DE202015101806U1 - Renewable Energy Plant and Renewable Energy Park - Google Patents

Abstract

Renewable Energy Plant (10), comprising
A power generation unit (11) capable of generating AC electrical power;
- An equipment transformer (12) with adjustable transmission ratio, whose primary side is connected to the power generation unit (11) and whose secondary side to a power supply (20) can be connected;
- A plant control system (13) connected to the plant transformer (12) and is designed such that it the transmission ratio of the plant transformer (12) in response to a plant reactive power and / or a plant blind output specification and / or from a primary-side plant voltage and / or from a primary-side plant voltage specification and / or from a secondary-side plant voltage and / or from a secondary-side plant voltage specification and / or from an operating point of the energy production unit (11) and / or from an operating point of the plant (10).

Description

The invention relates to a renewable energy system, in particular a wind turbine or photovoltaic system, and a renewable energy park, in particular wind farm and / or solar park.

DE 10 2008 018 748 A1 describes a wind turbine with a rotor, a generator driven therefrom with an inverter for generating electrical power, which is delivered via a transformer, for which a voltage monitoring is provided in a network, and a control system, which comprises a converter control, wherein the control system Applying control signal for a reactive component to the inverter, wherein a voltage measuring device is arranged on the transformer whose voltage signal is applied to an input of a state-dependent setpoint shifter whose output signal is applied to a limiting module for acting on the inverter reactive component.

This document also describes a method of operating the wind turbine with adjusting an output signal for a reactive component of the output power, measuring a voltage on the transformer, determining a correction signal for the reactive power measure using a state-dependent setpoint shifter, and using this shifted signal to limit the control signal of the reactive component ,

DE 10 2008 048 258 A1 describes a wind farm with a transfer station, where electric power generated in the wind farm is transferred from an internal wind park network to an external grid, a tap changer for setting the transmission ratio between the voltage in the wind farm internal network and the voltage in the external grid, and a wind farm controller; the stepper switch sets a gear ratio, the wind farm governor specifies the gear ratio as a function of the electrical load of a wind turbine of the wind farm. In a map memory, a UQ map is stored. A wind turbine of the wind farm comprises a logic module which compares the voltage U and the reactive component Q of the electrical energy emitted by the wind turbine with the UQ map. The wind farm controller comprises a logic module which compares the voltage U and the reactive component Q of the wind park-internal network with the UQ map. The wind farm controller comprises an evaluation module that decides on the basis of the current active power output and / or a voltage mean value and / or a state variable of the tap changer on whether the tap changer is toggled. The tap changer is designed to perform a change over several switching stages in a switching operation.

This document also describes a method for operating a wind farm, in which electrical energy generated in the wind farm is transported via a wind farm internal network to a transfer station and in which the electrical energy is transformed before being transferred to an external network to a voltage that by a selectable transmission ratio is higher than the voltage in the wind farm internal network, comprising the steps of: a) determining the electrical load of a wind turbine of the wind farm; and b) setting the transmission ratio as a function of the electrical load of the wind turbine. The electrical load of the wind turbine is determined by comparing voltage U and a reactive component Q of the electrical energy generated in the wind turbine with a U-Q map. Based on the U-Q map, a reactive power reserve of the wind turbine is determined. When the transmission ratio changes, new setpoint values for the voltage and / or the reactive component are predefined to the wind energy installations of the wind farm.

In this document it is described that the electrical utilization of the wind turbine is determined by comparing the voltage U and a reactive component Q of the electrical energy generated in the wind turbine with a UQ map, where reactive component is to be understood as the generic term Representation options such as reactive current, reactive power, phase angle, etc. includes. A UQ map is to be understood as follows. The generator of a wind turbine generates the electrical energy at low voltages, which are usually between 400 V and 6 kV. Before the transfer to the wind farm's internal network, the electrical energy is brought to a mean voltage of, for example, 20 kV with a transformer belonging to the wind turbine. Through the transformer of the wind turbine both the active component and the reactive component of the electrical energy is transmitted. It is known that the ability of the transformer to transmit the reactive component depends on the voltage with which the transformer is operated. At one end of the allowable voltage range, the wind turbine can generate capacitive reactive components without restriction (over-excited operation), while it reaches its system limits more quickly when transmitting an inductive reactive component (under-excited operation). At the other end of the allowable voltage range, the wind turbine may well generate an inductive reactive component while transmitting a reactive current capacitive reactive component reaches its system limits more quickly. This relationship is described in detail in DE 10 2008 018 748 , Considering a UQ map derived from this finding, two corners are missing compared to the rectangular shape that would be expected if the ability to transmit the dummy component were the same over the entire allowable voltage range. The shape of the UQ map thus approximates to a rhombus. Looking at the UQ map on the side of the wind park's internal network, the capacity to inject capacitive reactive components at high voltage and the capacity to inject inductive reactive components at low voltages are reduced. On the generator side, the signs are reversed. The voltage U is preferably considered on the side of the wind park-internal network, however, a view on the generator side is also possible. The UQ map changes depending on how much power the wind turbine delivers. Thus, a smaller proportion of reactive power can be used to feed in a larger proportion of reactive power. The rhombus-like shape of the UQ map remains intact. If one takes the operating point of the wind energy plant defined by the voltage U and the reactive component Q and compares this with the UQ characteristic map, it can be assumed that the wind energy plant has a low electrical load if the operating point is far away from all limits of the UQ characteristic map. The electrical load increases as the operating point approaches a limit of the UQ map. If the operating point approaches a boundary of the UQ map where there is no corner compared to the rectangle, it would be the classic reaction to reduce the reactive component Q and accept that the wind turbine can no longer meet the reactive power specification , Within the scope of the invention known from this document, the voltage in the wind farm internal network can instead be changed by changing the transmission ratio. The operating point of the wind turbine thereby moves away from the limits of the UQ map and the electrical load of the wind turbine is reduced. The margin thus gained can be used to increase the reactive component Q, so that the reactive power specification is met again.

This known wind farm includes a plurality of wind turbines. Each wind turbine includes a rotor whose rotation is converted into electrical energy by a generator. The of the generator with a voltage of z. B. 690 V generated electrical energy is already transformed in the wind turbine to a medium voltage of 20 kV. With the voltage of 20 kV, the electrical energy is fed into a wind farm-internal network and routed via the wind farm's internal network to a transfer station. The sections of the wind park's internal network also each have the effect of an inductance, a capacitance and a resistance. In the transfer station, a transformer is provided with a tap changer, with which the electrical energy is translated from the 20 kV medium voltage to a high voltage of 110 kV. In the transfer station, the electrical energy is transferred to an external network. The external network is normally a public power distribution network through which electrical energy is distributed to consumers. The wind farm controller is supplied with various information about the condition of the wind farm. The information includes the actual voltage and current in the wind park's internal grid, external requirements for the voltage and reactive power with which the electrical energy is to be transferred to the external grid, as well as information about the condition of the wind turbines. The wind farm controller processes this information and uses it to calculate specifications that are transmitted to the components of the wind farm. Thus, the tap changer receives a specification for the transmission ratio. The wind turbines are given specifications for the voltage and the reactive power.

