CN111563691A - Performance evaluation method for AC/DC hybrid power distribution network accessed with new energy - Google Patents
Performance evaluation method for AC/DC hybrid power distribution network accessed with new energy Download PDFInfo
- Publication number
- CN111563691A CN111563691A CN202010419490.4A CN202010419490A CN111563691A CN 111563691 A CN111563691 A CN 111563691A CN 202010419490 A CN202010419490 A CN 202010419490A CN 111563691 A CN111563691 A CN 111563691A
- Authority
- CN
- China
- Prior art keywords
- new energy
- distribution network
- power
- calculation model
- calculation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
- G06Q10/063—Operations research, analysis or management
- G06Q10/0639—Performance analysis of employees; Performance analysis of enterprise or organisation operations
- G06Q10/06393—Score-carding, benchmarking or key performance indicator [KPI] analysis
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
- G06Q50/06—Electricity, gas or water supply
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
Abstract
The invention discloses a performance evaluation method of an alternating current-direct current hybrid power distribution network accessed with new energy, which comprises the following steps: new energy is accessed based on the radial distribution network, the double-end distribution network and the annular distribution network respectively; establishing a comprehensive evaluation index system with four dimensions of economy, reliability, electric energy quality and new energy consumption capacity, and constructing a comprehensive evaluation index calculation model, wherein the comprehensive evaluation index calculation model comprises an economy index calculation model, a reliability index calculation model, an electric energy quality index calculation model and a new energy consumption capacity index calculation model; carrying out scene clustering based on the uncertainty of new energy, and solving the comprehensive evaluation index model; and planning the alternating current-direct current hybrid power distribution network based on the solving result. The comprehensive evaluation index system constructed by the invention considers the diversity of loads and the volatility of new energy, and provides a practical scheme for planning future alternating current and direct current power distribution networks.
Description
Technical Field
The invention relates to the technical field of alternating current and direct current hybrid power distribution networks, in particular to a new energy source accessed alternating current and direct current hybrid power distribution network performance evaluation method.
Background
Traditional alternating current distribution system faces a series of problems such as line loss height, power quality disturbance, voltage drop, is difficult to satisfy power consumer's growing electric power demand, compares with alternating current distribution network, and direct current power supply can effectively solve power quality problems such as harmonic, unbalanced three-phase, and the advantage is obvious in the aspect of improving power supply quality, and consequently, builds the development trend that the alternating current-direct current mixes the distribution network on alternating current distribution network's basis is the distribution network in the future.
At present, researches on the evaluation indexes of the power distribution network at home and abroad are carried out to different degrees, the evaluation indexes are established in various ways and relate to a direct current power distribution network, a traditional alternating current power distribution network and an alternating current and direct current hybrid power distribution network, but the comprehensive evaluation index system of the alternating current and direct current power distribution network is rarely researched, and the index system is relatively single; considering that the territory of China is wide, the difference of supply and demand of power distribution networks in different regions is large, the access situations of new energy are different, and the load demands of all regions are different, the power distribution network is planned to become the problem to be solved urgently in the future planning of the power distribution network by combining the actual situations of different regions and considering how the power distribution network should be planned after the new energy is accessed; however, the existing evaluation index is relatively single, the fluctuation and uncertainty of the comprehensive index after the new energy is accessed are not considered, and the problem that a practical scheme cannot be provided for planning the AC/DC power distribution network under the condition of accessing the new energy exists.
Disclosure of Invention
Aiming at the problems, the comprehensive evaluation index system provided by the invention considers the diversity of loads and the fluctuation of new energy, and provides a practical scheme for planning future alternating current and direct current power distribution networks.
The technical scheme adopted by the invention is as follows: a performance evaluation method for an AC/DC hybrid power distribution network accessed with new energy comprises the following steps:
s1: new energy is accessed based on the radial distribution network, the double-end distribution network and the annular distribution network respectively;
s2: establishing a comprehensive evaluation index system with four dimensions of economy, reliability, electric energy quality and new energy consumption capacity, and constructing a comprehensive evaluation index calculation model, wherein the comprehensive evaluation index calculation model comprises an economy index calculation model, a reliability index calculation model, an electric energy quality index calculation model and a new energy consumption capacity index calculation model;
s3: carrying out scene clustering based on the uncertainty of new energy, and solving the comprehensive evaluation index model;
s4: and planning the alternating current-direct current hybrid power distribution network based on the solving result.
Preferably, the building of the economic indicator calculation model in the step S2 includes building an investment economic calculation model and an operation economic calculation model; the operating economy includes converter loss rate and integrated line loss rate;
1) the investment economy is obtained by the following formula:
Ctotal＝CI+CO+CS(1)
in the formula, investment cost
Wherein N iskFor a certain equipment to number, PkThe price is the unit price corresponding to a certain equipment, and K is the number of the equipment; the operation and maintenance cost is
Wherein C ise、ClOperating maintenance costs of the equipment and lines, respectively, CO1The operation and maintenance cost of the first year, m is the discount rate, N is the year, and i is the year; cost of disposal
Wherein C isS_kThe disposal cost from the use to the scrapping of a certain device, and K is the number of the devices;
2) the converter loss rate is obtained by the following formula:
in the formula, rconIs converter loss rate △ Pi_VSCThe loss of the ith converter can be obtained by the optimal power flow calculation; n is the number of converters;
3) the comprehensive line loss rate is obtained by the following formula:
in the formula, ravg△ P as the comprehensive line loss rateiIs the power loss value of a certain line i, which can be obtained by the calculation of the optimal power flow, wherein, l is the number of the lines, βmProbability of the scene obtained for clustering; m is the number of scenes.
