WO2014067675A1

WO2014067675A1 - Supplying electricity to a consumer

Info

Publication number: WO2014067675A1
Application number: PCT/EP2013/064241
Authority: WO
Inventors: Winfried Seidel
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-10-30
Filing date: 2013-07-05
Publication date: 2014-05-08
Also published as: DE102012219837A1

Abstract

The invention relates to a method for controlling an electricity consumption of a consumer from an electric power grid. It is determined that the consumer has a power requirement and what the current price for electricity from the electric power grid is. The consumer is supplied with electricity from the electric power grid if the price of electricity lies under a predetermined threshold.

Description

description

Power supply of a consumer The invention relates to a technique for controlling a consumer

Power supply of a consumer. In particular, the invention relates to the control of the power supply of the consumer as a function of a current supply situation with electricity. In a power supply network, it is common for power to be provided in a power plant, distributed to a plurality of households via a power grid and removed there. Distributed households are therefore supplied with electricity from a central power station. It is the task of the operator of the power plant to ensure that at each time point for each household ^¬ a sufficient amount of current from the supply network versor ^¬ is removable. An average consumption of all households together is usually subject to a certain fluctuation.

As the use of intermittent energy sources, such as wind turbines or solar plants, increases, the availability of electricity in the power grid may be subject to additional fluctuations whose magnitude is significant. A control of a power plant to always feed the amount of electricity into the power grid, which is taken from the households, can be expensive.

More recently, it has been proposed to collect detailed power consumption information of households and to transmit it to the utility company. Such a power grid is sometimes referred to as "smart grid." An operator of the power plant can then use this information to control the supply of energy in the power grid.The disadvantage here is that a large amount of information is collected In addition, data protection issues can arise if information, which are a conclusion to an individual household Eger ^¬ ben stored or processed.

The invention is therefore based on the object to provide a simplified ^¬ fanned technique for controlling the power consumption of a consumer ^¬ Chers which allows an improved balancing Zvi ^¬'s supply and demand of current in a power network. The invention achieves this object by means of a procedural ^¬ Rens, a computer program product and a device having the features of the independent claims. Subclaims give preferred embodiments again.

An inventive method for controlling a power consumption of a consumer from a power grid comprises steps of detecting that the consumer has a power requirement, detecting a current electricity price for electricity from the power grid and supplying the consumer with power from the power grid, if the electricity price below a predetermined threshold is.

According to the invention, the circuit reflects an availability of electricity. If more electricity is fed into the grid than is taken by consumers through the grid, the price drops. If the power of the consumer to the price coupled, the consumer takes especially on power when the supply of current is large and the current is Güns ^¬ tig. Thus, the amount of current drawn can be adjusted to the amount of available or fed current. An over or under supply of electricity, which usually requires a power plant to lower or higher power, can thus be reduced. Fluctuations in the electricity supply, which may be caused by intermittent power plants, for example, which convert renewable energy into electricity, can thus be better compensated. It is not necessary to forward consumption data and collection and processing to an operator of a power plant or to another central office. Rather, it is sufficient if the operator the availability of electricity determined that maps to a current price and these published ^¬ light. The publication of the electricity tariff can ^¬ example as done via the Internet. In one embodiment, an urgency of the power requirement of the consumer is additionally detected and the vorbestimm ^¬ te threshold is increased with increasing urgency. While in some consumers, such as a Zimmerbe ^¬ lighting, there is little practical scope to make the power consumption or the operation of the current electricity price dependent, other consumers are well suited to take the required power too early or late. The urgency may indicate how much scope there is for a temporal shift in power consumption. Examples play as may require a freezer with enhancing Urgent ^¬ ness a current consumption, the closer its internal ^¬ temperature approaching from below 0 ° C. By considering the urgency, the operability of the consumer can be ensured.

In one embodiment, a profile of the current price is predicted and supplying the load with current to ^¬ retained when a falling circuit was predicted. The current consumption of the consumer can therefore take place at the time, which is optimal in terms of the price and thus be ^¬ gue the supply of electricity in the power grid. Here, the forecast price of electricity on the part of an energy ^¬ suppliers, the current fed into the grid, the part of a household current for the load from the power grid takes, or carried out by a third party.

