CN103679302B - A kind of household electricity optimization method based on electromobile energy storage characteristic - Google Patents

Abstract

The present invention discloses a kind of based on the energy storage characteristic of forecasted electricity market price and electromobile, electric cost according to household electrical appliance, the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and the electric discharge income of accumulator of electric car determine the battery charge will state SoC that electric cost is optimized, when electromobile is come back, the SoC state of its store battery is when meeting the battery charge will state SoC higher than electric cost optimization, non-adjustable load is powered, thus while reducing household electricity cost, reduce the load of electrical network in peak period. Simultaneously, can effectively avoid the new power load peak that high-power charging load is brought to electrical network on this basis, and according to forecasted electricity market price, adjustable load is adjusted to electricity consumption low peak period and the electricity price low ebb phase uses, fill up load valley to greatest extent, effectively solve the need for electricity of user and household electricity cost increase considerably between contradiction.

Description

A kind of household electricity optimization method based on electromobile energy storage characteristic

Technical field

The invention belongs to technical field of electric power, more specifically say, it relates to a kind of household electricity optimization method based on electromobile energy storage characteristic.

Background technology

Along with the development of electromobile correlation technique, electromobile is day by day universal. Electromobile charges under intelligent grid environment, the duration of charging needed is longer, and due to its charge power bigger, it is possible to electric net overload and time peak phenomenon can be caused, the serious safety and stability affecting electrical network, and increase grid generation cost and user power utilization spending.

Charging electric vehicle load, compared with other household electricity loads, possesses controllability in time scale, so, in residential electric power system, the discharge and recharge of electromobile is carried out rational scheduling meeting and brings income to user. It can be controlled by user according to the SoC state of the charge-discharge characteristic of accumulator of electric car and store battery, it is achieved household electricity minimizing costs.

How when meeting user power utilization demand, it is that electromobile is carried out the key of electricity consumption scheduling and charge and discharge control by the present invention that the discharge time currently carried out according to store battery chooses the best SoC state that store battery is non-adjustable load supplying. Network (V2G) technology both at home and abroad to electromobile, and namely electromobile is more with the interaction problems research of power supply side, but the optimization solution technique study that user's self-control electricity consumption strategy and electromobile carry out discharge and recharge under residential electric power system is less. After electromobile is universal in a large number, the need for electricity of user and household electricity cost increase considerably between contradiction reasonably do not solved.

Summary of the invention

It is an object of the invention to overcome the deficiencies in the prior art, a kind of household electricity optimization method based on electromobile energy storage characteristic is provided, household electricity cost is reduced as much as possible under the need for electricity prerequisite meeting user, extend accumulator of electric car work-ing life, for electromobile of introducing extensive under residential electric power system carries out discharge and recharge and lays the foundation.

For achieving the above object, the present invention is based on the household electricity optimization method of electromobile energy storage characteristic, it is characterised in that, comprise the following steps:

(1), intelligent electric meter carry out Research on electricity price prediction in conjunction with history electricity price data, obtain the forecasted electricity market price data on the same day;

(2), according to intelligent electric meter prediction the adjustable load of electricity price design data (adjustable load is the household electrical appliance that can adjust enabling time, such as washing machine, dryer, sterilizing-cabinet etc.) the electricity consumption period so that it is be operated in the time period that in time regulatable section, electricity price is minimum;

(3), according to the electricity price data of intelligent electric meter prediction, electromobile is adjusted to the electricity price minimum period to charge;

(4) if electromobile uses the moment of coming back for electricity price peak period, then the state of charge SoC of its store battery when intelligent electric meter is come back according to electromobile, judges whether to meet the battery charge will state SoC that electric cost is optimized^*If meeting the battery charge will state SoC namely optimized higher than electric cost^*, then intelligent electric meter adjustment accumulator of electric car is current is non-adjustable load (non-adjustable load is the household electrical appliance that can not adjust enabling time, such as refrigerator, head light, kitchen electricity consumption etc.) power supply, till not meeting; If not meeting, then electrical network is adopted to be directly non-adjustable load supplying;

Wherein, the battery charge will state of electric cost optimization is determined according to the electric discharge income of the electric cost of household electrical appliance, the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and accumulator of electric car.

