CN109217307A - A kind of analysis method of Rural Power Distribution Network to " coal changes electricity " maximum receiving ability - Google Patents
A kind of analysis method of Rural Power Distribution Network to " coal changes electricity " maximum receiving ability Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
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Abstract
(1), user's heat demand specificity analysis the present invention relates to a kind of Rural Power Distribution Networks to the analysis method of " coal changes electricity " maximum receiving ability, comprising the following steps:；(2), coal changes electric load analysis on Operating；(3), the impact analysis that " coal changes electricity " project runs power distribution network and plans；(4), Rural Power Distribution Network is maximum to " coal changes electricity " receives capability analysis.The impact evaluation work that the present invention can largely access local distribution network for " coal changes electricity " equipment provides guidance, theoretical direction is provided in " coal changes electricity " planning under the new situation and operation for power distribution network, cleaning heating be may advantageously facilitate in the further genralrlization of grass roots, push the development of the micro- energy net in rural area.
Description
Technical field
The present invention relates to power distribution network operation planning field, especially a kind of Rural Power Distribution Network is maximum to " coal changes electricity " to receive energy
The analysis method of power changes power distribution network operation and planning after electric equipment largely accesses local distribution network suitable for coal.
Background technique
With the continuous development of Chinese national economy, energy demand continuous enlargement, all types of energy consumptions in China increase steadily
Long, wherein building energy consumption, transportation and energy's consumption and industrial energy consumption have become three rich anies influential family of Chinese energy consumption.Especially
It is that at this stage, China's construction area quicklys increase, requirement of the resident to comfort level increasingly improves, so that China's building energy consumption is sharply
Rise, heating energy consumption becomes the Important Problems of energy-saving and emission-reduction.Central heating at present mainly based on the combusts fossil energy and stalk,
These fossil energies generated greenhouse gases, pernicious gas and dust particles in production, transmission, conversion and process of consumption,
It is the main reason for causing atmosphere pollution and haze.For the heating energy consumption and problem of environmental pollution for solving the problems, such as northern area, political affairs
Mansion proposes " coal changes electricity " etc. and successfully manages measure." coal changes electricity " is to solve heating area especially northern country area fire coal to adopt
The warm effective bodyfixed frame of problem, has spatter property, low-carbon, the feature of high efficiency, is to solve the problems, such as having for existing coal heating
Effect approach, government have put into effect multinomial incentives and have carried out demonstration project, promote a wide range of popularization of " coal changes electricity " policy.Example
Such as, " coal changes electricity " pilot work has been unfolded in multiple areas such as Beijing, Tianjin, Hebei, with push northern area cleaning heating,
" coal changes electricity " engineering development.
The transition of " coal changes electricity " as heating system, improves spatter property, the high efficiency, flexibility of heating process, but by
In the addition of a large amount of electric power heating loads, distribution network planning and operation are also influenced whether, be a kind of opportunity and a kind of challenge.
On the one hand, since area, building structure, construction material, user heating habit are different, so its heat demand is different, and not
For load curve when the electric heating equipment operation of same type there is also larger difference, electric load characteristic tends to be complicated；On the other hand,
The area that " coal changes electricity " equipment largely accesses at present is mostly rural area, and this area's grid structure is weak, a large amount of electric heating loads
Access increase power supply pressure, will to existing power distribution network run generate impact.Carry out " coal changes electricity " rural power distribution afterwards
Research of the net to " coal changes electricity " maximum receiving ability, can grasp the energy demand characteristic of different user, improve the clear of architectural energy consumption
Clean property enables grid company to successfully manage the new situations of a large amount of " coal changes electricity " equipment accesses, ensures that the safety of power distribution network is steady
Fixed operation.
Go out following characteristics in relation to analysis method major embodiment of the Rural Power Distribution Network to " coal changes electricity " maximum receiving ability at present:
First, based on theoretical and qualitative analysis, not yet form the analysis method compared with system；Second, only using coal change electric equipment as
One newly-increased electric load, the use that in-depth analysis coal changes electric load itself can feature.
Summary of the invention
It is an object of the invention to be changed in place of making up the deficiencies in the prior art based on coal, to be electrically accessed local distribution network steady safely
Surely the demand run proposes that a kind of Rural Power Distribution Network to the analysis method of " coal changes electricity " maximum receiving ability, is commented for grid company
Estimate coal and the influence offer theoretical direction for being electrically accessed and running and planning to power distribution network is provided, is connect with successfully managing a large amount of " coal changes electricity " equipment
The new situations entered ensure the safe and stable operation of power distribution network.
The purpose of the present invention is what is realized by following technological means:
The analysis method of a kind of Rural Power Distribution Network to " coal changes electricity " maximum receiving ability, it is characterised in that: including following step
It is rapid:
(1), user's heat demand specificity analysis
User's heat demand characteristic can be calculated by establishing thermal balance model, and building heat balance model is with following equalities come table
Show:
Q (t)=Q1(t)+Q2(t)-Q3(t)-Q4(t) (1)
In formula, Q (t) is building temperature rise heat consumption；Q1It (t) is heating equipment heat dissipation capacity；Q2(t) it (illuminates, cook a meal for inner heat source
Thing, human body etc.) heat dissipation capacity；Q3It (t) is the heat consump- tion in transfer of building enclosure；Q4(t) heat consumption is permeated for door and window；
(2), coal changes electric load analysis on Operating
The heat demand curve that coal changes electric load can be obtained by building thermal balance model, changed by the following coal that can be calculated
The electric load curve of electric load:
P (t)=Q (t)/COP (7)
In formula, P (t) is that coal changes the electric load curve of electric load, and COP is the Energy Efficiency Ratio of equipment, i.e., heats power with consumed
The ratio of electrical power；
(3), the influence that " coal changes electricity " project runs power distribution network and plans
1) " coal changes electricity " load accesses the influence to distribution network voltage deviation
Overall calculation thinking is the angle from user, through different type user after the access of " coal changes electricity " load
Power load curvilinear motion obtains the integral load situation of change in region, then changes electric load using the whole coal that superposition obtains
Curve calculates influence of " coal changes electricity " the load access to voltage deviation, wherein shadow of " coal changes electricity " the load access to voltage deviation
Sound can be calculated by following equation:
The load of distribution network system is evenly distributed on route feeder line point end, and load power is sized to Pl+jQl, connect in node
" coal changes electricity " load capacity at i is with PM+jQMIt indicates,
Voltage deviation △ U of the ideal power distribution network without " coal changes electricity " load at node jj' expression formula is as follows:
After the access of " coal changes electricity " load, when individually considering that " coal changes electricity " load acts on power distribution network, first by distribution
The system power supply side of net is short-circuit, and the impedance in distribution network line is smaller for load, therefore " coal changes electricity " load is to electricity
The effect of pressure deviation is mainly manifested in the route before " coal changes electricity " load to this section of system power supply, that is, i point；And for
Route after i point, " coal changes electricity " load do not influence voltage deviation directly, but due to the access of " coal changes electricity " load,
May play the role of reducing again to voltage, so that each point voltage deviation after i point can indirectly be influenced, therefore provide " coal herein
Changing electricity " load is positive to the effect of voltage drop；Therefore under " coal changes electricity " load independent role, the voltage landing of node j are as follows:
Utilize circuit superposition theorem: △ Vj=△ V0,j+△VM, obtain electric in system simultaneously at the j of any point in power distribution network
