maxFor described distributed photovoltaic power generation unit grid entry point upper voltage limit；v_pcc,minFor institute's distributed photovoltaic Generator unit grid entry point lower voltage limit；β and θ is voltage regulation limits coefficient, typically takes 1 ＜ β≤1.05,0.95≤θ ＜ 1； v_pvFor current described distributed photovoltaic power generation unit grid entry point magnitude of voltage.

Preferably, described step 6-1 includes:

Calculate the reactive power output maximum of distributed photovoltaic power generation unit i in real timeAnd minimum of a value

$q_{pv,max}^i=\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

$q_{pv,\min }^i=-\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

In formula,Reactive power output maximum for distributed photovoltaic power generation unit i；For distributed light The reactive power output minimum of a value of volt generator unit i；The specified appearance of combining inverter for distributed photovoltaic power generation unit i Amount；Real-time active power output for distributed photovoltaic power generation unit i.

Preferably, the full detail transmitting between described virtual power plant control centre and described distributed photovoltaic power generation unit All through data message encryption.

Preferably, each described scheduling slot when a length of 5 to 15 minutes.

It can be seen from above-mentioned technical scheme that, the invention provides a kind of distributed photovoltaic power generation based on virtual power plant Poewr control method；Active power Optimization Scheduling is run on virtual power plant control centre, by power grid regulation center The virtual power plant active power dispatch command assigned be optimized distribution and under reach each distributed photovoltaic power generation system in factory System；The node voltage reference value that virtual power plant control centre is assigned according to power grid regulation center, each distributed photovoltaic is sent out Electric system, according to voltage reference value and own reactive power adjustable adjusting range, automatically arranges sagging slope and carries out REACTIVE POWER/VOLTAGE Control.Method proposed by the present invention achieves the information management of distributed photovoltaic power generation；Decrease whole virtual power plant Abandon light cost, improve on-road efficiency；It is simultaneously achieved the Self Adaptive Control to grid-connected point voltage for the distributed photovoltaic power generation, Reduce the impact to line voltage for the distributed photovoltaic power generation it is ensured that the normal operation of electrical network.

With immediate prior art ratio, the technical scheme that the present invention provides has a following excellent effect:

1st, technical scheme provided by the present invention, by the active power Optimization Scheduling of virtual power plant distributed photovoltaic, The self adaptation REACTIVE POWER/VOLTAGE CONTROL method of virtual power plant distributed photovoltaic, and the letter of virtual power plant distributed photovoltaic Breath transmission method composition；It accesses, by distributed photovoltaic power generation " point is many, wide ", the monitoring and control hardly possible that electrical network is led to Topic provides a kind of effective technological approaches；Achieve the information management of distributed photovoltaic power generation；Decrease entirely virtual Power plant abandons light cost, improves on-road efficiency；It is simultaneously achieved the self adaptation to grid-connected point voltage for the distributed photovoltaic power generation Control, reduce the impact to line voltage for the distributed photovoltaic power generation it is ensured that the normal operation of electrical network.

2nd, technical scheme provided by the present invention, by active power and Reactive Power Control so that distributed photovoltaic is sent out The active power scheduling of electric participation system and REACTIVE POWER/VOLTAGE CONTROL.

3rd, technical scheme provided by the present invention, by security information transmission in virtual power plant it is achieved that distributed light The information management that volt generates electricity.

4th, technical scheme provided by the present invention, in virtual power plant active power economic load dispatching, decreases whole void That sends out power plant abandons light cost, improves on-road efficiency.

5th, technical scheme provided by the present invention, it is achieved that distributed photovoltaic power generation in REACTIVE POWER/VOLTAGE Self Adaptive Control Self Adaptive Control to grid-connected point voltage, reduces the impact to line voltage for the distributed photovoltaic power generation.

6th, the technical scheme that the present invention provides, is widely used, has significant Social benefit and economic benefit.