The goal of the invention of the present invention is achieved in that

The present invention is based on the household electricity optimization method of electromobile energy storage characteristic, consider the electric discharge income of the electric cost of household electrical appliance, the charging cost of electromobile, the loss cost of accumulator of electric car and accumulator of electric car, it is determined that the battery charge will state that electric cost is optimized. Household electricity cost is optimized and considers from following two aspects. First, carry out cost optimization for the electricity consumption of adjustable load and the charging of electromobile. Intelligent electric meter is equipped with in user's house inside, and following electricity price is predicted by this intelligent electric meter on the basis of history electricity price data, to provide Spot Price reference data. And intelligent electric meter regulates the enabling time of adjustable load and the duration of charging of electromobile according to forecasted electricity market price data, thus, the electric cost of this part equipment of minimumization; Secondly, for the electricity consumption of non-adjustable load, then electric discharge income according to the electric cost of household electrical appliance (comprising air-conditioning, refrigerator, TV etc.), the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and accumulator of electric car determines the battery charge will state that electric cost is optimized. Now, the SoC state of store battery when intelligent electric meter is come back according to electromobile, judges whether to meet the battery charge will state of electric cost optimization, if meeting, then intelligent electric meter adjustment accumulator of electric car is current is non-adjustable load supplying, till not meeting; If not meeting, then electrical network is adopted to be directly non-adjustable load supplying.

The present invention is based on the energy storage characteristic of forecasted electricity market price and electromobile, electric cost according to household electrical appliance, the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and the electric discharge income of accumulator of electric car determine the battery charge will state SoC that electric cost is optimized, when electromobile is come back, the SoC state of its store battery is when meeting the battery charge will state SoC higher than electric cost optimization, non-adjustable load is powered, thus while reducing household electricity cost, reduce the load of electrical network in peak period. Simultaneously, can effectively avoid the new power load peak that high-power charging load is brought to electrical network on this basis, and according to forecasted electricity market price, adjustable load is adjusted to electricity consumption low peak period and the electricity price low ebb phase uses, fill up load valley to greatest extent, effectively solve the need for electricity of user and household electricity cost increase considerably between contradiction.

Accompanying drawing explanation

Fig. 1 hardware architecture diagram that to be the present invention apply based on the household electricity optimization method of electromobile energy storage characteristic;

Fig. 2 is the schema of the present invention based on the household electricity optimization method of electromobile energy storage characteristic.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described, so that the technician of this area understands the present invention better. Requiring particular attention is that, in the following description, when perhaps the detailed description of known function and design can desalinate the main contents of the present invention, these descriptions will be ignored here.

In the present embodiment, as shown in Figure 1, 2, the following aspects is comprised:

1, Research on electricity price prediction

In the present embodiment, described Research on electricity price prediction is according to the day before yesterday, a few days ago corresponding with the last week of history electricity price on the same day weighting parameters k₁, k₂And k₇, and in conjunction with these history electricity price data of three daysWithObtain the forecasted electricity market price on the same dayWherein, h is time parameter, by hour in units of, h=1,2 ... 24, d represents the same day at place. Like this, intelligent electric meter forms following electricity price according to forecasted electricity market price data and walks power curve.

Walk power curve according to following electricity price, the adjustable load electricity consumption period is arranged in the time period that electricity price is minimum in time regulatable section. Meanwhile, according to the electricity price data of intelligent electric meter prediction, electromobile is adjusted to the electricity price minimum period and power load less period charges.

2, accumulator of electric car electric cost

The charging cost of accumulator of electric car and the loss cost of accumulator of electric car is comprised due to accumulator of electric car electric cost, and this two portions cost is all relevant to accumulator of electric car state of charge SoC, so first need to obtain the state of charge SoC of accumulator of electric car when every day, electromobile was come back, then calculate the electric cost of electromobile according to these data.

2.1, in the present embodiment, according to open circuit voltage and correspondenceState, draws the charging cost of accumulator of electric car, is expressed as follows:

$c_{\mathrm{chg}}=\frac{{\hat{a}}_d^h{t}_c{Q}_{\mathrm{batt}}(0.9-S\stackrel{\·}{o}C)}{{\mathrm{\η}}_{\mathrm{EVSE}}}---\left(1\right)$

Wherein, t_cFor long when accumulator of electric car charges, ��_EVSEFor accumulator of electric car charging efficiency, Q_battFor accumulator of electric car charging capacity,For the state of charge that stage open circuit voltage each when accumulator of electric car charges is corresponding, its expression formula is:

$S\stackrel{\·}{o}C=\frac{V_{\mathrm{oc}}-\sqrt{{V_{\mathrm{oc}}}^2-4P_{\mathrm{batt}}{R}_{\mathrm{batt}}}}{2Q_{\mathrm{batt}}{R}_{\mathrm{batt}}}---\left(2\right)$

V_ocFor accumulator of electric car open circuit voltage, P_battFor accumulator of electric car charge power, R_battFor accumulator of electric car resistance value.

