CN103559653A - Energy-storing configuration evaluation method based on microgrid - Google Patents

Abstract

The invention discloses an energy storage configuration evaluation method based on a microgrid, which includes the following steps: determining the evaluation object: the evaluation object is a power supply system including energy storage and distributed power supply, determining the evaluation scope and equipment composition, and retrieving and sorting out the power supply system The historical operation data within; determine the evaluation target of the system: the evaluation target of the system is mainly the target that the power supply system needs to achieve for the operation of the energy storage device, and it is the goal of the energy storage to improve the technology of the entire power supply system and the energy storage system Own economic goals; determination of evaluation indicators and calculation of basic indicators: determination of evaluation criteria, that is, comprehensive performance scoring, and evaluation results of energy storage configuration. Realize the advantages of scientific and rational evaluation of energy storage configuration.

Description

Energy storage configuration appraisal procedure based on micro-electrical network

Technical field

The present invention relates to power supply grid field, particularly, relate to a kind of energy storage configuration appraisal procedure based on micro-electrical network.

Background technology

At present, in distributed generation system, the configuration of energy-storage battery is mainly to take economy as target, layoutprocedure gathers the intermittence of considering distributed power source, the method existing institute in ripe software applies, the energy storage collocation method that the economy of take as just applied in homer software is target, its essence is that the intermittence for distributed power source generating compensates.Prior art is mainly before system Construction, to carry out sunykatuib analysis, the economy after temporary unmatchful energy storage configuration, the analysis and assessment of technical elements.

Distributed power source is grid-connected can be produced a lot of not enoughly, and basic reason is that it exerts oneself and have intermittence and randomness.In distributed system, introduce energy storage link, not only can promote the application of regenerative resource, also can improve distributed power source operation stability, maintain system frequency and voltage stabilization, the random fluctuation of compensation load, reduce power supply cost etc., be one of core technology of microgrid.In addition, energy storage technology has certain influence to the outfit of distributed power generation in microgrid, also significant with control to the operation of microgrid.Along with the increase of renewable distributed energy permeability, aggravated its impact to electrical network, this development to energy storage technology has proposed acid test more, becomes technical barrier urgently to be resolved hurrily.Therefore, the research to energy storage technology, has important practical significance and far-reaching significance to the development of power industry.Based on this, to energy-storage battery, the research aspect the collocation method in distributed generation system gets more and more present stage researchist.But up to now, there is no for the science of stored energy capacitance configuration and assess.

The technology of present stage is mainly before microgrid configuration, by simulating generating situation and the workload demand situation of each distributed power source, determines the demand of storage technical elements, then take economy as target contrasts by certain calculating, realizes the outfit to accumulator system.The technology of present stage mainly concentrates on the configuration to energy storage, and the economy after temporary unmatchful energy storage configuration, the assessment of technical elements make a search.This research is mainly for above-mentioned phenomenon, by after energy-storage battery access, the impact of the each side of original system being analyzed, by the calculating of the evaluation index to definite, weighs the rationality of energy-storage battery access capacity.Prior art is mainly before system Construction, to carry out sunykatuib analysis, the technical scheme of the economy after temporary unmatchful energy storage configuration, the analysis and assessment of technical elements.

Summary of the invention

The object of the invention is to, for the problems referred to above, propose a kind of energy storage configuration appraisal procedure based on micro-electrical network, to realize the advantage to energy storage scientific allocation, rational assessment.

For achieving the above object, the technical solution used in the present invention is:

An energy storage configuration appraisal procedure for micro-electrical network, comprises the following steps:

Step 1, determine evaluation object:

Evaluation object is the electric power system containing energy storage and distributed power source, determines that range of value, equipment form, and transfer the history data arranging in electric power system;

Step 2, determine the evaluation objective of system:

It is mainly that electric power system is moved the target of required realization to energy storage device that the evaluation objective of system is, and is energy storage target that whole electric power system is promoted technically and the economic goal of accumulator system self;

Step 3, determine that evaluation index and base values calculate:

It is mainly the evaluation index of determining accumulator system, mainly comprise accumulator system economically and technical index, its specific targets comprise: containing the power supply reliability of the electric power system of energy storage device, accumulator system to the compensation effect of distributed power source, containing the renewable energy utilization rate of energy storage device, containing the overall efficiency of energy storage device energy supplying system and the economic performance of energy-storage battery;

Step 4: determine that evaluation criterion is combination property marking;

Step 5: energy storage configuration evaluation result

According to above-mentioned steps one to the definite standard of step 4, by energy storage, configure evaluation index computing method and energy storage configuration evaluation index marking and weight calculation, obtain the comprehensive grading of the energy storage access scheme of needs assessment.