Brief description

Fig. 1 is a kind of flow chart of distributed photovoltaic power generation Poewr control method based on virtual power plant of the present invention；

Fig. 2 is the schematic flow sheet of the step 3 of control method of the present invention；

Fig. 3 is the schematic flow sheet of the step 5 of control method of the present invention；

Fig. 4 is the schematic flow sheet of the step 6 of control method of the present invention；

Fig. 5 is the signal of the application examples of the distributed photovoltaic power generation Poewr control method based on virtual power plant of the present invention Figure；

Fig. 6 is the distributed photovoltaic power generation unit active power controller schematic diagram in the application examples of the control method of the present invention；

Fig. 7 is distributed photovoltaic power generation p-v curve and v in the application examples of the control method of the present invention_pv,max, v_pv,min Schematic diagram；

Fig. 8 is the REACTIVE POWER/VOLTAGE CONTROL method of the distributed photovoltaic power generation unit in the application examples of the control method of the present invention Schematic diagram.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Ground description is it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Base In embodiments of the invention, those of ordinary skill in the art obtained under the premise of not making creative work all its His embodiment, broadly falls into the scope of protection of the invention.

As shown in figure 1, the present invention provides a kind of distributed photovoltaic power generation Poewr control method based on virtual power plant, side Method is realized by distributed photovoltaic power generation power control system, and control system includes virtual power plant control centre and distributed Photovoltaic generation unit locally controls；Virtual power plant control centre is interconnected with power grid regulation center, and distributed with each Photovoltaic generation unit carries out data transmission in wireless public network；

Method comprises the steps:

Step 1. is in a scheduling slot；Virtual power plant control centre receives each distributed photovoltaic power generation unit and sends Real-time traffic information, real-time traffic information include active power output, reactive power output, active power can adjust model Enclose, active power regulation scope and node voltage；

Step 2. virtual power plant control centre receives the active power to virtual power plant assigned at power grid regulation center and adjusts Degree instruction and the node voltage reference value of each distributed photovoltaic access point；

Step 3. virtual power plant control centre abandons the wattful power as target for the light cost minimization according to whole virtual power plant Rate Optimal Operation Model, obtains the active power dispatch command of each distributed photovoltaic power generation unit；

Step 4. virtual power plant control centre sends active power dispatch command and section to each distributed photovoltaic power generation unit Point voltage reference value；

Step 5. each distributed photovoltaic power generation unit carries out active according to the active power dispatch command receiving to its own Power Control；

Step 6. calculates the reactive power adjustable extent of distributed photovoltaic power generation unit and the node voltage receiving in real time Reference value, carries out self adaptation reactive power/voltage control；

Step 7. each distributed photovoltaic power generation unit sends the real time execution letter after controlling to virtual power plant control centre Breath；

The active power regulation model of the next scheduling slot virtual power plant of step 8. virtual power plant control centre assessment Enclose, and assessment result is sent to power grid regulation center, power supply network regulates and controls the active power that next scheduling slot is assigned at center Dispatch command.

As shown in Fig. 2 step 3 includes:

3-1. sets up and abandons the active power Optimal Operation Model as target for the light cost minimization with virtual power plant；

The object function of scheduling model is:

$min\underset{i=1}{\overset{n_p}{\σ}}{c}_{pv}^i(p_{pv,max}^i-p_{pv,ed}^i);$

3-2., under the constraints of scheduling model, solves scheduling model, obtains the active of each distributed photovoltaic power generation unit Power dispatching instructs, i.e. the disaggregation of object function；

Wherein, constraints is:

$\underset{i=1}{\overset{n_p}{\σ}}{p}_{pv,ed}^i=p_{vpp};$

$p_{pv,\min }^i\≤p_{pv,ed}^i\≤p_{pv,max}^i,i=1,2,...,n_p;$

In formula,Represent the active power dispatch command of distributed photovoltaic power generation unit i, the optimization for this model becomes Amount；p_vppThe active power dispatch command of the whole virtual power plant assigned for power grid regulation center；n_pRepresent virtual Distributed photovoltaic power generation unit number in power plant；Represent that distributed photovoltaic power generation unit i's abandons light cost； Maximum power generation for distributed photovoltaic power generation unit i；Minimum generating for distributed photovoltaic power generation unit i Power, wherein,0 ＜ α ＜ 1.

As shown in figure 3, step 5 includes:

The active power dispatch command that 5-1. each distributed photovoltaic power generation unit receives；

5-2. measures active power output valve p of each distributed photovoltaic power generation unit in real time_pv；

5-3. each distributed photovoltaic power generation unit carries out active power controller, will active power output valve p_pvWith wattful power Rate dispatch command p_pv,edConstitute difference power, and make difference power obtain combining inverter boost circuit through pi controller Dutycycle d, pi controlling unit be provided with output upper limit d_maxWith bottoming d_min.