2.2, in the present embodiment, being worn to this and obtain according to accumulator of electric car cycle life and depth of discharge DoD of accumulator of electric car.

But owing to the acquisition of accumulator of electric car resistive film increasing value is directly perceived not, and the loss cost of accumulator of electric car can by being accumulator of electric car discharge time by the battery discharging degree of depth (DoD) condition conversion and calculate work-ing life, the loss cost of accumulator of electric car represents and is:

$c_d=\frac{c_b{Q}_{\mathrm{batt}}+c_l{t}_l}{L_c\mathrm{DoD}}---\left(3\right)$

Wherein, c_bFor cost changed by store battery, c_lFor changing the labor cost of store battery, t_lFor changing the working time needed for store battery, L_cFor the life-span (cycle index) of store battery under depth of discharge, DoD is the battery discharging degree of depth, is also DoD=SoC-0.2.

2.3, above-mentioned explanation is visible, and accumulator of electric car electric cost is made up of charging electric vehicle cost and store battery loss cost two portions, is therefore a multi-objective optimization question. In order to conveniently, these two optimization aim in formula (1), (3) are integrated into a scalar aim parameter by linear weight �� by us. Thus can draw the electric cost of accumulator of electric car, be expressed as follows:

$\begin{array}{c}{c}_{\mathrm{PEV}}=\mathrm{\α}\·c_{\mathrm{chg}}+(1-\mathrm{\α})\·c_d\\ =\mathrm{\α}\frac{{\hat{a}}_d^h{t}_c{Q}_{\mathrm{batt}}(0.9-S\stackrel{\·}{o}C)}{{\mathrm{\η}}_{\mathrm{EVSE}}}+(1-\mathrm{\α})\frac{c_b{Q}_{\mathrm{batt}}+c_l{t}_l}{L_c(\mathrm{SoC}-0.2)}\end{array}---\left(4\right)$

3, according to user power utilization data and the forecasted electricity market price of record in intelligent electric meter, the electric cost of household electrical appliance can represent and is:

$c_{\mathrm{App}}=(\mathrm{\Σ}{x}_i^{\mathrm{sl}}{t}_i^{\mathrm{sl}}+\mathrm{\Σ}{x}_i^{\mathrm{hl}}{t}_i^{\mathrm{hl}}){\hat{a}}_d^h---\left(5\right);$

Wherein,Be i-th adjustable load by electrical power consumed,Be i-th non-adjustable load by electrical power consumed,When being the electricity consumption of i-th adjustable load long,When being the electricity consumption of i-th non-adjustable load long.

Namely the electric cost of household electrical appliance be all adjustable loads with electrical power consumed and all non-adjustable loads by the sum of electrical power consumed.

4, the electric discharge income of accumulator of electric car

In this embodiment, the residue electricity of accumulator of electric car can, to non-adjustable load supplying, be the income that user brings:

$g_{\mathrm{PEV}}=30I(\mathrm{SoC}-0.2)Q_{\mathrm{batt}}{\hat{a}}_d^h---\left(6\right)$

Wherein, I is battery discharging electric current.

5, objective function is determined according to the electric cost of accumulator of electric car electric cost, household electrical appliance, the electric discharge income of accumulator of electric car:

$\begin{array}{c}\mathrm{\ψ}=\underset{\mathrm{So}{C}^{*},\mathrm{\ΔSoC}}{\min }[c_{\mathrm{PEV}}+c_{\mathrm{App}}-g_{\mathrm{PEV}}]\\ =\underset{\mathrm{So}{C}^{*},\mathrm{\ΔSoC}}{\min }[\mathrm{\α}\frac{{\hat{a}}_d^h{t}_c{Q}_{\mathrm{batt}}(0.9-S\stackrel{\·}{o}C)}{{\mathrm{\η}}_{\mathrm{EVSE}}}+(1-\mathrm{\α})\frac{c_b{Q}_{\mathrm{batt}}+c_l{t}_l}{L_c({\mathrm{SoC}}_{j+1}-0.2)}\\ +(\mathrm{\Σ}{x}_i^{\mathrm{sl}}{t}_i^{\mathrm{sl}}+\mathrm{\Σ}{x}_i^{\mathrm{hl}}{t}_i^{\mathrm{hl}}){\hat{a}}_d^h-30I(\mathrm{SoC}-0.2)Q_{\mathrm{batt}}{\hat{a}}_d^h\left)\right]\end{array}---\left(7\right)$