Preferably, the building of the reliability index calculation model in step S2 includes building a system average power failure frequency calculation model, a system average power failure duration calculation model, and an average power supply availability calculation model;
1) the average power failure frequency of the system is obtained by the following formula:
in the formula, SAIFI is the average power failure frequency of the system, and the unit is times/(user year); lambda [ alpha ]iThe power failure probability of the load point i is obtained; n is a radical ofiThe number of users at the load point i;
2) the average power failure duration of the system is obtained by the following formula:
in the formula, SAIDI is the average power failure duration index of the system, and the unit is hour/(user.year); u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at the load point i;
3) the average power supply availability is obtained by the following formula:
in the formula, ASAI is an average power supply availability index; d is the hour number of one year, and 8760 hours are taken in calculation; u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at load point i.
Preferably, the step S2 of constructing the power quality index calculation model includes constructing a comprehensive voltage deviation calculation model and a voltage harmonic distortion calculation model;
1) the integrated voltage deviation is obtained by the following formula:
wherein f is the integrated voltage deviation of △ UmA certain scene voltage deviation; m is the number of scenes; ml,iIs the weight of node i in feeder l βmProbability of the scene obtained for clustering;
2) the voltage harmonic distortion rate is obtained by the following formula:
wherein THD is the voltage harmonic distortion rate; u shape1Is the fundamental voltage; u shapejIs the j harmonic corresponding to the voltage; j. the design is a squaremaxThe highest harmonic detected by each feeder line in the power distribution network; n is the number of power electronic periods; n is the number of nodes; j is the harmonic order.
Preferably, the step S2 is to construct a new energy consumption capability index calculation model, specifically:
wherein η is the new energy consumption rate, PLFor active load, PNEThe power generation capacity of new energy.
Preferably, in the step S3, the average distance between each cluster domain sample in the scene cluster and the cluster center is obtained by the following formula:
in the formula (I), the compound is shown in the specification,
is the average clustering distance; n is a radical ofcThe number of clustering centers; x is SjElements in the cluster; zjAs its clustering center; n is a radical ofcIs a clustering class number; sjIs a certain family; j is a variable of the cluster class number.
Preferably, the reliability calculation in step S3 adopts a sequential monte carlo method.
Preferably, the new energy consumption capability calculation in step S3 is specifically a power flow calculation of an ac/dc hybrid power distribution network.
Preferably, the operation economy calculation in step S3 is specifically a power flow calculation of the ac/dc hybrid power distribution network.
Preferably, the power flow calculation in the step S3 includes the following sub-steps:
s3-1: constructing a loss model of the current converter;
s3-2: and solving by adopting an alternative iteration method.
The beneficial effects of the technical scheme are as follows:
(1) the comprehensive index evaluation method performs comprehensive index evaluation on the alternating current-direct current hybrid power distribution network accessed with new energy.
(2) The invention overcomes the unscientific problem caused by excessive index, crossing and overlapping, and constructs a comprehensive index system according to the principles of complete coverage, representative classification index and non-repeated reflection factors.
(3) The comprehensive evaluation index system disclosed by the invention considers the diversity of loads and the volatility of new energy, and provides a practical scheme for planning future alternating current and direct current power distribution networks.
(4) The comprehensive index system disclosed by the invention improves the accuracy of the index calculation result.
Drawings
Fig. 1 is a flow chart of a performance evaluation method of an ac/dc hybrid power distribution network accessed with new energy according to the present invention;
FIG. 2 is a schematic diagram of the new energy source accessing a radial distribution network according to the present invention;
FIG. 3 is a schematic diagram of the new energy source accessing a double-ended power distribution network according to the present invention;
FIG. 4 is a schematic diagram of the new energy source accessing to the annular power distribution network according to the present invention;
FIG. 5 is a block diagram of the comprehensive evaluation index of the present invention;
FIG. 6 is a graph of 8 exemplary scenes and their probabilities obtained by ISODATA clustering algorithm according to the present invention.
Detailed Description
The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the invention and are not intended to limit the scope of the invention, i.e., the invention is not limited to the preferred embodiments described, but rather the scope of the invention is defined by the claims.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention and therefore the present invention is not limited to the specific embodiments disclosed below.
Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Example 1
As shown in fig. 1, the invention provides a performance evaluation method for an ac/dc hybrid power distribution network accessed with new energy, which comprises the following steps:
s1: new energy is accessed based on a radial distribution network, a double-end distribution network and an annular distribution network.
The method firstly analyzes the power supply structure of the existing AC/DC power distribution network, and selects a typical power supply structure of the AC/DC power distribution network suitable for consuming new energy. The AC/DC hybrid power distribution network is characterized in that an AC bus is connected with a DC bus through an AC/DC converter on the basis of an original AC power distribution network, so that the power distribution network supplies power to an AC load and a DC load simultaneously; the distributed photovoltaic, the fan and the stored energy are dispersedly connected to the low-voltage user side, and the voltage of the direct-current side is 750V or 375V, so that the local consumption and the network loss reduction are realized, and the investment of an AC/DC converter at the alternating-current side is also saved; however, the increase of direct current equipment (circuit breakers and converters) leads to the increase of economic investment, the improvement of failure rate and serious harmonic pollution, and based on the fact, the invention provides three typical alternating current and direct current power supply structures.
(1) Radial distribution network
As shown in fig. 2, the radial distribution network introduces a radial direct current power supply line for an a-type alternating current distribution network; according to the construction requirement of an alternating current-direct current power distribution network, an alternating current-direct current radial power supply mode is characterized in that 1 AC/DC converter, 2 direct current transformers and 3 circuit breakers are additionally arranged on the basis of a radial alternating current power distribution network.
The new energy, the energy storage and other equipment are respectively connected to a low-voltage alternating current bus or a low-voltage direct current bus, the radial alternating current-direct current power distribution network is converted into multi-power supply from a single-power supply mode, when an alternating current power supply or a load side fails, the downstream load of the alternating current power supply can be transferred to a line corresponding to the new energy, and therefore reliability is improved. During normal operation, a complementary operation strategy of wind, light and storage can be adopted, so that the influence of new energy on the system state is reduced, and the local consumption capability is improved. The power supply structure is suitable for supplying power to a cell or a house.