Wherein, output upper limit d in 5-3_maxWith bottoming d_minValue be:

$d_{max}=\frac{v_o-v_{pv,\min }}{v_o};$

$d_{\min }=\frac{v_o-v_{pv,max}}{v_o};$

In formula, v_oVoltage for combining inverter dc bus；v_pv,maxFor the photovoltaic battery array DC voltage upper limit； v_pv,minFor photovoltaic battery array DC voltage lower limit.

Wherein, photovoltaic battery array DC voltage upper limit v_pv,maxAnd photovoltaic battery array DC voltage lower limit v_pv,minAsk The process is taken to be:

A. the intensity of illumination in real-time measure environment variables and temperature；

B. according to intensity of illumination and temperature, obtain the p-v curve of distributed photovoltaic power generation unit；

C. on p-v curve, obtain the maximum power point p of distributed photovoltaic power generation unit_pv,maxAnd corresponding light Volt array DC voltage upper limit v_pv,max；

D. basisAnd 0 ＜ α ＜ 1, obtain the minimum power point p of distributed photovoltaic power generation unit_pv,min And corresponding photovoltaic battery array DC voltage lower limit v_pv,min.

As shown in figure 4, step 6, comprising:

6-1. calculates distributed photovoltaic power generation unit reactive power adjustable extent in real time, that is, be calculated distributed photovoltaic and send out The reactive power output maximum of electric unit iAnd minimum of a value

6-2. according to reactive power adjustable extent and the node voltage reference value receiving and receive node voltage ginseng Examine value v_pv,ref, the sagging slope k of calculating:

$k=\frac{{\mathrm{\βv}}_{pv,ref}-{\mathrm{\θv}}_{pv,ref}}{q_{pv,min}-q_{pv,max}};$

6-3. calculates reactive power instruction q_pv:

Work as v_pv≤min(v_pcc,max,βv_pv,ref) and v_pv≥max(v_pcc,min,θv_pv,ref) when,

$q_{pv}=\frac{1}{k}{v}_{pv}-v_{pv,ref};$

Work as v_pv≥min(v_pcc,max,βv_pv,ref) when,

q_pv=q_pv,min；

Work as v_pv≤max(v_pcc,min,θv_pv,ref) when,

q_pv=q_pv,max；

In formula, v_pcc,maxFor described distributed photovoltaic power generation unit grid entry point upper voltage limit；v_pcc,minFor institute's distributed photovoltaic Generator unit grid entry point lower voltage limit；β and θ is voltage regulation limits coefficient, typically takes 1 ＜ β≤1.05,0.95≤θ ＜ 1； v_pvFor current described distributed photovoltaic power generation unit grid entry point magnitude of voltage.

Wherein, step 6-1, comprising:

Calculate the reactive power output maximum of distributed photovoltaic power generation unit i in real timeAnd minimum of a value

$q_{pv,max}^i=\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

$q_{pv,\min }^i=-\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

In formula,Reactive power output maximum for distributed photovoltaic power generation unit i；For distributed light The reactive power output minimum of a value of volt generator unit i；The specified appearance of combining inverter for distributed photovoltaic power generation unit i Amount；Real-time active power output for distributed photovoltaic power generation unit i.

Between virtual power plant control centre and distributed photovoltaic power generation unit, the full detail of transmission is all through data message Encryption.

Each scheduling slot when a length of 5 to 15 minutes.

As shown in figure 5, the application examples of the present invention provides a kind of distributed photovoltaic power generation Power Control based on virtual power plant Method, method is realized by distributed photovoltaic power generation power control system, and control system includes virtual power plant control centre With distributed photovoltaic power generation unit；Virtual power plant control centre is interconnected with power grid regulation center, and distributed with each Photovoltaic generation unit carries out data transmission in wireless public network；

Wherein, to adjust the period for 5 minutes once in this application examples；α=0.8；As a example β=1.05 and θ=0.95, explanation should Method；

Comprise the steps:

(1) in virtual power plant control centre, receive the real-time traffic information that each distributed photovoltaic power generation unit sends, Including: active power output, reactive power output, active power adjustable extent, active power regulation scope and section Point voltage.

(2) in virtual power plant control centre, receive the virtual power plant active power scheduling assigned at power grid regulation center Instruction, and the node voltage reference value of each distributed photovoltaic access point, receive the period for every 5 minutes 1 time.