The battery charge will state that electric cost is optimized and the electric discharge threshold value SoC of store battery is determined according to objective function ��^*And accumulator of electric car is from initial discharge number of times L_cTo maximum discharge time L_{c_max}Corresponding optimal discharge state of charge �� SoC;

Wherein, final condition is $\left\{\begin{array}{c}{\mathrm{SoC}}_{\min }\≤\mathrm{SoC}\≤{\mathrm{SoC}}_{\max }\\ L_c\≤L_{c\_\max }\end{array}\right.,$

Wherein SoC_minFor the lower limit of accumulator of electric car discharge charge state, SoC_maxFor the upper limit of accumulator of electric car charging charge state, L_{c_max}For the maximum value of its discharge time within the scope of accumulator of electric car work-ing life.

6, after the electromobile of user uses and comes back, the intelligent electric meter in house in connection. Intelligent electric meter records the discharge time L of current accumulator of electric car_cWith accumulator of electric car state of charge SoC state. If electromobile uses the moment of coming back for electricity price peak period, then the battery charge will state SoC that the electric cost obtained according to the objective function intelligent electric meter in formula (7) again is optimized^*After, compare with current accumulator of electric car state of charge SoC, namely whether the battery charge will state judging whether to meet electric cost optimization now can remain electricity with store battery is non-adjustable load supplying, if the battery charge will state SoC optimized higher than electric cost^*, then intelligent electric meter adjustment accumulator of electric car is current non-adjustable load (non-adjustable load is the household electrical appliance that can not adjust enabling time, such as refrigerator, head light, kitchen electricity consumption etc.) power supply, till not meeting; If not meeting, then electrical network is adopted to be directly non-adjustable load supplying. If electromobile uses the moment of coming back for electricity price peak period, adopt electrical network directly for non-adjustable load supplying can be in harmonious proportion.

Example

Battery discharging number of times Lc	SoC*	��SoC
			Lc��1500	SoC*=37%	��SoC=55%
1500��Lc��2000	SoC*=35%	��SoC=65%
			2000��Lc��2500	SoC*=37.5%	��SoC=60%
2500��Lc��3000	SoC*=39%	��SoC=60%

Table 1

Table 1 is the battery charge will state specific examples that accumulator of electric car electric cost is optimized, and after electromobile use is come back, intelligent electric meter records the discharge time L of current accumulator of electric car_cWith accumulator of electric car state of charge SoC state, such as, according to the whether current non-adjustable load of battery charge will condition selecting (non-adjustable load is the household electrical appliance that can not adjust enabling time, refrigerator, head light, the kitchen electricity consumption etc.) power supply optimizing the optimization of accumulator of electric car electric cost out.

The optimization of the present invention comprises: encouraging electromobile user in night electrical network underrun period, also namely the electricity price relatively low stage charges. Running period at electrical network high loading, by adjustable load evenly distribute, in the low power consumption phase, to ensure, electrical network balancing the load runs. Under the need for electricity prerequisite meeting user, reduce household electricity cost as much as possible, extend accumulator of electric car work-ing life.

Although above the embodiment of the present invention's explanation property being described; so that those skilled in the art understand the present invention; but should be clear; the invention is not restricted to the scope of embodiment; to those skilled in the art; as long as various change is in appended scope and the spirit and scope of the present invention determined, these changes are apparent, and all utilize the innovation and creation of present inventive concept all at the row of protection.

Claims (2)

1. the household electricity optimization method based on electromobile energy storage characteristic, it is characterised in that, comprise the following steps:

(1), intelligent electric meter carry out Research on electricity price prediction in conjunction with history electricity price data, obtain the forecasted electricity market price data on the same day;

(2) the electricity consumption period of the adjustable load of electricity price design data, predicted according to intelligent electric meter so that it is being operated in the time period that in time regulatable section, electricity price is minimum, wherein, described adjustable load is the household electrical appliance that can adjust enabling time;

(3), according to the electricity price data of intelligent electric meter prediction, electromobile is adjusted to the electricity price minimum period to charge;