If the course of the electricity price is predicted, then electricity can also be taken from the power grid and stored in an intermediate store if the electricity price is low in order to charge the consumer with electricity from the grid at a later time for which the electricity price is predicted to be high ^¬ schenspeicher supply. The recharging of the cache can contribute to an oversupply of electricity in the Reduce power, even if no consumer with

Electricity demand is ready. The latch can, in particular an electric battery or an accumulator umfas ^¬ sen. In one embodiment, the accumulator is stationary, in another embodiment, it is comprised of a motor vehicle with electric drive, which is ver ^¬ connected with the power grid. The accumulator can also be considered as a consumer and charged from the mains, whereby a later operation of another consumer from the energy of the accumulator is possible.

In one embodiment, the consumer should be at a predetermined time a predetermined energy added ha ^¬ ben, wherein the urgency remain ^¬ the time until it is determined at the predetermined timing based on a. In ^¬ example, a night storage furnace can be operated as a consumer, wherein a thermal storage mass at a predetermined morning hour should have a predetermined temperature on ^¬ . The less time remains with approaching the predetermined time for electrically heating the thermal storage mass, the higher the urgency of the

Electricity requirements of night storage heating.

In a variant, the urgency can additionally be determined on the basis of an energy still to be absorbed by the consumer. Thus, it can be taken into account that a quantity of energy required by the consumer may possibly require a longer absorption of electricity from the power grid. This can be ^¬ come, for example, the above angesproche ^¬ nen battery of a motor vehicle with electric drive, the battery can be recharged only a finite rapidly with energy.

In one embodiment, a generator may be provided for feeding power into the grid and the load may be powered directly from the generator if a current gain for the generator is below the electricity price of the grid. This allows the above wrote procedure with respect to the electricity price controlled recording and a local power generator, in particular a micro-power plant, a biogas plant, a photovoltaic system or a similar device be extended.

In a further embodiment, a feed-in price for electricity fed into the grid from the generator is determined and the consumer is supplied with electricity if the feed-in price is negative. In particular, a negative feed-in price may arise if a large number of small and medium-sized producers connected to the electricity grid feed in changing amounts of energy into the grid. This can lead to periods of strong oversupply, where no financial incentive is offered to feed further electricity into the grid. By consuming the locally generated electricity, a ^charging of electricity to the power grid can be avoided.

An inventive computer program product comprising program code means for performing the method described above when the computer program product runs on a proces ^¬ processing device or stored on a computer readable medium. A device according to the invention for controlling a power consumption of a consumer from a power grid comprises a first interface for detecting that a consumer's power consumption is present, a second interface for Erfas ^¬ sung current electricity price for electricity from the power grid and a controller for supplying the consumer with electricity from the power grid, if the electricity price is below a predetermined threshold.

By means of the apparatus, the above-described method can be performed without complex processing or ^¬ tensive investment on the part of an operator of a

To require power plant. The device can in particular used to control consumers in a household or industrial plant.

In one embodiment, the second interface is connected to the power grid and the information of the electricity price is modulated onto the power. This can save the consumer a separate Ver ^¬ connection for the transmission of electricity prices from the producer. The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments, which will be described in detail in conjunction with the drawings

FIG. 1 shows a power supply system;

FIG. 2 is a flow chart of a first method;

FIG. 3 is a flowchart of a second method;

FIG. 4 shows curves on the power supply system of FIG. 1, and

Figure 5 shows a course of a feed-in price for electricity in

Power supply system of Figure 1

represents.

1 shows a power system 100. The power system 100 includes a power generator 105 and a power grid 110. The power generator 105 converts another form of power into electrical power provided in the power grid 110. Power grid 110 carries power from power generator 105 to a plurality of homes 115, one of which is shown in FIG. The household 115 may also be an industrial or public institution.

Household 115 has at least one electrical load 120 ready to be supplied with power from power grid 110. Exemplified are a washing machine or dishwasher 125, an accumulator 130, which can be configured in particular for the operation of a motor vehicle with Elek ^¬ ro drive, a cooling system 135, a storage heater 140 and a pumping device 145th

Household 115 also includes a device 150 ("broker box") for controlling the receipt of power from consumers 120 from power grid 110. Device 150 includes a number of first interfaces 155 for connection to one of consumers 120, respectively. a second interface 160 and a processing device 165. The second interface 160 is adapted to be connected to a data line via which a current price can be obtained for current taken from the power grid 110. In the illustration of Figure 1, the second interface is 160 connected to the data network 170, which may in ^¬ play, comprise a portion of the Internet, where in the power generator 105 preferably is also coupled to the data network 170 ^¬, riding determine to designate the price information. In an alternative embodiment,

Modulated data to the current in the current network 110, ^¬ example, by means of long-wave, and the second interface 160 is connected to the power supply 110 to demodulate the information from the power grid 110th The data network 170 is not required in this case. The price information can be provided in any case by the power generator 105 or third party.