(2) Double-end distribution network
As shown in fig. 3, the double-end distribution network is a B-type hand-in-hand AC line connected by a DC bus, the hand-in-hand AC distribution network itself has two power sources, and can perform load transfer after a fault occurs, and a B-type power supply mode is formed by adding 2 AC/DC converters, 2 DC transformers, and 6 DC breakers.
After the new energy is connected into the power distribution network, the power supply mode has three power supplies, the connection side of part of the new energy is improved to meet the N-2 criterion from meeting the N-1 criterion, and when the power supply or the load side breaks down, the downstream load can be transferred to the standby power supply and the power supply connected with the new energy, so that the transfer capability of the load side is improved, and the power supply reliability is further improved. A B-type power supply mode adopts a voltage margin control strategy, the method is improved on the basis of master-slave control, communication is not needed, the current converters have priorities, one current converter adopts constant voltage control, the other current converters adopt constant power control, if power fluctuation is caused by failure, only the master current converter provides power difference, and if the power fluctuation cannot be met, the next current converter is switched to according to the priority until the power requirement is met; when power fluctuation is caused by new energy grid connection, the fluctuation of power can be quickly restrained, and the consumption of new energy is effectively improved.
(3) Annular power distribution network
As shown in fig. 4, the ring-shaped power distribution network is a C-type hand-pull AC line and is communicated by a DC ring network, the AC power distribution network supplies power to two or more power sources, and is generally in a "closed-loop design and open-loop operation", on the basis, a C-type AC/DC power distribution network is formed by adding 2 AC/DC converters, 4 DC transformers and 14 DC breakers, and a ring-shaped power supply structure is formed on the DC side.
After new energy and direct current loads are accessed, the direct current ring network part can operate in a closed loop mode, if a certain line on the direct current side fails, the loads on the upstream or the downstream of the line can be supplied, and the reliability of the power distribution network is further improved; the control strategy adopted by the C-type power supply mode is the same as that of the B-type power supply mode, the direct current load area is concentrated, photovoltaic consumption is greatly promoted, but the equipment investment increased by the annular power distribution network and the complexity of the power distribution network are far greater than those of the A-type power supply mode and the B-type power supply mode, corresponding protection is more complex, reliability and economy are mutually restricted, further analysis is needed, and the power supply structure is suitable for the area with high requirement on power supply reliability and concentrated direct current load.
S2: and establishing a comprehensive evaluation index system.
The problem of new energy consumption is most urgently solved in the power distribution network at the present stage, and the establishment of the evaluation index system has certain purposiveness, logicality and hierarchy according to the establishment principle of the evaluation index system; as shown in fig. 5, in the invention, the comprehensive evaluation index system is established by mainly considering four dimensions of economic index, reliability index, power quality index and new energy consumption capability; meanwhile, an index system of three levels is constructed according to the comprehensive index, the classification index and the subclass index; the economic indexes comprise investment economy and operation economy, and the operation economy comprises converter loss rate and comprehensive line loss rate; the reliability index comprises the average power failure frequency of the system, the average power failure duration time of the system and the average power supply availability; the electric energy quality index comprises comprehensive voltage deviation and voltage harmonic distortion rate; the new energy consumption capability comprises a new energy consumption rate. In order to reflect the difference of the alternative objects in a key way, the invention overcomes the unscientific problem caused by greedy, crossing and overlapping indexes, and constructs a comprehensive index system according to the principles of complete coverage, representative classification indexes and non-repeated reflection factors.
(1) Economy of use
Economics fall into two broad categories, namely investment economics and operating economics. The number of the alternating current and direct current equipment in different power supply modes is different, so that not only is the investment cost influenced, but also the running cost is increased due to the loss of the current converter; the operational economics include converter loss rate and integrated line loss rate.
1) Economy of investment
Considering the total life cycle cost, establishing a cost model of the AC/DC power distribution network, wherein the total cost is CtotalThe method comprises the following steps: investment, operation and maintenance, and residual value. Wherein the investment cost CIThe method comprises the steps of considering the cost of all equipment (an alternating current and direct current line, a current converter, a circuit breaker, a direct current transformer, a tie switch and the like) and the occupied land cost, wherein the annual operation and maintenance cost of the equipment is CO(ii) a The cost of waste disposal from use to scrapping is CS。
Ctotal＝CI+CO+CS(1)
In the formula, investment cost
Wherein N iskFor a certain equipment to number, PkThe price is the unit price corresponding to a certain equipment, and K is the number of the equipment; the operation and maintenance cost is
Wherein C ise、ClOperating maintenance costs of the equipment and lines, respectively, CO1The operation and maintenance cost of the first year, m is the discount rate, N is the year, and i is the year; cost of disposal
Wherein C isS_kThe disposal cost from the use to the scrapping of a certain equipment, and K is the number of the equipment.
2) Economy of operation
Converter loss rate
Assuming that n converters exist in the power distribution network, the average value of the loss rates of the n converters is obtained as the loss rate of the converters of the power distribution network, and the loss rate of the converters is obtained through the following formula:
in the formula, rconIs converter loss rate △ Pi_VSCThe loss of the ith converter can be obtained by the optimal power flow calculation; n is the number of converters.
Integrated line loss ratio
Setting the number of main lines in a distribution power grid as l, and calculating the average value of line loss rates of the l lines as a comprehensive line loss rate; the comprehensive line loss rate is obtained by the following formula:
in the formula, ravg△ P as the comprehensive line loss rateiIs the power loss value of a certain line i, which can be obtained by the calculation of the optimal power flow, wherein, l is the number of the lines, βmProbability of the scene obtained for clustering; m is the number of scenes.
(2) Reliability of
The reliability of the alternating-current and direct-current hybrid power distribution network refers to the capability of continuously supplying power to direct-current and alternating-current users, the fault frequency of the power distribution network is increased by the fault probability of direct-current equipment, the reliability of multi-end power supply can be improved through load transfer, and the power supply reliability is the comprehensive embodiment of the number, the types, the network structure, the load rate and the load distribution of the equipment.
