阅读说明：本技术 用于控制能量系统的功率消耗和/或功率输出的控制设备和方法以及低压电网 (Control device and method for controlling the power consumption and/or power output of an energy system, and low-voltage power supply system ) 是由 A.阿姆索尔 M.梅茨格 S.尼森 S.施雷克 S.蒂姆 于 2020-02-26 设计创作，主要内容包括：提出了一种控制设备(42),其用于控制能量系统(6)经由低压电网(2)的电网连接点(4)的功率消耗和/或功率输出,其中,借助控制设备(42)能够采集电网连接点(4)处的电网电压。根据本发明,控制设备(42)被构建为：在电网电压低于第一阈值(421)的情况下,降低功率消耗和/或增加功率输出；和/或在电网电压高于第二阈值(422)的情况下,增加功率消耗和/或降低功率输出,第二阈值大于第一阈值(421)。此外,本发明涉及一种用于控制能量系统(6)的功率消耗和/或功率输出的方法以及一种低压电网(2)。(A control device (42) is proposed for controlling the power consumption and/or the power output of an energy system (6) via a grid connection point (4) of a low-voltage grid (2), wherein a grid voltage at the grid connection point (4) can be detected by means of the control device (42). According to the invention, the control device (42) is designed to: in case the grid voltage is below a first threshold (421), reducing the power consumption and/or increasing the power output; and/or increasing power consumption and/or decreasing power output in case the grid voltage is above a second threshold (422), the second threshold being larger than the first threshold (421). The invention further relates to a method for controlling the power consumption and/or the power output of an energy system (6) and to a low-voltage power supply system (2).)

1. A control device (42) for controlling the power consumption and/or the power output of an energy system (6) via a grid connection point (4) of a low-voltage grid (2), wherein a grid voltage at the grid connection point (4) can be detected by means of the control device (42), characterized in that the control device (42) is designed to

In case the grid voltage is below a first threshold (421), reducing power consumption and/or increasing power output; and/or

Increasing power consumption and/or decreasing power output in case the grid voltage is above a second threshold (422), the second threshold being larger than the first threshold (421).

2. The control device (42) according to claim 1, characterized in that the power consumption can be based onIn which u (t) tableIndicating the collected grid voltage u₀Which represents the nominal value of the voltage of the electricity network,represents the average power consumption (420), and f_inRepresents a characteristic curve (423) of the control, and f is the value of the grid voltage below a first threshold value (421)_in(u(t)-u₀) < 0, and in case the grid voltage is above a second threshold (422), f_in(u(t)-u₀)＞0。

3. The control device (42) according to claim 1 or 2, characterised in that the power output is dependent onWhere u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power output, and_outrepresents a characteristic curve (423) of the control, and f is the value of the grid voltage below a first threshold value (421)_out(u(t)-u₀) < 0, and in case the grid voltage is above a second threshold (422), f_out(u(t)-u₀)＞0。

4. Control device (42) according to any of the preceding claims, characterized in that power consumption and/or power output can be dependent on Where u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power consumption (420), and f_in/outCorresponding characteristic curves (423) representing the control, wherein f is respectively_in/out(u(t)-u₀)＝-F₁Θ(u₁-u(t))+F₂Θ(u(t)-u₂) And F is₁And F₂Is constant and is greater than zero.

5. A method for controlling power consumption and/or power output of an energy system (6) via a grid connection point (4) of a low voltage grid (2), wherein a grid voltage of the low voltage grid (2) is collected at the grid connection point (4), characterized by the steps of:

-in case the grid voltage is below a first threshold (421), reducing power consumption and/or increasing power output; and/or

Increasing power consumption and/or decreasing power output in case the grid voltage is above a second threshold (422), the second threshold being larger than the first threshold (421).