Voltage drop under source and the effect of " coal changes electricity " load:
By front it is found that the line termination voltage of this power distribution network is V0, then the voltage of any point j is in route:
Then, voltage deviation △ U of the ideal power distribution network of " coal changes electricity " load access at node jjExpression formula is as follows:
By equation (12) it is found that the access capacity of " coal changes electricity " load, on-position influence whether power distribution network node
Voltage deviation；
It enablesWhen, equation (11) is simplified, such as
Shown in following formula:
According to equation (13) using the position of node j as variable, j ∈ [1, i] is defined as distribution network line front half section, it will
J ∈ [i+1, N] is defined as the distribution network line second half section, is specifically illustrated respectively:
It, can be by △ V when j ∈ [1, i]j=-j (2N-j+1) X/2-jY+ (V0-VN)/VNIt arranges:
Above formula is the quadratic function about j, due to △ Uj> 0, on section [0, N+Y/X+1/2], △ UjIt is monotonic increase
, and j≤(N+Y/X+1/2), therefore the line voltage distribution deviation amplitude of power distribution network front half section is in gradually incremental trend；
It, can be by △ U as j ∈ [i+1, N]j=-j (2N-j+1) X/2-iY+ (V0-VN)/VNIt arranges:
From the above equation, we can see that as j ∈ [i+1, N], △ UjIt is monotonic increase, i.e. the line for the distribution network line second half section
Road, line node voltage deviation amplitude in gradually incremental trend, and " coal changes electricity " load access point its voltage deviation most
It is small；
2) " coal changes electricity " load accesses the influence to power distribution network three-phase imbalance
Overall calculation thinking is the angle from user, is accessed wherein by different type user in " coal changes electricity " load
Thus power load curvilinear motion after one phase calculates its positive sequence and negative phase-sequence to obtain the out of phase voltage of each node
Influence of " coal changes electricity " the load access to power distribution network three-phase imbalance is calculated in voltage, wherein the access pair of " coal changes electricity " load
The influence of power distribution network three-phase imbalance can be calculated by following equation:
The component of three-phase voltage is obtained by Fortescue transformation matrix S first, the expression formula of S is as follows:
Wherein
And symmetrical components formula are as follows:
Voltage unbalance factor can be calculated using the symmetrical components ingredient obtained, and the definition of voltage tri-phase unbalance factor is negative
The ratio of sequence voltage component and positive sequence voltage component, such as following formula:
Wherein, VUF indicates voltage unbalance factor, U2For negative sequence voltage components, U1For positive sequence voltage component；" coal changes electricity "
Before load access, power distribution network tri-phase unbalance factor is 0, and when " coal changes electricity " load accesses A phase, the load between three-phase is no longer
It is equal, and three-phase phase voltage UAAnd UBWith UCAlso no longer equal, it is possible thereby to calculate positive sequence and negative sequence voltage is respectively as follows:
The tri-phase unbalance factor when access of " coal changes electricity " load can be acquired by above formula；
In a wherein phase for " coal changes electricity " load access three-phase, it will lead to power distribution network and the case where three-phase imbalance occur,
Thus the electric energy loss that may cause route increases, and the electric energy loss of distribution transformer increases, and distribution transforming power output is reduced, and generates zero sequence
Electric current is to generate magnetic hysteresis and eddy-current loss, to influence the safe operation of electrical equipment；
3) influence of " coal changes electricity " the load project to distribution network planning
There is this index of capacity-load ratio when planning in used data, the calculating needs of this index of capacity-load ratio are matched by difference
Piezoelectric transformer load factor is calculated, and is to calculate " coal changes electricity " on the calculating that distribution network planning influences for " coal changes electricity " project
The situation of change of distribution transformer load factor after load access；
In planning, it is necessary to carry out substation capacity under the premise of not reducing security reliability and meeting load factor
It chooses and track remodelling works, therefore, substation's load capacity situation is to carry out needing emphasis to consider when substation capacity planning
The problem of, and substation's load factor is the index of a single substation's load capacity of reflection, it can be by load factor
It limits to complete the planning problem of each substation capacity；
Overall calculation thinking is the angle from substation, through different type user after the access of " coal changes electricity " load
Power load curvilinear motion, obtain the burden with power maximum value of each substation, then calculate " coal using obtained data
Change electricity " influence of the load access to distribution transformer load factor, calculate distribution transformer load factor after the access of " coal changes electricity " load
Situation of change formula it is as follows:
Load factor is then the index towards single substation, it describes the band burden with power of each substation and becomes
The ratio of depressor capacity is calculated when carrying out substation capacity planning using load factor index,
The calculation formula of substation's load factor is as follows:
In formula, β is substation's load factor, PiFor substation's on-load active power maximum value, SbFor substation capacity；
For the substation of different voltages grade, capacity-load ratio has different range values, according to the value of capacity-load ratio
It is different it can be concluded that region Rate of average load value range, specific calculation formula is as follows:
In formula,For power factor, R is capacity-load ratio,For region Rate of average load；
After obtaining the Rate of average load in region, using region Rate of average load as all changes under this voltage class
The load factor in power station calculates the capacity of different distribution transformings by following formula, it can obtains the capacity of distribution transform after we plan；
(4), Rural Power Distribution Network is calculated to " coal changes electricity " maximum receiving ability
Before calculating maximum receiving ability, first have to construct maximum receiving capability model, it is suitable to choose on this basis
Derivation algorithm is solved；
1) maximum to receive capability model
Maximum receiving ability described in this patent, which refers to, considers that voltage is not out-of-limit, the not super constraint of tri-phase unbalance factor and distribution transforming
In the case where not heavily loaded, " coal changes electricity " load active power maximum value that power distribution network can access；
It is provided in " power quality admissible deviation of supply volt- age " GB12325-90,10kV and following three phase supply voltage are permitted
Perhaps deviation is the 7% of voltage rating；It is provided in " power quality-three-phase imbalance " GB/T15543-2008, power grid is normally transported
When row, negative sequence voltage degree of unbalancedness is no more than 2%, is no more than 4% in short-term；It is defined as needing satisfaction negative distribution transformer load rate
Load rate is less than 70%；
Objective function is that power distribution network accesses maximum to " coal changes electricity " load:
In formula, NiFor system interior joint number, PA,iFor " coal changes electricity " load capacity that node i is accessed in A phase, PB,iFor node
" coal changes electricity " load capacity that i is accessed in B phase, PC,i" coal the changes electricity " load capacity accessed for node i in C phase；
Constraint condition includes voltage deviation constraint, tri-phase unbalance factor constraint and the constraint of distribution transformer load rate, and specific formula is such as
Under:
(1) voltage deviation constrains:
(2) tri-phase unbalance factor constrains:
(3) distribution transformer load rate constrains:
In formula, Δ UjFor node voltage deviation, VUF is tri-phase unbalance factor, and β is then distribution transformer load rate；
2) model solution algorithm
The solution of model is carried out using particle swarm algorithm herein, Rural Power Distribution Network accesses maximum receiving ability to " coal changes electricity "
Analysis is a non-linear single-object problem, and the optimized variable of the model includes out of phase " coal changes electricity " of each node
Load access capacity；If the position vector of particle is zi=(zi1,zi2,…,zid,…,ziD), each coordinate is optimized variable,
As " coal changes electricity " load access capacity, calculation process are as follows:
(1) population in initialization algorithm, sets the number m of particle in population, and the first of each particle is arranged
Value；
(2) according to fitness function, i.e. formula (23) calculates the fitness function value of each particle；
(3) according to fitness function value come more new individual extreme value piWith global extremum pg；
(4) according to formula (27) and formula (28) come the position of more new particle；
In formula: d=1,2 ..., D；W is inertia weight；K is the number of iterations；Random number of the r1 and r2 between [0,1]；c1
It is Studying factors with c2；
(5) judge whether to meet iteration stopping condition, if meeting stop condition, iteration stopping finds global optimum；It is no
Then return to (2).