1) System average power failure frequency (SAIFI)
The system average outage frequency indicator (SAIFI) refers to the average number of times of outage per unit time for each user powered by the system, and is obtained by the following formula:
in the formula, SAIFI is the average power failure frequency of the system, and the unit is times/(user year); lambda [ alpha ]iThe power failure probability of the load point i is obtained; n is a radical ofiThe number of users at load point i.
2) System Average Interruption Duration Index (SAIDI)
The system average outage duration indicator (SAIDI) refers to the average outage duration experienced by each user powered by the system over the course of a year, and is derived from the following equation:
in the formula, SAIDI is the average power failure duration index of the system, and the unit is hour/(user.year); u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at load point i.
3) Average power availability index (ASAI)
The average power availability indicator (ASAI) refers to the ratio of the total number of uninterruptible hours experienced by a user to the total number of hours of power requested by the user over the course of a year, and is obtained by the following equation:
in the formula, ASAI is an average power supply availability index; d is the hour number of one year, and 8760 hours are taken in calculation; u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at load point i.
(3) Quality of electric energy
Because the direct current and alternating current hybrid power distribution network is discussed, the comprehensive indexes of direct current and alternating current are required to be integrated, so that the indexes related to frequency are not considered, and the main indexes are voltage related indexes; in addition, power electronic devices are added when direct current loads and new energy are connected, harmonic sources are added to a power distribution network by the power electronic devices, and therefore the second-layer indexes corresponding to the quality of electric energy are comprehensive voltage deviation and voltage harmonic distortion rate.
1) Integrated voltage deviation
Considering that the new energy and the load access have uncertainties which cause line voltage fluctuation, different power supply modes have different risks of suffering the new energy fluctuation, the voltage deviation refers to the difference value of the actual voltage and the nominal voltage of each feeder point, and the voltage deviation is obtained by the following formula:
in the formula, U is voltage deviation; u shapetIs the actual voltage; u shapeNIs the nominal voltage.
The comprehensive voltage deviation f is respectively summed by the products of the voltage deviation and the weight, the weight depends on the position of a feeder line node, the position of new energy access and the output, and the weight of a node i in a feeder line l is Ml,iObtained by the following formula:
in the formula, ZiIs the impedance from node i to the beginning of the branch; zmaxThe maximum value of the impedance between the starting end and each tail end of the branch circuit; st,iThe apparent power of the ith new energy source at the moment t; stIs the sum of the apparent power of the branch load; z0lImpedance from the new energy access point to the balancing node; zilImpedance of node i to the new energy access point, when ZilGreater than Z0lWhile, correcting Z0l-ZilIs zero.
Wherein f is the integrated voltage deviation of △ UmA certain scene voltage deviation; m is the number of scenes; ml,iIs the weight of node i in feeder l βmThe probability of the scene obtained for clustering.
2) Voltage harmonic distortion rate
No matter the alternating current distribution network or the direct current distribution network has harmonic waves, sinusoidal wave components exist in certain alternating current or direct current voltage, and the use of a converter is increased due to the access of new energy sources, namely a semiconductor element containing power electronic devices and equipment containing electric arcs and ferromagnetic nonlinearity are harmonic wave sources, the harmonic wave problem has certain representativeness in the reaction of electric energy quality, and the harmonic wave problem can be obtained according to GB/T14549-93:
wherein THD is the voltage harmonic distortion rate; u shape1Is the fundamental voltage; u shapejIs the j harmonic corresponding to the voltage; j. the design is a squaremaxThe highest harmonic detected by each feeder line in the power distribution network; n is the number of power electronic periods; n is the number of nodes; j is the harmonic order.
(4) New energy consumption capacity
In recent years, new energy is vigorously developed in China, but the consumption of the new energy also brings problems, so that the power grid structure and the load matching degree can be effectively improved by determining the consumption rate of the new energy, the stability of the power grid can be further improved, and the consumption rate of the new energy is the ratio of the generated energy of the new energy to the load basic value and is obtained through the following formula:
wherein η is the new energy consumption rate, PLFor active load, PNEThe power generation capacity of new energy.
S3: and carrying out scene clustering based on the uncertainty of the new energy, and solving the comprehensive index.
S3-1: scene clustering based on uncertainty of new energy
The new energy comprises photovoltaic, wind turbine and energy storage. Wind and light output characteristic regions have great relations among seasons, weather conditions and geographic conditions, and in order to calculate various indexes by considering uncertainty, scene clustering is adopted to convert the uncertainty into the certainty.
The traditional clustering method has high requirement on initial values, the finally obtained optimal solution is only local optimal and global optimal solution is difficult to achieve, the improved ISODATA clustering scene partitioning is adopted, the algorithm is improved on the basis of the original clustering algorithm, merging and splitting operations are added, and the method is expressed by the following formula:
in the formula, thetasThe sample values are distributed in the cluster domain; n is a radical ofCIs a clustering class number;
the class j corresponds to the maximum standard deviation; c is the total number of clusters expected to be obtained; if the class standard deviation is greater than the required value and the number of the clustering classes is less than half of the expected number of the classes, a 'splitting' measure is taken. On the contrary, if the classification effect is too dispersed, "merging" is selected.
Judging and correcting each clustering center, namely photovoltaic output and fan output, according to the distance from each initial scene to the clustering center, introducing a heuristic step and combining human-computer interaction to improve clustering precision, specifically, converting a random output sampling set of wind power and photovoltaic into a point set of a multi-dimensional coordinate system, wherein each clustering center correspondingly represents a typical scene parameter of each class, and obtaining an optimal typical scene set by continuously optimizing the distance between each class; the average distance from each cluster domain sample to the cluster center is obtained by the following formula:
in the formula (I), the compound is shown in the specification,
is the average clustering distance; n is a radical ofcThe number of clustering centers; x is SjElements in the cluster; zjAs its clustering center; n is a radical ofcIs a clustering class number; sjIs a certain family; j is a variable of the cluster class number.