6. The method of claim 5, wherein the power consumption is based on Where u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power consumption (420), and f_inRepresents a characteristic curve (423) of the control, and f is the value of the grid voltage below a first threshold value (421)_in(u(t)-u₀) < 0, and in case the grid voltage is above a second threshold (422), f_in(u(t)-u₀)＞0。

7. A method according to claim 5 or 6, wherein the power output is based onWhere u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power output (420), and f_outA characteristic curve representing the control, wherein f is determined when the grid voltage is below a first threshold value (421)_out(u(t)-u_Soll) < 0, and when the grid voltage is above a second threshold (422), f_out(u(t)-u₀)＞0。

8. Method according to any of claims 5 to 7, wherein the power consumption and/or power output is based on Where u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power consumption (420), and f_in/outCorresponding characteristic curves (423) representing the control, wherein f is respectively_in/out(u(t)-u₀)＝-F₁Θ(u₁-u(t))+F₂Θ(u(t)-u₂) And F is₁And F₂Is constant and is greater than zero.

9. Method according to any of claims 5-8, characterized in that power consumption and/or power output is controlled such that the amount of energy exchanged via the grid connection point (4) over a time range equals a prescribed amount of energy.

10. A low voltage power grid (2) comprising at least one grid connection point (4) for an energy system (6), characterized in that the low voltage power grid comprises a control device (42) according to any of claims 1-4.

11. The low-voltage power network (2) according to claim 10, characterized in that the control device (42) is arranged at a network connection point (4) of an energy system (6).

Technical Field

The invention relates to a control device according to the preamble of claim 1, a method according to the preamble of claim 4 and a low-voltage network according to the preamble of claim 8.

Background

Energy supply systems usually have a connection partner which is connected to the distribution network of the energy supply system via a grid connection (Point of Common Coupling, abbreviated PCC). The connection participants are usually energy systems, such as industrial facilities, private and/or commercial apartment blocks. After the grid connection point, each energy system has a different energy facility for generating, consuming and/or storing electrical energy. For example, the energy system is a private apartment building with photovoltaic facilities.

If electric power or energy is consumed and/or produced within the energy system, the voltage at the grid connection point may change. However, operators of power distribution networks are obligated to keep the grid voltage within certain tolerances. For example, in germany, the grid voltage of the low-voltage grid (single-phase) must have a value between 207V and 253V (VDE AR-N4100). The nominal voltage, i.e. the network voltage, is 230V. Furthermore, the maximum permissible thermal limit current of the operating device of the low-voltage network must not be exceeded. Especially with regard to renewable energy and its feeding through multiple energy systems, the mentioned limitations may be violated without other methods to coordinate the feeding or consumption of the energy systems.

According to the prior art, in the case of low-voltage networks, the components of the respective energy system are directly influenced via the network connection stripThe components and/or the use of corresponding technical operating devices ensure that the system voltage is kept within limits. For example, if the grid voltage drops significantly, the individual components of the energy system, for example the heat pump, can be switched off by means of the ripple control signal. The increased grid voltage is generally attributable to the feeding in of renewable energy. In this case, the power rating of the relevant installation, for example a photovoltaic installation, has hitherto been limited by the grid connection conditions and/or, for example, by a fixed phase shift angleA fixed ratio between active power and reactive power is given in advance.

Another possibility for solving the mentioned problems with the grid voltage of the low-voltage grid is to use technical operating devices, for example adjustable local grid substations, which can be adjusted dynamically to the respective grid voltage on the line. However, these operating devices are associated with high expenditure and costs. The common denominator of the mentioned methods is that the operator of the low-voltage network must always take measures to maintain the network voltage.

Disclosure of Invention

The object of the present invention is therefore to provide an improved control of the network voltage of a low-voltage network.

This object is achieved by a control device having the features of independent claim 1, by a method having the features of independent claim 4, and by a low-voltage network having the features of independent claim 8. Advantageous embodiments and developments of the invention are specified in the dependent claims.

With the control device according to the invention for controlling the power consumption and/or the power output of an energy system via a grid connection point of a low-voltage grid, a grid voltage can be detected at the grid connection point. According to the invention, the control device is constructed as

In the event that the grid voltage is below a first threshold, reducing power consumption and/or increasing power output; and/or

In case the grid voltage is above a second threshold, which is larger than the first threshold, the power consumption is increased and/or the power output is decreased.