Moreover, (1) various difference can be calculated step by following equation in the formula:
1) temperature rise heat consumption Q (t) is built
In formula, cnFor room air specific heat；ρnFor the atmospheric density under indoor air temperature；V is that architecture indoor air is overall
Product；For indoor air temperature change rate；
2) heating equipment heat dissipation capacity Q1(t)
Q1(t)=η Qh(t) (3)
In formula, η is radiator entrance radiating efficiency, is taken as 0.9；Q (t) is total heating of t moment heat resource equipment input
Power；
3) inner heat source heat dissipation capacity Q2(t)
Q2(t)=3.8W/m2 (4)
According to " Civil Building Energy Conservation design standard " build in heat gain from occupant and number and its behavior, illuminate, cook a meal
Thing etc. is related, therefore the heat radiation power of unit area takes 3.8W/m2；
4) the heat consump- tion in transfer Q of building enclosure3(t)
In formula, NiFor room difference building enclosure inner surface sum；FkFor building enclosure k internal surface area (m2)；KkTo go along with sb. to guard him
Heat transfer coefficient (the W/m of structure k2·℃)；TnIt (t) is calculating temperature (DEG C) in t moment room；TwIt (t) is t moment outdoor temperature
(℃)；
5) door and window permeates heat consumption Q4(t)
Q4(t)=0.278 × cwρwV0[Tn(t)-Tw(t)] (6)
In formula, CwFor outdoor air specific heat, 1.004kJ/kg DEG C is taken；ρwFor the atmospheric density under outside air temperature, take
1.293kg/m3；V0For outdoor air infiltration capacity (m3/h)。
Moreover, step (2) in due to distinct device COP value difference it is larger, it is therefore desirable to change electric equipment for different coals
Calculate separately configuration power:
The type that coal changes electric equipment has very much, at present most widely used " coal changes electricity " equipment mainly include air source heat pump,
Directly-heated type electric heater, regenerative electrochemical heating, centralized electric boiler, carbon crystal plate etc., different coals change heating principle and the spy of electric equipment
Point is different, and COP value also differs larger, wherein the COP value of air source heat pump is usually between 2.5-3.8, specific value
Positive correlation is showed with outdoor temperature；The COP value of directly heating electric heater is generally 0.95 or more, reaches as high as 0.99；Heat accumulating type
The COP value of electric heater is generally 0.95 or more；The COP value of accumulated electric heater can be calculated according to 0.98；The COP value of carbon crystal plate can
It is calculated according to 0.99.
The advantages and positive effects of the present invention are:
The invention proposes one kind be suitable for heating districts coal change electric equipment largely access after power distribution network power distribution network operation and
The method of planning, this method can sufficiently analyze being ground with energy demand based on different configuration of " coal changes electricity " scheme for user
Study carefully Rural Power Distribution Network and adaptability and maximum receiving ability are accessed to " coal changes electricity ".The present invention can be a large amount of for " coal changes electricity " equipment
The impact evaluation work for accessing local distribution network provides guidance, mentions for power distribution network in " coal changes electricity " planning under the new situation and operation
For theoretical direction, it may advantageously facilitate cleaning heating in the further genralrlization of grass roots, push the development of the micro- energy net in rural area.
Detailed description of the invention
Fig. 1 is building heat balance Principle of Process figure；
Fig. 2 is multinode invariable power distribution network schematic diagram；
Fig. 3 is example of calculation model schematic.
Specific embodiment
With reference to the accompanying drawing in detail narration the embodiment of the present invention, it should be noted that the present embodiment be it is narrative, no
It is restrictive, this does not limit the scope of protection of the present invention.
The present invention relates to a kind of Rural Power Distribution Networks to the analysis method of " coal changes electricity " maximum receiving ability, including following step
It is rapid:
(1), user's heat demand specificity analysis
User's heat demand characteristic is influenced by many factors such as climatic factor, architectural character, user's habits, these influences
Factor acts on building, causes the variation of room temperature and heats power.The dissipation and heating of building construction are one multiple
Miscellaneous thermal balance process, material, structure, solar radiation, the activity of people, outdoor temperature, the heating equipment heat production power in house etc.
Room temperature will be influenced, to have an impact to its heating demand, user's heat demand characteristic proposed by the invention can be by building
Vertical thermal balance model calculates.Its building heat balance Principle of Process is as shown in Fig. 1, the building heat balance after Rational Simplification
Model is indicated with following equalities:
Q (t)=Q1(t)+Q2(t)-Q3(t)-Q4(t) (1)
In formula, Q (t) is building temperature rise heat consumption；Q1It (t) is heating equipment heat dissipation capacity；Q2(t) it (illuminates, cook a meal for inner heat source
Thing, human body etc.) heat dissipation capacity；Q3It (t) is the heat consump- tion in transfer of building enclosure；Q4(t) heat consumption is permeated for door and window.Various difference can
It is calculated by following equation:
1) temperature rise heat consumption Q (t) is built
In formula, cnFor room air specific heat；ρnFor the atmospheric density under indoor air temperature；V is that architecture indoor air is overall
Product；For indoor air temperature change rate.
2) heating equipment heat dissipation capacity Q1(t)
Q1(t)=η Qh(t) (3)
In formula, η is radiator entrance radiating efficiency, is taken as 0.9；Q (t) is total heating of t moment heat resource equipment input
Power.
3) inner heat source heat dissipation capacity Q2(t)
Q2(t)=3.8W/m2 (4)
According to " Civil Building Energy Conservation design standard " build in heat gain from occupant and number and its behavior, illuminate, cook a meal
Thing etc. is related, therefore the heat radiation power of unit area takes 3.8W/m2。
4) the heat consump- tion in transfer Q of building enclosure3(t)
In formula, NiFor room difference building enclosure inner surface sum；FkFor building enclosure k internal surface area (m2)；KkTo go along with sb. to guard him
Heat transfer coefficient (the W/m of structure k2·℃)；TnIt (t) is calculating temperature (DEG C) in t moment room；TwIt (t) is t moment outdoor temperature
(℃)。
5) door and window permeates heat consumption Q4(t)
Q4(t)=0.278 × cwρwV0[Tn(t)-Tw(t)] (6)
In formula, CwFor outdoor air specific heat, 1.004kJ/kg DEG C is taken；ρwFor the atmospheric density under outside air temperature, take
1.293kg/m3；V0For outdoor air infiltration capacity (m3/h)。
(2), coal changes electric load analysis on Operating
Due to " coal changes electricity " equipment accessed in power distribution network it is larger, part throttle characteristics will to the integrated curved of distribution produce
Raw significant impact, may change the peak interval of time and peak load power of load curve.And as undertaking user's heat supply in winter
The heating demands of capital equipment, part throttle characteristics and user are closely related.
The heat demand curve that coal changes electric load can be obtained by building thermal balance model, changed by the following coal that can be calculated
The electric load curve of electric load:
P (t)=Q (t)/COP (7)
In formula, P (t) is that coal changes the electric load curve of electric load, and COP is the Energy Efficiency Ratio of equipment, i.e., heats power with consumed
The ratio of electrical power.Since the COP value difference of distinct device is larger, it is therefore desirable to change electric equipment for different coals and calculate separately
Configure power.