S3-2: solving for the composite index
(1) Reliability calculation
And in consideration of the complicated operation of the AC/DC power distribution network, a sequential Monte Carlo method is adopted for reliability calculation. The fault scene is a single fault, and the fault equipment is divided into: considering the complexity difference of three power supply modes, namely an alternating current side fault, a direct current side fault and a converter fault, the fault consequence analysis method is described by taking an annular alternating current-direct current power distribution network as an example:
1) when an alternating current side circuit fails, if the fault current reaches 1.5-2 times, the AC/DC converter is locked, the initial breaker of a feeder where the circuit is located acts, the fault side is powered off, the converter recovers the working state, and alternating current loads at the downstream of the fault can be supplied to an opposite-end power supply;
2) when a direct current side circuit fails, the fault current rapidly rises, if the fault current reaches 1.5-2 times, the converter is locked until the fault is removed by the traveling wave protection action, the converter normally works, the non-fault part normally supplies power, and the mode is the same as a double-end power supply mode;
3) when one side converter fails, the failed converter can be quickly locked and quit operation, the alternating current power supply at the side of the failed converter only supplies power to the adjacent alternating current load, the direct current load supplied by the alternating current power supply at the side of the converter is transferred to the power supply at the opposite end, if the failed converter is the main controller, the converter is quickly switched to the next stage converter according to the priority, if the converters at both sides fail, the converter is locked, and the direct current side is coordinately supplied with power by new energy and stored energy.
If the standby power supply or the new energy power supply can not support all loads of the non-fault section to supply power after the fault, part of the loads are cut off by scheduling the traditional switch, and the method adopts a strategy of cutting off according to the important user level.
(2) Calculation of economy, electric energy quality and new energy consumption
1) Calculation of running economy, comprehensive voltage deviation and new energy consumption rate
In order to calculate evaluation indexes such as operation economy, voltage deviation, new energy consumption rate and network loss, the load flow of the AC/DC hybrid power distribution network needs to be calculated. And carrying out load flow calculation aiming at a certain determined scene obtained by clustering. The investment economy is directly calculated according to a formula.
Firstly, a converter loss model is established, see a formula [21-22], and an alternating iteration method is adopted for load flow calculation. According to the method, nodes on two sides of a converter and a DC/DC converter are equivalent, an alternating current side is equivalent to a PQ node, a direct current side is equivalent to a constant voltage node, a constant power node and a droop control node according to different control strategies, then load flow calculation is carried out on the alternating current side and the direct current side, and a forward-backward substitution method is adopted for calculation. According to the initial value of the converter station, load flow calculation is carried out on the alternating current side, then the loss of the converter is calculated to obtain the voltage and the power of the direct current side, and further the load flow value of the direct current side is obtained through calculation.
First, alternating current side tide
And according to the converter control strategy and the initial value thereof, the direct current side is equivalent to the voltage and the power of the converter side, and the voltage and the power of each node of the alternating current side are calculated by forward substitution and backward substitution.
In the formula, Pi(U,) is active; qi(U,) is idle; u shapeiIs the i node voltage; u shapejIs the j node voltage; gijIs the conductance;iis the i-node phase angle;jis the j node phase angle; b isijIs a susceptance.
The active and reactive power flowing into the converter can be regarded as an alternating current power supply, so that the power mismatch vector equation is as follows:
in the formula (I), the compound is shown in the specification,
is the active correction amount;
active for generating electricity;
inputting active power for the current converter; psiOutputting active power for the converter; piActive for the load; u shape(j)Is the node voltage;(j)is node phase angle △ Qi (j)Is the reactive correction;
the power generation is idle;
inputting reactive power for the converter; qsiOutputting reactive power for the converter; qiIs reactive to the load.
The most common control strategies for inverters are: constant voltage control, droop control and constant power control. In the case of multiple converters, it is common for one and only one converter to employ constant voltage control, with the remainder employing constant power or droop control. Suppose there are k converters, the 1 st converter adopts constant voltage control.
In the formula (I), the compound is shown in the specification,
is the converter initial power; psjThe converter is active; k is the number of converters; j is the inverter number variable.
And calculating the loss of the converter by utilizing the power of the alternating current side according to the loss model of the converter so as to calculate the side tidal current of the converter.
In the formula, PlossIs converter loss; a. b and c are loss coefficients of the current converter; i iscPassing current through the converter; pcInputting active power for the current converter; qcInputting reactive power for the converter; u shapecIs the inverter voltage.
② direct current side tide
The power and the voltage of the direct current side are input into the known converter in the step 1), the voltage and the power of the direct current side are solved by utilizing a forward-backward substitution method, compared with the alternating current side, the reactive power is not needed to be considered at the direct current side, and the calculation is simpler and more convenient.
In the formula, PdcIs the power of the direct current side; u shapedcIs the dc side voltage.
In addition, neither the AC side power flow nor the DC side power flow can cause voltage current out-of-limit, i.e. voltage current out-of-limit
(Uk,i_min)2≤Uk,i 2≤(Uk,i_max)2(23)
0≤Ik,i 2≤(Ik,i_max)2(24)
In the formula of Uk,iThe voltage of a kth feeder node i; u shapek,i_min、Uk,i_maxRespectively the maximum value and the minimum value of the voltage of the node i of the kth feeder line; i isk,iThe current of the ith branch of the feeder k is the current of the ith branch of the feeder k; i isk,i_maxThe rated current of the ith branch of the feeder k.
Through the formula, the power balance of each node is realized, and the voltage and the current on each branch circuit are not out of limit.
③ alternate iterative process
Firstly, inputting original data of a power distribution network, numbering the power distribution network, and determining an initial value and a control mode of a converter station. And secondly, calculating the power flow at the AC side until convergence, calculating the injection power of the converter, and judging whether the converter is out of limit or not. And then, calculating the power flow at the direct current side until convergence, judging whether the alternating current and the direct current are converged, if so, outputting a calculation result, and otherwise, returning to continue the calculation.