By means of the power consumption and/or power output in the time range, the corresponding consumed or output energy amount in the time range is obtained. In this sense, the terms power and energy are equivalent in the present invention.

According to the invention, the network voltage is time-dependent and is therefore detected currently, for example continuously or in discrete time steps. The control according to the invention is carried out as a function of the current value of the collected grid voltage. Here, the control includes regulation. It is possible to control the grid voltage via the power consumption and/or power output of the energy system, since according to the invention it is a low voltage grid, wherein the grid voltage is mainly determined by the exchanged active power.

The grid connection point is the region (PCC) in which the energy system is coupled to the low voltage grid for power and/or energy exchange. The grid connection point may also be referred to as a link point.

Furthermore, the control according to the invention can be provided for a plurality of energy systems, wherein each of the energy systems is connected to the low-voltage power supply system for power exchange (power consumption and/or power output) by means of a grid connection point.

The normal range of the grid voltage is characterized or limited by the first and second threshold values. In other words, the normal range is defined by the voltage range [ u ]₁，u₂]Characterization of u₁Represents a first threshold value of the grid voltage and u₂A second threshold value representing the grid voltage, where u₁＜u₂. Rated value of the network voltage, e.g. 230V, may be u₀Is shown and arranged in the normal range u₁，u₂]And (4) the following steps. Preferably, u here₁＝u₀- Δ u and u₂＝u₀+ Δ u, thereby constructing a normal range of the grid voltage that is symmetric about the nominal value of the grid voltage. The normal range has a size of 2 Δ u. For example, according to VDE AR-N4100, the grid voltage is rated at u₀230V, Δ u 23V, so that the normal range of the network voltage here is from 207V extends to 253V.

According to the invention, the power consumption and/or the power output of the energy system is thus dynamically changed, i.e. increased or decreased, depending on the grid voltage, at least during certain periods of time.

According to the invention, the power consumption of the energy system is reduced in the case of a grid voltage below a first threshold value. In other words, the load of the low-voltage network is so heavy that the network voltage drops below the first threshold value. The reduction of the power consumption according to the invention advantageously makes it possible to reduce the load on the low-voltage network. Thereby, a further drop of the grid voltage can be counteracted.

Furthermore, according to the invention, the power output of the energy system is increased in case the grid voltage is below the first threshold value. In this way, the low-voltage network can also be advantageously supported, so that a drop in the network voltage can be at least reduced and, in the best case, stopped or prevented.

According to the invention, the power consumption of the energy system is increased in case the grid voltage is above a second threshold value, which is larger than the first threshold value. In other words, the load of the low-voltage network is so low that the network voltage rises above the second threshold value. The increase in power consumption according to the invention advantageously makes it possible to load the low-voltage network. Thereby, a further increase of the grid voltage can be resisted.

Furthermore, according to the invention, the power output of the energy system is reduced in case the grid voltage is above the second threshold value. In this way, the low-voltage network can also be advantageously supported, so that a rise in the network voltage can be at least reduced and, in the best case, stopped or prevented.

Advantageously, according to the invention, changes in the grid voltage with respect to its nominal value can be advantageously resisted. The network voltage is thereby returned to its normal range in the best case. To this end, the control device according to the invention forms a measuring device for detecting the (current) grid voltage, and a control device and/or a regulating device for the power consumption and/or the power output of the energy system.

An advantage of the invention is that the energy system or its power consumption and/or power output is controlled as a whole. Thus, advantageously no control at the component level is required, for example shutting down the heat pump or shutting down the photovoltaic installation. However, such control of the respective components may be additionally provided. Furthermore, the flexibility in the energy system, for example the storage and/or temporary storage of energy, can thereby be used in an improved manner.

Furthermore, due to the local control according to the invention, technically complex and expensive operating devices for the low-voltage network for controlling/regulating its network voltage can be dispensed with. In particular, no additional communication interface between one or more energy systems and the control/regulation of the low-voltage power grid is required. However, these communication interfaces may be additionally provided.