The apparatus 150 is configured to determine a demand for power of each of the loads 120 and to provide the load 120 with power from the power grid 110 when the power price received via the second interface 160 is below a predetermined threshold. Different approaches can be used to form the predetermined threshold. The following are the consumers represented at ^¬ way of example be described as an example in this regard shortly 120th The washing machine 125 may be assigned a fixed predetermined threshold to run the washing machine 125 when a decrease in the price of electricity occurs, such as might be expected during the hours of the night.

The accumulator 130 may then be charged from the grid 110 when the price of electricity is below another associated predetermined threshold. It may be considered that the charging of the accumulator 130 may require a longer time, for example several hours. To control the charging start of the accumulator 130, it may therefore be useful to ^{vorzusa ¬} the course of the electricity price, in order to carry out as possible the entire charging during a phase of a low electricity price. If the charging process is not started in time, a higher electricity price may have to be accepted in order to ensure sufficient charging of the battery at a predetermined time.

In one embodiment, a low current price, regardless of its duration, may cause charging of the accumulator 130 if it is receptive. If the accumulator 130 is connected to a motor vehicle with an electric drive, then this charging can take place, for example, even if the state of charge of the accumulator 130 already enables intended operation of the motor vehicle. In both cases, one of the other consumers 120 of the household 115 can be supplied with power from the accumulator 130 at a later time. This procedure is particularly suitable if it is to be assumed that, after a phase of low electricity prices, one of the consumers 120 is to be operated at a phase of high electricity prices.

The cooling system 135 cools a cooling space by means of electric current. In this case, an exact temperature of the cooling space may be of minor importance, as long as it is below a predetermined threshold. The cooling system 135 may, for example, keep the cooling space below the predetermined cooling temperature. To cool down temperature, while the price of electricity is low, so that the temperature can then be maintained without removal of power from the power grid 110 below the cooling temperature. If the temperature approaches the predetermined temperature after some time, then an urgency of the cooling system 135 increases, to cool the cooling space by means of electricity from the power grid 110 again.

The storage heater 140 comprises a thermal mass which is heated by means of current and can be delivered at a later time when play ^¬ by means of a blower to an environment. In order to perform an adequate heating of the environment, it can be provided that the storage heater 140 their thermal mass regularly at a predetermined time to a predetermined temperature it ^¬ hitzt. The urgency of a current consumption of the Speicherhei ^¬ Zung 140 may be determined from a still be received energy of the thermal mass, which can be read from a difference between the predetermined temperature and the current temperature. Additionally or alternatively, the urgency may be determined based on a remaining time until the predetermined time.

The pumping device 145 may include, for example, a sewage lifting plant, which are operated not only when a predetermined level is reached, but also when the electricity price is favorable. If there is no wastewater to be lifted, then the pump device 145 is turned off in any case. If the wastewater reaches a predetermined level, the pumping device 145 is operated regardless of the price of electricity.

In addition or as an alternative to the described consumers 120, other electrical consumers in the household 115 can be supplied with power in a corresponding manner. If the household 115 comprises an industrial installation, cooling in the food industry or in the hotel industry, in particular, can be an industrial dishwashing or washing machine. a ventilation or an electric heater are operated as a consumer 120.

Optionally, the household 115 comprises a generator 175 for feeding electricity into the power grid 110. The generator 175 may in particular comprise a wind turbine, a solar system, a biogas plant or a hydroelectric power plant. For electricity fed into the grid 110, a feed-in price is usually paid to the household 115. The feed-in price is usually below the current price and can be ^¬ Sonder vulnerable to short-term price fluctuations to be. Non-constant power supplies of a plurality of generators 175, which may be distributed over the power grid 110, may act the same or rock each other, so that in the short term there may be a strong over- or under-supply of electricity in the power grid 110. The feed-in price can reflect this supply situation. If the oversupply of electricity in the power grid 110 is particularly large, then the

Feed-in price will be negative, so that household 115 will have to pay net for fed electricity from producer 175. In this case, to avoid shutting off the generator 175, the locally generated power may be consumed by one of the consumers 120. This situation can be treated as a particularly low electricity price of electricity from grid 110.