Further, in described step 3, index calculating is specially:

(1) power supply reliability is mainly to use loss of supply rate to weigh, and loss of supply rate refers to that the interior unappeasable workload demand of electric power system accounts for the ratio of assessment phase total load demand, uses η _lPSPrepresent, it is an engineering application standard that is widely used in optimizing capacity configuration in wind-solar-storage joint system, when battery discharging is to minimum value C _batmintime, control system disconnects the connection of accumulator and load, and workload demand can not meet, and the loss of supply value of t in the time is:

E _LPS(t)=P _loadΔt-[P _PV(t)Δt+P _WG(t)Δt+C _bat(t)-C _batmin]η _inv

In assessment phase T, loss of supply rate is expressed as:

${\mathrm{\η}}_{\mathrm{LPSP}}\left(t\right)=\underset{t=1}{\overset{T}{\mathrm{\Σ}}}{E}_{\mathrm{LPS}}\left(t\right)/\underset{t=1}{\overset{T}{\mathrm{\Σ}}}{P}_{\mathrm{load}}\mathrm{\Δt}$

Wherein: E _lPSfor loss of supply value, P _loadfor system loading, P _pvfor photovoltaic generation power, P _wGfor wind turbine power generation power, C _bat(t) be that battery is at t moment energy storage state, C _batminfor energy-storage battery minimum energy storing state, Δ t is the step-length for calculating; T is the assessment phase, and in the assessment phase, wind, light generated output remain unchanged;

(2) accumulator system mainly represents by r.m.s. deviation the compensation effect of distributed power source, do not configuring under energy storage state, electric power system power supply containing distributed power generation device has undulatory property, after energy storage configuration, expectation energy storage can coordinate the common energy supply of distributed power generation device, to realize steady electricity supply

R.m.s. deviation represents with RMS, refers to electric power system output power fluctuation r.m.s. deviate in range of value, and each point extracts square root after divided by number of data points with the quadratic sum of aim curve deviation, and the computing formula of r.m.s. deviation is:

$\mathrm{RMS}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{(P_{\mathrm{Ci}}-P_{\mathrm{Clim}})}^2}{N}}$

Wherein: P _climfor default permission undulating quantity, P _cifor actual undulating quantity;

(3) overall efficiency is mainly to use proportion of goods damageds index expression, accumulator system overall efficiency refers to the loss that has comprised whole accumulator system by this parameter, comprise the efficiency of inverter, efficiency and the network efficiency that energy storage discharges and recharges, overall efficiency is higher, the loss of each equipment is lower, the performance of whole system is better, the loss of consideration equipment is subject to the properties influence of equipment self, evaluation index is only considered Network Loss Rate, the difference of configuration energy storage position can cause loss in various degree to network, and the computing formula of via net loss rate is:

(4) the renewable energy utilization rate that contains energy storage device is mainly with referring to energy dissipation rate η _excrepresent, refer to cannot dissolve the completely ratio of distributed power source electricity energy and load total amount of system loading,

${\mathrm{\η}}_{\mathrm{exc}}\left(T\right)=E_{\mathrm{WE}}\left(T\right)/\left[2\underset{t=1}{\overset{T}{\mathrm{\Σ}}}{P}_{\mathrm{load}}\left(t\right)\mathrm{\Δt}\right]$

η _excfor the ratio of the power of wind-force, the photovoltaic generation waste power requirement total with assessing phase load, work as P _wG(t)+P _pV(t)+P _bat(t)=P _total(t) >P _ref(t), time, the computing formula of wind-force and photovoltaic generation waste energy is:

E _WE(t)=[P _PV(t)+P _WG(t)]Δt-{P _refΔt/η _inv+[C _batmax-C _bat(t-1)/η _cha]}

E wherein _wE(t) be to meet on the basis of burden requirement and energy-storage travelling wave tube charging requirement, the energy of wind-power electricity generation and photovoltaic generation waste;

(5) economic benefit is mainly with internal rate of return and two index expressions of interest provision rate.