A further advantage of the invention is that supply contracts regarding consumption and/or feeding of specific amounts of energy can be complied with. This is because the amount of energy is derived from the power consumption and/or power output integrated over time. Thus, the power consumption and/or power output can be adjusted or varied arbitrarily, as long as the integral of the power consumption and/or power output is constant and equal to the amount of energy to be consumed or supplied.

In the method according to the invention for controlling the power consumption and/or the power output of an energy system via a grid connection point of a low-voltage grid, a grid voltage of the low-voltage grid is detected at the grid connection point. The method according to the invention is characterized by at least the following steps:

-in case the grid voltage is below a first threshold, reducing the power consumption and/or increasing the power output; and/or

In case the grid voltage is above a second threshold, which is larger than the first threshold, the power consumption is increased and/or the power output is decreased.

The advantages of the method according to the invention similar and equivalent to those of the control device according to the invention result.

The low-voltage network according to the invention comprises the control device according to the invention and/or one of its embodiments.

The control device is preferably arranged at a grid connection point of the energy system.

The advantages of the low-voltage network according to the invention similar and equivalent to the control device according to the invention result.

According to an advantageous embodiment of the invention, the power consumption can be determined according to Where u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power consumption, and f_inRepresents a characteristic curve of the control, and in the case of a (detected) grid voltage below a first threshold value f_in(u(t)-u₀) < 0 and f in case the (harvested) grid voltage is above the second threshold_in(u(t)-u₀)＞0。

In other words, the power consumption is favorably controlled within a range around the average power consumption according to the characteristic curve. The average power consumption may be determined by the amount of energy E to be provided during a time interval T_TTo characterize the location of the target, i.e.,furthermore, the subscript in denotes the power flow into the energy system, i.e. the power consumption of the energy system. Characteristic curve f_inFunctionally dependent on the grid voltage u (t) measured at the time t and the setpoint value u₀The difference in composition. In principle, a plurality of functional dependencies can be provided. Thereby, the characteristic curve f_inThe control/regulation is substantially characterized.

Particularly advantageous characteristic curve f_inBy applying a pressure in u (t). ltoreq.u₁In case of (f)_in(u(t)-u₀)＝-F₁In u₁＜u(t)＜u₂In case of (f)_in(u(t)-u₀)＝0 and u (t) ≧ u₂In case of (f)_in(u(t)-u₀)＝F₂Is characterized in that, here, F₁And F₂Is constant and is greater than zero. In other words, the power consumption P of the energy system_inIn u (t) is less than or equal to u₁Is reduced or lowered toAbove, u (t) ≧ u₂To within a range ofAnd in u₁＜u(t)＜u₂Is maintained unchanged within the range ofIn (1). In other words, f_in(u(t)-u₀)＝-F₁Θ(u₁-u(t))+F₂Θ(u(t)-u₂) Where Θ denotes a Helavisside-fusion, which is defined by Θ (x) being 0 when x < 0 and Θ (x) being 1 when x ≧ 0. If a fixed or specific supply energy or energy quantity is set within the time period T, the characteristic curve must satisfy the condition ^ j_Tf_in(u(t)-u₀) dt is 0. This condition may imply F₁And F₂An association between them. Preferably, F₁＝F₂。

In an advantageous embodiment of the invention, the power output can be based on Where u (t) denotes the collected grid voltage, u₀Which represents the nominal value of the voltage of the electricity network,represents the average power output, and_outrepresenting the characteristic curve of the control and in the (collected) gridIn the case of a voltage lower than a first threshold value, f_out(u(t)-u₀) < 0, and in case the (harvested) grid voltage is above a second threshold value, f_out(u(t)-u₀)＞0。

In other words, the power output is advantageously controlled in a range around the average power output according to the characteristic curve. The average power output may be determined by the amount of energy E to be provided during a time interval T_TTo characterize the location of the target, i.e.,furthermore, the subscript out denotes the power flow from the energy system into the low voltage grid, i.e. the power output of the energy system. Characteristic curve f_outFunctionally dependent on the grid voltage u (t) measured at the time t and the setpoint value u₀The difference in composition. In principle, a plurality of functional dependencies can be provided. Thereby, the characteristic curve f_outThe control/regulation is substantially characterized.