The type that coal changes electric equipment has very much, at present most widely used " coal changes electricity " equipment mainly include air source heat pump,
Directly-heated type electric heater, regenerative electrochemical heating, centralized electric boiler, carbon crystal plate etc., different coals change heating principle and the spy of electric equipment
Point is different, and COP value also differs larger, wherein the COP value of air source heat pump is usually between 2.5-3.8, specific value
Positive correlation is showed with outdoor temperature；The COP value of directly heating electric heater is generally 0.95 or more, reaches as high as 0.99；Heat accumulating type
The COP value of electric heater is generally 0.95 or more；The COP value of accumulated electric heater can be calculated according to 0.98；The COP value of carbon crystal plate can
It is calculated according to 0.99.
(3), the influence that " coal changes electricity " project runs power distribution network and plans is calculated
The load of conventional electrical distribution net, which does not include generally, has coal to change electric equipment, after the access of " coal changes electricity " load, will cause use
Family power load increases, can the electrical load characteristics curve to user impact, the problem of bringing can be run to power distribution network, it is main
It include the influence of the influence and power distribution network three-phase imbalance to voltage deviation.And work as " coal changes electricity " load access power distribution network it
Afterwards, it also will increase the maximum value of substation's burden with power, to influence the selection of capacity of distribution transform, and then influence power distribution network
Planning.
1) " coal changes electricity " load accesses the influence to distribution network voltage deviation
Overall calculation thinking is the angle from user, through different type user after the access of " coal changes electricity " load
Power load curvilinear motion obtains the integral load situation of change in region.Then change electric load using the whole coal that superposition obtains
Curve calculates influence of " coal changes electricity " the load access to voltage deviation.Wherein shadow of " coal changes electricity " the load access to voltage deviation
Sound can be calculated by following equation.
Multinode invariable power distribution network schematic diagram is as shown in Fig. 2.The load of distribution network system is evenly distributed on route feedback
Line point end, load power are sized to Pl+jQl, " coal changes electricity " load capacity at node i is connect with PM+jQMIt indicates.
Voltage deviation △ U of the ideal power distribution network without " coal changes electricity " load at node jj' expression formula is as follows:
After the access of " coal changes electricity " load, when individually considering that " coal changes electricity " load acts on power distribution network, first by distribution
The system power supply side of net is short-circuit, and the impedance in distribution network line is smaller for load, therefore " coal changes electricity " load is to electricity
The effect of pressure deviation is mainly manifested in the route before " coal changes electricity " load to this section of system power supply, that is, i point；And for
Route after i point, " coal changes electricity " load do not influence voltage deviation directly, but due to the access of " coal changes electricity " load,
May play the role of reducing again to voltage, so that each point voltage deviation after i point can indirectly be influenced, therefore provide " coal herein
Changing electricity " load is positive to the effect of voltage drop.Therefore under " coal changes electricity " load independent role, the voltage landing of node j are as follows:
Utilize circuit superposition theorem: △ Vj=△ V0,j+△VM, obtain electric in system simultaneously at the j of any point in power distribution network
Voltage drop under source and the effect of " coal changes electricity " load:
By front it is found that the line termination voltage of this power distribution network is V0, then the voltage of any point j is in route:
Then, voltage deviation △ U of the ideal power distribution network of " coal changes electricity " load access at node jjExpression formula is as follows:
By equation (12) it is found that the access capacity of " coal changes electricity " load, on-position influence whether power distribution network node
Voltage deviation.
It enablesWhen, equation (12) is simplified, such as following formula
It is shown:
According to equation (13) using the position of node j as variable, j ∈ [1, i] is defined as distribution network line front half section, it will
J ∈ [i+1, N] is defined as the distribution network line second half section, is specifically illustrated respectively.
It, can be by △ V when j ∈ [1, i]j=-j (2N-j+1) X/2-jY+ (V0-VN)/VNIt arranges:
Above formula is the quadratic function about j, due to △ Uj> 0, on section [0, N+Y/X+1/2], △ UjIt is monotonic increase
, and j≤(N+Y/X+1/2), therefore the line voltage distribution deviation amplitude of power distribution network front half section is in gradually incremental trend.
It, can be by △ U as j ∈ [i+1, N]j=-j (2N-j+1) X/2-iY+ (V0-VN)/VNIt arranges:
From the above equation, we can see that as j ∈ [i+1, N], △ UjIt is monotonic increase, i.e. the line for the distribution network line second half section
Road, line node voltage deviation amplitude in gradually incremental trend, and " coal changes electricity " load access point its voltage deviation most
It is small.
2) " coal changes electricity " load accesses the influence to power distribution network three-phase imbalance
Overall calculation thinking is the angle from user, is accessed wherein by different type user in " coal changes electricity " load
Thus power load curvilinear motion after one phase calculates its positive sequence and negative phase-sequence to obtain the out of phase voltage of each node
Influence of " coal changes electricity " the load access to power distribution network three-phase imbalance is calculated in voltage.Wherein " coal changes electricity " load access pair
The influence of power distribution network three-phase imbalance can be calculated by following equation.
The component of three-phase voltage is obtained by Fortescue transformation matrix S first, the expression formula of S is as follows:
Wherein
And symmetrical components formula are as follows:
Voltage unbalance factor can be calculated using the symmetrical components ingredient obtained.The definition of voltage tri-phase unbalance factor is negative
The ratio of sequence voltage component and positive sequence voltage component, such as following formula:
Wherein, VUF indicates voltage unbalance factor, U2For negative sequence voltage components, U1For positive sequence voltage component." coal changes electricity "
Before load access, power distribution network tri-phase unbalance factor is 0, and when " coal changes electricity " load accesses A phase, the load between three-phase is no longer
It is equal, and three-phase phase voltage UAAnd UBWith UCAlso no longer equal, it is possible thereby to calculate positive sequence and negative sequence voltage is respectively as follows:
The tri-phase unbalance factor when access of " coal changes electricity " load can be acquired by above formula.
In a wherein phase for " coal changes electricity " load access three-phase, it will lead to power distribution network and the case where three-phase imbalance occur,
Thus the electric energy loss that may cause route increases, and the electric energy loss of distribution transformer increases, and distribution transforming power output is reduced, and generates zero sequence
Electric current is to generate magnetic hysteresis and eddy-current loss, to influence the safe operation of electrical equipment.
3) influence of " coal changes electricity " the load project to distribution network planning
There is this index of capacity-load ratio when planning in used data, the calculating needs of this index of capacity-load ratio are matched by difference
Piezoelectric transformer load factor is calculated.It is to calculate " coal changes electricity " on the calculating that distribution network planning influences for " coal changes electricity " project
The situation of change of distribution transformer load factor after load access.
In planning, it is necessary to carry out substation capacity under the premise of not reducing security reliability and meeting load factor
It chooses and track remodelling works.Therefore, substation's load capacity situation is to carry out needing emphasis to consider when substation capacity planning
The problem of, and substation's load factor is the index of a single substation's load capacity of reflection, it can be by load factor
It limits to complete the planning problem of each substation capacity.
Overall calculation thinking is the angle from substation, through different type user after the access of " coal changes electricity " load
Power load curvilinear motion, obtain the burden with power maximum value of each substation.Then " coal is calculated using obtained data
Change electricity " influence of the load access to distribution transformer load factor.Calculate distribution transformer load factor after " coal changes electricity " load accesses
Situation of change formula it is as follows.
Load factor is then the index towards single substation, it describes the band burden with power of each substation and becomes
The ratio of depressor capacity is calculated when carrying out substation capacity planning using load factor index.