(3) in virtual power plant control centre, set up and solve and light cost minimization is abandoned as target with whole virtual power plant Active power Optimal Operation Model, obtain the active power dispatch command of each distributed photovoltaic power generation unit, meet electrical network The virtual power plant active power dispatch command that regulation and control center is assigned, and each distributed photovoltaic power generation unit active power tune Adjusting range constrains.Active power Optimal Operation Model is:

Object function:

$min\underset{i=1}{\overset{n_p}{\σ}}{c}_{pv}^i(p_{pv,max}^i-p_{pv,ed}^i);$

Constraints:

$\underset{i=1}{\overset{n_p}{\σ}}{p}_{pv,ed}^i=p_{vpp};$

$p_{pv,min}^i\≤p_{pv,ed}^i\≤p_{pv,max}^i,i=1,2,...,n_p;$

Wherein:

Represent the active power dispatch command of distributed photovoltaic power generation unit i, for the optimized variable of this model；p_vpp The active power dispatch command of the whole virtual power plant assigned for power grid regulation center；n_pRepresent in virtual power plant Distributed photovoltaic power generation unit number；Represent that distributed photovoltaic power generation unit i's abandons light cost；For recording in advance The maximum power generation of the distributed photovoltaic power generation unit i arriving；Minimum for distributed photovoltaic power generation unit i is sent out Electrical power, general setting

(4) in virtual power plant control centre, to each distributed photovoltaic power generation unit send active power dispatch command and Node voltage reference value.

(5) local in each distributed photovoltaic power generation unit, receive the active power tune that virtual power plant control centre assigns Degree instruction and node voltage reference value.

(6) as shown in fig. 6, local in each distributed photovoltaic power generation unit, the active power scheduling that foundation receives refers to Order, carries out active power controller；The active power output p of measurement distributed photovoltaic power generation unit in real time_pv, its with active Power dispatching instructs p_pv,edDifference obtain dutycycle d of combining inverter boost circuit through pi controlling unit.Pi is controlled Link processed is provided with output bound d_max, d_min, its value is,

$d_{max}=\frac{v_o-v_{pv,min}}{v_o};$

$d_{min}=\frac{v_o-v_{pv,max}}{v_o};$

Wherein, v_oVoltage for combining inverter dc bus；v_pv,max, v_pv,minFor photovoltaic battery array DC voltage Bound.

v_pv,max, v_pv,minComputational methods as shown in fig. 7, becoming according to environment such as the intensity of illumination of real-time measurement, temperature Amount, obtains the p-v curve of distributed photovoltaic power generation unit, thus obtaining the maximum power point of distributed photovoltaic power generation unit p_pv,maxAnd corresponding voltage v_pv,max, then according to the p setting_pv,min=0.8p_pv,max, obtain distributed photovoltaic The minimum power point p of generator unit_pv,minAnd its corresponding voltage v_pv,min.

(7) local in each distributed photovoltaic power generation unit, calculate distributed photovoltaic power generation unit reactive power in real time adjustable Adjusting range:

$q_{pv,max}^i=\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2}$

$q_{pv,\min }^i=-\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2}$

Wherein:

Reactive power output maximum for distributed photovoltaic power generation unit i；For distributed photovoltaic power generation The reactive power output minimum of a value of unit i；Combining inverter rated capacity for distributed photovoltaic power generation unit i； Real-time active power output for distributed photovoltaic power generation unit i；

As shown in figure 8, simultaneously according to the node voltage reference value receiving, carrying out REACTIVE POWER/VOLTAGE CONTROL.Survey according to real-time The node voltage value of amount calculates the reactive power instruction of distributed photovoltaic power generation unit.In figure: v_pv,refFor the section receiving Point voltage reference value；v_pcc,maxFor grid entry point upper voltage limit；v_pcc,minFor grid entry point lower voltage limit；v_pvFor current institute State distributed photovoltaic power generation unit grid entry point magnitude of voltage.