Further, described (5) described internal rate of return and interest provision rate is:

Internal rate of return: the discount rate when cash flow net present value (NPV) that refers to receipts and expenditures is zero is also the important indicator of reflection project profitability;

If P _tbe the free cash flow of t, i ^*for internal rate of return to be asked, n is equipment Economic Life, and the computing formula of internal rate of return is:

$\underset{t=0}{\overset{n}{\mathrm{\Σ}}}\frac{P_t}{{(1+i^{*})}^t}=0$

Interest provision rate also claims Number of times interest earned, and the project that refers to each year within the maturity of borrowing money can be used for the ratio of profit and current interest in red expense before the tax breath of interest payment,

ICR=EBIT/PI

Profit/current interest in red * 100%=(total profit+current interest in red before interest provision rate=tax breath)/current interest in red * 100%,

EBIT (tax breath before profit) is total profit and the interest expense sum that counts total cost, i.e. profit=total profit before tax breath+count interest expense of total cost;

PI (current interest in red) is the whole interests that count total cost,

ICR>1, represents that there is the ability of repaying interest in enterprise; During ICR<1, represent that enterprise does not have enough payment funding interests, pay a debt very risky.

Technical scheme of the present invention has following beneficial effect:

Technical scheme of the present invention, by clear and definite energy storage configuration target, structure energy storage configuration appraisement system, carries out systematic evaluation at stage constructions such as economy, technology, reaches the object to energy storage scientific allocation, rational evaluation.

Below by drawings and Examples, technical scheme of the present invention is described in further detail.

Accompanying drawing explanation

Fig. 1 is the energy storage configuration appraisal procedure process flow diagram based on micro-electrical network described in the embodiment of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described, should be appreciated that preferred embodiment described herein, only for description and interpretation the present invention, is not intended to limit the present invention.

As shown in Figure 1, a kind of energy storage configuration appraisal procedure based on micro-electrical network, comprises the following steps:

Step 1, determine evaluation object:

Evaluation object is the electric power system containing energy storage and distributed power source, determines that range of value, equipment form, and transfer the history data arranging in electric power system;

Step 2, determine the evaluation objective of system:

It is mainly that electric power system is moved the target of required realization to energy storage device that the evaluation objective of system is, and is energy storage target that whole electric power system is promoted technically and the economic goal of accumulator system self;

Step 3, determine that evaluation index and base values calculate:

It is mainly the evaluation index of determining accumulator system, mainly comprise accumulator system economically and technical index, its specific targets comprise: containing the power supply reliability of the electric power system of energy storage device, accumulator system to the compensation effect of distributed power source, containing the renewable energy utilization rate of energy storage device, containing the overall efficiency of energy storage device energy supplying system and the economic performance of energy-storage battery;

Step 4: determine that evaluation criterion is combination property marking;

Step 5: energy storage configuration evaluation result

According to above-mentioned steps one to the definite standard of step 4, by energy storage, configure evaluation index computing method and energy storage configuration evaluation index marking and weight calculation, obtain the comprehensive grading of the energy storage access scheme of needs assessment.

Wherein, in step 3, index calculating is specially:

(1) power supply reliability is mainly to use loss of supply rate to weigh, and loss of supply rate refers to that the interior unappeasable workload demand of electric power system accounts for the ratio of assessment phase total load demand, uses η _lPSPrepresent, it is an engineering application standard that is widely used in optimizing capacity configuration in wind-solar-storage joint system, when battery discharging is to minimum value C _batmintime, control system disconnects the connection of accumulator and load, and workload demand can not meet, and the loss of supply value of t in the time is:

E _LPS(t)=P _loadΔt-[P _PV(t)Δt+P _WG(t)Δt+C _bat(t)-C _batmin]η _inv

In assessment phase T, loss of supply rate is expressed as:

${\mathrm{\&eta;}}_{\mathrm{LPSP}}\left(t\right)=\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{E}_{\mathrm{LPS}}\left(t\right)/\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\mathrm{\&Delta;t}$

Wherein: E _lPSfor loss of supply value, P _loadfor system loading, P _pvfor photovoltaic generation power, P _wGfor wind turbine power generation power, C _bat(t) be that battery is at t moment energy storage state, C _batminfor energy-storage battery minimum energy storing state, Δ t is the step-length for calculating; T is the assessment phase, and in the assessment phase, wind, light generated output remain unchanged;