(4) if electromobile uses the moment of coming back for electricity price peak period, then the state of charge SoC of its store battery when intelligent electric meter is come back according to electromobile, judges whether to meet the battery charge will state SoC that electric cost is optimized^*If meeting, then intelligent electric meter adjustment accumulator of electric car is current is non-adjustable load supplying, till not meeting; If not meeting, then adopting electrical network to be directly non-adjustable load supplying, wherein, described non-adjustable load is the household electrical appliance that can not adjust enabling time;

Wherein, the battery charge will state of electric cost optimization is determined according to the electric discharge income of the electric cost of household electrical appliance, the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and accumulator of electric car;

Described Research on electricity price prediction is according to the day before yesterday, a few days ago corresponding with the last week of history electricity price on the same day weighting parameters k₁, k₂And k₇, and in conjunction with these history electricity price data of three daysWithObtain the forecasted electricity market price on the same dayWherein, h is time parameter, by hour in units of, h=1,2 ... 24, d represents the same day at place;

Described accumulator of electric car electric cost is:

$\begin{array}{c}{c}_{PEV}=\mathrm{\α}\·c_{chg}+\left(1-\mathrm{\α}\right)\·c_d\\ =\mathrm{\α}\frac{{\hat{a}}_d^h{t}_c{Q}_{batt}\left(0.9-S\stackrel{\·}{o}C\right)}{{\mathrm{\η}}_{EVSE}}+\left(1-\mathrm{\α}\right)\frac{c_b{Q}_{batt}+c_l{t}_l}{L_c\left(SoC-0.2\right)}\end{array};$

Wherein, c_chgFor the charging cost of accumulator of electric car, t_cFor long when accumulator of electric car charges, ��_EVSEFor accumulator of electric car charging efficiency, Q_battFor accumulator of electric car charging capacity,For the state of charge that stage open circuit voltage each when accumulator of electric car charges is corresponding, its expression formula is:

$S\stackrel{\·}{o}C=\frac{V_{oc}-\sqrt{{V_{oc}}^2-4P_{batt}{R}_{batt}}}{2Q_{batt}{R}_{batt}};$

�� is linear weight, V_ocFor accumulator of electric car open circuit voltage, P_battFor accumulator of electric car charge power, R_battFor accumulator of electric car resistance value;

c_dFor the loss cost of accumulator of electric car, c_bFor cost changed by store battery, c_lFor changing the labor cost of store battery, t_lFor changing the working time needed for store battery, L_cFor life-span and the cycle index of store battery under depth of discharge, DoD is the battery discharging degree of depth, is also DoD=SoC-0.2.

2. household electricity optimization method according to claim 1, it is characterized in that, the battery charge will state of described electric cost optimization is defined as according to the electric discharge income of the electric cost of household electrical appliance, the charging cost of accumulator of electric car, the loss cost of accumulator of electric car and accumulator of electric car:

Electric cost according to accumulator of electric car electric cost, household electrical appliance, the electric discharge income of accumulator of electric car determine objective function:

$\begin{array}{c}\mathrm{\Ψ}=\underset{SoC*,\mathrm{\Δ}SoC}{\min }\[c_{PEV}+c_{App}-g_{PEV}\]\\ =\underset{SoC*,\mathrm{\Δ}SoC}{\min }\[\mathrm{\α}\frac{{\hat{a}}_d^h{t}_c{Q}_{batt}\left(0.9-S\stackrel{\·}{o}C\right)}{{\mathrm{\η}}_{EVSE}}+\left(1-\mathrm{\α}\right)\frac{c_b{Q}_{batt}+c_l{t}_l}{L_c\left({\mathrm{SoC}}_{j+1}-0.2\right)}\\ +\left({\mathrm{\Σx}}_i^{sl}{t}_i^{sl}+{\mathrm{\Σx}}_i^{hl}{t}_i^{hl}\right){\hat{a}}_d^h-30I\left(SoC-0.2\right)Q_{batt}{\hat{a}}_d^h)\]\end{array};$

The battery charge will state that electric cost is optimized and the electric discharge threshold value SoC of store battery is determined according to objective function ��^*And accumulator of electric car is from initial discharge number of times L_cTo maximum discharge time L_{c_max}Corresponding optimal discharge state of charge �� SoC;

Wherein, final condition is

Wherein, c_AppFor the electric cost of household electrical appliance,Be i-th adjustable load by electrical power consumed,Be i-th non-adjustable load by electrical power consumed,When being the electricity consumption of i-th adjustable load long,When being the electricity consumption of i-th non-adjustable load long;

g_PEVFor the electric discharge income of accumulator of electric car, I is battery discharging electric current.