Sagging slope is calculated by following formula,

$k=\frac{1.05v_{pv,ref}-0.95v_{pv,ref}}{q_{pv,min}-q_{pv,max}};$

The computational methods of reactive power instruction are as follows,

Work as v_pv≤min(v_pcc,max,1.05v_pv,ref) and v_pv≥max(v_pcc,min,0.95v_pv,ref) when,

$q_{pv}=\frac{1}{k}{v}_{pv}-v_{pv,ref};$

Work as v_pv≥min(v_pcc,max,0.95v_pv,ref) when,

q_pv=q_pv,min；

Work as v_pv≤max(v_pcc,min,0.95v_pv,ref) when,

q_pv=q_pv,max；

(8) local in each distributed photovoltaic power generation unit, send next scheduling slot to virtual power plant control centre Active power regulation scope.

(9) in virtual power plant control centre, the active power regulation of the assessment whole virtual power plant of next scheduling slot Scope, and send to power grid regulation center, so that dispatch command is assigned at power grid regulation center.

Above example is only not intended to limit in order to technical scheme to be described, although with reference to above-described embodiment to this Invention has been described in detail, and those of ordinary skill in the art still can enter to the specific embodiment of the present invention Row modification or equivalent, and these are without departing from any modification of spirit and scope of the invention or equivalent, it is equal Within the claims applying for the pending present invention.

Claims (9)

1. a kind of distributed photovoltaic power generation Poewr control method based on virtual power plant is it is characterised in that methods described Realized by distributed photovoltaic power generation power control system, described control system includes virtual power plant control centre and distribution Formula photovoltaic generation unit locally controls；Described virtual power plant control centre and power grid regulation center interconnect, and with each Distributed photovoltaic power generation unit carries out data transmission in wireless public network；

Methods described comprises the steps:

Step 1. is in a scheduling slot；Described virtual power plant control centre receives each described distributed photovoltaic power generation The real-time traffic information that unit sends, described real-time traffic information includes active power output, reactive power exports, active Power adjustable adjusting range, active power regulation scope and node voltage；

What described in step 2., the described power grid regulation center of virtual power plant control centre reception was assigned has to virtual power plant The instruction of work(power dispatching and the node voltage reference value of each distributed photovoltaic access point；

Virtual power plant control centre described in step 3. abandons light cost minimization as target according to entirely described virtual power plant Active power Optimal Operation Model, obtain the active power dispatch command of each described distributed photovoltaic power generation unit；

Virtual power plant control centre described in step 4. sends described active power to each described distributed photovoltaic power generation unit Dispatch command and described node voltage reference value；

The each described distributed photovoltaic power generation unit of step 5. is according to the described active power dispatch command receiving to its own Carry out active power controller；

Reactive power adjustable extent and the described node receiving that step 6. calculates distributed photovoltaic power generation unit in real time Voltage reference value, carries out self adaptation reactive power/voltage control；

Each distributed photovoltaic power generation unit described in step 7. sends described real-time after controlling to virtual power plant control centre Operation information；

Described in the next scheduling slot of virtual power plant control centre assessment described in step 8., virtual power plant is described active Power regulating range, and assessment result is sent to power grid regulation center, assign next scheduling for described power grid regulation center The described active power dispatch command of period.

2. the method for claim 1 is it is characterised in that described step 3 includes:

3-1. sets up and described abandons the active power Optimal Operation Model as target for the light cost minimization with described virtual power plant；

The object function of described scheduling model is:

$min\underset{i=1}{\overset{n_p}{\σ}}{c}_{pv}^i(p_{pv,max}^i-p_{pv,ed}^i);$

3-2., under the constraints of described scheduling model, solves described scheduling model, obtains each described distributed photovoltaic and send out The active power dispatch command of electric unit, i.e. the disaggregation of described object function；

Wherein, described constraints is:

$\underset{i=1}{\overset{n_p}{\σ}}{p}_{pv,ed}^i=p_{vpp};$

$p_{pv,\min }^i\≤p_{pv,ed}^i\≤p_{pv,max}^i,i=1,2,...,n_p;$

In formula,Represent the active power dispatch command of distributed photovoltaic power generation unit i, the optimization for this model becomes Amount；p_vppThe active power dispatch command of the whole virtual power plant assigned for power grid regulation center；n_pRepresent virtual Distributed photovoltaic power generation unit number in power plant；Represent that distributed photovoltaic power generation unit i's abandons light cost； Maximum power generation for described distributed photovoltaic power generation unit i；Minimum for distributed photovoltaic power generation unit i Generated output, wherein, $p_{pv,\min }^i={\mathrm{\&alpha;p}}_{pv,max}^i,0<\mathrm{\&alpha;}<1.$

3. method as claimed in claim 2 is it is characterised in that described step 5 includes:

The described active power dispatch command that each described distributed photovoltaic power generation unit of 5-1. receives；

5-2. measures active power output valve p of each described distributed photovoltaic power generation unit in real time_pv；

The each described distributed photovoltaic power generation unit of 5-3. carries out active power controller, will described active power output valve p_pv With active power dispatch command p_pv,edConstitute difference power, and make described difference power obtain parallel network reverse through pi controller Dutycycle d of device boost circuit, described pi controlling unit is provided with output upper limit d_maxWith bottoming d_min.