This document shows an in 6 reproduced in the present application UQ map indicating the work area within which a wind turbine can feed electrical energy into the wind farm's internal network. In the UQ characteristic field, the voltage U is specified on one axis in standardized units, a value of 1.00 corresponding to nominal voltage. On the other axis, the reactive component Q is also plotted in normalized units, with current and voltage in phase at a value of Q = 0.0. At Q = 0.0, therefore, only active power is transmitted, the reactive component is 0. For positive values Q, capacitive reactive power is fed in, for negative values Q inductive reactive power. If the wind turbine were able to provide reactive power to the same extent over the entire permitted voltage range between 0.95 and 1.06, the UQ characteristic map would have the shape of a rectangle. However, as explained above, at low voltages, the ability to inject inductive reactive power is reduced. On the other hand, in the case of voltages at the upper end of the permissible range, the ability to supply capacitive reactive power is reduced. Compared to a rectangle, the corner on the bottom left and the corner on the top right are missing, the map is approximating the shape of a rhombus.

If one determines the voltage U and the reactive component Q with which the wind energy system feeds electrical energy into the wind farm's internal network, the UQ characteristic map of the wind energy system can be used 6 Draw the working point at which the wind turbine works. In general, an operating point in the middle of the UQ map indicates a low electrical load on the wind turbine. An operating point near the boundary of the UQ map is an indication of a high electrical load of the wind turbine. The figure shown applies to a high or normal active power output. For the range of low active power output another limit function would be used, in which z. For example, the work area of the UQ diagram is enlarged left and right. In the UQ map of the 6 is a possible working point 116 drawn a wind turbine. The voltage U is at 1.04 of the rated voltage and so much capacitive reactive power is supplied that the operating point is directly at the boundary of the UQ map. The working point 116 can be maintained if the wind turbine can deliver just enough reactive power as required. In another case, the wind turbine would actually have to deliver more reactive power to meet the reactive power requirement, but because of high electrical load, it can not do so. An increase in the reactive power component would result in an operating point outside the UQ map and thus outside the permissible range. In this case, the wind turbine sends a message about its high electrical load to the wind farm controller. The wind farm controller can respond according to the inventive method by the tap changer is switched by one stage, so that the voltage in the wind park internal network drops. The working point 116 becomes the working point 116a , The controller of the wind turbine determines that the electrical load of the wind turbine at the operating point 116a in comparison to the operating point 116 has sunk. Should the capacitive reactive power at the operating point 116a insufficient, then the controller of the wind turbine would be the operating point 124 to adjust. At the working point 124 So the wind energy plant is different than at the working point 116 able to meet a demand for increased capacitive reactive power. At the same time, the electrical load is at the operating point 124 less than at the operating point 116 because of the working point 124 still has a distance to the boundaries of the UQ map. By operating the tap changer so the operating point of the wind turbine is initially shifted so that reduces the electrical load. Part of the resulting space is used to feed more capacitive reactive power.

The requirements for the operation of wind turbines and wind farms as well as in general also of other renewable energy plants and renewable energy parks are defined by the grid operators in grid connection rules and tightened ever further. Such grid connection rules are in Germany, for example, in the by the BDEW Bundesverband der Energie- und Wasserwirtschaft e. V. issued BDEW Guideline "Generation Plants on the Medium-Voltage Grid", June 2008 issue (MSR 2008) and the "Fourth supplement" of January 2013 (4th supplement to the MSR 2008) contain. This Directive applies to the design, construction, operation and modification of generation plants connected to the medium-voltage grid of a grid operator and operated in parallel with that grid. It also applies if the grid connection point of the generating plant in the low-voltage grid is the point of connection to the public grid but in the medium-voltage grid. Hereby z. B. generating plants, which are connected to a low-voltage network, which is connected via a separate customer transformer to the medium voltage network of the network operator and to which no customers of the general supply are connected. For generating plants whose grid connection point is in the medium-voltage grid but whose point of connection is in the high-voltage or extra-high-voltage grid, the corresponding technical connection rules must be applied. However, for generating plants having their grid connection point and their point of connection in the low - voltage grid, the VDEW guideline "Generating plants on the low-voltage grid" , Generating plants within the meaning of this guideline are, for example, wind turbines, hydropower plants, CHP plants (eg biomass or biogas or natural gas power plants) and photovoltaic plants. A generating plant can consist of a single generator or several generating units (eg wind farm). The electrical energy can be generated by synchronous or asynchronous generators with or without converters or by DC generators (eg solar cells of photovoltaic systems) with inverters.

The well-known wind turbines, wind farms, photovoltaic systems and solar parks can, however, according to the current grid connection rules, by the said 4. Supplement to the MSR 2008 with effect from January 2013 have been tightened, to be provided reactive power at low voltage in the network or only with difficulty and effort, for example, by active power reduction provide or even need to be taken off the grid. This is especially true for wind turbines without full inverter, z. B. with double-fed asynchronous machine. Known wind turbines with full converter can do this by the integration of power electronic auxiliary cabinets in the wind turbine, however, such full converter and power electronic additional cabinets are very expensive.

Against this background, the invention proposes the subject matters of the independent claims in front. Advantageous developments and embodiments of the invention are described in the dependent claims.

• – eine Energieerzeugungseinheit, die elektrischen Wechselstrom, insbesondere Drehstrom erzeugen kann;
• – einen Anlagentransformator mit einstellbarem Übersetzungsverhältnis, dessen Primärseite an die Energieerzeugungseinheit angeschlossen ist und dessen Sekundärseite an ein Stromnetz angeschlossen werden kann;
• – ein Anlagensteuersystem, das an den Anlagentransformator angeschlossen und derart ausgebildet ist, dass es das Übersetzungsverhältnis des Anlagentransformators in Abhängigkeit von einer Anlagenblindleistung oder einer aktuellen Blindleistung, die die Anlage liefert, und/oder von einer Anlagenblindleistungsvorgabe oder einer vorbestimmten Blindleistung, die die Anlage, insbesondere gemäß einer Forderung eines Netzbetreibers, an das Stromnetz liefern soll, und/oder von einer primärseitigen Anlagenspannung oder einer aktuellen Spannung, die an der Primärseite des Anlagentransformators anliegt, und/oder von einer primärseitigen Anlagenspannungsvorgabe oder einer vorbestimmten Spannung, die an der Primärseite des Anlagentransformators anliegen soll, und/oder von einer sekundärseitigen Anlagenspannung oder einer aktuellen Spannung, die an der Sekundärseite des Anlagentransformators anliegt, und/oder von einer sekundärseitigen Anlagenspannungsvorgabe oder einer vorbestimmten Spannung, die an der Sekundärseite des Anlagentransformators, insbesondere gemäß einer Forderung eines Netzbetreibers, anliegen soll, und/oder von einem Arbeits- oder Betriebspunkt der Energieerzeugungseinheit und/oder von einem Arbeits- oder Betriebspunkt der Anlage einstellen kann.