2) Voltage harmonic distortion rate calculation
The voltage harmonic distortion rate is obtained by performing fast Fourier transform on the voltage of the corresponding line of each power electronic device through simulation acquisition.
S4: and planning the alternating current-direct current hybrid power distribution network based on the solution result.
Example 2
This example is an example analysis:
(1) basic parameters of arithmetic example
Taking a newly-built high-tech district power distribution network in a certain area as an example, the area is powered by a 110kV transformer substation through 2 alternating current 10V lines at present, the existing load is 17 ten thousand kilowatts, the newly-built alternating current and direct current load is 2500kW, wherein the direct current load is 1800kW, and the alternating current load is 700 kW. The wind and light resources are rich, and a large amount of new energy is accessed in the future. In order to meet the requirements of new energy and direct current load access, green power grid transformation is implemented, and an alternating current-direct current hybrid power distribution network is introduced. The selected converter and the DC/DC converter have a capacity of 2 MW.
And according to the new energy ratio selected by the installed capacity of the local photovoltaic fan, preparing a certain ratio of stored energy. As shown in table 1.
TABLE 1 wind and light storage capacity corresponding to different new energy consumption rates
(2) Scene clustering and index calculation results
1) Scene clustering: taking local whole-year wind, light resource and load data, sampling 500 running scenes according to different seasonal temperatures and difference of load sizes by taking 15 minutes as a period, and obtaining 8 typical scenes and probability thereof by using an ISODATA clustering algorithm as shown in FIG. 6.
2) And (3) index calculation: based on the source and load information of 8 scenes and scene probability, when the new energy consumption rate is 30%, 60% and 80%, calculating performance indexes of the three alternating current and direct current hybrid power distribution networks. The results of the calculations are shown in tables 2-10.
Table 2 radial power supply mode reliability calculation results
TABLE 3 double-ended Power supply mode reliability calculation results
TABLE 4 calculation results of reliability of the ring power supply mode
Table 5 radial power supply mode power quality calculation result
Table 6 calculation results of electric energy quality in dual-end power supply mode
TABLE 7 calculation results of power quality in ring power supply mode
TABLE 8 calculation of radial power mode economics
TABLE 9 double-ended Power supply mode economics calculation results
TABLE 10 Loop Power supply mode economics calculation results
(3) Alternating current-direct current hybrid power distribution network based on different demands of above-mentioned solution result planning
And aiming at different power supply requirements, planning the AC/DC hybrid power distribution network according to the solving result.
According to the invention, comprehensive index evaluation is carried out on the AC/DC hybrid power distribution network accessed with new energy; the invention overcomes the unscientific problem caused by excessive index, crossing and overlapping, and constructs a comprehensive index system according to the principles of complete coverage, representative classification index and non-repeated reflection factors.
The comprehensive evaluation index system disclosed by the invention considers the diversity of loads and the fluctuation of new energy, and provides a practical scheme for planning future AC/DC distribution networks; the comprehensive index system disclosed by the invention improves the accuracy of the index calculation result.
While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims (10)
1. A performance evaluation method for an AC/DC hybrid power distribution network accessed with new energy is characterized by comprising the following steps:
s1: new energy is accessed based on the radial distribution network, the double-end distribution network and the annular distribution network respectively;
s2: establishing a comprehensive evaluation index system with four dimensions of economy, reliability, electric energy quality and new energy consumption capacity, and constructing a comprehensive evaluation index calculation model, wherein the comprehensive evaluation index calculation model comprises an economy index calculation model, a reliability index calculation model, an electric energy quality index calculation model and a new energy consumption capacity index calculation model;
s3: carrying out scene clustering based on the uncertainty of new energy, and solving the comprehensive evaluation index model;
s4: and planning the alternating current-direct current hybrid power distribution network based on the solving result.
2. The evaluation method according to claim 1, wherein the constructing of the economic indicator calculation model in the step S2 includes constructing an investment economic calculation model and an operation economic calculation model; the operating economy includes converter loss rate and integrated line loss rate;
1) the investment economy is obtained by the following formula:
Ctotal＝CI+CO+CS(1)
in the formula, investment cost
Wherein N iskFor a certain equipment to number, PkThe price is the unit price corresponding to a certain equipment, and K is the number of the equipment; the operation and maintenance cost is
Wherein C ise、ClOperating maintenance costs of the equipment and lines, respectively, CO1The operation and maintenance cost of the first year, m is the discount rate, N is the year, and i is the year; cost of disposal
Wherein C isS_kFor disposal cost of a certain facility to scrap, K isThe number of devices;
2) the converter loss rate is obtained by the following formula:
in the formula, rconIs converter loss rate △ Pi_VSCThe loss of the ith converter can be obtained by the optimal power flow calculation; n is the number of converters;
3) the comprehensive line loss rate is obtained by the following formula:
in the formula, ravg△ P as the comprehensive line loss rateiIs the power loss value of a certain line i, which can be obtained by the calculation of the optimal power flow, wherein, l is the number of the lines, βmProbability of the scene obtained for clustering; m is the number of scenes.
3. The assessment method according to claim 1, wherein the constructing of the reliability index calculation model in step S2 includes constructing a system average outage frequency calculation model, a system average outage duration calculation model and an average power supply availability calculation model;
1) the average power failure frequency of the system is obtained by the following formula:
in the formula, SAIFI is the average power failure frequency of the system, and the unit is times/(user year); lambda [ alpha ]iThe power failure probability of the load point i is obtained; n is a radical ofiThe number of users at the load point i;
2) the average power failure duration of the system is obtained by the following formula:
in the formula, SAIDI is the average power failure duration index of the system, and the unit is hour/(user.year); u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at the load point i;
3) the average power supply availability is obtained by the following formula:
in the formula, ASAI is an average power supply availability index; d is the hour number of one year, and 8760 hours are taken in calculation; u shapeiThe average annual power failure time of the load point i; n is a radical ofiThe number of users at load point i.