(2) accumulator system mainly represents by r.m.s. deviation the compensation effect of distributed power source, do not configuring under energy storage state, electric power system power supply containing distributed power generation device has undulatory property, after energy storage configuration, expectation energy storage can coordinate the common energy supply of distributed power generation device, to realize steady electricity supply

R.m.s. deviation represents with RMS, refers to electric power system output power fluctuation r.m.s. deviate in range of value, and each point extracts square root after divided by number of data points with the quadratic sum of aim curve deviation, and the computing formula of r.m.s. deviation is:

$\mathrm{RMS}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(P_{\mathrm{Ci}}-P_{\mathrm{Clim}})}^2}{N}}$

Wherein: P _climfor default permission undulating quantity, P _cifor actual undulating quantity;

(3) overall efficiency is mainly to use proportion of goods damageds index expression, accumulator system overall efficiency refers to the loss that has comprised whole accumulator system by this parameter, comprise the efficiency of inverter, efficiency and the network efficiency that energy storage discharges and recharges, overall efficiency is higher, the loss of each equipment is lower, the performance of whole system is better, the loss of consideration equipment is subject to the properties influence of equipment self, evaluation index is only considered Network Loss Rate, the difference of configuration energy storage position can cause loss in various degree to network, and the computing formula of via net loss rate is:

(4) the renewable energy utilization rate that contains energy storage device is mainly with referring to energy dissipation rate η _excrepresent, refer to cannot dissolve the completely ratio of distributed power source electricity energy and load total amount of system loading,

${\mathrm{\&eta;}}_{\mathrm{exc}}\left(T\right)=E_{\mathrm{WE}}\left(T\right)/\left[2\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\left(t\right)\mathrm{\&Delta;t}\right]$

η _excfor the ratio of the power of wind-force, the photovoltaic generation waste power requirement total with assessing phase load, work as P _wG(t)+P _pV(t)+P _bat(t)=P _total(t) >P _ref(t), time, the computing formula of wind-force and photovoltaic generation waste energy is:

E _WE(t)=[P _PV(t)+P _WG(t)]Δt-{P _refΔt/η _inv+[C _batmax-C _bat(t-1)/η _cha]}

E wherein _wE(t) be to meet on the basis of burden requirement and energy-storage travelling wave tube charging requirement, the energy of wind-power electricity generation and photovoltaic generation waste;

(5) economic benefit is mainly with internal rate of return and two index expressions of interest provision rate.

Internal rate of return: the discount rate when cash flow net present value (NPV) that refers to receipts and expenditures is zero is also the important indicator of reflection project profitability;

If P _tbe the free cash flow of t, i ^*for internal rate of return to be asked, n is equipment Economic Life, and the computing formula of internal rate of return is:

$\underset{t=0}{\overset{n}{\mathrm{\&Sigma;}}}\frac{P_t}{{(1+i^{*})}^t}=0$

Interest provision rate also claims Number of times interest earned, and the project that refers to each year within the maturity of borrowing money can be used for the ratio of profit and current interest in red expense before the tax breath of interest payment,

ICR=EBIT/PI

Profit/current interest in red * 100%=(total profit+current interest in red before interest provision rate=tax breath)/current interest in red * 100%,

EBIT (tax breath before profit) is total profit and the interest expense sum that counts total cost, i.e. profit=total profit before tax breath+count interest expense of total cost;

PI (current interest in red) is the whole interests that count total cost,

ICR>1, represents that there is the ability of repaying interest in enterprise; During ICR<1, represent that enterprise does not have enough payment funding interests, pay a debt very risky.

Its detailed process is as follows:

Step 1: determine evaluation object

Evaluation object is the electric power system containing energy storage and distributed power source, determines that range of value, equipment form, and transfer the history data arranging in electric power system.General data is that the indices of mentioning in step 3 calculates needed basic data.

Step 2: the evaluation objective of determining system

It is mainly that electric power system is moved the target of required realization to energy storage device that the evaluation objective of system is, and main in this method what consider is energy storage target that whole electric power system is promoted technically and the economic goal of accumulator system self.

Step 3: determine evaluation index and base values calculating

This step is mainly to determine the evaluation index of accumulator system, mainly comprises accumulator system economically and technical index.Its specific targets comprise: containing the power supply reliability of the electric power system of energy storage device, accumulator system to the compensation effect of distributed power source, containing the renewable energy utilization rate of energy storage device, containing the overall efficiency of energy storage device energy supplying system and the economic performance of energy-storage battery.