The invention proposes according to a first aspect of a renewable energy plant, in particular a wind turbine or photovoltaic system, before, comprising or comprising

• - A power generation unit that can generate electrical alternating current, in particular three-phase current;
• - An installation transformer with adjustable transmission ratio, the primary side is connected to the power generation unit and the secondary side can be connected to a power grid;
• A plant control system connected to the plant transformer and arranged to provide the transformation ratio of the plant transformer as a function of a plant reactive power or current reactive power supplied by the plant, and / or of a plant reactive power demand or a predetermined reactive power which the plant, in particular according to a demand of a grid operator to supply power to the grid, and / or from a primary-side plant voltage or a current voltage applied to the primary side of the plant transformer, and / or from a primary-side plant voltage preset or a predetermined voltage at the primary side of Anlagentransformators should abut, and / or from a secondary-side system voltage or a current voltage applied to the secondary side of the plant transformer, and / or from a secondary-side plant voltage preset or a predetermined S voltage, which should be applied to the secondary side of the plant transformer, in particular according to a requirement of a network operator, and / or set by a working or operating point of the power generation unit and / or from a working or operating point of the system.

The proposed system according to the first aspect allows the fulfillment of stricter or tightened grid connection rules, in particular reactive power specifications.

The plant control system is preferably designed such that it is this ratio as a function of the operating or operating point of the power generation unit, which is defined for example by their current voltage, their current active power and their current reactive power, and / or from the working or operating point of the system , which can be set, for example, by their current voltage, whose current reactive power and their actual active power is defined. Each of these operating points may also be differently defined as required, for example by the corresponding current voltage, the corresponding actual active power and the corresponding current phase shift or by the corresponding current voltage, the corresponding current and the corresponding current phase shift or by another combination of power and / or voltage and / or phase shift and / or active power and / or reactive power and / or apparent power.

The plant transformer can be configured as desired in any manner, for example as a dry transformer or as an oil transformer. Its primary side is also referred to here as undervoltage side or generator side, and its secondary side is also referred to here as the high-voltage side or the network side.

The power grid can be configured as desired in any way, for example, as a park power network to which several systems are connected and typically has a rated voltage in the medium voltage range, for example 12 kV or 24 kV or 36 kV, or as a consumer power grid or distribution network or Composite network, which typically has a rated voltage in the medium voltage range, for example, 12 kV or 24 kV or 36 kV, or in the high voltage range, for example, 110 kV or 120 kV. Preferably, the power grid is the park power network of one of the parks proposed according to the second aspect.

The plant control system can be configured as desired in any manner, for example, such that it can set this ratio by the plant transformer can drive in response to the plant blind output specification such that it has a gear ratio with which the system one of the plant blind output specification Provide reactive power and / or can supply to the power grid.

• – einen Rotor;
• – einen Generator, der an den Rotor gekoppelt ist und den elektrischen Wechselstrom erzeugen kann.

It can be provided that each of the proposed plants is a wind energy plant, wherein the energy generation unit comprises

• A rotor;
• - A generator which is coupled to the rotor and can generate the electrical alternating current.

The generator can be designed as desired in any desired manner, for example as a single-phase or multi-phase or three-phase generator or as an alternator and / or in such a way that it is coupled via a gear or directly to the rotor.

It can be provided that each of the proposed systems comprises a power converter, namely a converter which is connected to the generator and the primary side.

Since the system transformer can be used to change the system voltage as required, the converter can be designed for a lower rated power compared to known systems and thus be more cost-effective.

The power converter can be designed as desired in any desired manner and, for example, have a DC intermediate circuit or a DC intermediate circuit or no intermediate circuit or be a cycloconverter or matrix converter.

It can be provided that the generator is a synchronous generator.

Thus, the primary side is connected to the generator via the power converter.

Typically, this generator generates a voltage in the low voltage range, for example of 690 V.

• – der Generator ein doppeltgespeister Asynchrongenerator mit einem Ständer und einem Läufer, insbesondere Schleifringläufer ist;
• – der Ständer an die Primärseite angeschlossen ist;
• – der Läufer an den Stromrichter angeschlossen ist.

It can be provided that

• - The generator is a double-fed asynchronous generator with a stator and a rotor, in particular slip ring rotor;
• - the stand is connected to the primary side;
• - The rotor is connected to the power converter.

Thus, the primary side is connected to the generator via the power converter.

Typically, this generator generates a voltage in the low-voltage range, for example of 690 V, on the stator and on the rotor, or a voltage in the low medium-voltage range, for example of 6 kV, at the stator, and a voltage in the low-voltage range, for example of 690 V, at the rotor.

It can be provided that the plant transformer has a primary winding or a primary winding per phase, which is connected to the stator and to the power converter.

Thus, the primary winding is connected to the rotor via the power converter.

It can be provided that the plant transformer has a first primary winding or per phase, a first primary winding which is connected to the stator, and a second primary winding or per phase, a second primary winding which is connected to the power converter.

Thus, the second primary winding is connected via the power converter to the rotor.

• – ein Solarmodul;
• – einen Stromrichter, nämlich einen Wechselrichter, der an das Solarmodul angeschlossen ist und den elektrischen Wechselstrom erzeugen kann.

It can be provided that each of the proposed systems is a photovoltaic system, wherein the power generation unit comprises

• A solar module;
• - A power converter, namely an inverter, which is connected to the solar module and can generate the electrical alternating current.

Since the system transformer can be used to change the system voltage as required, the converter can be designed for a lower rated power compared to known systems and thus be more cost-effective.

The power converter can be designed as required in any desired manner, for example as a single-phase or multi-phase or three-phase power converter. Typically, this power converter generates a voltage in the low voltage range, for example of 230 V or 690 V.

The energy generating unit can be designed as desired in any desired manner and, for example, comprise or have at least one additional or further solar module and / or at least one additional or further power converter.

