Distributed power source maximum permeability appraisal procedure based on time scene access analysis
Technical field
The invention belongs to the distribution network planning technical field, be specifically related to a kind of distributed power source maximum permeability appraisal procedure of analyzing based on time scene access.
Background technology
Being incorporated into the power networks of distributed energy will make traditional power distribution network become an active network by a radial passive network, and this has changed, and the original trend in the electric power system distributes and protection arranges.Simultaneously, because distributed power source has characteristics such as quantity is many, scope is wide, capacity is little, randomness, intermittence, along with the large-scale application of distributed power source, distribution network planning will be subjected to appreciable impact with operation.
(Penetration Level is to weigh the important indicator that distributed power source influences power distribution network in a certain zone PL) to the distributed power source permeability, and it is defined as the ratio of distributed power source gross capability and regional power load.The assessment of distributed power source maximum permeability namely provides a certain electrical network the maximum of distributed power source is admitted capacity.Satisfy this condition, need electrical network all to be at any one time within the various electric constraints.Along with distributed power source quantity progressively increases, the analysis and assessment of distributed power source maximum permeability have become the important content of distribution network planning, also can produce useful influence to the lifting of distributed power source utilization ratio and power distribution network overall efficiency simultaneously.
At present, the assessment of distributed power source maximum permeability is generally stipulated according to the correlation technique guide rule, or it is definite based on planning personnel's experience, assessment result can not truly reflect power distribution network to the admittance ability of distributed power source, therefore needs a kind of distributed power source maximum permeability appraisal procedure of systematic science badly.
Summary of the invention
In order to overcome above-mentioned the deficiencies in the prior art, the invention provides a kind of distributed power source maximum permeability appraisal procedure of analyzing based on time scene access, this method is by analyzing network load characteristic and distributed power source power producing characteristics, choose electrical network time scene, and under selected electrical network time scene, carry out the capacity analysis of electrical network access, and then obtain distributed power source maximum permeability assessment result, can be good at solving the evaluation problem that distributed power source is admitted ability.
In order to realize the foregoing invention purpose, the present invention takes following technical scheme:
A kind of distributed power source maximum permeability appraisal procedure of analyzing based on time scene access is provided, said method comprising the steps of:
Step 1: network load characteristic and distributed power source power producing characteristics are analyzed;
Step 2: choose electrical network time scene;
Step 3: analyze the electrical network access capacity under the electrical network time scene;
Step 4: the maximum permeability of comprehensively determining distributed power source.
In the described step 1, described network load characteristic comprises year part throttle characteristics and daily load characteristic; Based on the network load historical data, analysis electrical network year part throttle characteristics and electrical network daily load characteristic are determined the peak interval of time of electrical network year part throttle characteristics and the peak interval of time of electrical network daily load characteristic, namely finish the analysis to the network load characteristic.
Described electrical network year part throttle characteristics peak interval of time and the peak interval of time load of the peak interval of time correspondence of electrical network daily load characteristic be defined as:
PL
Peak(t)=PL (t), and PL (t)>PL
Min+ 80% (PL
Max-PL
Min) (1)
PL
Valley(t)=PL (t), and PL (t)<PL
Min+ 20% (PL
Max-PL
Min) (2)
Wherein, PL
Peak(t) be electrical network load peak period, PL
Valley(t) be electrical network low-valley interval load, PL (t) is the network load of moment t, PL
MaxBe electrical network peak load, PL
MinBe the electrical network minimum load.
In the described step 1, based on distributed power source power producing characteristics model and local climate historical data, obtain the year power producing characteristics curve of distributed power source by Monte Carlo simulation, determine the peak interval of time of distributed power source year power producing characteristics and the peak interval of time of daily output characteristic, namely finish the analysis to the distributed power source power producing characteristics.
Peak interval of time and the peak interval of time corresponding distributed power supply peak interval of time of daily output characteristic of power producing characteristics exerted oneself and be defined as described distributed power source year:
PG
Peak(t)=PG (t), and PG (t)>PG
Min+ 80% (PG
Max-PG
Min) (3)
PG
Valley(t)=PG (t), and PG (t)<PG
Min+ 20% (PG
Max-PG
Min) (4)
Wherein, PG
Peak(t) exert oneself PG peak period for distributed power source
Valley(t) exert oneself for the distributed power source low-valley interval, PG (t) exerts oneself PG for the distributed power source of moment t
MaxBe distributed power source maximum output, PG
MinFor the distributed power source minimum is exerted oneself.
In the described step 2, comprehensive network load characteristic and distributed power source power producing characteristics analysis result, select electrical network to face the worst moment of electric situation, namely choose distributed power source and exert oneself moment with network load ratio maximum as electrical network time scene, concrete choosing method is as follows:
Wherein, T is the moment of choosing.
In the described step 3, based on the above electrical network time scene of choosing, carry out the analysis of electrical network access capacity;
Described electrical network access capacity satisfies:
Wherein, P
LineBe line power, P
LimitBe circuit maximum transmission power, V
NodeBe node voltage, V
Limit-HighAnd V
Limit-LowBe respectively the upper limit and the lower limit of line voltage, I
SBe system short-circuit electric current, I
LimitBe the short circuit current limit value.
In the described step 4, the electrical network access capacity under the electrical network time scene that obtains based on above analysis determines that comprehensively the maximum of distributed power source is admitted capacity, i.e. distributed power source maximum permeability.