The calculation formula of substation's load factor is as follows:
In formula, β is substation's load factor, PiFor substation's on-load active power maximum value, SbFor substation capacity.
For the substation of different voltages grade, capacity-load ratio has different range values, according to the value of capacity-load ratio
It is different it can be concluded that region Rate of average load value range, specific calculation formula is as follows:
In formula,For power factor, R is capacity-load ratio,For region Rate of average load.
After obtaining the Rate of average load in region, using region Rate of average load as all changes under this voltage class
The load factor in power station calculates the capacity of different distribution transformings by following formula, it can obtains the capacity of distribution transform after we plan.
(4), Rural Power Distribution Network is calculated to " coal changes electricity " maximum receiving ability
Maximum receiving ability described in this patent, which refers to, considers that voltage is not out-of-limit, the not super constraint of tri-phase unbalance factor and distribution transforming
In the case where not heavily loaded, " coal changes electricity " load active power maximum value that power distribution network can access.Calculate maximum receiving ability it
Before, it first has to construct maximum receiving capability model, chooses suitable derivation algorithm on this basis and solved.
1) maximum to receive capability model
It is provided in " power quality admissible deviation of supply volt- age " GB12325-90,10kV and following three phase supply voltage are permitted
Perhaps deviation is the 7% of voltage rating；It is provided in " power quality-three-phase imbalance " GB/T15543-2008, power grid is normally transported
When row, negative sequence voltage degree of unbalancedness is no more than 2%, is no more than 4% in short-term；It is defined as needing satisfaction negative distribution transformer load rate
Load rate is less than 70%.
Objective function is that power distribution network accesses maximum to " coal changes electricity " load:
In formula, NiFor system interior joint number, PA,iFor " coal changes electricity " load capacity that node i is accessed in A phase, PB,iFor node
" coal changes electricity " load capacity that i is accessed in B phase, PC,i" coal the changes electricity " load capacity accessed for node i in C phase.
Constraint condition includes voltage deviation constraint, tri-phase unbalance factor constraint and the constraint of distribution transformer load rate, and specific formula is such as
Under.
(1) voltage deviation constrains:
(2) tri-phase unbalance factor constrains:
(3) distribution transformer load rate constrains:
In formula, Δ UjFor node voltage deviation, VUF is tri-phase unbalance factor, and β is then distribution transformer load rate.
2) model solution algorithm
The solution of model is carried out using particle swarm algorithm herein, Rural Power Distribution Network accesses maximum receiving ability to " coal changes electricity "
Analysis is a non-linear single-object problem, and the optimized variable of the model includes out of phase " coal changes electricity " of each node
Load access capacity.If the position vector of particle is zi=(zi1,zi2,…,zid,…,ziD), each coordinate is optimized variable,
As " coal changes electricity " load access capacity.Calculation process is as follows:
(1) population in initialization algorithm, sets the number m of particle in population, and the first of each particle is arranged
Value.
(2) according to fitness function, i.e. formula (23) calculates the fitness function value of each particle.
(3) according to fitness function value come more new individual extreme value piWith global extremum pg。
(4) according to formula (27) and formula (28) come the position of more new particle.
In formula: d=1,2 ..., D；W is inertia weight；K is the number of iterations；Random number of the r1 and r2 between [0,1]；c1
It is Studying factors with c2.
(5) judge whether to meet iteration stopping condition, if meeting stop condition, iteration stopping finds global optimum；It is no
Then return to (2).
Enumerating a preferred forms below, the present invention is described in detail:
(1), the influence that " coal changes electricity " project runs power distribution network and plans is calculated
1) influence of " coal changes electricity " the load access to distribution network voltage deviation calculates
This example is as shown in Fig. 3, and regional distribution network includes 2 branches altogether, 5 nodes, and every route is connected to 10kV change
Power station, and all have the load of certain power.The load that wherein 4 and 5 nodes are accessed is residential block load, the access of 2 nodes
Load is shopping centre load, and it is industrial area load, node 2, node 3, node 4, the load value at node 5 that 3 nodes, which access load,
Respectively 244kW, 343.5kW, 198.5kW, 198.5kW, each line segment length take 1km, and coal changes electric load access capacity difference
It is set as 100kW, 200kW and 400kW, the node 4 of line attachment 1-2-3-4." coal the changes electricity " load of research institute's access holds
Amount changes constantly, changes the situation of change of the power distribution network node voltage deviation of electric load containing coal.
1 node voltage deviation of table is influenced (△ V%) by " coal changes electricity " load access capacity
By table 1 it is found that power distribution network node voltage deviation and " coal changes electricity " load access capacity are positively correlated, with node
The increase of " coal changes electricity " load, power distribution network node voltage deviation are also increase accordingly, when " coal changes electricity " load takes 400kW, distribution
It is maximum to net each node voltage deviation.Significantly, since node 5 is in different each lines of feedback from its excess-three node
Section, therefore it is by being influenced very little.
2) influence of " coal changes electricity " the load access to power distribution network tri-phase unbalance factor calculates
Example is shown in attached drawing 3, and coal changes the A phase of the node 4 of electric load line attachment 1-2-3-4." the coal of research institute's access
Changing electricity " load capacity when changing, contains each node three-phase imbalance situation of power distribution network of " coal changes electricity " load.
2 node tri-phase unbalance factor of table is influenced (%) by " coal changes electricity " load access capacity
By table 2 it is found that power distribution network node tri-phase unbalance factor and " coal changes electricity " load access capacity are positively correlated, with section
The power distribution network node tri-phase unbalance factor of the increase of point " coal changes electricity " load, access " coal changes electricity " load is also increase accordingly, when " coal
Changing electricity " for load when taking 400kW, this node tri-phase unbalance factor is maximum.It is worth noting that, not accessing " coal changes electricity " load
Node, tri-phase unbalance factor variation is smaller, but increases on the whole also with the increase of " coal changes electricity " access capacity.
3) influence of " coal changes electricity " the load access to distribution network planning calculates
Problem involved in this example is the station location selection that coal changes 110kV substation and 10kV distribution transforming after electric equipment access,
Supply district is it has been determined that determine the capacity of its distribution transformer, to meet the requirement of ratio of transformer capacity to load.Wherein 4 and 5 nodes are connect
The load entered is resident load, and it is Commercial Load that 2 nodes, which access load, and it is industrial load that 3 nodes, which access load,.
First example is to consider that four different node access coals change electricity respectively when 10kV distribution transforming capacity-load ratio is 1.8
The 10kV capacity of distribution transform planned after equipment and before access, obtained capacity is 10kV capacity of distribution transform lower limit at this time；The
Two examples are to consider that four different node access coals change institute before and after electric equipment respectively when 10kV distribution transforming capacity-load ratio is 2.2
The 10kV capacity of distribution transform of planning, obtained capacity is the 10kV capacity of distribution transform upper limit at this time.
1) 10kV capacity of distribution transform lower limit
Using considering that all loads do not access the case where coal changes electric equipment first, then consider that four nodes sequentially add
Coal changes the case where electric equipment.
Scene one does not access coal for all load points and changes electric equipment, and scene two is that the access coal of node 2 changes electric equipment, scene
Three be that the access coal of node 3 changes electric equipment, and scene four is that the access coal of node 4 changes electric equipment, and scene five changes electricity for the access coal of node 5 and sets
Standby, obtained result is as shown in table 5-2.