• – einen Anlagenblindleistungssensor, der die Anlagenblindleistung erfassen und ein entsprechendes Anlagenblindleistungssignal erzeugen kann und der insbesondere an das Anlagensteuersystem angeschlossen ist;

wobei das Anlagensteuersystem derart ausgebildet ist, dass es das Übersetzungsverhältnis des Anlagentransformators in Abhängigkeit von dem Anlagenblindleistungssignal einstellen kann.It can be provided that includes each of the proposed facilities

• A blind power sensor, which can detect the blind power and produce a corresponding blind power signal and which is in particular connected to the system control system;

wherein the plant control system is adapted to adjust the gear ratio of the plant transformer in response to the plant blank power signal.

The plant reactive power sensor may be formed as desired in any way and be connected for example to the primary side and / or the secondary side of the plant transformer and / or sensors for voltage, current and phase shift of the system and generate corresponding measurement signals from which he or the plant control system can determine the plant reactive power and in particular the effective plant performance.

The plant control system may be designed as desired in any manner, for example, in such a way that it can set this transmission ratio as a function of the system reactive power signal by setting this transmission ratio as a function of a comparison of the system reactive power signal with the system reactive power specification or by setting this transmission ratio by such a comparison.

• – einen Anlagenspannungssensor, der die primärseitige Anlagenspannung erfassen und ein entsprechendes Anlagenspannungssignal erzeugen kann und der insbesondere an das Anlagensteuersystem angeschlossen ist; und/oder
• – einen Anlagenspannungssensor, der die sekundärseitige Anlagenspannung erfassen und ein entsprechendes Anlagenspannungssignal erzeugen kann und der insbesondere an das Anlagensteuersystem angeschlossen ist;

wobei das Anlagensteuersystem derart ausgebildet ist, dass es das Übersetzungsverhältnis des Anlagentransformators in Abhängigkeit von wenigstens einem dieser Anlagenspannungssignale einstellen kann.It can be provided that includes each of the proposed facilities

• A system voltage sensor which can detect the primary-side system voltage and generate a corresponding system voltage signal and which in particular is connected to the system control system; and or
• A system voltage sensor which can detect the secondary side system voltage and generate a corresponding system voltage signal and which in particular is connected to the system control system;

wherein the plant control system is adapted to adjust the gear ratio of the plant transformer in response to at least one of these plant voltage signals.

The plant control system may be configured as desired in any manner, for example, such that it can adjust this gear ratio as a function of at least one of these plant voltage signals, by making this ratio in response to a comparison of the primary-side plant voltage signal with the primary-side plant voltage specification or by this Ratio can adjust by such a comparison and / or by this transmission ratio in response to a comparison of the secondary-side system voltage signal with the secondary-side system voltage default or by this transmission ratio can be adjusted by such a comparison.

It can be provided that the plant control system can be connected to a remote control signal generating remote control system and is designed such that it can set the transmission ratio of the plant transformer in response to the remote control signals.

The remote control system may be configured as desired in any manner and may include, for example, the parking control system of one of the parks proposed according to the second aspect.

It can be provided that each of the proposed systems comprises an on-load tap changer for setting the transmission ratio of the system transformer.

This on-load tap-changer can be configured as desired in any desired manner and is arranged, for example, on a housing of the system transformer, which is designed in particular as a dry-type transformer, or in a housing of the system transformer, which is designed in particular as an oil transformer. Preferably, this on-load tap-changer is designed for a transformer power with which the system can be connected to a medium-voltage network, for example for an apparent power of the plant transformer of at least 300 kVA and / or at most 6 MVA or at least 6 MVA and / or for a mains voltage of 12 kV or 24 kV or 36 kV and / or for a continuous current or maximum rated current of at least 30 A or at least 100 A per phase.

It can be provided that this on-load tap-changer comprises at least one switch which serves for switching between windings or taps of the system transformer and comprises at least one vacuum interrupter and / or at least one power semiconductor.

• – der Stromrichter ein Stromrichter mit einstellbarer Phasenverschiebung zwischen dem von ihm gelieferten Strom und der von ihm gelieferten Spannung ist;
• – das Anlagensteuersystem an den Stromrichter angeschlossen und derart ausgebildet ist, dass es die Phasenverschiebung des Stromrichters in Abhängigkeit von der Anlagenblindleistung und/oder von der Anlagenblindleistungsvorgabe und/oder von der primärseitigen Anlagenspannung und/oder von der primärseitigen Anlagenspannungsvorgabe und/oder von der sekundärseitigen Anlagenspannung und/oder von der sekundärseitigen Anlagenspannungsvorgabe und/oder von dem Betriebspunkt der Energieerzeugungseinheit und/oder von dem Betriebspunkt der Anlage einstellen kann.

It can be provided that

• - The power converter is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it;
• - The system control system is connected to the power converter and is designed such that there is the phase shift of the power converter in dependence on the reactive power and / or the plant blind output specification and / or from the primary-side system voltage and / or from the primary-side system voltage specification and / or from the secondary-side system voltage and / or from the secondary-side system voltage specification and / or from the operating point of the energy-generating unit and / or from the operating point of the system.

The plant control system can be configured as desired in any manner, for example, such that it can adjust the phase shift by the converter can drive in response to the plant blind output specification such that it has a phase shift with which the system one of the plant blind output specification Provide reactive power and / or can supply to the power grid.

• – ein Parkstromnetz;
• – wenigstens zwei Erneuerbare-Energie-Anlagen, von denen jede wie eine der gemäß dem ersten Aspekt vorgeschlagenen Anlagen ausgebildet ist und mit der Sekundärseite ihres Anlagentransformators an das Parkstromnetz angeschlossen ist;
• – einen Parktransformator mit einstellbarem Übersetzungsverhältnis, dessen Primärseite an das Parkstromnetz angeschlossen ist und dessen Sekundärseite an ein Verbraucherstromnetz angeschlossen werden kann;
• – ein Parksteuersystem, das an den Parktransformator angeschlossen und derart ausgebildet ist, dass es das Übersetzungsverhältnis des Parktransformators in Abhängigkeit von einer Parkblindleistung oder einer aktuellen Blindleistung, die der Park liefert, und/oder von einer Parkblindleistungsvorgabe oder einer vorbestimmten Blindleistung, die der Park, insbesondere gemäß einer Forderung eines Netzbetreibers, an das Verbraucherstromnetz liefern soll, und/oder von einer primärseitigen Parkspannung oder einer aktuellen Spannung, die an der Primärseite des Parktransformators anliegt, und/oder von einer primärseitigen Parkspannungsvorgabe oder einer vorbestimmten Spannung, die an der Primärseite des Parktransformators, insbesondere gemäß einer Forderung eines Netzbetreibers, anliegen soll, und/oder von einer sekundärseitigen Parkspannung oder einer aktuellen Spannung, die an der Sekundärseite des Parktransformators anliegt, und/oder von einer sekundärseitigen Parkspannungsvorgabe oder einer vorbestimmten Spannung, die an der Sekundärseite des Parktransformators, insbesondere gemäß einer Forderung eines Netzbetreibers, anliegen soll, und/oder von einem Arbeits- oder Betriebspunkt des Parks einstellen kann.