(1) power supply reliability aspect is mainly to use loss of supply rate to weigh, and loss of supply rate refers to that the interior unappeasable workload demand of electric power system accounts for the ratio of assessment phase total load demand, this patent η _lPSPrepresent.It is an engineering application standard that is widely used in optimizing capacity configuration in wind-solar-storage joint system.When battery discharging is to minimum value C _batmintime, control system disconnects the connection of accumulator and load, and workload demand can not meet.The loss of supply value of t in the time is:

E _LPS(t)=P _loadΔt-[P _PV(t)Δt+P _WG(t)Δt+C _bat(t)-C _batmin]η _inv （1）

In assessment phase T, loss of supply rate is expressed as:

${\mathrm{\&eta;}}_{\mathrm{LPSP}}\left(t\right)=\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{E}_{\mathrm{LPS}}\left(t\right)/\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\mathrm{\&Delta;t}---\left(2\right).$

(2) accumulator system mainly represents by r.m.s. deviation the compensation effect of distributed power source.Do not configuring under energy storage state, containing the electric power system of distributed power generation device, powering and have undulatory property, after energy storage configuration, expectation energy storage can coordinate the common energy supply of distributed power generation device, to realize steady electricity supply.

R.m.s. deviation represents with RMS, refers to electric power system output power fluctuation r.m.s. deviate in range of value.Each point extracts square root after divided by number of data points with the quadratic sum of aim curve deviation.The computing formula of r.m.s. deviation is:

$\mathrm{RMS}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(P_{\mathrm{Ci}}-P_{\mathrm{Clim}})}^2}{N}}---\left(4\right).$

(3) overall efficiency is mainly to use proportion of goods damageds index expression, and accumulator system overall efficiency refers to the loss that has comprised whole accumulator system by this parameter, comprises the efficiency of inverter, efficiency and the network efficiency that energy storage discharges and recharges.Overall efficiency is higher, and the loss of each equipment is lower, and the performance of whole system is better.The loss of consideration equipment is subject to the properties influence of equipment self, and evaluation index is only considered Network Loss Rate.The difference of configuration energy storage position can cause loss in various degree to network.The computing formula of via net loss rate is:

(4) the renewable energy utilization rate that contains energy storage device is mainly with referring to energy dissipation rate η _excrepresent, refer to cannot dissolve the completely ratio of distributed power source electricity energy and load total amount of system loading.

${\mathrm{\&eta;}}_{\mathrm{exc}}\left(T\right)=E_{\mathrm{WE}}\left(T\right)/\left[2\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\left(t\right)\mathrm{\&Delta;t}\right]---\left(6\right)$

η _excratio for the power of wind-force, the photovoltaic generation waste power requirement total with assessing phase load.Work as P _wG(t)+P _pV(t)+P _bat(t)=P _total(t) >P _ref(t), time, the computing formula of wind-force and photovoltaic generation waste energy is:

E _WE(t)=[P _PV(t)+P _WG(t)]Δt-{P _refΔt/η _inv+[C _batmax-C _bat(t-1)/η _cha]} （7）

E wherein _wE(t) be to meet on the basis of burden requirement and energy-storage travelling wave tube charging requirement, the energy of wind-power electricity generation and photovoltaic generation waste.

(5) economic benefit is mainly with internal rate of return and two index expressions of interest provision rate.

1) internal rate of return.Internal rate of return is the discount rate while instigating scheme cash flow net present value (NPV) of a series of receipts and expenditures within the research phase to be zero, is also the important indicator of reflection project profitability.

If P _tbe the free cash flow of t, i ^*for internal rate of return to be asked, n is equipment Economic Life, and the computing formula of internal rate of return is:

$\underset{t=0}{\overset{n}{\mathrm{\&Sigma;}}}\frac{P_t}{{(1+i^{*})}^t}=0---\left(8\right)$

2) interest provision rate

Interest provision rate (Interest Coverage Ratio) also claim Number of times interest earned, and the project that refers to each year within the maturity of borrowing money can be used for the ratio of profit and current interest in red expense before the tax breath of interest payment.

ICR=EBIT/PI（10）

Profit/current interest in red * 100%=(total profit+current interest in red before interest provision rate=tax breath)/current interest in red * 100%

EBIT (tax breath before profit) is total profit and the interest expense sum that counts total cost, i.e. profit=total profit before tax breath+count interest expense of total cost;

PI (current interest in red) is for counting whole interests of total cost.