4. The evaluation method according to claim 1, wherein the constructing of the power quality index calculation model in the step S2 includes constructing a comprehensive voltage deviation calculation model and a voltage harmonic distortion calculation model;
1) the integrated voltage deviation is obtained by the following formula:
wherein f is the integrated voltage deviation of △ UmA certain scene voltage deviation; m is the number of scenes; ml,iIs the weight of node i in feeder l βmProbability of the scene obtained for clustering;
2) the voltage harmonic distortion rate is obtained by the following formula:
wherein THD is the voltage harmonic distortion rate; u shape1Is the fundamental voltage; u shapejIs the j harmonic corresponding to the voltage; j. the design is a squaremaxThe highest harmonic detected by each feeder line in the power distribution network; n is the number of power electronic periods; n is the number of nodes; j isThe number of harmonics.
5. The assessment method according to claim 1, wherein the step S2 is implemented by constructing a new energy consumption capability index calculation model, specifically:
wherein η is the new energy consumption rate, PLFor active load, PNEThe power generation capacity of new energy.
6. The method for evaluating of claim 1, wherein the average distance between the cluster domain samples in the scene cluster of step S3 and the cluster center is obtained by the following formula:
in the formula (I), the compound is shown in the specification,
is the average clustering distance; n is a radical ofcThe number of clustering centers; x is SjElements in the cluster; zjAs its clustering center; n is a radical ofcIs a clustering class number; sjIs a certain family; j is a variable of the cluster class number.
7. The method of claim 1, wherein the reliability calculation in step S3 employs a sequential monte carlo method.
8. The evaluation method according to claim 1, wherein the new energy consumption capability calculation in step S3 is specifically a power flow calculation of an ac/dc hybrid power distribution network.
9. The evaluation method according to claim 2, wherein the operation economy calculation in step S3 is specifically a power flow calculation of the ac/dc hybrid power distribution network.
10. The evaluation method according to claim 8 or 9, wherein the power flow calculation in the step S3 includes the sub-steps of:
s3-1: constructing a loss model of the current converter;
s3-2: and solving by adopting an alternative iteration method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010419490.4A CN111563691B (en) | 2020-05-18 | 2020-05-18 | Performance evaluation method of AC/DC hybrid power distribution network connected with new energy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010419490.4A CN111563691B (en) | 2020-05-18 | 2020-05-18 | Performance evaluation method of AC/DC hybrid power distribution network connected with new energy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111563691A true CN111563691A (en) | 2020-08-21 |
| CN111563691B CN111563691B (en) | 2023-08-04 |
Family
ID=72070985
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010419490.4A Active CN111563691B (en) | 2020-05-18 | 2020-05-18 | Performance evaluation method of AC/DC hybrid power distribution network connected with new energy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111563691B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112350369A (en) * | 2020-10-20 | 2021-02-09 | 清华四川能源互联网研究院 | Energy efficiency evaluation method for optical storage and charging integrated power station |
| CN113193561A (en) * | 2021-03-30 | 2021-07-30 | 中国农业大学 | Direct current transformation control method for power distribution network |
| CN113690920A (en) * | 2021-08-16 | 2021-11-23 | 华中科技大学 | Method for evaluating applicability of alternating current and direct current hybrid wiring mode of power distribution network |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6792399B1 (en) * | 1999-09-08 | 2004-09-14 | C4Cast.Com, Inc. | Combination forecasting using clusterization |
| CN103745267A (en) * | 2013-10-24 | 2014-04-23 | 国家电网公司 | Distributed photovoltaic system grid connection influence evaluation method |
| JP2015192502A (en) * | 2014-03-27 | 2015-11-02 | 富士通株式会社 | Power consumption prediction method, power consumption prediction program and power consumption prediction device |
| JP2016031546A (en) * | 2014-07-25 | 2016-03-07 | 清水建設株式会社 | Green space evaluation system and green space evaluation method |
| CN105761161A (en) * | 2015-12-21 | 2016-07-13 | 国家电网公司 | AC and DC power distribution network power supply mode evaluation method |
| CN106410852A (en) * | 2016-11-24 | 2017-02-15 | 国家电网公司 | Evaluation method and equipment for absorption of power grid for new energy power generation |
| CN107301472A (en) * | 2017-06-07 | 2017-10-27 | 天津大学 | Distributed photovoltaic planing method based on scene analysis method and voltage-regulation strategy |
| CN107316125A (en) * | 2017-05-12 | 2017-11-03 | 燕山大学 | A kind of active distribution network economical operation evaluation method based on economical operation domain |
| US20180049043A1 (en) * | 2005-10-04 | 2018-02-15 | Steven M. Hoffberg | Multifactorial optimization system and method |
| CN109325694A (en) * | 2018-09-30 | 2019-02-12 | 国网宁夏电力有限公司经济技术研究院 | Power distribution network preferred method based on bearing capacity |
| CN109598377A (en) * | 2018-11-28 | 2019-04-09 | 国网江苏省电力有限公司 | A kind of alternating current-direct current mixing power distribution network robust planing method based on failure constraint |
| CN110414796A (en) * | 2019-07-03 | 2019-11-05 | 南方电网科学研究院有限责任公司 | A kind of alternating current-direct current mixing distribution network structure planing method, device and storage medium |
| CN110969347A (en) * | 2019-11-22 | 2020-04-07 | 国网山东省电力公司临沂供电公司 | Power transmission network structure form evaluation method |
-
2020
- 2020-05-18 CN CN202010419490.4A patent/CN111563691B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6792399B1 (en) * | 1999-09-08 | 2004-09-14 | C4Cast.Com, Inc. | Combination forecasting using clusterization |
| US20180049043A1 (en) * | 2005-10-04 | 2018-02-15 | Steven M. Hoffberg | Multifactorial optimization system and method |