The invention proposes, according to a second aspect, a renewable energy park, in particular a wind farm or solar park or wind and solar park, before, comprising or comprising

• - a park electricity network;
• - at least two renewable energy installations, each of which is designed as one of the plants proposed according to the first aspect and is connected to the secondary side of its plant transformer to the park power network;
• - A parking transformer with adjustable transmission ratio, whose primary side is connected to the park power network and whose secondary side can be connected to a load current network;
• A parking control system which is connected to the parking transformer and is designed such that it determines the gear ratio of the parking transformer in dependence on a park blind power or a current reactive power that the park supplies, and / or on a parking blind demand or a predetermined reactive power which the park, in particular according to a demand of a network operator to deliver to the consumer power grid, and / or of a primary-side park voltage or a current voltage applied to the primary side of the park transformer, and / or of a primary-side Parkspannungsvorgabe or a predetermined voltage, on the primary side of the Parking transformer, in particular according to a requirement of a network operator, should lie, and / or by a secondary-side parking voltage or a current voltage applied to the secondary side of the parking transformer, and / or from a secondary-side Parkspannungsvor gabe or a predetermined voltage to be applied to the secondary side of the parking transformer, in particular according to a request of a network operator, and / or set from a working or operating point of the park.

The proposed according to the second aspect of the park allows the fulfillment of stricter or tightened grid connection rules, in particular reactive power specifications.

The parking control system is preferably designed such that it can set this transmission ratio as a function of the operating or operating point of the park, which is defined, for example, by its current voltage, its current reactive power and its actual active power. This operating point can also be defined differently as required, for example by its current voltage, its actual active power and its current phase shift or by its current voltage, its current and current phase shift or by another combination of current and / or voltage and / or Phase shift and / or active power and / or reactive power and / or apparent power.

The park proposed in accordance with the second aspect can be designed as desired in any desired manner and can comprise or comprise, for example, at least one additional or further parking transformer and / or at least one additional or further parking control system.

The parking transformer can be designed as desired in any desired manner, for example as a dry transformer or as an oil transformer. Its primary side is also referred to here as undervoltage side or plant side, and its secondary side is referred to here as the high-voltage side or network side.

The consumer power network can be configured as desired in any manner, for example, as a distribution network or network, which typically has a rated voltage in the medium voltage range, for example 12 kV or 24 kV or 36 kV, or in the high voltage range, for example, 110 kV. Preferably, the park power grid is the power grid of the plants proposed according to the first aspect.

The parking control system can be configured as desired in any manner, for example, such that it can set the transmission ratio by the parking transformer in response to the Parkindindleistungsvorgabe can drive such that it has a gear ratio with which the park one of the Parkblindleistungsvorgabe corresponding Provide reactive power and / or can deliver to the consumer power grid.

It can be provided that the parking control system is connected to the plant control systems and is designed such that it the gear ratio of each plant transformer in dependence on the Parkblindleistung and / or the Parkblindleistungsvorgabe and / or the primary-side park voltage and / or the primary-side Parkspannungsvorgabe and / or from the secondary-side parking voltage and / or from the secondary-side parking voltage specification and / or from the operating point of the park.

The parking control system can be configured as desired in any manner, for example, such that it can set the gear ratio of each plant transformer by the plant transformers depending on the Parkindindleistungsvorgabe and in particular by the corresponding plant blind output specifications such that they each one Have ratio ratio with which the plants can jointly provide a reactive blind power corresponding to the parking blind demand and / or can deliver to the consumer power grid.

It can be provided that each of the proposed parks comprises a parking sensor which can detect the parking blind power and generate a corresponding parking blind power signal and which is in particular connected to the parking control system;
wherein the parking control system is adapted to adjust the gear ratio of the parking transformer in response to the park blind power signal.

The park blind power sensor may be formed as desired in any manner and connected, for example, to the primary side and / or the secondary side of the park transformer and / or include sensors for voltage, current and phase shift of the park and generate corresponding measurement signals from which he or the parking control system determine the Parkblindleistung and in particular the Parkwirkleistung.

The parking control system can be configured as desired in any manner, for example, such that it can set this transmission ratio in dependence on the park blind power signal by this gear ratio depending on a comparison of the park blind power signal with the park blind power setting or by this gear ratio by such Can adjust comparison.

• – einen Parkspannungssensor, der die primärseitige Parkspannung erfassen und ein entsprechendes Parkspannungssignal erzeugen kann und der insbesondere an das Parksteuersystem angeschlossen ist; und/oder
• – einen Parkspannungssensor, der die sekundärseitige Parkspannung erfassen und ein entsprechendes Parkspannungssignal erzeugen kann und der insbesondere an das Parksteuersystem angeschlossen ist;

wobei das Parksteuersystem derart ausgebildet ist, dass es das Übersetzungsverhältnis des Parktransformators in Abhängigkeit von wenigstens einem dieser Parkspannungssignale einstellen kann.It can be provided that each of the proposed parks includes

• A parking voltage sensor capable of detecting the primary side parking voltage and generating a corresponding parking voltage signal, and in particular connected to the parking control system; and or
• A parking voltage sensor capable of detecting the secondary side parking voltage and generating a corresponding parking voltage signal, and in particular connected to the parking control system;

wherein the parking control system is configured such that it can set the transmission ratio of the parking transformer in response to at least one of these Park voltage signals.

The parking control system can be configured as desired in any manner, for example, such that it can set this ratio as a function of at least one of these Parkspannungssignale by this ratio depending on a comparison of the primary-side parking voltage signal with the primary-side Parkspannungsvorgabe or by this Ratio can adjust by such a comparison and / or by this gear ratio in dependence on a comparison of the secondary-side parking voltage signal with the secondary-side Parkspannungsvorgabe or by setting this ratio by such a comparison.

It can be provided that the parking control system can be connected to a remote control signal generating remote control system and is designed such that it can set the transmission ratio of the parking transformer in dependence on the remote control signals.

It can be provided that each of the proposed parks comprises an on-load tap changer for setting the transmission ratio of the parking transformer.