Under normal circumstances, ICR>1, represents that there is the ability of repaying interest in enterprise; During ICR<1, represent that enterprise does not have enough payment funding interests, pay a debt very risky.

Step 4: determine that evaluation criterion is combination property marking, mainly as shown in table one, table two.

Table one, micro-grid system energy storage configuration appraisement system and weight contrast table:

Table two, micro-grid system energy storage configuration basic unit index standards of grading table:

Step 5: energy storage configuration evaluation result

By energy storage, configure evaluation index computing method and energy storage configuration evaluation index marking and weight calculation, can obtain the comprehensive grading of the energy storage access scheme of needs assessment.All kinds of performances that can analysis project by comprehensive grading result.

Integrate score is greater than 90 timesharing, shows that its energy storage allocation plan belongs to allocation optimum; Integrate score belongs to sub-optimal configuration in 85-90 timesharing; Integrate score is possible arrangement in 60-85 timesharing; Integrate score below 60 minutes time, belongs to not recommended configuration.When allocation optimum, without special rectification allocation plan.When sub-optimal configuration and possible arrangement, can, by all kinds of indexs of inquiry, by adjusting the allocation plan of energy storage, optimize original configuration.In recommended configuration, do not need detailed each influence index is analyzed, adjusting energy storage configuring condition until all kinds of performance can reach comprehensive more excellent state.

In sum, the present invention also has the following advantages:

1, use the method to carry out energy storage configuration assessment, can analyze fully the rear economic performance of energy storage configuration and technical feature.

2, can use this research method for instructing the configuration of planning and design energy storage again, on the basis of original energy storage configuration, change accordingly, by contrasting each performance, propose optimum allocation plan.

3, energy storage technology has a certain impact to the outfit tool of distributed power generation in microgrid, by the research of this report, can realize the science of energy storage configuration.The method proposing by this patent, can coordinate and better utilize distributed power source generating.

Finally it should be noted that: the foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, although the present invention is had been described in detail with reference to previous embodiment, for a person skilled in the art, its technical scheme that still can record aforementioned each embodiment is modified, or part technical characterictic is wherein equal to replacement.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims (3)

1. the configuration of the energy storage based on a micro-electrical network appraisal procedure, is characterized in that, comprises the following steps:

Step 1, determine evaluation object:

Evaluation object is the electric power system containing energy storage and distributed power source, determines that range of value, equipment form, and transfer the history data arranging in electric power system;

Step 2, determine the evaluation objective of system:

It is mainly that electric power system is moved the target of required realization to energy storage device that the evaluation objective of system is, and is energy storage target that whole electric power system is promoted technically and the economic goal of accumulator system self;

Step 3, determine that evaluation index and base values calculate:

It is mainly the evaluation index of determining accumulator system, mainly comprise accumulator system economically and technical index, its specific targets comprise: containing the power supply reliability of the electric power system of energy storage device, accumulator system to the compensation effect of distributed power source, containing the renewable energy utilization rate of energy storage device, containing the overall efficiency of energy storage device energy supplying system and the economic performance of energy-storage battery;

Step 4: determine that evaluation criterion is combination property marking;

Step 5: energy storage configuration evaluation result

According to above-mentioned steps one to the definite standard of step 4, by energy storage, configure evaluation index computing method and energy storage configuration evaluation index marking and weight calculation, obtain the comprehensive grading of the energy storage access scheme of needs assessment.

2. the energy storage configuration appraisal procedure based on micro-electrical network according to claim 1, is characterized in that, in described step 3, index is calculated and is specially:

(1) power supply reliability is mainly to use loss of supply rate to weigh, and loss of supply rate refers to that the interior unappeasable workload demand of electric power system accounts for the ratio of assessment phase total load demand, uses η _lPSPrepresent, it is an engineering application standard that is widely used in optimizing capacity configuration in wind-solar-storage joint system, when battery discharging is to minimum value C _batmintime, control system disconnects the connection of accumulator and load, and workload demand can not meet, and the loss of supply value of t in the time is:

E _LPS(t)=P _loadΔt-[P _PV(t)Δt+P _WG(t)Δt+C _bat(t)-C _batmin]η _inv

In assessment phase T, loss of supply rate is expressed as:

${\mathrm{\&eta;}}_{\mathrm{LPSP}}\left(t\right)=\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{E}_{\mathrm{LPS}}\left(t\right)/\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\mathrm{\&Delta;t}$

Wherein: E _lPSfor loss of supply value, P _loadfor system loading, P _pvfor photovoltaic generation power, P _wGfor wind turbine power generation power, C _bat(t) be that battery is at t moment energy storage state, C _batminfor energy-storage battery minimum energy storing state, Δ t is the step-length for calculating; T is the assessment phase, and in the assessment phase, wind, light generated output remain unchanged;

(2) accumulator system mainly represents by r.m.s. deviation the compensation effect of distributed power source, do not configuring under energy storage state, electric power system power supply containing distributed power generation device has undulatory property, after energy storage configuration, expectation energy storage can coordinate the common energy supply of distributed power generation device, to realize steady electricity supply

R.m.s. deviation represents with RMS, refers to electric power system output power fluctuation r.m.s. deviate in range of value, and each point extracts square root after divided by number of data points with the quadratic sum of aim curve deviation, and the computing formula of r.m.s. deviation is:

$\mathrm{RMS}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(P_{\mathrm{Ci}}-P_{\mathrm{Clim}})}^2}{N}}$

Wherein: P _climfor default permission undulating quantity, P _cifor actual undulating quantity;

(3) overall efficiency is mainly to use proportion of goods damageds index expression, accumulator system overall efficiency refers to the loss that has comprised whole accumulator system by this parameter, comprise the efficiency of inverter, efficiency and the network efficiency that energy storage discharges and recharges, overall efficiency is higher, the loss of each equipment is lower, the performance of whole system is better, the loss of consideration equipment is subject to the properties influence of equipment self, evaluation index is only considered Network Loss Rate, the difference of configuration energy storage position can cause loss in various degree to network, and the computing formula of via net loss rate is:

(4) the renewable energy utilization rate that contains energy storage device is mainly with referring to energy dissipation rate η _excrepresent, refer to cannot dissolve the completely ratio of distributed power source electricity energy and load total amount of system loading,

${\mathrm{\&eta;}}_{\mathrm{exc}}\left(T\right)=E_{\mathrm{WE}}\left(T\right)/\left[2\underset{t=1}{\overset{T}{\mathrm{\&Sigma;}}}{P}_{\mathrm{load}}\left(t\right)\mathrm{\&Delta;t}\right]$

η _excfor the ratio of the power of wind-force, the photovoltaic generation waste power requirement total with assessing phase load, work as P _wG(t)+P _pV(t)+P _bat(t)=P _total(t) >P _ref(t), time, the computing formula of wind-force and photovoltaic generation waste energy is:

E _WE(t)=[P _PV(t)+P _WG(t)]Δt-{P _refΔt/η _inv+[C _batmax-C _bat(t-1)/η _cha]}

E wherein _wE(t) be to meet on the basis of burden requirement and energy-storage travelling wave tube charging requirement, the energy of wind-power electricity generation and photovoltaic generation waste;

(5) economic benefit is mainly with internal rate of return and two index expressions of interest provision rate.

3. the energy storage configuration appraisal procedure based on micro-electrical network according to claim 2, is characterized in that, described (5) described internal rate of return and interest provision rate is:

Internal rate of return: the discount rate when cash flow net present value (NPV) that refers to receipts and expenditures is zero is also the important indicator of reflection project profitability;

If P _tbe the free cash flow of t, i ^*for internal rate of return to be asked, n is equipment Economic Life, and the computing formula of internal rate of return is:

$\underset{t=0}{\overset{n}{\mathrm{\&Sigma;}}}\frac{P_t}{{(1+i^{*})}^t}=0$

Interest provision rate also claims Number of times interest earned, and the project that refers to each year within the maturity of borrowing money can be used for the ratio of profit and current interest in red expense before the tax breath of interest payment,

ICR=EBIT/PI

Profit/current interest in red * 100%=(total profit+current interest in red before interest provision rate=tax breath)/current interest in red * 100%,

EBIT (tax breath before profit) is total profit and the interest expense sum that counts total cost, i.e. profit=total profit before tax breath+count interest expense of total cost;

PI (current interest in red) is the whole interests that count total cost,

ICR>1, represents that there is the ability of repaying interest in enterprise; During ICR<1, represent that enterprise does not have enough payment funding interests, pay a debt very risky.

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