The capacity of distribution transform program results (unit: kVA) of 10kV distribution transforming when 3 capacity-load ratio of table is 1.8
| Scene | 10kV distribution transforming 2 | 10kV distribution transforming 3 | 10kV distribution transforming 4 | 10kV distribution transforming 5 |
| Scene one | 439.2 | 618.3 | 357.3 | 357.3 |
| Scene two | 620.5 | — | — | — |
| Scene three | — | 698.5 | — | — |
| Scene four | — | — | 501.5 | — |
| Scene five | — | — | — | 501.5 |
Through table 3 it is found that after load point has accessed " coal changes electricity " load, the distribution transforming of this node planning originally can be made
Capacity increases, and the capacity of distribution transform of other nodes is then almost unchanged, therefore when carrying out 10kV distribution transforming construction, needs to consider
" coal the changes electricity " load accessed suitably increases the influence of capacity of distribution transform the capacity of its distribution transforming.
2) the 10kV capacity of distribution transform upper limit
Consider that all loads do not access the case where coal changes electric equipment first, then considers that four nodes sequentially add coal and change
The case where electric equipment, obtained result such as table 4.
Scene setting is identical as example one, and scene one does not access coal for all load points and changes electric equipment, and scene two is 2 sections
Point access coal changes electric equipment, and scene three is that 3 nodes access coal changes electric equipment, and scene four accesses coal for 4 nodes and changes electric equipment, scene
Five, which access coal for 5 nodes, changes electric equipment.
Capacity of distribution transform program results (unit: kVA) when 4 10kV distribution transforming capacity-load ratio of table is 2.2
| Scene | 10kV distribution transforming 2 | 10kV distribution transforming 3 | 10kV distribution transforming 4 | 10kV distribution transforming 5 |
| Scene one | 536.8 | 755.7 | 436.7 | 436.7 |
| Scene two | 758.5 | — | — | — |
| Scene three | — | 853.5 | — | — |
| Scene four | — | — | 613 | — |
| Scene five | — | — | — | 613 |
The case where analysis and capacity-load ratio for 4 data of table are 1.8 is identical, can learn when load point has accessed " coal
Change electricity " after load, the capacity of distribution transform of this node planning originally can be made to increase, and the capacity of distribution transform of other nodes is then hardly
Become, therefore when carrying out 10kV distribution transforming construction, needs to consider influence of " coal the changes electricity " load accessed to capacity of distribution transform
Suitably to increase the capacity of its distribution transforming.
(2), Rural Power Distribution Network is calculated to " coal changes electricity " maximum receiving ability
Example is to study different node accesses, different mutually access, different load types for " coal changes electricity " shown in attached drawing 3
The receiving ability of load.
1) different the maximum of node access receive capability analysis
The load that 4 and 5 nodes are accessed is residential block load, and it is shopping centre load, the access of 3 nodes that 2 nodes, which access load,
Load is industrial area load.It is respectively node 2,3,4 that example, which is set as the access of " coal changes electricity " equipment,.It receives ability concrete condition
As shown in table 5.
Table 5 " coal changes electricity " load maximum receives ability (kW)
As shown in Table 5 when access node difference, the main factor for restricting the access of " coal changes electricity " load is that voltage is inclined
Difference, on-position closer to line end, caused by voltage deviation it is bigger, it is possible to " coal changes electricity " load of access is got over
It is few.And as " coal changes electricity " load of every phase access, thirdly when mutually accessing identical " coal changes electricity " load, caused by voltage deviation
Minimum can access more loads in voltage out-of-limit.
2) different the maximum of mutually access receive capability analysis
According to the definition of tri-phase unbalance factor, it is known that when " coal changes electricity " equipment is independently accessed a wherein phase, for three
The influence of phase degree of unbalancedness is the same, thus only research " coal changes electricity " load access A phase when the case where.Consider four kinds of different fields
Scape, respectively the A phase of " coal changes electricity " equipment access node 2,3,4 are with access A phase but access node is not fixed.It receives ability tool
Body situation is as shown in table 6.
Table 6 " coal changes electricity " load maximum receives ability (kW)
As shown in Table 6 when accessing the A phase of different nodes, the main factor for restricting the access of " coal changes electricity " load is three
Phase degree of unbalancedness, the tri-phase unbalance factor of each scene reaches limitation, but voltage deviation and line load rate are also providing
Range.And each node tri-phase unbalance factor in scene four meets constraint requirements, but the voltage deviation of node 4 has reached limit
System is big when overall receiving ability is than only accessing a node.
3) the maximum of different original load types receives capability analysis
Consider influence of original load type difference for receiving ability, " coal changes electricity " load can access any section at this time
Any phase of point.Consider four kinds of different scenes, the load that scene one is accessed by 4 and 5 nodes is residential block load, 2 nodes
Access load is shopping centre load, and it is industrial area load that 3 nodes, which access load, and scene 234 is that all nodes are that resident is negative
Lotus, Commercial Load and industrial load.It receives ability concrete condition as shown in table 7.
Table 7 " coal changes electricity " load maximum receives ability (kW)
As can be seen from Table 7, the receiving ability of scene 234 successively declines, and major influence factors are line load rate
It influences, and because the load maximum value of resident load, Commercial Load and industrial load is sequentially increased, original load is bigger,
Then receptive " coal changes electricity " load is fewer.And the different types of load of scene one also has resident load to receive " coal changes electricity " negative
Lotus is more, the situation that industrial load receives " coal changes electricity " load few.
The mentioned method of the present invention can effectively be calculated coal and change electric load curve, and not from voltage deviation, three-phase voltage
Two aspect of balance calculates coal and changes the influence that electric load access runs power distribution network, accesses from " coal changes electricity " load to distribution transformer
Illustrate that coal changes influence of the electric load access to distribution network planning in terms of the influence of load factor.By maximum receive capability model and
Method for solving carries out the Rural Power Distribution Network under different scenes to the receiving ability of " coal changes electricity " load.Therefore, the present invention can be
The impact evaluation work that " coal changes electricity " equipment largely accesses local distribution network provides reference, is power distribution network in " coal changes electricity " new situations
Under planning and operation provide theoretical direction.
Claims (3)
1. a kind of Rural Power Distribution Network is to the analysis method of " coal changes electricity " maximum receiving ability, it is characterised in that: the following steps are included:
(1), user's heat demand specificity analysis
User's heat demand characteristic can be calculated by establishing thermal balance model, and building heat balance model is indicated with following equalities:
Q (t)=Q1(t)+Q2(t)-Q3(t)-Q4(t) (1)
In formula, Q (t) is building temperature rise heat consumption；Q1It (t) is heating equipment heat dissipation capacity；Q2It (t) is inner heat source (illumination, cooking, people
Body etc.) heat dissipation capacity；Q3It (t) is the heat consump- tion in transfer of building enclosure；Q4(t) heat consumption is permeated for door and window；
(2), coal changes electric load analysis on Operating
The heat demand curve that coal changes electric load can be obtained by building thermal balance model, electric bear is changed by the following coal that can be calculated
The electric load curve of lotus:
P (t)=Q (t)/COP (7)
In formula, P (t) is the electric load curve that coal changes electric load, and COP is the Energy Efficiency Ratio of equipment, i.e. heats power and institute's power consumption function
The ratio of rate；
(3), the influence that " coal changes electricity " project runs power distribution network and plans
1) " coal changes electricity " load accesses the influence to distribution network voltage deviation
Overall calculation thinking is the angle from user, passes through electricity consumption of the different type user after the access of " coal changes electricity " load
Load curve variation, obtains the integral load situation of change in region, then changes electric load curve using the whole coal that superposition obtains,
It calculates " coal changes electricity " load and accesses influence to voltage deviation, wherein influence of " coal changes electricity " the load access to voltage deviation can be by
Following equation is calculated:
The load of distribution network system is evenly distributed on route feeder line point end, and load power is sized to Pl+jQl, connect at node i
" coal changes electricity " load capacity with PM+jQMIt indicates,
Voltage deviation △ U of the ideal power distribution network without " coal changes electricity " load at node jj' expression formula is as follows:
After the access of " coal changes electricity " load, when individually considering that " coal changes electricity " load acts on power distribution network, first by power distribution network
System power supply side is short-circuit, and the impedance in distribution network line is smaller for load, therefore " coal changes electricity " load is inclined to voltage
The effect of difference is mainly manifested in the route before " coal changes electricity " load to this section of system power supply, that is, i point；And for i point
Route later, " coal changes electricity " load do not influence voltage deviation directly, but due to the access of " coal changes electricity " load, may
Play the role of reducing again to voltage, so that each point voltage deviation after i point can indirectly be influenced, therefore provides " coal changes electricity " herein
Load is positive to the effect of voltage drop；Therefore under " coal changes electricity " load independent role, the voltage landing of node j are as follows:
Utilize circuit superposition theorem: △ Vj=△ V0,j+△VM, obtain in power distribution network at the j of any point simultaneously in system power supply and
Voltage drop under the effect of " coal changes electricity " load:
By front it is found that the line termination voltage of this power distribution network is V0, then the voltage of any point j is in route:
Then, voltage deviation △ U of the ideal power distribution network of " coal changes electricity " load access at node jjExpression formula is as follows:
By equation (12) it is found that the access capacity of " coal changes electricity " load, on-position influence whether the electricity of power distribution network node
Press deviation；
It enablesWhen, equation (11) is simplified, such as following formula
It is shown:
According to equation (13) using the position of node j as variable, j ∈ [1, i] is defined as distribution network line front half section, by j ∈
[i+1, N] is defined as the distribution network line second half section, is specifically illustrated respectively:
It, can be by △ V when j ∈ [1, i]j=-j (2N-j+1) X/2-jY+ (V0-VN)/VNIt arranges:
Above formula is the quadratic function about j, due to △ Uj> 0, on section [0, N+Y/X+1/2], △ UjIt is monotonic increase, and
J≤(N+Y/X+1/2), therefore the line voltage distribution deviation amplitude of power distribution network front half section is in gradually incremental trend；
It, can be by △ U as j ∈ [i+1, N]j=-j (2N-j+1) X/2-iY+ (V0-VN)/VNIt arranges:
From the above equation, we can see that as j ∈ [i+1, N], △ UjIt is monotonic increase, i.e. the route for the distribution network line second half section,
Line node voltage deviation amplitude is in gradually incremental trend, and its voltage deviation is minimum in " coal changes electricity " load access point；
2) " coal changes electricity " load accesses the influence to power distribution network three-phase imbalance
Overall calculation thinking is the angle from user, accesses a wherein phase in " coal changes electricity " load by different type user
Thus power load curvilinear motion afterwards calculates its positive sequence and negative sequence voltage to obtain the out of phase voltage of each node,
Influence of " coal changes electricity " the load access to power distribution network three-phase imbalance is calculated, wherein the access of " coal changes electricity " load is to power distribution network
The influence of three-phase imbalance can be calculated by following equation:
The component of three-phase voltage is obtained by Fortescue transformation matrix S first, the expression formula of S is as follows:
Wherein
And symmetrical components formula are as follows:
Voltage unbalance factor can be calculated using the symmetrical components ingredient obtained, and voltage tri-phase unbalance factor is defined as negative phase-sequence electricity
The ratio of component and positive sequence voltage component is pressed, such as following formula:
Wherein, VUF indicates voltage unbalance factor, U2For negative sequence voltage components, U1For positive sequence voltage component；In " coal changes electricity " load
Before access, power distribution network tri-phase unbalance factor is 0, the load no longer phase when " coal changes electricity " load accesses A phase, between three-phase
Deng, and three-phase phase voltage UAAnd UBWith UCAlso no longer equal, it is possible thereby to calculate positive sequence and negative sequence voltage is respectively as follows:
The tri-phase unbalance factor when access of " coal changes electricity " load can be acquired by above formula；
In a wherein phase for " coal changes electricity " load access three-phase, it will lead to power distribution network and the case where three-phase imbalance occur, thus
The electric energy loss that may cause route increases, and the electric energy loss of distribution transformer increases, and distribution transforming power output is reduced, and generates zero-sequence current
To generate magnetic hysteresis and eddy-current loss, to influence the safe operation of electrical equipment；
3) influence of " coal changes electricity " the load project to distribution network planning
There is this index of capacity-load ratio when planning in used data, the calculating needs of this index of capacity-load ratio are become by different distribution
Depressor load factor is calculated, and is to calculate " coal changes electricity " load on the calculating that distribution network planning influences for " coal changes electricity " project
The situation of change of distribution transformer load factor after access；
In planning, it is necessary to carry out substation capacity selection under the premise of not reducing security reliability and meeting load factor
It works with track remodelling, therefore, substation's load capacity situation is to carry out needing asking for emphasis consideration when substation capacity planning
Topic, and substation's load factor is the index of a single substation's load capacity of reflection, can pass through the limitation to load factor
To complete the planning problem of each substation capacity；
Overall calculation thinking is the angle from substation, passes through use of the different type user after the access of " coal changes electricity " load
Electric load curvilinear motion, obtains the burden with power maximum value of each substation, then calculates that " coal changes using obtained data
Electricity " load accesses the influence to distribution transformer load factor, calculates distribution transformer load factor after " coal changes electricity " load accesses
The formula of situation of change is as follows:
Load factor is then the index towards single substation, it describes each substation band burden with power and transformer
The ratio of capacity is calculated when carrying out substation capacity planning using load factor index,
The calculation formula of substation's load factor is as follows:
In formula, β is substation's load factor, PiFor substation's on-load active power maximum value, SbFor substation capacity；
For the substation of different voltages grade, capacity-load ratio has different range values, different according to the value of capacity-load ratio
It can be concluded that the value range of region Rate of average load, specific calculation formula is as follows:
In formula,For power factor, R is capacity-load ratio,For region Rate of average load；
After obtaining the Rate of average load in region, using region Rate of average load as all substations under this voltage class
Load factor, the capacity of different distribution transformings is calculated by following formula, it can obtain the capacity of distribution transform after we plan；
(4), Rural Power Distribution Network is calculated to " coal changes electricity " maximum receiving ability
Before calculating maximum receiving ability, first has to construct maximum receiving capability model, choose suitable solve on this basis
Algorithm is solved；
1) maximum to receive capability model
Maximum receiving ability described in this patent, which refers to, considers that voltage is not out-of-limit, and the not super constraint of tri-phase unbalance factor and distribution transforming do not weigh
In the case where load, " coal changes electricity " load active power maximum value that power distribution network can access；
It is provided in " power quality admissible deviation of supply volt- age " GB12325-90,10kV and following three phase supply voltage allow partially
Difference is the 7% of voltage rating；It is provided in " power quality-three-phase imbalance " GB/T15543-2008, when power grid operates normally,
Negative sequence voltage degree of unbalancedness is no more than 2%, is no more than 4% in short-term；For distribution transformer load rate be defined as needing meet load factor
Less than 70%；
Objective function is that power distribution network accesses maximum to " coal changes electricity " load:
In formula, NiFor system interior joint number, PA,iFor " coal changes electricity " load capacity that node i is accessed in A phase, PB,iIt is node i in B
Mutually " coal changes electricity " load capacity of access, PC,i" coal the changes electricity " load capacity accessed for node i in C phase；
Constraint condition includes voltage deviation constraint, tri-phase unbalance factor constrains and the constraint of distribution transformer load rate, specific formula is as follows:
(1) voltage deviation constrains:
(2) tri-phase unbalance factor constrains:
(3) distribution transformer load rate constrains:
In formula, Δ UjFor node voltage deviation, VUF is tri-phase unbalance factor, and β is then distribution transformer load rate；
2) model solution algorithm
The solution of model is carried out using particle swarm algorithm herein, Rural Power Distribution Network accesses maximum receiving capability analysis to " coal changes electricity "
It is a non-linear single-object problem, the optimized variable of the model includes out of phase " coal the changes electricity " load of each node
Access capacity；If the position vector of particle is zi=(zi1,zi2,…,zid,…,ziD), each coordinate is optimized variable, as
" coal changes electricity " load access capacity, calculation process are as follows:
(1) population in initialization algorithm, sets the number m of particle in population, and the initial value of each particle is arranged；
(2) according to fitness function, i.e. formula (23) calculates the fitness function value of each particle；
(3) according to fitness function value come more new individual extreme value piWith global extremum pg；
(4) according to formula (27) and formula (28) come the position of more new particle；
In formula: d=1,2 ..., D；W is inertia weight；K is the number of iterations；Random number of the r1 and r2 between [0,1]；C1 and c2
For Studying factors；
(5) judge whether to meet iteration stopping condition, if meeting stop condition, iteration stopping finds global optimum；Otherwise it returns
It returns (2).
2. Rural Power Distribution Network according to claim 1 exists to the analysis method of " coal changes electricity " maximum receiving ability, feature
Various difference can be calculated by following equation in: the step (1) formula:
1) temperature rise heat consumption Q (t) is built
In formula, cnFor room air specific heat；ρnFor the atmospheric density under indoor air temperature；V is architecture indoor total volume of air；For indoor air temperature change rate；
2) heating equipment heat dissipation capacity Q1(t)
Q1(t)=η Qh(t) (3)
In formula, η is radiator entrance radiating efficiency, is taken as 0.9；Q (t) is total heats power of t moment heat resource equipment input；
3) inner heat source heat dissipation capacity Q2(t)
Q2(t)=3.8W/m2 (4)
Interior heat gain from occupant and number and its behavior, illumination, cooking etc. are built according to " Civil Building Energy Conservation design standard "
It is related, therefore the heat radiation power of unit area takes 3.8W/m2；
4) the heat consump- tion in transfer Q of building enclosure3(t)
In formula, NiFor room difference building enclosure inner surface sum；FkFor building enclosure k internal surface area (m2)；KkFor building enclosure k
Heat transfer coefficient (W/m2·℃)；TnIt (t) is calculating temperature (DEG C) in t moment room；TwIt (t) is t moment outdoor temperature (DEG C)；
5) door and window permeates heat consumption Q4(t)
Q4(t)=0.278 × cwρwV0[Tn(t)-Tw(t)] (6)
In formula, CwFor outdoor air specific heat, 1.004kJ/kg DEG C is taken；ρwFor the atmospheric density under outside air temperature, take
1.293kg/m3；V0For outdoor air infiltration capacity (m3/h)。
3. Rural Power Distribution Network according to claim 1 exists to the analysis method of " coal changes electricity " maximum receiving ability, feature
In: step (2) in due to the COP value difference of distinct device it is larger, it is therefore desirable to change electric equipment for different coals and calculate separately and match
Set power:
The type that coal changes electric equipment has very much, and " coal changes electricity " equipment most widely used at present mainly includes air source heat pump, directly-heated
Formula electric heater, regenerative electrochemical heating, centralized electric boiler, carbon crystal plate etc., different coals, which change the heating principle of electric equipment and feature, to be had
Institute is different, and COP value also differs larger, wherein the COP value of air source heat pump is usually between 2.5-3.8, specific value and room
Outer temperature shows positive correlation；The COP value of directly heating electric heater is generally 0.95 or more, reaches as high as 0.99；Heat-accumulating type electric-heating
The COP value of device is generally 0.95 or more；The COP value of accumulated electric heater can be calculated according to 0.98；The COP value of carbon crystal plate can be according to
0.99 calculates.
Priority Applications (1)
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111061827A (en) * | 2019-12-30 | 2020-04-24 | 广东电网有限责任公司 | Construction method of electric energy supply and demand balance thermodynamic diagram of power distribution network |
| CN111193268A (en) * | 2019-12-30 | 2020-05-22 | 国网北京市电力公司 | Method and device for processing electric heating equipment |
| CN112234614A (en) * | 2020-09-30 | 2021-01-15 | 清华大学 | Power distribution network bearing capacity assessment method considering heat accumulation type electric heating large-scale access |
| CN112491046A (en) * | 2020-11-25 | 2021-03-12 | 国网湖北省电力有限公司咸宁供电公司 | Load access position decision method, device, equipment and storage medium |
| CN113094902A (en) * | 2021-04-08 | 2021-07-09 | 国网上海市电力公司 | Multi-station fusion capacity joint planning method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108009683A (en) * | 2018-01-30 | 2018-05-08 | 国网辽宁省电力有限公司 | A kind of high-capacity direct control load improves the dispatching method that wind-powered electricity generation receives ability |
| CN108256723A (en) * | 2017-11-27 | 2018-07-06 | 国网河北省电力公司经济技术研究院 | Coal changes the assessment of economic benefit method and terminal device for being electrically accessed power grid |
-
2018
- 2018-10-23 CN CN201811236332.4A patent/CN109217307B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108256723A (en) * | 2017-11-27 | 2018-07-06 | 国网河北省电力公司经济技术研究院 | Coal changes the assessment of economic benefit method and terminal device for being electrically accessed power grid |
| CN108009683A (en) * | 2018-01-30 | 2018-05-08 | 国网辽宁省电力有限公司 | A kind of high-capacity direct control load improves the dispatching method that wind-powered electricity generation receives ability |
Non-Patent Citations (1)
| Title |
|---|
| 齐晓光等: "配电网对分布式光伏的接纳能力分析", 《电力与能源进展》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111061827A (en) * | 2019-12-30 | 2020-04-24 | 广东电网有限责任公司 | Construction method of electric energy supply and demand balance thermodynamic diagram of power distribution network |
| CN111193268A (en) * | 2019-12-30 | 2020-05-22 | 国网北京市电力公司 | Method and device for processing electric heating equipment |
| CN111193268B (en) * | 2019-12-30 | 2021-12-10 | 国网北京市电力公司 | Method and device for processing electric heating equipment |
| CN111061827B (en) * | 2019-12-30 | 2023-04-18 | 广东电网有限责任公司 | Construction method of power distribution network electric energy supply and demand balance thermodynamic diagram |
| CN112234614A (en) * | 2020-09-30 | 2021-01-15 | 清华大学 | Power distribution network bearing capacity assessment method considering heat accumulation type electric heating large-scale access |
| CN112234614B (en) * | 2020-09-30 | 2022-08-26 | 清华大学 | Power distribution network bearing capacity assessment method considering heat accumulation type electric heating large-scale access |
| CN112491046A (en) * | 2020-11-25 | 2021-03-12 | 国网湖北省电力有限公司咸宁供电公司 | Load access position decision method, device, equipment and storage medium |
| CN113094902A (en) * | 2021-04-08 | 2021-07-09 | 国网上海市电力公司 | Multi-station fusion capacity joint planning method |
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