Particularly advantageous characteristic curve f for power output_outThis is also given by the characteristic curves already discussed and described for the case of power consumption. In other words, here preferably f_out(u(t)-u₀)＝-F₁Θ(u₁-u(t))+F₂Θ(u(t)-u₂). Currently, the difference between power output and power consumption is reflected for P_outOr P_inIn different symbols in the equations of (1). In summary, a common equation for control/regulation may be used for power consumption and power output Wherein, with regard to the energy system, the power consumption P_inIs considered positive, and power output P_outConsidered negative. In other words, sgn (P)_in) 1 and sgn (P)_out) Is-1. Preferably, f_in＝f_out. However, in principle, power consumption and work may beThe rate output sets different characteristic curves. It is important that, in the case of an agreed amount of energy, this agreed amount of energy is also observed by varying or changing the power. In other words, in the case of a negotiated energy quantity E, E ═ jj must always be satisfied, regardless of power consumption or power output_TP (t) dt. Here, p (t) denotes the current signed power, which is assumed to be positive for power consumption and negative for power output.

According to an advantageous embodiment of the invention, the power consumption and/or the power output are thereby advantageously controlled in such a way that the amount of energy exchanged via the grid connection point in the time range is equal to the specified amount of energy.

In this way, for example, a defined amount of energy exchanged in the time range T is advantageously observed. However, a beneficial and local control/regulation of the grid voltage to the grid can be achieved via power exchange.

Drawings

Further advantages, features and details of the invention are given in the examples described below and in the figures. Here schematically:

fig. 1 shows an energy system connected to a low voltage grid;

fig. 2 shows a diagram of an advantageous characteristic curve; and

fig. 3 shows a line graph of an exemplary temporal profile of power consumption.

Similar, equivalent or identically functioning elements may have the same reference numerals in one of the figures or in the figures.

Detailed Description

Fig. 1 shows a schematic energy system 6, which is connected to the low-voltage power supply system 2 via the grid connection point 4 for power and/or energy exchange.

The low-voltage network 2 is a distribution network with a nominal voltage (rating) of, for example, 230V (single phase). The network voltage is the current voltage of the low-voltage network 2, which generally varies around its nominal value. Alternatively, the grid voltage is rated at 400V (three-phase). The low-voltage network 2 can be rated up to 1000V. Further target values for the network voltage can be set, in particular outside germany or europe. It is important that the power exchange between the energy system 6 and the low-voltage power supply system 2 is determined primarily by the active power, so that the target value for identifying whether the system voltage of the low-voltage power supply system 2 is present in the sense of the invention is secondary.

Fig. 1 also shows a plurality of grid connection points 4 for a further, not shown energy system.

The energy system 6 can have a plurality of modules 61, in particular energy engineering installations. For example, the energy system 6 is a private apartment building with at least one heat pump and a photovoltaic installation as the module 61 or energy technology installation. In this case, power and/or energy is exchanged via the grid connection point 4. In other words, the energy system 6, for example its heat pump, consumes electrical energy and feeds the electrical energy that has been generated by means of the photovoltaic installation into the low-voltage power grid 2 via the grid connection point 2.

According to the invention, a control device 42 is provided, which is designed to control the power exchange and/or the energy exchange between the energy system 6 and the low-voltage power network 2 as a function of the network voltage of the low-voltage power network 2. Here, the concept of control includes regulation. Furthermore, the control device 42 is designed to detect the network voltage or its current value.

The control device 42 is designed to reduce the power consumption of the energy system 6 depending on the detected grid voltage if the grid voltage is below a first threshold value. Furthermore, the control device 42 is designed to increase the power output of the energy system 6 as a function of the detected grid voltage if the grid voltage falls below a first threshold value.