4. method as claimed in claim 3 is it is characterised in that described output upper limit d in described 5-3_maxWith defeated Go out lower limit d_minValue be:

$d_{max}=\frac{v_o-v_{pv,\min }}{v_o};$

$d_{\min }=\frac{v_o-v_{pv,max}}{v_o};$

In formula, v_oVoltage for combining inverter dc bus；v_pv,maxFor the photovoltaic battery array DC voltage upper limit； v_pv,minFor photovoltaic battery array DC voltage lower limit.

5. method as claimed in claim 4 is it is characterised in that described photovoltaic battery array DC voltage upper limit v_pv,max And described photovoltaic battery array DC voltage lower limit v_pv,minProcess of asking for be:

A. the intensity of illumination in real-time measure environment variables and temperature；

B. according to described intensity of illumination and temperature, obtain the p-v curve of described distributed photovoltaic power generation unit；

C. on described p-v curve, obtain the maximum power point p of described distributed photovoltaic power generation unit_pv,maxAnd and its Corresponding described photovoltaic battery array DC voltage upper limit v_pv,max；

D. basisAnd 0 ＜ α ＜ 1, obtain the minimum power point p of distributed photovoltaic power generation unit_pv,min And corresponding described photovoltaic battery array DC voltage lower limit v_pv,min.

6. method as claimed in claim 5 is it is characterised in that described step 6, comprising:

6-1. calculates distributed photovoltaic power generation unit reactive power adjustable extent in real time, that is, be calculated described distributed light The reactive power output maximum of volt generator unit iAnd minimum of a value

6-2. is according to reactive power adjustable extent and the described node voltage reference value receiving and the described section receiving Point voltage reference value v_pv,ref, the sagging slope k of calculating:

$k=\frac{{\mathrm{\&beta;v}}_{pv,ref}-{\mathrm{\&theta;v}}_{pv,ref}}{q_{pv,\min }-q_{pv,max}};$

6-3. calculates described reactive power and instructs q_pv:

Work as v_pv≤min(v_pcc,max,βv_pv,ref) and v_pv≥max(v_pcc,min,θv_pv,ref) when,

$q_{pv}=\frac{1}{k}{v}_{pv}-v_{pv,ref};$

Work as v_pv≥min(v_pcc,max,βv_pv,ref) when,

q_pv=q_pv,min；

Work as v_pv≤max(v_pcc,min,θv_pv,ref) when,

q_pv=q_pv,max；

In formula, v_pcc,maxFor described distributed photovoltaic power generation unit grid entry point upper voltage limit；v_pcc,minFor institute's distributed photovoltaic Generator unit grid entry point lower voltage limit；β and θ is voltage regulation limits coefficient, typically takes 1 ＜ β≤1.05,0.95≤θ ＜ 1； v_pvFor current described distributed photovoltaic power generation unit grid entry point magnitude of voltage.

7. method as claimed in claim 6 is it is characterised in that described step 6-1 includes:

Calculate the reactive power output maximum of distributed photovoltaic power generation unit i in real timeAnd minimum of a value

$q_{pv,max}^i=\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

$q_{pv,\min }^i=-\sqrt{{s_{pv}^i}^2-{p_{pv}^i}^2};$

In formula,Reactive power output maximum for distributed photovoltaic power generation unit i；For distributed light The reactive power output minimum of a value of volt generator unit i；The specified appearance of combining inverter for distributed photovoltaic power generation unit i Amount；Real-time active power output for distributed photovoltaic power generation unit i.

8. the method for claim 1 is it is characterised in that described virtual power plant control centre and described distribution Between formula photovoltaic generation unit, the full detail of transmission is all through data message encryption.

9. the method for claim 1 it is characterised in that each described scheduling slot when a length of 5 to 15 points Clock.