This on-load tap changer can be configured as desired in any desired manner and is arranged, for example, on a housing of the parking transformer, which is designed in particular as a dry transformer, or arranged in a housing of the parking transformer, which is designed in particular as an oil transformer.

It can be provided that this on-load tap-changer comprises at least one switch which serves for switching between windings or taps of the parking transformer and comprises at least one vacuum interrupter and / or at least one power semiconductor.

• – jeder Stromrichter ein Stromrichter mit einstellbarer Phasenverschiebung zwischen dem von ihm gelieferten Strom und der von ihm gelieferten Spannung ist;
• – das Parksteuersystem an die Stromrichter angeschlossen und derart ausgebildet ist, dass es die Phasenverschiebung jedes Stromrichters in Abhängigkeit von der Parkblindleistung und/oder von der Parkblindleistungsvorgabe und/oder von der primärseitigen Parkspannung und/oder von der primärseitigen Parkspannungsvorgabe und/oder von der sekundärseitigen Parkspannung und/oder von der sekundärseitigen Parkspannungsvorgabe und/oder von dem Betriebspunkt des Parks einstellen kann.

It can be provided that

• - Each power converter is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it;
• - The parking control system is connected to the power converters and is designed such that there is the phase shift of each converter depending on the Parkblindleistung and / or the Parkblindleistungsvorgabe and / or the primary-side parking voltage and / or the primary-side Parkspannungsvorgabe and / or the secondary-side Park voltage and / or from the secondary-side parking voltage specification and / or from the operating point of the park.

The parking control system can be configured as desired in any manner, for example, such that it can adjust the phase shift of each power converter by the Converter in response to the Parkblindleistungsvorgabe and in particular of the corresponding blind power requirements can control such that they each have a phase shift, with which the plants together provide one of the Parkblindleistungsvorgabe corresponding reactive power and / or can deliver to the load current network.

• – die Anlage umfasst
• • eine Energieerzeugungseinheit, die elektrischen Wechselstrom erzeugen kann;
• • einen Anlagentransformator mit einstellbarem Übersetzungsverhältnis, dessen Primärseite an die Energieerzeugungseinheit angeschlossen ist und dessen Sekundärseite an ein Stromnetz angeschlossen werden kann;
• – das Übersetzungsverhältnis des Anlagentransformators in Abhängigkeit von einer Anlagenblindleistung und/oder von einer Anlagenblindleistungsvorgabe und/oder von einer primärseitigen Anlagenspannung und/oder von einer primärseitigen Anlagenspannungsvorgabe und/oder von einer sekundärseitigen Anlagenspannung und/oder von einer sekundärseitigen Anlagenspannungsvorgabe und/oder von einem Arbeits- oder Betriebspunkt der Energieerzeugungseinheit und/oder von einem Arbeits- oder Betriebspunkt der Anlage eingestellt wird.

The invention proposes, according to a third aspect, a method for operating a renewable energy plant, wherein

• - includes the plant
• • a power generation unit that can generate AC electrical power;
• • an adjustable transformation ratio system transformer whose primary side is connected to the power generation unit and whose secondary side can be connected to a mains supply;
• - The transmission ratio of the plant transformer in response to a plant reactive power and / or a plant blind output specification and / or from a primary-side plant voltage and / or from a primary-side plant voltage specification and / or a secondary-side system voltage and / or secondary-side system voltage specification and / or by a working - or operating point of the power generation unit and / or is set from a working or operating point of the system.

The method proposed according to the third aspect enables the fulfillment of stricter grid connection rules, in particular reactive power specifications.

The setting of this transmission ratio is preferably carried out as a function of the operating or operating point of the power generation unit, which is defined for example by their current voltage, their current active power and their reactive power, and / or from the working or operating point of the system, for example by their current voltage whose current reactive power and its actual active power are defined. Each of these operating points may also be differently defined as required, for example by the corresponding current voltage, the corresponding actual active power and the corresponding current phase shift or by the corresponding current voltage, the corresponding current and the corresponding current phase shift or by another combination of power and / or voltage and / or phase shift and / or active power and / or reactive power and / or apparent power.

The setting of this ratio can be done as needed in any way, for example by the plant transformer is driven in response to the plant blind output specification such that it has a gear ratio with which provide the plant a reactive power corresponding to the plant blind output specification and / or deliver to the power grid can.

The system may be designed as desired in any manner, such as one of the systems proposed according to the first aspect.

• – der Stromrichter ein Stromrichter mit einstellbarer Phasenverschiebung zwischen dem von ihm gelieferten Strom und der von ihm gelieferten Spannung ist;
• – die Phasenverschiebung des Stromrichters in Abhängigkeit von der Anlagenblindleistung und/oder von der Anlagenblindleistungsvorgabe und/oder von der primärseitigen Anlagenspannung und/oder von der primärseitigen Anlagenspannungsvorgabe und/oder von der sekundärseitigen Anlagenspannung und/oder von der sekundärseitigen Anlagenspannungsvorgabe und/oder von dem Betriebspunkt der Energieerzeugungseinheit und/oder von dem Betriebspunkt der Anlage eingestellt wird.

It can be provided that

• - The power converter is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it;
• - The phase shift of the converter as a function of the reactive power and / or the plant blind output specification and / or from the primary-side system voltage and / or from the primary-side system voltage specification and / or the secondary-side system voltage and / or the secondary-side system voltage specification and / or from the operating point the power generation unit and / or from the operating point of the system is set.

The adjustment of the phase shift can be carried out as required in any desired manner, for example by the converter being controlled in dependence on the plant reactive power specification such that it has a phase shift, with which the plant provide reactive power corresponding to the plant reactive power specification and / or deliver it to the power grid can.

• – der Park umfasst
• • ein Parkstromnetz;
• • wenigstens zwei Erneuerbare-Energie-Anlagen, von denen jede wie eine der gemäß dem ersten Aspekt vorgeschlagenen Anlagen ausgebildet ist und mit der Sekundärseite ihres Anlagentransformators an das Parkstromnetz angeschlossen ist;
• • einen Parktransformator mit einstellbarem Übersetzungsverhältnis, dessen Primärseite an das Parkstromnetz angeschlossen ist und dessen Sekundärseite an ein Verbraucherstromnetz angeschlossen werden kann;
• – das Übersetzungsverhältnis des Parktransformators in Abhängigkeit von einer Parkblindleistung und/oder von einer Parkblindleistungsvorgabe und/oder von einer primärseitigen Parkspannung und/oder von einer primärseitigen Parkspannungsvorgabe und/oder von einer sekundärseitigen Parkspannung und/oder von einer sekundärseitigen Parkspannungsvorgabe und/oder von einem Arbeits- oder Betriebspunkt des Parks eingestellt wird.