Compared with prior art, beneficial effect of the present invention is:
(1) the distributed power source maximum permeability appraisal procedure of analyzing based on time scene access provided by the invention, the entire flow of distributed power source permeability assessment has been proposed, this method is based on the network load characteristic, the analytical calculation of the simulation analysis of distributed power source power producing characteristics and electrical network access capacity, not only assessed the admittance ability of electrical network at the different time section, and considered the stochastic behaviour of distributed power source and network load, permeability assessment result adaptability is stronger, has solved the problem that present distributed power source permeability assessment too relies on experience or imposes uniformity without examining individual cases according to the technology guide rule.
(2) the distributed power source maximum permeability appraisal procedure of analyzing based on time scene access provided by the invention, the choosing method of electrical network time scene has been proposed, namely select distributed power source to exert oneself the moment the highest with network load ratio, the method of the annual 8760 hours electric situations of electrical network of this method and emulation is compared, and has reduced the analytical work amount greatly guaranteeing to assess under the prerequisite of accuracy.
Description of drawings
Fig. 1 is based on the distributed power source maximum permeability appraisal procedure flow chart that time scene access is analyzed;
Fig. 2 is the year part throttle characteristics schematic diagram in selected area in the embodiment of the invention;
Fig. 3 is the typical daily load characteristic schematic diagram in selected area in the embodiment of the invention;
Fig. 4 is the year wind power in selected area in the embodiment of the invention;
Fig. 5 is the year photovoltaic power curve figure in selected area in the embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing the present invention is described in further detail.
Fig. 1 is the distributed power source maximum permeability appraisal procedure flow chart of analyzing based on time scene access.
Present embodiment is example with certain medium-sized city, the north, choose certain typical 10kV circuit, look to the future and to insert two kinds of distributed power sources of photovoltaic (inverter type) and blower fan (type synchronously), line load characteristic and climate change characteristic are assessed at the distributed power source maximum permeability that this circuit carries out analyzing based on time scene access all with reference to this area's actual load data and climatic data.
One, analyzes the network load characteristic
Analyze the year part throttle characteristics and typical daily load characteristic of this area, respectively shown in accompanying drawing 2, accompanying drawing 3.
The network load specificity analysis can obtain, and loads in electrical network year to occur in summer (August) peak period, and occur in winter (February) another peak period of load in electrical network year, and a year load valley period occurs in spring (April); The electrical network daily load generally occurs in night () at 20~21 o'clock peak period, and the daily load low-valley interval generally occurs in morning () at 4~5 o'clock, and the low-valley interval in the daytime of daily load occurs in noon () at 13 o'clock.
Two, analysis distribution formula power supply power producing characteristics
Utilize distributed power source exert oneself model, installation scale and local climate data, emulation obtains the year power producing characteristics of photovoltaic and blower fan, respectively shown in accompanying drawing 4, accompanying drawing 5.
The analysis of distributed power source power producing characteristics can obtain because this area's wind speed in spring is bigger, wind power generally occur in the night in spring year peak period; The year that the solar irradiation intensity maximum in same spring, photovoltaic are exerted oneself generally occurs in the noon in spring peak period.
Three, scene is chosen the electrical network time
According to the analysis of above part throttle characteristics and power supply power producing characteristics, choose the time scene of electrical network access capacity analysis.When the distributed power source of certain permeability can not pass through the electric constraint of electrical network under this time scene, think that namely this permeability level has exceeded the admittance ability of electrical network.It is as shown in table 1 that the time scene is chosen the result:
Table 1
The DG type |
Date |
Constantly |
The line load rate |
The DG power factor |
Blower fan |
Spring (April 20) |
4 o'clock |
20% |
90% |
Photovoltaic |
Spring (April 20) |
13 o'clock |
40% |
100% |
Four, analyze electrical network access capacity
Respectively blower fan and photovoltaic are carried out the analysis of electrical network access under the time corresponding scene, by the power constraint situation under the different permeabilities of heuristic analysis, simulation result (only having listed near two kinds of situations of maximum permeability critical value) as shown in table 2:
Table 2
Can be seen by last table result:
(1) after blower fan access electrical network permeability reaches 65%, when the on-position is positioned at line end, the voltage of blower fan and site (U3) out-of-limit (10.7kV), short circuit current and line load are within constraint.It is 60% o'clock that blower fan inserts the electrical network permeability, all can not break through power constraint under the various access waies.
(2) after photovoltaic access electrical network permeability reaches 95%, when the on-position is positioned at line end, the voltage of grid-connected point (U3) out-of-limit (10.7kV), short circuit current and line load are within constraint.It is 90% o'clock that photovoltaic inserts the electrical network permeability, all can not break through power constraint under the various access waies.
Five, comprehensively determine the distributed power source maximum permeability
According to the electrical network access capacity analysis under the above time scene:
(1) blower fan access electrical network permeability is 60% o'clock, all can not break through power constraint under the various access waies, can determine that therefore the maximum permeability of blower fan access electrical network in the present embodiment is 60%;
(2) after photovoltaic access electrical network permeability reaches 90%, all can not break through power constraint under the various access waies, can determine that therefore the maximum permeability of photovoltaic access electrical network in the present embodiment is 90%.
Six, conclusion
(1) since analysis and assessment based on the emulation to this area's distributed power source and network load stochastic behaviour, so science and adaptability that permeability is assessed are stronger.
(2) distributed power source is exerted oneself the bigger electric ill-conditioned moment by the selection network load is less, not only can reflect well that distributed power source is to the influence of power distribution network, and compare with the method for the annual 8760 hours electric situations of electrical network of emulation, can reduce the workload of analyzing greatly.
Should be noted that at last: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment the present invention is had been described in detail, those of ordinary skill in the field are to be understood that: still can make amendment or be equal to replacement the specific embodiment of the present invention, and do not break away from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of the claim scope of the present invention.