FIG. 2 shows a flowchart of a first method 200, which is set up in particular for execution on the processing device 165 of the device 150 in FIG. In a first step 205, the electricity price for electricity taken from the power grid 110 is determined. In this case, information that has been received by means of the second interface 165 can be used. In addition, the feed-in price may also be determined if a generator 175 is provided by the household 110.

In an optional step 210, the urgency of a power demand of a load 120 is determined. As described above has already been described, the urgency may be dependent on or based on a time, energy, or other device parameter. On the basis of the urgency or, for example, a user-controlled default, a maximum price which is acceptable for power to operate the load 120 is then determined in a step 220.

In a step 225, it is checked whether the current electricity price is below the determined maximum price. If this is the case, then the consumer 120 is supplied with power from the power grid 110 in a step 230. Otherwise, the method 200 returns to step 205 and may run again.

FIG. 3 shows a flow chart of a second method 300 for controlling a current consumption of a consumer 120 from FIG. 1. The method 300 is similar in part to method 200 and is based thereon. The method 300 is also suitable for execution on the processing device 165 from FIG.

In a step 305, the ent ^¬ speaks step 205 from Figure 2, the price of electricity and optionally of

Entry price determined. In a step 310, a ^¬ Ver running the electricity price is predicted. The prediction may ^¬ least 115 of the budget is done by recourse example, historical data or past trend is extrapolated. The prediction may alternatively together with the current price of electricity through the second interface of ^¬ le respect 160 are. The prediction may be provided by the power generator 105 or third party.

In the following step 315, as in step 210 of Figure 2, the urgency of a power demand of a consumer

120 determined. Thereafter, in a step 320, a temporal prediction of the course of the urgency is made. The pre ^¬ forecasting is usually carried out by the budget and 115 can also be done on the basis of historical data from consumers 120 power consumption.

In a step 325, a maximum waiting time until power consumption is determined. The maximum waiting time represents the time that the consumer 120 can get by without power at most. As the maxi ^¬ male waiting time on the basis of different parameters can be determined urgency in step 315, such as an energy level or a device parameter of the consumer 120th

In a step 330, it is checked whether the waiting time determined in step 325 has expired. If this is the case, the consumer 120 is immediately supplied with power, waiving further optimizations, as shown below. Otherwise, in a step 335, a minimum current ^¬ rate is determined during the maximum waiting time.

In a step 340, a maximum acceptable price is determined based on the determined minimum electricity price and a predetermined security. In a following step 345 it is checked whether the current electricity price has fallen below the maximum price determined in step 340. If this is not the case, the method 300 branches back to step 305 and can go through again. Otherwise, the consumer 120 is supplied with power from the power grid 110 in a step 350.

For some of the provisions of method 300, particularly at steps 315, 320, 325, 335, or 340, different heuristics may be used. In one embodiment, at least one of these heuristics can be influenced by a user. Different heuristics can also be selected by the user. Heuristics may also be re-sourced and installed in the method 300 in one embodiment. For example, a gerä ^¬ tebezogene heuristics, such as the urgency of the determination of the current demand of a load 120 in step 315, by a heuristic supplied or updated by the manufacturer of the consumer 120.

FIG. 4 shows exemplary courses on the power supply system 100 of FIG. 1. In the horizontal direction is a

Time applied and in the vertical direction, an electricity price is offered, which is negatively dependent on an availability of electricity in the power grid 110. A first curve 405 represents the price of electricity. The higher the price of electricity, the more were less the availability of power in the power grid is 110. Ov ^¬ SHORT- moves the price of electricity within a

Fluctuation width 410, whose limits can be determined empirically or, for example, by the power generator 105 mandatory ^¬ said.

A second profile 415 reflects the urgency of a current consumption of a first consumer 120 and a third profile 420 the urgency of a current consumption of a two ^¬ ten consumer 120. The two courses 415 and 420 are given in the form of the maximum acceptable price of electricity, each of the urgency was determined.

At a time TO exceeds the maximum acceptable

Current price of the second course 415 the current electricity price 405. In a non-predictive strategy, the corresponding consumer 120 can be powered at this time. However, if at least a prediction of the current price of 405 is performed, at the time TO BE ^¬ known that the price of electricity will fall even further. The

Power consumption by the consumer 120 can be exposed, therefore, until the urgency of its current consumption reaches a uppermost limit 425, which must not be exceeded to avoid a malfunction or an insufficient power ^¬ ability of the consumer 120th This condition occurs at time T2. A time period between a current time and the time T2 corresponds to that in step 325 of the method 300 of Figure 3, certain ma imum ^¬ waiting time. Since the course 405 of the electricity price between If the times TO and T2 fall strictly monotonically, it is advantageous to supply the first load 120 with power as late as possible, that is, only at time T2. In one embodiment, a prediction of a confidence interval is assigned that indicates an area around the predicted value, the predicted value with a vorbe ^¬ agreed probability in the confidence interval. The further the forecast for the future, the greater the confidence interval. It can too

Confidence intervals for different periods of time in the future can be determined. In one embodiment, a "worst case" prediction of the price of electricity is performed by always assuming the upper bound of the confidence interval for the predicted current price of the first curve 405. Other approaches, such as "best case", always use the lower bound of the confidence interval for the predicted electricity price is also possible.

The third profile 420 of the urgency of a current consumption of the second consumer 120 increases strictly monotonically and exceeds the value of the first course 405 of the electricity price at the time T 1. In a non-predictive strategy, it may be started at time T 1 to power the second load 120. In a forward-looking strategy, a forecast for the first course of 405 is present, so it is known that the price of electricity will continue to sin ^¬ ken. Without waiting until a time T4 at which the third run 420 has reached the uppermost limit 425 and needs to be powered regardless of the price of electricity, the optimal time to supply the second load 120 with power may be the time T3, to which the electricity price is minimal.

FIG. 5 shows an exemplary course 505 of a

Feed-in price for electricity of the generator 175 of the household 115 from FIG. 1. The dotted line shown in FIG. presented average of the feed-in price 505 corresponds qua ^¬ litativ the first course of 405 the price of electricity in Figure 4. It is good to see that short-term peaks in posi ^¬ tive and negative direction the average price exceed significantly. In two places it falls

Fee 505 even negative.

Although the invention in detail by the preferred embodiment has been illustrated and described in detail, the invention is not limited ^¬ by the disclosed examples and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention.

Claims

claims

A method (200, 300) for controlling a power consumption of a load (120) from a power grid (110), comprising the steps of:

Detecting (210, 315) that the consumer (120) has a

Has electricity needs;

Detecting (205, 305) a current power price for power from the power grid (110), and

Supplying (230, 350) of the load (120) with power from the power grid (120) if the power price is below a predetermined threshold (415, 420).

The method (200, 300) of claim 1 further comprising detecting an urgency of the power demand (210, 315) and increasing the predetermined threshold (415, 420) with increasing urgency.

Method (200, 300) according to one of the preceding

Claims, wherein a history (405) of the electricity price is predicted (310) and the consumer's supply (415, 420) is retained with power when a falling electricity price has been predicted.

Method (200, 300) according to one of the preceding

Claims, wherein a history (405) of the electricity price is predicted (310) and power is taken from the power grid (110) and stored in a cache memory (130) when the electricity price is low to the consumer (120) at a later time for which the electricity price is predicted to be high, with electricity from the

To provide temporary storage (230, 350).

Method (200, 300) according to one of the preceding

Claims, wherein the consumer (120) to a

predetermined time a predetermined energy

should have taken and the urgency on the basis of a remaining time to the predetermined Time determines (210, 315) will be.

The method (200, 300) of claim 5, wherein the

Urgency additionally determined on the basis of an energy still to be absorbed by the consumer (210, 315).

Method (200, 300) according to one of the preceding

Claims, wherein a generator (175) is ready for feeding power into the power grid (110) and the

Consumer (120) is powered directly from the generator (175), if a current gain for the power from the generator (175) is below the electricity price of the power grid.

Method (200, 300) according to one of the preceding

Claims, wherein a generator (175) is provided for feeding electricity into the power grid (110) in the area of the consumer and a feed - in price (505) for

supplied power is determined and the load (120) is supplied with power (230, 350), if the

Entry price is negative.

Computer program product with program code means for

Carrying out a method (200, 300) according to one of the preceding claims, when the computer program product runs on a processing device (165) or is stored on a computer-readable data carrier.

Apparatus (150) for controlling a power consumption of a load (120) from a power grid (110), comprising:

a first interface (155) for detecting that a power demand of the load (120) is present;

a second interface (160) for detecting a current electricity price for power from the power grid (110), and a control device (165) for supplying the

Consumer (120) with electricity from the power grid (110), if the electricity price below a predetermined

Threshold is.

11. Device (150) according to claim 10, wherein the second

Interface (160) is connected to the power grid (110) and the information of the electricity price is modulated onto the power.