The invention proposes a method for operating a renewable energy park according to a fourth aspect, wherein

• - the park includes
• • a park electricity network;
• At least two renewable energy plants, each of which is designed as one of the plants proposed according to the first aspect and connected to the secondary side of its plant transformer to the park power network;
• • an adjustable ratio parking transformer whose primary side is connected to the park current network and whose secondary side can be connected to a load current network;
• - The transmission ratio of the parking transformer in response to a park blind power and / or a parking blind power setting and / or from a primary-side Park voltage and / or from a primary-side Parkspannungsvorgabe and / or from a secondary-side parking voltage and / or from a secondary-side Parkspannungsvorgabe and / or from a working or operating point of the park is set.

The method proposed according to the fourth aspect enables the fulfillment of stricter grid connection rules, in particular reactive power specifications.

The setting of this transmission ratio is preferably carried out as a function of the working or operating point of the park, which is defined for example by its current voltage, its current reactive power and its actual active power. This operating point can also be defined differently as required, for example by its current voltage, its actual active power and its current phase shift or by its current voltage, its current and current phase shift or by another combination of current and / or voltage and / or Phase shift and / or active power and / or reactive power and / or apparent power.

The setting of this transmission ratio can be done in any desired manner, for example by the parking transformer is driven in response to the Parkindindleistungsvorgabe such that it has a gear ratio with which the Park provide the Parkblindleistungsvorgabe corresponding park blind power and / or deliver to the load power grid can.

The park may be formed as desired in any manner, such as one of the parks proposed according to the second aspect.

Each plant may be designed as desired in any manner and may be operated or operated by, for example, one of the methods proposed by the third aspect for operating a renewable energy plant.

It can be provided that the transmission ratio of each plant transformer in dependence on the park blind power and / or the Parkblindleistungsvorgabe and / or the primary-side park voltage and / or the primary-side Parkspannungsvorgabe and / or the secondary-side parking voltage and / or the secondary-side Parkspannungsvorgabe and / or is set from the operating point of the park.

The setting of the transmission ratio of each plant transformer can be done as needed in any manner, for example by the plant transformers are driven in response to the Parkindindleistungsvorgabe and in particular by the corresponding plant reactive power specifications such that they each have a gear ratio with which the plants together one of the Parkblindleistungsvorgabe provide appropriate reactive power and / or can deliver to the consumer power grid.

• – jeder Stromrichter ein Stromrichter mit einstellbarer Phasenverschiebung zwischen dem von ihm gelieferten Strom und der von ihm gelieferten Spannung ist;
• – die Phasenverschiebung jedes Stromrichters in Abhängigkeit von der Parkblindleistung und/oder von der Parkblindleistungsvorgabe und/oder von der primärseitigen Parkspannung und/oder von der primärseitigen Parkspannungsvorgabe und/oder von der sekundärseitigen Parkspannung und/oder von der sekundärseitigen Parkspannungsvorgabe und/oder von dem Betriebspunkt des Parks eingestellt wird.

It can be provided that

• - Each power converter is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it;
• - The phase shift of each converter as a function of the park blind power and / or the Parkblindleistungsvorgabe and / or the primary-side parking voltage and / or from the primary-side Parkspannungsvorgabe and / or the secondary-side parking voltage and / or from the secondary-side Parkspannungsvorgabe and / or from the operating point of the park.

The setting of the phase shift of each converter can be done as required in any way, for example by the converters are controlled in dependence on the Parkblindleistungsvorgabe and in particular by the corresponding blind power requirements such that they each have a phase shift with which the system one of the Parkblindleistungsvorgabe corresponding Provide reactive power and / or can deliver to the power grid.

For example, one of the proposed methods can be carried out with each of the proposed systems and parks.

It can be provided that each of the proposed systems and parks is designed and / or serves and / or is suitable for carrying out and / or executing one of the proposed methods.

The statements and explanations concerning one of the aspects of the invention, in particular regarding individual features of this aspect, apply correspondingly also analogously to the other aspects of the invention.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings. However, the resulting individual features are not limited to the individual embodiments, but may be connected and / or combined with individual features described above and / or with individual features of other embodiments. The details in the drawings are to be interpreted as illustrative, but not restrictive. The reference signs contained in the claims are not intended to limit the scope of the invention in any way, but merely refer to the embodiments shown in the drawings. The drawings show in

1 a first embodiment of a renewable energy plant, namely a wind turbine with synchronous generator and full converter;

2 a second embodiment of a renewable energy plant, namely a wind turbine with asynchronous generator, partial converter and plant transformer with a primary winding;

3 a third embodiment of a renewable energy plant, namely a wind turbine with asynchronous generator, partial converter and plant transformer with two primary windings;

4 a fourth embodiment of a renewable energy plant, namely a photovoltaic system with inverter;

5 a preferred embodiment of a renewable energy park;

6 a UQ map of a wind turbine for a mean effective power.

In 1 is a first embodiment of a renewable energy plant 10 , which is an example of a wind turbine here, shown schematically.

This plant 10 includes a power generation unit 11 that can generate AC electrical power, a plant transformer 12 with adjustable gear ratio, a plant control system 13 , a power converter 14 , a plant reactive power sensor 15 and one into the plant transformer 12 integrated on-load tap-changer 16 for setting the transmission ratio of the plant transformer 12 ,

In this embodiment, the power generation unit includes 11 a rotor drivable by wind 17 and a generator 18 that is attached to the rotor 17 is coupled and can generate the electrical alternating current. The generator 18 Here is an example of a three-phase synchronous generator, the direct, so without gearbox to the rotor 17 is coupled.

In this embodiment, the power converter is 14 an inverter, with its input to the generator 18 and with its output to the primary side of the plant transformer 12 , which is also referred to as undervoltage side or generator side, is connected.

In this embodiment, the plant transformer 12 one primary winding per phase 19 on, connected to the output of the power converter 14 connected. Consequently, the primary side is above the power converter 14 to the power generation unit 11 connected. The plant transformer 12 can be connected with its secondary side, which is also referred to as the high-voltage side or network side, to a power grid, the example of a park power network 20 ( 5 ) of a wind farm 25 ( 5 ).

In this embodiment, the plant control system is 13 to the on-load tap-changer 16 and thus to the plant transformer 12 , as well as to the power converter 14 and the plant reactive power sensor 15 connected.

In this embodiment, the plant reactive power sensor comprises 15 not shown sensors for the voltage, the current and the phase shift of the system 10 on the primary side of the plant transformer 12 which can generate corresponding measurement signals from which he determine the system reactive power Q _WEA and generate a corresponding blind power signal and, together with the measurement signals to the plant control system 13 can send. This voltage is also referred to here as the primary-side system voltage.

