DE102011103600B4 - Method for controlling a device, in particular plant or machine, for the optimal utilization of an energy source - Google Patents

Abstract

A method for controlling a device for optimal utilization of a power source, wherein the device can be supplied from a solar power plant, wherein the temporal course of the power of the solar power plant is predicted, wherein the device is controlled so that it carries out a process which is started at a start time and a planned desired course of electrical power, wherein the starting time is determined such that the energy required for the process or at least as large a proportion of the energy required for the process is generated by the solar power plant, under one condition, the charging of a Accumulator includes or is, wherein the start time is determined such that the accumulator is fully loaded as possible, characterized in that the start time is determined by a convolution integral between desired course and predicted course of the Leistu ng of the solar power plant is determined and an extremum is determined depending on the start time, wherein the convolution integral of the temporally integrated course of the product of desired course and predicted course is, as a condition of an earliest and a latest start time is taken into account, satellite based on weather data and Recording the cloud cover for the geodetic position of the solar power plant, a progression of the solar light quantity is predicted and thus the course of the generated electric power is forecasted.

Description

The invention relates to a method for controlling a device, in particular plant or machine, for optimum utilization of an energy source.

It is known to generate electrical power from solar power plants and to supply energy to electrical consumers.

From the JP2011 - 92 002 A is known as the closest and generic state of the art to predict the solar power.

From the publication "Short term scheduling in a wind-diesel autonomous energy system" is known for a wind energy source to create a predictive model based on probabilities.

From the publication "Case studies on the use of solar irridiance" by Wittmann et al it is known to consider the deviation of the generated solar energy from the solar prognosis.

From the JP 2000 - 316 282 A is a solar powered air conditioning known.

The invention is therefore based on the object of developing the construction of decentralized cells, in particular smart grids, by supplying as little energy as possible via supply lines to the public utility grid.

According to the invention the object is achieved in the method according to the features specified in claim 1 and in the apparatus according to the features indicated in claim 2.

Important features of the invention in the method for controlling a device, in particular plant or machine, for optimal utilization of an energy source,
wherein the device can be supplied from a solar power plant,
wherein the temporal course of the power of the solar power plant, in particular the electrical power of the solar power plant, is predicted, in particular by a cloud prediction is created satellite-based,
wherein the device is controlled to perform a process that is started at a start time and has a planned target history of electric power,
wherein the starting time is determined such that the energy required for the process or at least as large a proportion of the energy required for the process is generated by the solar power plant.

The advantage here is that the process as possible without or at least with the lowest possible power supply from the public utility network is executable. Thus, the most decentralized utilization of the solar power is executable.

According to the invention, the start time is determined by determining a convolution integral, in particular the convolution, between the desired course and the predicted course of the power of the solar power plant, and an extremum, in particular a maximum, being determined as a function of the start time, depending on the start time.
in particular, taking into account as an initial condition an earliest and a latest start time,
in particular, wherein the convolution integral is the temporally integrated course of the product of desired course and predicted course. The advantage here is that the optimal start time is calculated in a simple manner and thus a quick and easy determination on the basis of the forecast weather data, especially taking into account the cloud prediction, is possible.

According to the invention, the process comprises or is a charging of a rechargeable battery under a boundary condition,
wherein the starting time is determined such that the accumulator is fully charged as possible,
in particular wherein as a boundary condition a latest start time is taken into account. The advantage here is that before starting the process, the energy generated by the solar power plant is the public utility network available or power from the public grid and / or from the solar power plant can be supplied to the accumulator and thus the public network is buffers, so the accumulator is usable as a buffer. In addition, the process is only released if a sufficient sunshine duration and thus sufficient continuous power generation can be expected.

In an advantageous embodiment, a progression of the solar amount of light is predicted satellite-based from weather data and coverage of the clouds for the geodetic position of the solar power plant and thus predicted the course of the electric power generated. The advantage here is that the most accurate prediction of the solar energy can be executed. Thus, even for the position of the solar power plant, a prediction can be generated, which can be used for the optimal determination of the starting time.

In an advantageous embodiment, electrical lines with a larger cross-section of the line are arranged between the solar power plant and the consumer than the electrical lines between the device and the public AC line. Have supply network. The advantage here is that the lowest possible power supply from the public utility network is possible and large services can be transferred within the smart grid formed from the solar power plant and the device. In particular, DC voltage can even be used within the SmartGride, so that the DC voltage generated by solar cells of the solar power plant can be fed directly into the DC link of converter-fed drives.

In an advantageous embodiment, in addition to the solar power plant another power plant is connected to the device, wherein the further power plant generates energy from an energy source with predictable temporal course of the generated electric power,
in particular wherein the energy source is the wind, in particular wind speed, and the further power plant is a wind power plant. The advantage here is that instead of solar energy and other renewable energy sources can be used. In this case, a particular suitability of the invention in energy sources is given, the time course of performance varies and predictable and / or predictable. Especially suitable for the prognosis is a satellite-based weather data acquisition system.

In an advantageous embodiment, the solar power plant on a solar thermal and / or solar electric power plant. The advantage here is that when using solar cells, ie photoelectric converter units, the power generated very quickly follows the solar radiation performance and thus varies very dynamically.

In an advantageous embodiment, the device is an industrial drive or a household appliance, such as dishwasher, washing machine or tumble dryer. The advantage here is that the device is applicable in different devices. In particular for smart grids, ie decentralized power supply cells, the invention is advantageously applicable. In addition, when connecting an industrial manufacturing plant to the public grid a smaller line cross-section can be used and thus costs for manufacturing a system can be reduced.

In an advantageous embodiment, DC voltage generated by the solar power plant supplies the intermediate circuit of an inverter, whose inverter feeds an electric motor, in particular wherein from the public utility power via a rectifier to the intermediate circuit can be fed. The advantage here is that energy losses during DC / AC and AC / DC conversion can be avoided.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination possibilities of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task arise.

• In der 1 ist ein prognostizierter zeitlicher Verlauf der Leistung P_S eines Solarkraftwerks und ein zeitlicher Verlauf der Verbraucherleistung P_V gezeigt in Abhängigkeit von der Zeit t.

The invention will now be explained in more detail with reference to schematic illustrations:

• In the 1 is a predicted time course of performance P_S of a solar power plant and a temporal course of consumer service P_V shown as a function of time t ,

In the invention, for example, by satellite-based detection of the cloud image taking into account weather data, a solar forecast is executed. In this way it is possible to predict the course of the solar radiation intensity for the position of a solar power plant. For example, for a short period of time at the position of the solar power plant, the sun will shine and then be obscured by a cloud field. After that, a cloud-free sky appears again, which is only covered by clouds after a long time - followed by a short period of time in which the sun shines again.

The solar power plant has solar cells to convert solar radiation into electrical energy. As a solar power plant but also a solar thermal power plant is used.

In the invention, the determined by a first computer solar forecast, ie the course of performance P_S transmitted via a data exchange connection to a second computer which controls an industrial plant or an industrial machine or a household appliance, such as a dishwasher, washing machine or the like.

The second computer controls a process with a consumer power P_V , He knows the planned, in particular also predicted, course of consumer service P_V , From the two courses, the computer determines an optimal start time for the process.

This is preferably carried out by determining the convolution integral of the two courses, which depends on the start time, and thereby determining the maximum with respect to the start time. This determination takes place under the boundary condition of an earliest and latest start time.

In this way, therefore, the process can be started as soon as possible at such a start time, so that the energy generated by the solar power plant supplies as completely as possible the energy required for the entire process. Thus, a supply of energy via supply lines from a public AC power supply network is avoidable or at least the energy supply low durable. In particular, the line cross-section of these supplying supply lines is thus less feasible than the line cross-section of the lines between the solar power plant and the machine or system carrying out the process.

Thus, the highest possible level of supply of the process from sustainable energy is feasible.

The process is, for example, a transport task, ie the transport of an object from a first position to a second position. In this case, the process is a non-time-critical process, ie a process that does not have to be processed with the highest priority.

Another example of a process is also a household appliance, such as a washing machine, dishwasher or tumble dryer. In this case, the energy required for the process or even the power curve required for the process is essentially known or can be estimated by means of an upper limit value or limiting value profile. In this way, the process can be started as far as possible at a start time, so that the supply from the solar power plant takes place completely or almost completely.

As a process, it is also possible to charge a rechargeable battery, for example an electric car.

The required amount of charge energy is essentially known. In this case, the latest time is determined at which the charging is to be started to still charge the accumulator within the predetermined boundary condition. In this way, the amount of residual energy available in the accumulator is available to the public supply network until the start time. So if, for example, the forecast for morning cloudiness and afternoon sunshine, the rest of the energy of the battery is fed into the morning and charged in the afternoon, the battery from the solar plant. In this way, the public network is bufferable over bad weather periods. The boundary condition may also be, for example, that the user of the electric car pretends that he would like to use the car only the next morning and while the accumulator should be half charged. Then the charging time is determined according to the state of charge and from this the latest starting time for the charging process is determined. Up to this time a buffering of the public network is executable. It is charged in the sunshine of the accumulator and discharged in cloudy weather. Depending on the state of charge then the start time is even further displaced.

Thus, therefore, a decentralized cell can be formed from the solar power plant and from the machine and plant carrying out the process, which only has to be connected to a public supply network via supply lines with a small line cross section. Within the decentralized cell larger cable cross sections are necessary.

In further exemplary embodiments according to the invention, the entire process carried out consists of two or more individual process steps to which a respective desired course of power consumption is assigned, wherein the individual process steps may be spaced from each other in time. Again, the optimal start times are determined based on respective convolutions and the constraint that the process steps are executed sequentially, as well as the constraint that the process must be completed between an earliest start time and a later end time.

An optimal exploitation of the solar power curve is thus guaranteed.

In further embodiments of the invention, instead of the solar power plant, which is based on solar thermal energy production and / or the solar cell for converting the light into electric power, or in addition to this solar power plant, a wind power plant used and / or based on a different variable physical size power plant. Here, instead of the solar forecast, ie forecast for the time course of the light radiation at the site of the power plant, or in addition to this solar forecast, a forecast of the temporal value curve of the physical quantity, such as wind speed, is taken into account. As another example of such a variable physical quantity, the wave strength can also be used.

LIST OF REFERENCE NUMBERS

P_S

predicted time course of the performance of the solar power plant

P_V

Time course of consumer service

t

Time

Claims (4)

A method for controlling a device for optimal utilization of a power source, wherein the device can be supplied from a solar power plant, wherein the temporal profile of the power of the solar power plant is predicted, wherein the device is controlled such that it carries out a process which is started at a start time and has a planned desired course of electrical power, wherein the starting time is determined such that the energy required for the process or at least as large a proportion of the energy required for the process is generated by the solar power plant, under one constraint, the process charging a accumulator comprises or is, wherein the start time is determined such that the accumulator is fully loaded as possible, characterized in that the start time is determined by a folding integral between desired course and predicted course depending on the start time the power of the solar power plant is determined and an extremum is determined as a function of the starting time, wherein the convolution integral of the temporally integrated course of the product of desired course and predicted course is, as a condition of an earliest and a latest start time is taken into account, satellite based on weather data and recording the cloud cover for the geodetic position of the solar power plant, a progression of the solar light quantity is predicted and thus the course of the producible electric power is forecasted. Apparatus for carrying out a method according to Claim 1 , characterized in that between the solar power plant and consumer electrical lines are arranged with a larger cross-section than the electrical lines between the device and public AC power supply network, wherein in addition to the solar power plant another power plant is connected to the device, the further power plant from an energy source generated with predictable time course of the electric power produced energy, wherein the DC power generated by the solar power plant supplies the intermediate circuit of an inverter whose inverter feeds an electric motor, from the public utility power via a rectifier to the DC link can be supplied, the device is an industrial drive or a Household machine, such as dishwasher, washing machine or dryer is. Device after Claim 2 , characterized in that the energy source of the further power plant is the wind and the further power plant is a wind power plant. Device after Claim 2 or 3 , characterized in that the solar power plant has a solar thermal and / or solar electric power plant.

Images