Furthermore, the control device 42 is designed to increase the power consumption of the energy system as a function of the detected grid voltage if the grid voltage is above a second threshold value, which is greater than the first threshold value. Furthermore, the control device 42 is designed to reduce the power output of the energy system depending on the detected grid voltage if the grid voltage is above a second threshold value.

In other words, the power exchange between the low-voltage network 2 and the energy system 6 is controlled by means of the control device 42 as a function of the detected network voltage in such a way that the grid voltage is counteracted from deviating from a normal range defined by the threshold value. For example, the grid voltage is rated at 230V, the first threshold is 207V, and the second threshold is 253V. If a grid voltage below and/or at 207V is collected, the power consumption of the energy system 6 is reduced and/or the power output of the energy system 6 is increased. If a grid voltage above and/or at 253V is collected, the power consumption of the energy system 6 is increased and/or the power output of the energy system 6 is decreased. This advantageously has a positive effect on the system voltage, so that the system voltage is returned to its normal range between 203V and 253V in the best case.

Fig. 2 shows a diagram of an advantageous characteristic curve 423.

On the abscissa 100 of the diagram, the difference u (t) -u₀Plotted in arbitrary units, where u (t) denotes the network voltage detected at time t, and u (t) denotes the network voltage detected at time t₀Representing the nominal value of the grid voltage.

The values of the dimensionless characteristic curve 423 in the present case are plotted on the ordinate 101.

A characteristic 423 may be set for power consumption and/or power output. The power or energy exchange is carried out by means of or on the basis of a characteristic curve 423 To control. Here, with respect to the energy system 6, the power consumption P_inIs considered positive, and power output P_outConsidered negative. In other words, sgn (P)_in) 1 and sgn (P)_out) Is-1. Preferably, as shown, f_in＝f_out。

The characteristic 423 is shown with a functional representation f_in/out(u(t)-u₀)＝-F₁Θ(u₁-u(t))+F₂Θ(u(t)-u₂) Wherein Θ denotes a Helavisside-Funktion, which is defined by Θ (x) being 0 when x < 0 and Θ (x) being 1 when x ≧ 0. Further, u1 denotesFirst threshold 421 and u₂Representing a second threshold 422.

Fig. 3 shows a line graph of an exemplary time profile 424 of power consumption.

On the abscissa 100 of the diagram, time is plotted in arbitrary units.

On the ordinate 101 of the diagram, the power consumption is plotted in arbitrary units.

The curve 424 or the curve 424 illustrates the time curve 424 of the power consumption.

Furthermore, a time range T is shown, which is limited by a start time point 103 and an end time point 104. In other words, T is ═ T₀，t₁]Wherein t is₀Characterizing the starting time 104 and t₁The end time point is characterized. In the time range T, an energy quantity E should be consumed by the energy system 6_T. In other words, the energy amount E should be adjusted_TThe energy system 6 is supplied via the low-voltage network 2. This corresponds to the average power consumptionWhich is represented by dashed curve 420. Typically, the power consumption of the energy system 6 is performed at a substantially constant power, which corresponds to the average power.

At the first point in time 105, the collected grid voltage is below a first threshold 421. Thus, the control device 42 reduces power consumption relative to the average power consumption 420. This continues until a second point in time 106. From time 106, the power consumption increases relative to its average value 420, for example because the grid voltage lies above a second threshold 422. Alternatively or additionally, the amount of energy E_TThe energy system 6 must be supplied such that after a time range of lower power consumption relative to the average power consumption there must always be a time range of increased power consumption relative to the average power consumption within this time range T.

Although the invention has been illustrated and described in detail in the context of preferred embodiments, it is not limited to the disclosed examples or other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

List of reference numerals

2 low-voltage network

4 grid connection point

6 energy system

42 control device

61 Assembly

100 abscissa

101 ordinate of the

103 start time point

104 end time point

105 first time point

106 second time point

420 dotted line (average power)

421 first threshold value

422 second threshold

423 characteristic curve

424 curves (time trend of power consumption)