| CN103745267A (en) * | 2013-10-24 | 2014-04-23 | 国家电网公司 | Distributed photovoltaic system grid connection influence evaluation method |
| JP2015192502A (en) * | 2014-03-27 | 2015-11-02 | 富士通株式会社 | Power consumption prediction method, power consumption prediction program and power consumption prediction device |
| JP2016031546A (en) * | 2014-07-25 | 2016-03-07 | 清水建設株式会社 | Green space evaluation system and green space evaluation method |
| CN105761161A (en) * | 2015-12-21 | 2016-07-13 | 国家电网公司 | AC and DC power distribution network power supply mode evaluation method |
| CN106410852A (en) * | 2016-11-24 | 2017-02-15 | 国家电网公司 | Evaluation method and equipment for absorption of power grid for new energy power generation |
| CN107316125A (en) * | 2017-05-12 | 2017-11-03 | 燕山大学 | A kind of active distribution network economical operation evaluation method based on economical operation domain |
| CN107301472A (en) * | 2017-06-07 | 2017-10-27 | 天津大学 | Distributed photovoltaic planing method based on scene analysis method and voltage-regulation strategy |
| CN109325694A (en) * | 2018-09-30 | 2019-02-12 | 国网宁夏电力有限公司经济技术研究院 | Power distribution network preferred method based on bearing capacity |
| CN109598377A (en) * | 2018-11-28 | 2019-04-09 | 国网江苏省电力有限公司 | A kind of alternating current-direct current mixing power distribution network robust planing method based on failure constraint |
| CN110414796A (en) * | 2019-07-03 | 2019-11-05 | 南方电网科学研究院有限责任公司 | A kind of alternating current-direct current mixing distribution network structure planing method, device and storage medium |
| CN110969347A (en) * | 2019-11-22 | 2020-04-07 | 国网山东省电力公司临沂供电公司 | Power transmission network structure form evaluation method |
Non-Patent Citations (3)
| Title |
|---|
| JIAWEI WANG; ZHI ZHANG; HAIBO ZHAO; YANHUI YANG; RONGJIE WANG; ZEYUAN SHEN; ENDE HU: "Comprehensive Evaluation of AC/DC Distribution Network with Distributed Generation" * |
| YANG Y, XUE Y, LIU W, ET A1: "Study on Power Supply Structure of AC/DC Distribution Network Considering Different Proportion of New Energy Access" * |
| 汪海瑛: "含大规模可再生能源的电力系统可靠性问题研究", no. 7 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112350369A (en) * | 2020-10-20 | 2021-02-09 | 清华四川能源互联网研究院 | Energy efficiency evaluation method for optical storage and charging integrated power station |
| CN112350369B (en) * | 2020-10-20 | 2022-04-05 | 清华四川能源互联网研究院 | Energy efficiency evaluation method for optical storage and charging integrated power station |
| CN113193561A (en) * | 2021-03-30 | 2021-07-30 | 中国农业大学 | Direct current transformation control method for power distribution network |
| CN113690920A (en) * | 2021-08-16 | 2021-11-23 | 华中科技大学 | Method for evaluating applicability of alternating current and direct current hybrid wiring mode of power distribution network |
| CN113690920B (en) * | 2021-08-16 | 2023-08-22 | 华中科技大学 | Method for evaluating applicability of AC/DC hybrid wiring mode of power distribution network |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111563691B (en) | 2023-08-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9618914B2 (en) | Energy resource-grid-load automatic control system of smart microgrid and control methods thereof | |
| CN101685968B (en) | Failure propagation method for evaluating reliability of distribution network | |
| CN111563691B (en) | Performance evaluation method of AC/DC hybrid power distribution network connected with new energy | |
| CN102427243B (en) | Multi-terminal DC (Direct Current) power transmission system for combined synchronization of wind power plant and conventional power plant | |
| CN113191675B (en) | Multi-direct-current-sending-end power grid planning scheme adaptability evaluation method and system | |
| CN115358623A (en) | Artificial intelligence regional power grid power quality configuration method and comprehensive evaluation method | |
| Zhu et al. | Two-stage coordinated control strategy of AC/DC hybrid power system based on steady-state security region | |
| CN109002938B (en) | Double-layer planning method for alternating current-direct current hybrid power distribution network considering N-1 safety criterion | |
| Hou et al. | Research on bi-level planning method of active distribution network considering flexible interconnection of source network load and storage | |
| CN112736913B (en) | Method for analyzing influence factors of power optimization mode of power distribution network containing distributed power supply | |
| Liu et al. | Analysis of grid-connected operation characteristics and limit access capacity of offshore wind farms | |
| Li et al. | Distributed power dispatching solution for a future economic and environment-friendly energy internet | |
| Shen et al. | Research on key technology of planning and design for AC/DC hybrid distribution network | |
| Li et al. | Optimization of the offshore wind power grid-connected structure based on an improved genetic algorithm | |
| Zhao et al. | More Efficient Energy Management for Networked Hybrid AC/DC Microgrids With Multivariable Nonlinear Conversion Losses | |
| Zhang et al. | Safety assessment of charging stations connected to the power grid considering distribution network constraints | |
| Li | Advanced control of grid-forming inverters under uncertain operating conditions in AC microgrids | |
| CN109245170B (en) | Distribution network-friendly distributed power supply grid-connected case library design method | |
| Kawan et al. | Impact of Series Resonant Power Conditioning System Losses in Optimal Power Flow | |
| Zhao et al. | Economy Optimization Configuration Scheme for the MMC-MTDC System with Renewable Energies | |
| Cheng | Optimal control of output power of micro-inverter based on circuit design | |
| Li et al. | Power Balance Warning Method of Regional Power Grid Considering Photovoltaic Capacity Ratio | |
| Li et al. | Research on DC voltage class series with AHP | |
| Liang et al. | Research on Factors Affecting Power Flow of Direct Current Grid Considering Different Control Modes | |
| Feng et al. | The best power supply capability evaluation of the active distribution system considering the interruption cost |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |