DE102022203456A1 - Grid-friendly load management for a heat pump - Google Patents

Abstract

A method and a device (2) for operating a heat pump (4) are specified. The device (2) comprises the heat pump (4), which can be connected directly or indirectly to a public power grid (12) via a local power distribution (8) and can be operated with an operating current (IB). A default value (V) that limits the operating current (IB) is specified in a time-varying manner, so that the default value (V) varies in the opposite direction to the network utilization of the power grid (12).

Description

The invention relates to a method and a device for operating a heat pump.

A heat pump can usually be connected to a public power grid directly or indirectly via a local power distribution system. Here and below, “local power distribution” refers to the electrical installation that is separated from the public power grid by a network connection point, e.g. of a house (domestic power installation) or commercial business. The local electricity distribution therefore includes those electrical lines and consumers as well as any existing electrical storage and/or power generation units that, from the heat pump's perspective, are located on this side of the network connection point and therefore do not belong to the public electricity network.

The invention primarily relates to a heat pump with output that can be controlled continuously or in several stages, in particular to a so-called inverter heat pump, in which the speed of the compressor can be controlled by an upstream converter (inverter) or to heat pumps with several compressors, which are used for Variation of the overall performance can be controlled individually or in groups. In principle, the invention can also be used in heat pumps whose output can only be controlled in a binary manner, i.e. which can only be switched on and off.

As heat pumps become more widespread for generating heating and/or hot water in private homes and commercial businesses, heat pumps are having an increasing impact on the utilization of public power grids. What is particularly problematic is that heat pumps regularly draw particularly high electrical power at times when the network utilization is particularly high anyway. For example, heat pumps are typically switched on in the morning or evening or run at increased output, as there is an increased need for heating and hot water at these times, especially during the winter months. At these times, the average network load on public electricity networks typically shows characteristic peaks (morning peak and evening peak), regardless of the power used by heat pumps.

As a result, heat pumps already have a destabilizing influence on the network load by causing network load peaks to increase. This problem will become more acute in the foreseeable future as a result of the intended reduction in global CO ₂ emissions and the proliferation of heat pumps promoted in this context. It is therefore foreseeable that with the existing network infrastructure, the expected future electricity demand will not be able to be provided without supporting measures, especially since the electricity networks will also experience a significantly increasing burden due to increasing e-mobility.

The invention is based on the object of providing network-friendly load management for a heat pump. The method should be particularly inexpensive to implement.

With regard to a method for operating a heat pump, this object is solved according to the invention by the features of claim 1. With regard to a device for operating a heat pump, the above object is solved according to the invention by the features of claim 10. Advantageous and partly inventive embodiments of the invention are set out in the subclaims and the following description.

The invention is based on a heat pump that can be connected indirectly via a local power distribution or directly to a public power grid and operated with an operating current. During operation, the performance of the heat pump is regulated in an expedient embodiment in such a way that a measured actual temperature of a heat circuit or heat storage device, which is supplied with heat by the heat pump, is adjusted to a predetermined target temperature. Optionally, this temperature control is provided with a hysteresis, according to which a threshold for increasing the heat pump output is set lower than a threshold for decreasing the heat pump output. For example, as part of the control, the heat pump output is increased when the actual temperature is 2 °C below the target temperature, and shut down when the actual temperature exceeds the target temperature.

wobei V den Vorgabewert, L die Betriebsstromkurve und t die Zeit repräsentiert. Alternativ kann die Betriebsstromkurve im Rahmen der Erfindung aber auch so definiert sein, dass sie nur den Verlauf des Vorgabewerts abbildet und mit letzterem in einer - z.B. linearen - Beziehung steht: $$\text{V}=\text{k}\cdot \text{L}\left(\text{t}\right),$$

wobei k für einen (von null verschiedenen) konstanten oder ebenfalls veränderlichen Parameter steht.According to the invention, it is provided that a default value for the operating current of the heat pump is specified in a time-varying manner, so that the default value varies in the opposite direction to a network utilization of the power grid. The default value limits the operating current, i.e. it sets the maximum current strength or (electrical) power of the operating current that can be drawn from the heat pump, for example as Absolute value or as a percentage of the maximum current or maximum power. The default value is varied in particular continuously or in several stages. Preferably, the default value is determined based on a stored operating current curve, which is stored in particular in the form of a time-dependent mathematical function (i.e. a mathematical formula) depending on time, in the form of a base point table or in a mixed form of base points and formula. Within the scope of the invention, the operating current curve can directly reflect the default value to be set: $$\text{v}=\text{L}\left(\text{t}\right),$$

where V represents the default value, L the operating current curve and t the time. Alternatively, within the scope of the invention, the operating current curve can also be defined in such a way that it only represents the course of the default value and has a - for example linear - relationship with the latter: $$\text{v}=\text{k}\cdot \text{L}\left(\text{t}\right),$$

where k stands for a (non-zero) constant or also variable parameter.

Within the scope of the invention, the operating current curve can be programmed by the manufacturer into the control electronics of the heat pump or an external control device or made available on a storage medium (e.g. an SD card or a USB stick). Alternatively, the operating current curve can be transferred to the heat pump or the external control device via download (e.g. via a mobile phone network, LAN, WiFi or via Bluetooth using a mobile device). The operating current curve can either be made available once or updated regularly or irregularly.

Within the scope of the invention, the operating current curve can be defined (exclusively) as a function of the time of day (of a single day), so that the operating current curve has the same shape on every day. If the operating current curve is available as a reference point table, in this version it includes, for example, 24 points (i.e. one point per hour), 96 points (i.e. one point per quarter of an hour) or 1440 points (i.e. one point per minute). Alternatively, the operating current curve can cover a period of less than 24 hours. In this case, the operating current curve is preferably only processed within a section of each day (e.g. only between 7 a.m. and 10 p.m.). However, the operating current curve is preferably also variable on a time scale that exceeds 24 hours, in particular for a week, one or more months or - preferably - a whole year. Instead of a single connected operating current curve, the operating current curve can also be composed of several curve pieces (or files) that are used alternatively to one another. For example, a separate operating current curve is stored for each month of the year.

The operating current curve is preferably stored in the heat pump itself. Alternatively, the operating current curve can also be stored in an external data memory (i.e. not belonging to the heat pump), e.g. a memory card or the memory of an external control device (e.g. a central computer or cloud server) and from there made available to the heat pump during operation become.

Controlling the default value based on the stored operating current curve has the advantage that network-friendly load management is possible without complex installation, in particular without the use of external electricity meters or current sensors and their data transmission connection to the heat pump. An interaction of the heat pump with an external electricity meter or current sensor is therefore not provided for in preferred embodiments of the heat pump according to the invention. Furthermore, in some embodiments of the invention, the heat pump can be operated offline, i.e. without permanently connecting the heat pump to a regional or supra-regional data transmission network such as the Internet and/or a mobile phone network. In particularly simple versions, the heat pump therefore does not include any interfaces for connection to such data transmission networks.

In certain embodiments of the method according to the invention and the device according to the invention, data from a current sensor at the network connection point of the local power distribution or an upstream line harness or transformer of the power network can be taken into account as an additional parameter when determining the default value. For example, the default value resulting from the operating current curve depends on the measured current on the network connection The starting point of the local power distribution or the upstream cable harness or transformer of the power grid or the measured grid voltage is scaled or shifted.

The variation of the default value, which is opposite to the network utilization of the power network, means that the default value of the operating current is always reduced or even reduced to zero when the network utilization of the electricity network is particularly high, whereas the default value is increased in times of low network utilization. This ensures that the heat pump does not contribute to increasing fluctuations in network utilization, but rather helps network operators to better distribute network utilization over time and thus to provide a particularly large amount of operating electricity for the generation of heat with comparatively low peak network utilization.

In a preferred embodiment of the invention, a network utilization curve is specified as the operating current curve, which represents the network utilization of the power network in a time-resolved manner. The default value is determined based on the distance (ie the difference) of a current value of the network utilization curve to a predetermined threshold value, for example according to $$\text{v}=\text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}.$$

The default value V is expediently set within specified limit values [V _min ; V _max ] held. In the above equation, V again stands for the default value, k for a constant or variable parameter, A(t) for the current value of the network utilization curve and A _max for the threshold value. Preferably, the default value is also reduced to zero when the current value of the network utilization curve exceeds the threshold value and the difference A(t) - A _max thus becomes negative.

• - das Land oder den Landesteil (z.B. Bundesstaat oder Verwaltungsbezirk), oder
• - die Stadt oder den Postleitzahlenbereich,

in dem bzw. der sich die Wärmepumpe befindet, spezifisch ist. Alternativ hierzu wird die Betriebsstromkurve in einer bevorzugten Ausführung der Erfindung spezifisch für die konkreten geographischen Koordinaten des Standorts der Wärmepumpe bestimmt.In an advantageous embodiment, the operating current curve (in particular in the form of the network utilization curve, also known as the “load profile”) is defined specifically for the geographical location of the heat pump. The geographical location of the heat pump can be limited to varying degrees of precision within the scope of the invention. For example, the operating current curve can be specified in different versions in such a way that it is for

• - the country or part of the country (e.g. federal state or administrative district), or
• - the city or postal code area,

in which the heat pump is located is specific. Alternatively, in a preferred embodiment of the invention, the operating current curve is determined specifically for the specific geographical coordinates of the location of the heat pump.

Alternatively, within the scope of the invention, the operating current curve can also be calculated and specified specifically for a delimited network area of the power network to which the heat pump is connected, for example for a line harness, a distribution network area, a balancing group or a local, regional network operator or a transformer the medium voltage is transformed down to the low voltage of the network segment to which the heat pump is connected. The delimited network area can include one or more network levels.

• - für unterschiedliche Wochentage,
• - für unterschiedliche Halbjahre, Trimester, Quartale oder Monate,
• - für die Jahreszeiten Frühjahr, Sommer, Herbst, Winter oder
• - für jeden Tag im Jahr

jeweils einen individuellen Tagesverlauf aufweist. Dem liegt die Erkenntnis zugrunde, dass die durchschnittliche Netzauslastung typischerweise einen Tagesverlauf mit drei Maxima (Peaks), nämlich einem Morgen-Peak, einem Mittags-Peak und einem Abend-Peak, aufweist. In den Wintermonaten sind hierbei typischerweise der Morgen-Peak und der Abend-Peak besonders ausgeprägt, da zu diesen Zeiten vermehrt elektrische Energie für Beleuchtung und zur Wärmeerzeugung verwendet wird. In den Sommer-Monaten ist dagegen der Mittags-Peak besonders ausgeprägt, da hier in der Tagesmitte vermehrt elektrische Energie zum Kühlen verbraucht wird. Zudem weist die durchschnittliche Netzauslastung auch starke Unterschiede zwischen Werktagen und arbeitsfreien Tagen auf. So tritt an arbeitsfreien Tagen (insbesondere im Westeuropäischen Raum an Sonntagen) der Morgen-Peak deutlich später auf als an Werktagen und verschmilzt dabei unter Umständen (insbesondere in den Wintermonaten) mehr oder weniger mit dem Mittags-Peak. Diese Unterschiede der durchschnittlichen Netzauslastungskurve werden vorzugsweise in der Betriebsstromkurve berücksichtigt. Hierdurch wird der Vorgabewert während des Morgen-Peaks, des Mittags-Peaks und/oder des Abend-Peaks vorübergehend, gegebenenfalls bis auf null, reduziert.In a simple to implement but still effective embodiment of the invention, the operating current curve is specified in such a way that it is adapted to the average differences in network utilization over the course of the week, month and/or year. Within the scope of the invention, the average difference in network utilization over the course of the year can be depicted in the operating current curve with different temporal precision. For example, the operating current curve can be specified in the context of the invention in such a way that it

• - for different days of the week,
• - for different half-years, trimesters, quarters or months,
• - for the seasons spring, summer, autumn, winter or
• - for every day of the year

each has an individual daily course. This is based on the knowledge that the average network utilization typically has a daily course with three maxima (peaks), namely a morning peak, a midday peak and an evening peak. This is more typical in the winter months The morning peak and the evening peak are particularly pronounced, as at these times more electrical energy is used for lighting and heat generation. In the summer months, however, the midday peak is particularly pronounced, as more electrical energy is used for cooling in the middle of the day. In addition, the average network utilization also shows strong differences between working days and non-working days. On non-working days (particularly on Sundays in Western Europe) the morning peak occurs significantly later than on working days and under certain circumstances (particularly in the winter months) merges more or less with the midday peak. These differences in the average network utilization curve are preferably taken into account in the operating current curve. This temporarily reduces the default value during the morning peak, the midday peak and/or the evening peak, possibly down to zero.

In particular, if the heat pump is an air heat pump, the default value is optionally varied depending on the air temperature. The default value is increased in particular as the air temperature increases, since the efficiency of the air heat pump increases with increasing air temperature and thus the heat (needed immediately or at a later point in time) can be generated with comparatively little electrical energy expenditure.

• - die gemessene Netzspannung (insbesondere anhand von Messdaten eines in die Wärmepumpe integrierten Netzspannungssensors), und/oder
• - die gemessene Netzfrequenz, und/oder
• - Prognosedaten bezüglich einer zu erwartenden Netzauslastung sowie - optional - der Lufttemperatur

herangezogen.In a further advantageous embodiment of the invention, the default value of the operating current is varied depending on information about the (current or forecast) actual network utilization at the geographical location of the heat pump or in the delimited network area. In particular, information about the actual network utilization is provided

• - the measured mains voltage (in particular based on measurement data from a mains voltage sensor integrated into the heat pump), and/or
• - the measured network frequency, and/or
• - Forecast data regarding expected network utilization and - optionally - the air temperature

used.

The optional use of the mains voltage and/or the mains frequency as a control variable for setting the default value of the operating current is based on the knowledge that the mains voltage fluctuates slightly with the local and regional network load. In particular, the default value of the operating current is increased when the mains voltage is comparatively high and reduced when the mains voltage is comparatively low. The variant of the invention described above has the advantage that the measurement of the mains voltage can take place (and preferably takes place) in the heat pump itself or in the immediate vicinity thereof, so that a complex installation is not necessary (and in particular is not available).

In an advantageous embodiment of the invention, the course of the mains voltage is recorded continuously or at least over a longer period of time by the heat pump or an external control device. If this recording is carried out by the external control device, if present, this is preferably arranged in the local power distribution, in particular in terms of circuitry close to the heat pump. By averaging the time of day and, if necessary, additional temporal smoothing of the measured mains voltage, an average daily course of the mains voltage is determined - by the heat pump or the external control device - for the location of the heat pump. During operation of the heat pump, the default value of the operating current is varied depending on the deviation of a currently measured value of the mains voltage from the value to be expected based on the average daily course. The default value is increased in particular if the currently measured mains voltage is above the value expected for the respective time of day. The default value is reduced accordingly if the currently measured mains voltage is below the value expected for the respective time of day.

Forecast data about network utilization is automatically retrieved from the Internet by the heat pump or an external control device.

In a particularly advantageous embodiment of the invention, the forecast data is downloaded or determined using a software application (app) installed on a mobile terminal (e.g. smartphone or tablet), this app using a transmitting and receiving unit of the terminal for data transmission, for example via Bluetooth , can be connected to the heat pump. This app (also known as the “control app”) is preferably used for configuring and/or remotely controlling the heat pump set up and thus designed to be regularly connected to the heat pump by a user of the heat pump. The app is set up to transfer the forecast data to the heat pump whenever the app is connected to the heat pump; in particular whenever the mobile device on which the app is installed is near the heat pump, or when the user operates the heat pump using this app. In this case, not only a current forecast value (for example for the coming hour) is preferably transmitted, but also a long-term forecast that contains forecast data for several days, for example for every hour of the next 16 days. Whenever the app is reconnected to the heat pump, the long-term forecast stored in the heat pump is overwritten with updated values. In a variant of this embodiment, an adapted operating current curve is calculated using the app based on the forecast data. In this case - in addition to or instead of the raw forecast data of the expected network utilization - the operating current curve adjusted based on the forecast is transferred to the heat pump when the mobile device is connected to the heat pump.

A major advantage of these embodiments is that the heat pump itself can (and preferably will) be operated offline. In this embodiment, the heat pump itself is preferably not equipped with means for connecting the control electronics to the Internet, which enables the heat pump to be implemented simply and inexpensively. A further advantage of this embodiment is that the computing capacity of the mobile terminal can be used to obtain the forecast data and, if necessary, to calculate the adapted operating current curve. This allows a correspondingly smaller dimensioning of the computing power of the control electronics.

The information about the actual network utilization can be used within the scope of the invention in combination with a stored operating current curve or independently thereof. In the former case, for example, the specified operating current curve is increased/decreased or scaled depending on the information about the actual network utilization. In the latter case, no stored operating current curve is used to adapt the default value of the operating current. Rather, the default value is only varied taking into account the information about the actual network utilization.

In a further advantageous embodiment of the invention, the default value is determined based on a control signal from a network operator that is dependent on the network utilization. In the context of the invention, the control signal can be a (binary) switch-off signal, through which - especially in the event of an impending network overload - the default value of the operating current is set to zero and which thus causes an interruption in the operation of the heat pump. Alternatively, the control signal can also be a differentiated signal, which, for example, causes the default value to be reduced to a specified percentage of the maximum operating current when the network is busy. Preferably, the control signal - if available - is taken into account in addition to the average network utilization and/or the actual network utilization when determining the default value. For example, the master signal is always used to determine the default value - e.g. instead of the stored operating current curve or instead of forecast values of the expected network utilization - when the master signal is supplied to the heat pump. A control signal that may be present is therefore given priority. However, whenever the control signal is not present (e.g. because the transmission of the control signal is disrupted or the network operator does not provide such a control signal), other means are used to determine the default value, e.g. a stored operating current curve or forecast values of the expected network utilization . Alternatively, in expedient embodiments of the invention, the control signal is combined with the stored operating current curve or the forecast values of the expected network utilization in such a way that the default value resulting from the operating current curve or the forecast values is scaled or shifted depending on the control signal.

Often, the operation of the heat pump does not allow for a continuous variation of the operating current, but rather changes the operating current in discrete steps. In particular, the heat pump usually requires a minimum operating current of, for example, 2A. If the available operating current falls below this minimum operating current (also known as the switch-off threshold), the operation of the heat pump is completely interrupted. It has been recognized that this shutdown threshold could lead to shock-like load changes in the power grid, which could endanger grid stability under certain circumstances. Such a case could occur, for example, if a large number of heat pumps operating according to the method according to the invention are installed in a regional subnet as the network load increases due to a stored operating current curve, due to information about the actual network utilization or due to of the energy supplier's control signal at the same time, so that a multiple of the minimum operating current is suddenly released.

In order to avoid such shock-like load changes that are dangerous for network stability, a change in the default value, in particular a reduction of the default value to zero, caused by the operating current curve, the information about the actual network utilization or the energy supplier's control signal, is preferably not carried out immediately in the course of the method , but with a time delay compared to the triggering event. In the case of unforeseeable events (e.g. an increase in the actual network load or a change in the control signal), the default value is always changed with a time delay after the event (in particular set to zero). In the case of a permanently stored operating current curve, the default value can alternatively be changed proactively (i.e. with a negative time offset before the triggering event), in particular set to zero. The time offset is varied in a manner specific to the heat pump or the current operating cycle. For example, the time offset is dependent on a duration of a current operating cycle, an amount of energy charged during the current operating cycle, a random number or - preferably - the deviation of an actual temperature from a target temperature in a heating or hot water circuit or energy storage heated by the heat pump varies.

The time offset can optionally be chosen to be the same or different for negative changes in the default value (in particular shutdown processes) and positive changes in the default value (in particular restart processes). The time offset when switching off (i.e. reducing the default value to zero) is preferably chosen to be shorter than when switching on again (i.e. increasing the default value from zero to a positive value). For example, the time offset for switching off is determined such that the heat pump switches off 15 seconds before a predetermined switch-off time for each minute of previous operating time in the current operating cycle. If the heat pump had already been operated for 30 minutes before the intended switch-off time, the heat pump will, for example, be switched off by a time delay of 7.5 minutes (namely 30 x 15 seconds) before the switch-off time. For restarting, for example, a double time offset of 30 seconds per minute of operating time is provided after a restart time, so that the heat pump resumes the operating cycle with a time delay of 15 minutes after the restart time if the operating time preceding the switch-off was 30 minutes. The “operating cycle” refers to an interval in which heat is generated by the heat pump - continuously or with short interruptions. Different operating cycles are separated from each other by (especially longer) standby phases.

What all of the variants described above have in common is that the time offset is usually different for different heat pumps, even with the same configuration and the same network load, so that the heat pumps change the default value, in particular switch off, at different times even under the same network conditions.

In addition or as an alternative to the time-delayed switching off and restarting of the heat pump, it is optionally provided that the rate of change (i.e. the temporal edge steepness of a change in the default value) is limited. For example, the rate of change of the default value is limited to one amp per minute. This limitation of the rate of change of the default value also dampens rapid (shock-like) load changes in network utilization, which can otherwise lead to network instability. Within the scope of the invention, the limitation of the rate of change of the default value can be provided in the entire value range of the default value or - preferably - only for small default values in the vicinity of the switch-off threshold or at high network utilization. Furthermore, the limit value for negative rates of change of the default value (i.e. for a reduction in the default value) can be chosen to be the same as or different from the limit value for positive rates of change of the default value (i.e. for an increase in the default value). For example, the decrease in the default value before switching off is limited to 1 ampere per minute and the increase in the default value after reconnection is limited to 0.5 amperes per minute.

• - mindestens eine weitere Wärmepumpe, die mit der ersten Wärmepumpe Daten austauscht,
• - ein übergeordnetes Steuergerät, das neben der (ersten) Wärmepumpe optional mindestens eine gegebenenfalls vorhandene weitere Wärmepumpe ansteuert,
• - ein Programmiergerät, z.B. in Form einer Fernsteuerung, zur Konfiguration der Wärmepumpe, und/oder
• - einen Netzspannungssensor.

In simple embodiments of the invention, the device according to the invention consists exclusively of the (one or first) heat pump. In more complex embodiments of the invention, the device comprises, in addition to this heat pump, at least one peripheral device, for example

• - at least one other heat pump that exchanges data with the first heat pump,
• - a higher-level control device which, in addition to the (first) heat pump, optionally controls at least one additional heat pump that may be present,
• - a programming device, for example in the form of a remote control, for configuring the heat pump, and/or
• - a mains voltage sensor.

For example, the device can include several heat pumps in an apartment block or residential area controlled by a common control device. Each of these heat pumps can optionally include several compressors.

In a particularly preferred embodiment, the device comprises, in addition to the heat pump, a software application (operating app) which is intended and set up for configuration and/or remote control of the heat pump and which is available on a smartphone or computer (e.g. a notebook or tablet). can be installed. The smartphone or the computer are generally not part of the device according to the invention and are regularly manufactured and sold independently of the device. Rather, the smartphone or computer is only used by the facility as an external resource for computing power, storage space and communication services (similar to how the public power grid is only used by the facility as a resource for electrical power without becoming part of the facility). . The operating app can be connected to the heat pump or any external control device of the device, preferably via a wireless data transmission link (in particular via Bluetooth or mobile communications). For this purpose, the operating app uses a corresponding transmitting and receiving unit on the smartphone or computer.

• • der durchschnittlich zu erwartenden Sonneneinstrahlung oder Windstärke,
• • Prognosedaten der Sonneneinstrahlung oder Windstärke,
• • in Abhängigkeit von der tatsächlichen (insbesondere gemessenen) Sonneneinstrahlung bzw. Windstärke am Standort der Wärmepumpe oder
• • der gemessenen Leistung einer gegebenenfalls in der lokalen Stromverteilung vorhandenen Photovoltaikanlage bzw. Windkraftanlage

variiert. Dabei wird die Soll-Temperatur insbesondere umso höher eingestellt, je höher die durchschnittliche, prognostizierte oder tatsächliche Sonneneinstrahlung bzw. Windstärke oder die gemessene Leistung der PV-Anlage bzw. Windkraftanlage ist. Hierdurch wird erreicht, dass bei hoher Sonneneinstrahlung oder Windstärke (und somit einem höheren Solar- bzw. Windstromanteil) besonders viel elektrische Energie in Wärme gespeichert wird, um dafür in folgenden Zeiten geringerer oder fehlender Sonneneinstrahlung oder Windstärke (m Falle der Sonneneinstrahlung insbesondere während der Nacht) weniger elektrische Energie beziehen zu müssen.In an expedient embodiment of the method, the target temperature of the heat circuit or heat storage, according to which the performance of the heat pump is regulated, or a target temperature of a heated object depending on

• • the average expected solar radiation or wind strength,
• • forecast data for solar radiation or wind strength,
• • depending on the actual (especially measured) solar radiation or wind strength at the location of the heat pump or
• • the measured output of a photovoltaic system or wind turbine that may be present in the local power distribution system

varies. In particular, the target temperature is set higher, the higher the average, forecast or actual solar radiation or wind strength or the measured output of the PV system or wind turbine. This ensures that when there is high solar radiation or wind strength (and thus a higher solar or wind power share), a particularly large amount of electrical energy is stored in heat in order to be able to use it in subsequent times of lower or no solar radiation or wind strength (in the case of solar radiation, especially during the night ) having to draw less electrical energy.

The target temperature is preferably additionally varied depending on the actual or predicted air temperature. In particular, the target temperature is set higher the lower the measured or predicted outside temperature is. In particular, the target temperature is increased or decreased in advance (i.e. with a time lead) in the opposite direction to predicted temperature changes in order to proactively adapt the heat stored in the heating circuit or heat storage and/or a heated object to expected temperature changes. For example, a heat storage device and/or a heated object (e.g. a residential building or a commercial property) is heated up particularly strongly (e.g. by 2 °C above the usual target temperature) by increasing the target temperature during the day when solar power is available and/or there is low grid utilization. if a particularly cold night is forecast in order to reduce the heating energy required during the night.

In an advantageous further development of the invention, the power consumption of at least one further electrical consumer in the local power distribution is taken into account when controlling the power of the heat pump, in particular the power consumption of a charging station for charging the battery of an electric vehicle. In particular, the heat pump and the other Ver The electrical power received by each consumer is controlled in such a way that the total electrical power received by the heat pump and the other consumer or the power obtained from the local power distribution from the power grid does not exceed a predetermined limit value. If the limit value is likely to be exceeded, the performance of the heat pump and/or the other electrical consumer is reduced. For example, the output of the heat pump and the other electrical consumer is reduced in the same ratio (e.g. by 20% each) or by the same amount (e.g. by 1 A each). Alternatively, predetermined priority rules are taken into account when reducing the respective output of the heat pump and/or the other electrical consumer. For example, the charging station is set up to send a priority signal to the heat pump at the start of a charging cycle if the limit value is about to be exceeded, as a result of which the heat pump temporarily reduces its output. This is not critical because heated objects such as residential buildings or commercial properties regularly have a high thermal capacity and therefore a time shift in heat generation can occur without noticeable restrictions on the needs-based provision of heating power.

Preferably, a reduction of the default value, in particular a reduction of the default value to zero, can be overwritten by a user command (“override command”), so that the user - for example in the event of an acute heat requirement - can set an operating cycle of the heat pump with a higher operating current, in particular with maximum operating current, can be enforced. However, the override command may be tied to a special fee or a special electricity tariff by the network operator. In an expedient embodiment of the invention, the heat pump is set up against this background to report the override command to a network operator or an electricity meter of the local electricity distribution in order to trigger the special charge or the special electricity tariff.

The device according to the invention is generally set up to carry out the method according to the invention described above. Embodiments of the method therefore correspond to corresponding embodiments of the device. Explanations of variants of the method and their respective effects and advantages must be transferred accordingly to the facility and vice versa.

Specifically, the device comprises a heat pump of the type described above, which can be connected to a public power grid either directly or indirectly via a local power distribution (in particular an electrical house power installation) and can be operated with an operating current. The device further includes control electronics that are set up to control the operation of the heat pump (and thus in particular the current or electrical power drawn by the heat pump). The control electronics are set up in particular to vary the output of the heat pump for the controlled generation of thermal energy in a binary manner, continuously or in several steps. The control electronics is also set up to preset a default value of the operating current in a time-varying manner, in particular continuously or in several stages, so that the default value varies in the opposite direction to the network utilization of the power grid. As described above, the default value limits the operating current, i.e. sets the maximum value of the current or power that can be obtained from the heat pump. Taking into account this default value that limits the operating current, the control electronics varies the power or current of the heat pump in particular in such a way that an actual temperature of a heat circuit or heat storage heated by the heat pump is adjusted to a predetermined target temperature.

The control electronics are preferably set up to determine the default value of the operating current based on an operating current curve stored in the heat pump or an external data memory, in particular in the form of a time-dependent mathematical function or base table. The control electronics are preferably (completely) integrated into the heat pump itself. In an alternative embodiment, the control electronics are arranged in an external control device, which in particular controls several heat pumps together. In yet another alternative embodiment, part of the control electronics is integrated in the heat pump itself, while another part of the control electronics is arranged in an external control device.

The control electronics preferably comprises a programmable component, e.g. a microprocessor or single-board computer, in which software (firmware) implementing the functions of the control electronics is installed and ready to run. Alternatively, the control electronics can also be formed by a non-programmable hardware circuit (e.g. in the form of an ASIC). Alternatively, the control electronics can be formed by a combination of programmable and/or non-programmable components.

In an advantageous embodiment of the device, a network utilization curve is specified as the operating current curve, which specifically reflects the average network utilization at the geographical location of the heat pump or in the delimited network area in which the heat pump is connected. The control electronics are set up to determine the default value based on the distance between a current value of the network utilization curve and a predetermined threshold value. Alternatively, within the scope of the invention, the operating current curve can also be specified in such a way that it varies in the opposite direction to the average network utilization at the geographical location or the delimited network area.

The control electronics are preferably set up to vary the default value depending on information about the (current or predicted) actual network utilization at the geographical location of the heat pump or in the delimited network area in which the heat pump is connected. If a high network utilization is determined, the default value in particular is adjusted to lower values than when the network utilization is low.

In an advantageous embodiment, the control electronics are set up to use measurement data from a network voltage sensor or network frequency sensor integrated into the heat pump or connected to the heat pump and/or forecast data regarding an expected network load as information about the actual network load. The sensors mentioned above can be a separate component of the device according to the invention. Alternatively, within the scope of the invention, the control electronics can also access data from external sensors, e.g. sensors of a smart home system, etc.

Additionally or alternatively, the control electronics are set up to receive (wirelessly or wired) a control signal from a network operator that depends on the network utilization. The control electronics are set up to determine the default value (if necessary) based on the control signal.

In an advantageous embodiment, the control electronics is set up to carry out a change in the default value, in particular a reduction of the default value to zero, with a time offset caused by the operating current curve, the information about the actual network utilization or the control signal from the energy supplier, and the time offset in a for to vary the heat pump or the current operating cycle in a specific way. In particular, the time offset is varied by the control electronics depending on a duration of an ongoing operating cycle, a difference between the actual temperature and the target temperature of a heat circuit or heat storage unit supplied by the heat pump, an amount of energy charged during the ongoing operating cycle, or a random number.

Optionally, the heat pump or any external control device of the device is equipped with communication electronics, for example a mobile radio, LAN and/or WLAN adapter, for wired or wireless data exchange with a remote server, in particular on the Internet, for example to provide forecast data regarding the expected network load independently.

The heat pump also optionally includes a receiver for signals from a global positioning system (e.g. a GPS receiver). The control electronics are set up to automatically determine the geographical location of the heat pump. Alternatively, the control electronics is set up to automatically determine the geographical location of the heat pump by communicating with a data transmission network (e.g. a mobile phone or WLAN network) using the receiver mentioned. Alternatively, within the scope of the invention, the geographical location of the heat pump is stored manually in the control electronics (e.g. using the operating app described above). Alternatively, within the scope of the invention, the geographical location of the heat pump can be automatically determined by the operating app that may be present and transmitted to the heat pump or taken into account when creating the operating current curve. In particularly simple versions, the heat pump is alternatively intended exclusively for offline operation. In these versions, the heat pump preferably does not include any interfaces for communication with a WLAN or mobile phone network.

The heat pump is preferably equipped with a real-time clock in order to determine the default value depending on the time of day and optionally the day of the week and/or the position of the current day of the year. The real-time clock is preferably designed to synchronize itself with respect to the time using a GPS time signal, a GSM time signal, a radio clock signal or through communication with a mobile device temporarily connected to the heat pump.

Communication between the heat pump and an electricity meter or other electricity measuring device is not required in all of the exemplary embodiments described above and is therefore preferably not provided.

• 1 in einem schematischen Blockschaltbild eine Einrichtung zum Betrieb einer Wärmepumpe, mit einer Wärmepumpe, die über eine lokale Stromverteilung (hier beispielhaft eine elektrische Haustrominstallation) an ein öffentliches Stromnetz anschließbar ist, wobei die Wärmepumpe einen den Betriebsstrom limitierenden Vorgabewert anhand einer hinterlegten, zeitabhängigen Netzauslastungskurve bestimmt, so dass der Vorgabewert gegenläufig zu dem durchschnittlichen Verlauf der Netzauslastung des Stromnetzes an dem geographischen Standort der Wärmepumpe variiert,
• 2 in einem schematischen Diagramm gegen die Zeit drei typische Tagesverläufe der Netzauslastung im Winter, nämlich einen Tagesverlauf der Netzauslastung für einen Werktag (durchgezogene Linie), einen Tagesverlauf der Netzauslastung für einen Samstag (gestrichelte Linie) und einen Tagesverlauf der Netzauslastung für einen Sonntag (strichpunktierte Linie),
• 3 in zwei übereinander angeordneten, chronologischen Diagrammen den Tagesverlauf der Netzauslastung für einen Werktag aus 2 sowie einen oberen Schwellwert und einen unteren Schwellwert für die Netzauslastung (oberes Diagramm) und den Verlauf des aus dem Abstand der Netzauslastung zu dem oberen Schwellwert abgeleiteten Vorgabewerts der Betriebsstromstärke (unteres Diagramm),
• 4 in Darstellung gemäß 3 wiederum den Tagesverlauf der Netzauslastung für einen Werktag aus 2 (oberes Diagramm) sowie den Verlauf des Vorgabewerts der Betriebsstromstärke (unteres Diagramm), wobei der Vorgabewert nach einem alternativen Verfahren aus dem Abstand der Netzauslastung zu dem oberen Schwellwert abgeleitet ist, und
• 5 in Darstellung gemäß 3 und 4 wiederum den Tagesverlauf der Netzauslastung für einen Werktag aus 2 (oberes Diagramm) sowie den Verlauf des Vorgabewerts der Betriebsstromstärke (unteres Diagramm), wobei bei der Bestimmung des Vorgabewerts zusätzlich die durchschnittliche Änderung der Sonneneinstrahlung im Tagesverlauf berücksichtigt ist.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Show in it:

• 1 in a schematic block diagram a device for operating a heat pump, with a heat pump that can be connected to a public power grid via a local power distribution (here, for example, an electrical house power installation), the heat pump determining a default value that limits the operating current based on a stored, time-dependent grid utilization curve, so that the default value varies in the opposite direction to the average course of the network utilization of the electricity network at the geographical location of the heat pump,
• 2 in a schematic diagram against time, three typical daily patterns of network utilization in winter, namely a daily pattern of network utilization for a working day (solid line), a daily pattern of network utilization for a Saturday (dashed line) and a daily pattern of network utilization for a Sunday (dash-dotted line). ),
• 3 shows the daily course of network utilization for a working day in two chronological diagrams arranged one above the other 2 as well as an upper threshold value and a lower threshold value for the network utilization (upper diagram) and the course of the default value of the operating current derived from the distance between the network utilization and the upper threshold value (lower diagram),
• 4 in representation according to 3 in turn shows the daily course of network utilization for a working day 2 (upper diagram) and the course of the default value of the operating current (lower diagram), whereby the default value is derived according to an alternative method from the distance between the network utilization and the upper threshold value, and
• 5 in representation according to 3 and 4 in turn shows the daily course of network utilization for a working day 2 (upper diagram) as well as the course of the default value of the operating current (lower diagram), whereby the average change in solar radiation over the course of the day is also taken into account when determining the default value.

Corresponding parts and sizes are always provided with the same reference numbers in all figures.

1 shows a device 2 for operating a heat pump 4. The device 2 includes, on the one hand, the heat pump 4 itself, which in the example shown supplies a heat storage 6 (buffer storage) with heat W (in particular in the form of heated water). Electrically, the heat pump 4 is integrated into an electrical house power installation 8, which in turn is connected to a public power network 12 (namely a three-phase alternating current low-voltage network) at a network connection point 10. In addition to the heat pump 4 and other electrical consumers (not shown in detail), a photovoltaic system (PV system 14) is optionally connected to the house electricity installation 8.

In the example shown, the heat pump 4 is an inverter heat pump. The heat pump 4 here comprises a compressor 16 operated with an electric three-phase motor, which is supplied with a drive current I _A (for example in the form of a three-phase three-phase current of variable frequency) by means of an upstream converter 18 (inverter). The converter 18 is in turn connected to a main power line 24 of the house power installation 8. The heat pump 4 also includes control electronics 26, which is formed, for example, by a microcontroller or a single-board computer. The functions of the control electronics 26, described in more detail below, are implemented in the form of software (firmware 28) which is installed in the control electronics 26 so that it can run. The control electronics 26 is connected to the converter 18 via a data line 30.

The control electronics 26 further includes a first transmitting and receiving unit (transceiver 34), which is only indicated, which enables wireless communication of the control electronics 26 with other electronic devices, for example using Bluetooth.

Optionally, the control electronics 26 also includes a second transmitting and receiving unit (transceiver 36), which is also only indicated, and which enables wireless communication of the control electronics 26 with a control center of the network operator. The transceiver 36 is designed, for example, as a mobile radio or WLAN transceiver and establishes a data transmission connection with the control center via a mobile device radio network or via the Internet. In addition or as an alternative to the transceiver 36, the control electronics 26 includes an interface for wired communication with the control center. The control center is preferably a technical (in particular fully automated) device which records the network utilization and transmits the status using a control signal. The control center can be arranged anywhere in the power network, for example in a network connection point between two network levels, for example a substation or a transformer station.

During operation of the heat pump 4, an operating current I _B is supplied to the converter 18 via the main power line 24.

During operation of the heat pump 4, the control electronics 26 regulates the performance of the compressor 16 by appropriately controlling the converter 18 in such a way that an actual temperature T _I of the heat storage device 6 measured by means of a temperature sensor 37 - preferably with a predetermined hysteresis - corresponds to a predetermined target value. Temperature Ts is adjusted. In this regulation, the control electronics 26 takes into account a further condition that the current strength of the operating current I _B does not exceed a preset value V. The default value V thus determines the maximum current strength of the operating current I _B that the heat pump 4 can draw from the house power installation 8.

The default value V is determined by the control electronics 26 in the example 1 until 3 output as a quasi-continuous variable (ie in many small steps) between a minimum value V _min (e.g. corresponding to an operating current of 2A) and a maximum value V _max (e.g. corresponding to an operating current of 6A). At times in which the heat pump 4 does not emit any heat and the converter 18 is not supposed to draw any electrical power, the default value V preferably has the value zero.

The control electronics 26 determines the default value V based on an operating current curve stored in the heat pump 4 itself (in particular in a data memory of the control electronics 26) as a function of the time t.

In the in 1 until 3 In the example shown, the operating current curve is predetermined in the opposite direction to the desired course of the default value V, so that it reflects the course of the average network utilization of the power grid 12 at the geographical location of the heat pump 4, for example as a percentage value relative to the maximum utilization of the power grid 12. The operating current curve defined in this way is also referred to below as the network utilization curve A (A = A(t)). In 2 three exemplary sections of the network utilization curve A are shown versus time t, each of which corresponds approximately to a typical daily course of network utilization in a geographical area with residential development; The times t ₁ and t ₂ marked with dashed vertical lines correspond, for example, to 4:00 a.m. and 9:00 p.m. With a solid line is in 2 the average daily course of network utilization on a working day (Monday to Friday) is shown. In comparison, the average daily course of network utilization on a Saturday is shown with a dashed line. Finally, the average daily course of network utilization on a Sunday is shown with a dash-dotted line.

According to the representation 2 It can be seen that the average network utilization on working days has a daily course with three distinct maxima (peaks), namely a morning peak, a midday peak and an evening peak. On weekends, the morning peak typically occurs later and, in particular, merges more or less strongly with the midday peak. In addition, there are typically higher peaks in network utilization on weekends compared to weekdays.

2 shows the typical course of network utilization in winter. In the summer months, the midday peak is typically more pronounced, as more electrical energy is used for cooling in the middle of the day. In contrast, the morning peak and the evening peak are typically weaker in the summer months because less electrical energy is used for lighting and heat. Network utilization in industrial areas behaves differently again, with characteristic differences occurring over the course of the week and year.

These differences in the average network utilization over the course of the week, month and/or year are taken into account when determining the default value V in that the network utilization curve A is preferably defined over the entire (calendar) year. For example, the network utilization curve A is implemented in the form of a support point table, which is within the framework of a specified time resolution (e.g every 5 minutes) has a specific assigned value for each point in time during the year. The control electronics 26 has, for example, a real-time clock and successively reads out value by value from the reference point table based on the time t output by this clock (e.g. every 5 minutes).

$$\text{V}={\text{V}}_{\text{max}}\text{ f}\ddot{\text{u}}\text{r k}\cdot \left({\text{A}}_{\text{max}}-\text{A}\left(\text{t}\right)\right)+{\text{V}}_{\text{min}}>{\text{V}}_{\text{max}}$$

$$\text{V}=0\text{ sonst}$$

The control electronics 26 determines the default value V by subtracting the current value A(t) of the stored network utilization curve A from a predetermined threshold value A _max and - preferably - multiplying the difference by a predetermined proportionality factor k: $$\text{v}=\text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}{\text{f}\ddot{\text{u}}\text{r V}}_{\text{Max}}\ge \text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}\ge {\text{v}}_{\text{min}}$$

$$\text{v}={\text{v}}_{\text{Max}}\text{f}\ddot{\text{u}}\text{r k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}>{\text{v}}_{\text{Max}}$$

$$\text{v}=0\text{otherwise}$$

From the above equations it can be seen that the default value V is reduced to zero when the current value A(t) of the stored network utilization curve A exceeds the threshold value A _max . On the other hand, the default value V is limited to the maximum value V _max when the network load is low.

This procedure for determining the default value V is shown in the two diagrams 3 illustrated. The upper diagram shows the daily course of the network utilization curve A for a working day 2 shown. Additionally, in the diagram above are the 3 the threshold value A _max and another threshold value A _min are entered. The difference between the current value A(t) of the network utilization curve A and the threshold value A _max is illustrated by an arrow 38. The second threshold value A _min limits a control range of network utilization in which a restriction of the operating current I _B through the heat pump 4 makes sense. As long as this second threshold value A _min is undershot, the default value is set by the heat pump 4 to the maximum value V _max .

This is from the diagram below 3 can be seen in which the course of the default value V determined according to the principle described above is plotted against time t.

In the comparison of the two diagrams 3 It can be seen that at a time t ₃ , for example at approximately 7:00 a.m., the current value A(t) of the network utilization curve A exceeds the second threshold value A _min for the first time during the day, whereupon the control electronics 26 counteracts the default value V reduced to the further course of network utilization.

During a time period limited by two times t ₄ and t ₅ between the midday peak and the evening peak, for example between 3:00 p.m. and 4:30 p.m., the average network load in the example shown temporarily falls below the second threshold value A _min , so that the default value V is set back to the maximum value V _max in this time interval. During the evening peak, between times t ₆ and t ₇ (e.g. between 5:45 p.m. and 7:45 p.m.), the network utilization exceeds the upper threshold value A _max . Accordingly, the control electronics 26 sets the default value V to zero in this period of time and thus interrupts any operating cycle of the heat pump 4 that may be running. At a time t ₈ (for example at approximately 10:15 p.m.) the average network utilization falls below the second threshold value A _min , so that the default value V is set again to the maximum value V _max .

In a variant of the device 2, the control electronics 26 receives via a mobile phone network or the Internet and the transceiver 36 a control signal from the network operator that is dependent on the actual network utilization, which sets a guideline value for the default value V and that from the control electronics 26 alternatively or in addition to the one stored Network utilization curve A is taken into account. For example, the control electronics 26 is set up to always determine the default value V based on the control signal when it is available, and alternatively to determine the default value V based on the stored network utilization curve A. The design of the control electronics 26 makes it possible to operate the same heat pump 4 in a network-friendly manner both online (with a connection to the network operator's control center) and offline (without a connection to the network operator's control center).

In a further variant of the device 2, the control electronics 26 basically determines the default value V in the manner described above and in 3 illustrated way. However, the control electronics 26 switches - as in 4 is illustrated - the default value V if the current value A(t) of the network utilization curve A exceeds the upper threshold value A _max or if the control signal that may be received requires the default value V to be reduced to zero, the default value V is not immediately changed Minimum value V _min to zero. Rather, the control electronics 26 leaves the default value V in this case (in the example shown at time t ₆ ) initially at the minimum value V _min for a predetermined time offset, and only switches the default value V to zero after the time offset has elapsed, if then the current value A(t) of the network utilization curve A still exceeds the upper threshold A _max .

The time offset is selected differently for each heat pump 4, and preferably also for each shutdown process. For example, the time offset is varied depending on the duration of an ongoing operating cycle or on an amount of energy charged during the ongoing operating cycle. The time offset is preferably varied depending on the difference between the measured actual temperature T _I of the heat storage 6 and the target temperature Ts. In particular, the time offset is chosen to be shorter, the more the actual temperature T _I is below the target temperature T _S and the greater the heat requirement to be covered by the heat pump 6. In an alternative embodiment of the invention, the time offset is determined according to a random number, this random number being determined again either once and specifically for each heat pump 4 or with each shutdown process. Both measures described above achieve the effect that several heat pumps 4 operating according to the method according to the invention generally do not reduce the default value to zero at the same time, even under the same network conditions. This means that sudden changes in the network load due to the simultaneous switching off of a large number of heat pumps 4 are avoided.

In a further embodiment of the device 2, the rate of change of the default value V is limited to predetermined limit values, for example to a maximum of 1 ampere per minute for reducing the default value V and a maximum of 0.5 amperes per minute for increasing the default value V. This leads to the in 3 and 4 The course of the network utilization curve A shown means that in the area of times t ₆ and t ₇ (i.e. before switching off and after switching back on) the default value V is only reduced or increased with a limited edge steepness.

To configure the heat pump 4, the device 2 points according to 1 In addition to the heat pump 4, there is a software application (hereinafter operating app 40), which in the example shown is installed on a smartphone 42. Unlike the operating app 40, the smartphone 42 is not part of the device 2, but is only used by it as an external resource for computing power, storage space and communication services.

Before the heat pump 4 is put into operation, the operating app 40 is connected to the firmware 28 of the control electronics 26 via a particularly wireless data transmission link 44 (preferably via Bluetooth). The operating app 40 accesses a corresponding transmitting and receiving unit of the smartphone 42, which establishes a data transmission connection to the transceiver 34 of the heat pump 4.

Using the operating app 40, a user (in particular a technician or an owner of the heat pump 4) can then save the network utilization curve A calculated specifically for the location of the heat pump 4 in a memory of the control electronics 26. The network utilization curve A is preferably calculated beforehand by the network operator or a service provider and downloaded to the smartphone 42 via the Internet. When the heat pump 4 is in operation, a data transmission connection between the heat pump 4 and the operating app 40 is not required and is not usually present. However, the operating app 40 optionally also serves as a remote control for heat pump 4, e.g. for manually triggering or canceling operating cycles or for setting the target temperature, and in this case is temporarily connected to the heat pump 4 at regular or irregular intervals.

In a variant of the device 2, instead of an unchanging network utilization curve A, a long-term forecast of the expected network utilization is stored as a network utilization curve A in the control electronics 26. The long-term forecast differs from the average network utilization in that foreseeable deviations from the average network utilization values, e.g. due to foreseeable weather events, are taken into account in the network utilization curve A. As a rule, the closer the forecast point in time is to the present, the more the long-term forecast deviates from the average network utilization and reflects the actual network utilization more accurately. For points in the more distant future, however, the long-term forecast changes to the average network utilization.

The network utilization curve A, which is calculated based on the long-term forecast, is updated by the network operator or service provider at short intervals (e.g. every two hours). The updated network output The curve A is always downloaded from the operating app 40, for example via the Internet, and stored in the memory of the control electronics 26 of the heat pump 4 when the operating app 40 is connected to the control electronics 26.

In a further variant of the invention, the control electronics 26 continuously measures the magnitude of the network voltage U as a measure of the actual network utilization. It compares the actual network utilization with the average network utilization (i.e. the current value of the stored network utilization curve) and corrects the default value V if there is a significant deviation. For example, the proportionality factor k in the above equation is defined as a function of the measured grid voltage U and the grid utilization curve A: $$\text{v}=\text{k}\left(\text{A}\left(\text{t}\right),\text{U}\right)\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}$$

In a further embodiment of the device 2, when determining the default value V, whether the house electricity installation 8 includes a PV system 14 is also taken into account. In this case, for example, the proportionality factor k in the above equation is defined as a function of the average solar radiation S over the course of the day $$\text{v}=\text{k}\left(\text{S}\left(\text{t}\right)\right)\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}$$

1. a) geographischer Standort der Wärmepumpe 4, z.B. in Form einer Postleitzahl
2. b) optional Nennleistung der PV-Anlage 14,
3. c) optional Neigung der PV-Anlage 14, und
4. d) optional geographische Ausrichtung der PV-Anlage 14 bezüglich der Himmelsrichtungen (insbesondere Azimutwinkel).

When determining the function k(S(t)), in addition to the solar radiation S, the following parameters of the PV system 14 can also be taken into account:

1. a) geographical location of the heat pump 4, for example in the form of a postal code
2. b) optional nominal power of the PV system 14,
3. c) optional inclination of the PV system 14, and
4. d) optional geographical alignment of the PV system 14 with respect to the cardinal points (in particular azimuth angles).

The function k can either be determined directly by the operating app 40 or by the network operator or a service provider.

Alternatively, the variation in solar radiation can be included directly in the network utilization curve A or an operating current curve calculated from this.

All variants described above result in the default value V of the operating current being set higher in house electricity installations 8 with a PV system 14 for a given network utilization in the event of high average solar radiation (particularly over the middle of the day) than in house electricity installations 8 without a PV system 14. This effect is in 5 illustrated. In the upper diagram of this figure, in addition to the daily course of the network utilization curve A (according to 2 ) the average daily course of solar radiation S is plotted. In the diagram below the 5 In addition to the daily course of the default value V for a house electricity installation 8 without a PV system 14 (dash-dotted line), the daily chart of the default value V for a house electricity installation 8 with a PV system 14 (solid line) is also entered.

The invention is particularly clear from the exemplary embodiments described above, but is not limited to these exemplary embodiments. Rather, further embodiments of the invention can be derived from the claims and the above description. In particular, the individual features of the method and the device described in the above exemplary embodiments can also be combined with one another in a different way within the scope of the claims.

Reference symbol list

2

Furnishings

4

Heat pump

6

Heat storage

8th

House electricity installation

10

Network connection point

12

power grid

14

PV system

16

compressor

18

Inverter

24

Main power line

26

Control electronics

28

Firmware

30

Data line

34

Transceivers

36

Transceivers

37

Temperature sensor

38

Arrow

40

Operating app

42

Smartphone

44

Data transmission route

t

Time

t1-t8

time

IA

Drive current

IB

Operating current

A

Network utilization curve

Amax

Threshold

Amine

Threshold

S

Sunlight

T.I

Actual temperature

Ts

Target temperature

U

Mains voltage

v

Default value

Vmax

Maximum value

Vmin

Minimum value

W

warmth

Claims (17)

Method for operating a heat pump (4), wherein the heat pump (4) can be connected directly or indirectly to a public power grid (12) via a local power distribution (8) and can be operated with an operating current (I _B ), whereby the operating current (I _B ) limiting default value (V) is specified in a time-varying manner, so that the default value (V) varies in the opposite direction to a network utilization of the power grid (12). Procedure according to Claim 1 , whereby the default value (V) is determined based on an operating current curve stored in the heat pump (4) or an external data memory, in particular in the form of a time-dependent mathematical function or reference point table. Procedure according to Claim 2 , whereby a network utilization curve (A) is specified as the operating current curve, which specifically reflects the network utilization at the geographical location of the heat pump (4) or in a delimited network area of the power network to which the heat pump (4) is connected, and where the default value ( V) is determined based on the distance of a current value of the network utilization curve (A) to a predetermined threshold value (A _max ). Procedure according to Claim 2 or 3 , whereby the operating current curve is adapted to average differences in network utilization over the course of the week, month and/or year. Procedure according to one of the Claims 1 until 4 , whereby the default value (V) is varied depending on information about the actual network utilization. Procedure according to Claim 5 , whereby - the measured network voltage, and/or - the measured network frequency, and/or - forecast data regarding an expected network utilization are used as information about the actual network utilization. Procedure according to Claim 6 , wherein the forecast data, in particular in the form of a long-term forecast covering several days, is determined by means of an app (40) installed on a mobile device, which can be connected to the control electronics (26) of the heat pump (4) via data transmission technology, and where the forecast data or the Depending on this, an adapted operating current curve is transmitted from the mobile device to the heat pump (4) when the app (40) is connected to the heat pump (4). Procedure one of the Claims 1 until 7 , whereby the default value (V) is determined based on a control signal from a network operator that depends on the network utilization. Procedure according to one of the Claims 1 until 8th , according to which a change in the default value (V), in particular a reduction of the default value (V) to zero, caused by the operating current curve, by the information about the actual network utilization or by the network operator's control signal, is carried out with a time offset, and the time offset in is varied in a manner specific to the heat pump (4) or the current operating cycle of the heat pump (4). Device (2) for operating a heat pump (4), with a heat pump (4), which can be connected directly or indirectly via a local power distribution (8) to a public power grid (12) and can be operated with an operating current (I _B ), and with control electronics (26), which is set up to control the operation of the heat pump (4) and to specify a specified value (V) that limits the operating current (I _B ) in a time-varying manner, so that the specified value (V) is opposite to the network utilization of the power grid (12) varies. Device (2) after Claim 10 , wherein the control electronics (26) is set up to determine the default value (V) of the operating current based on an operating current curve stored in the heat pump (4) or an external data memory, in particular in the form of a time-dependent mathematical function or base point table. Device (2) after Claim 11 , whereby a network utilization curve (A) is specified as the operating current curve, which specifically reflects the network utilization at the geographical location of the heat pump (4) or in a delimited network area of the power network to which the heat pump (4) is connected, and wherein the control electronics ( 26) is set up to determine the default value (V) based on the distance of a current value of the network utilization curve (A) to a predetermined threshold value (A _max ). Device (2) after Claim 11 or 12 , whereby the operating current curve is adapted to average differences in network utilization over the course of the week, month and/or year. Device (2) according to one of the Claims 10 until 13 , wherein the control electronics (26) are set up to vary the default value (V) of the operating current depending on information (M) about the actual network utilization. Device (2) after Claim 14 , wherein the control electronics (26) are set up to use - the measured network voltage, and / or - the measured network frequency, and / or - forecast data from a network operator regarding an expected network utilization as information about the actual network utilization. Facility (2) one of the Claims 10 until 15 , wherein the control electronics (26) is set up to receive a control signal from a network operator that depends on the network utilization, and wherein the control electronics (26) is set up to determine the default value (V) based on the control signal. Procedure according to one of the Claims 10 until 16 , according to which the control electronics (26) is set up to carry out a change in the default value (V), in particular a reduction of the default value (V) to zero, with a time offset, caused by the operating current curve, the information about the actual network utilization or the network operator's control signal , and to vary the time offset in a manner specific to the heat pump (4) or the current operating cycle of the heat pump (4).

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