In this embodiment, the plant control system is 13 designed such that it is the transmission ratio of the plant transformer 12 depending on the system reactive power signal and thus set by the plant reactive power and in dependence on a plant blind output specification. The plant reactive power specification is a characteristic in a memory of the plant control system 13 deposited. If the plant 10 can not meet the plant blind output specification, so can the plant control system 13 For example, set the transmission ratio so that the primary-side system voltage drops to a value at which the system 10 can supply sufficient reactive power.

In 2 is a second embodiment of a renewable energy plant 10 shown schematically. This second embodiment is similar to the first embodiment, so that below all the differences are explained in more detail below.

In this embodiment, the generator 18 For example, a double-fed three-phase asynchronous generator with a stator 21 and one runner 22 which exemplifies a slip ring rotor here. The generator 18 is about a gearbox 23 to the rotor 17 coupled. The stand 21 is connected to the primary side, and the runner 22 to the power converter 14 , Thus, the primary side is above the power converter 14 to the generator 18 connected.

The primary winding 19 is on the one hand directly to the stand 21 and on the other hand to the output of the power converter 14 and thus via the power converter 14 to the runner 22 connected.

In this embodiment, the plant reactive power sensor comprises 15 not shown sensors for the voltage, the current and the phase shift of the system 10 on the secondary side of the plant transformer 12 which can generate corresponding measurement signals from which he determine the system reactive power Q _WEA and generate a corresponding blind power signal and, together with the measurement signals to the plant control system 13 can send. This voltage is also referred to here as the secondary-side system voltage.

In 3 is a third embodiment of a renewable energy plant 10 shown schematically. This third embodiment is similar to the second embodiment, so that below the differences are explained in more detail below.

In this embodiment, the plant transformer 12 each phase a first primary winding 19 ' and a second primary winding 19 '' on. The first primary winding 19 ' is right on the stand 21 connected. The second primary winding 19 '' is to the output of the power converter 14 and thus via the power converter 14 to the runner 22 connected.

In 4 is a fourth embodiment of a renewable energy plant 10 , which is an example of a photovoltaic system here, shown schematically. This fourth embodiment is similar to the first embodiment, so that below the differences are explained in more detail below.

In this embodiment, the power generation unit includes 11 a solar module 24 and is the power converter 14 an inverter attached to the solar panel 24 is connected and can generate the electrical alternating current.

In 5 is a preferred embodiment of a renewable energy park 25 , which is an example of a wind farm here, shown schematically.

In this embodiment, the park includes 25 a park electricity network 20 , two renewable energy plants 10 , a park transformer 26 with adjustable gear ratio, a parking control system 27 , a park blind power sensor 28 and one in the park transformer 26 integrated on-load tap-changer 29 for setting the gear ratio of the parking transformer 26 ,

The facilities 10 are formed according to the first embodiment and with the secondary side of their plant transformer 12 to the park power network 20 connected. The park transformer 26 is with its primary side, which is also referred to here as the low voltage side or generator side, to the park power network 20 connected and can with its secondary side, which is also referred to here as the high-voltage side or network side, to a load current network 30 be connected.

In this embodiment, the parking control system is 27 to the on-load tap-changer 29 and thus to the park transformer 26 , as well as to the plant control systems 13 the plants 10 and the park blind power sensor 28 connected.

In this embodiment, the park blind power sensor 28 Similar to the plant reactive power sensor 15 formed and includes sensors, not shown, for the voltage, the current and the phase shift of the park 25 on the secondary side of the park transformer 26 , which can generate corresponding measurement signals, from which he determine the park blind power Q _WP and generate a corresponding parking blind power signal and together with the measurement signals to the parking sensor 28 can send. This voltage is also referred to here as secondary-side park voltage.

In this embodiment, the parking control system is 27 designed so that it is the gear ratio of the parking transformer 26 depending on the park blind power signal and thus of the park blind power and depending on a Parkblindleistungsvorgabe can set. The Parkblindleistungsvorgabe is as a characteristic in a memory of the parking control system 27 deposited. If the park 25 can not meet the Parkblindleistungsvorgabe, so the parking control system 27 for example, the gear ratio of the parking transformer 26 adjust so that the secondary side park voltage drops to a value at which the park 25 can supply sufficient reactive power.

In this embodiment, the parking control system is 27 designed such that it is the gear ratio of each plant transformer 12 depending on the park blind power signal and the parking blind power setting. The parking control system sets the gear ratio of each plant transformer 12 one by using the plant transformers 12 with the help of associated asset control systems 13 in response to the Parkblindleistungsvorgabe such that they each have a gear ratio with which the facilities 10 together provide the parking dummy power setting and to the load power grid 30 can deliver.

In 6 is a UQ map 31 by way of example for an installation designated by the index i 10 of the park 25 represented, in which for a mean system active power P _WEAi this Appendix 10 the secondary-side system _voltage U _{WEAi is plotted} against the system _{reactive power} Q _WEAi . The assigned asset control system 13 can be self-employed and / or at the direction of the parking tax system 27 the transmission ratio of the respective plant transformer 12 by appropriate activation of the on-load tap-changer 16 set so that the system _voltage U _WEAi decreases and the current operating point 116 this plant 10 to 116a is moved. Because at this new operating point 116a a larger capacitive system _{reactive power} Q _{WEAi is} possible, can now the system control system 13 the power converter 14 such that it delivers a higher reactive power.

The control of the plant transformers 12 through the asset control system 13 and the parking control system 27 For example, analogous to that in the DE 10 2008 048 258 A1 described control of the park transformer 26 respectively.

A similar UQ map can also be used for a park 25 provided and for example in its parking control system 27 deposited or stored.

LIST OF REFERENCE NUMBERS

10

investment

11

Power generation unit

12

plant transformer

13

Plant control system

14

power converters

15

Plant reactive power sensor

16

On-load tap-changer of 12

17

rotor

18

generator

19

primary

20

Electricity network, park electricity network

21

stand

22

runner

23

transmission

24

solar module

25

park

26

Park transformer

27

Parking control system

28

Park reactive power sensor

29

On-load tap-changer of 26

30

Consumer power grid

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008018748 A1 [0002]
• DE 102008048258 A1 [0004, 0121]
• DE 102008018748 [0006]

Cited non-patent literature

• BDEW Guideline "Generation Plants on the Medium-Voltage Grid", issue June 2008 (MSR 2008) [0010]
• "Fourth supplement" of January 2013 (4th amendment to the MSR 2008) [0010]
• VDEW guideline "Self-Generating Systems on the Low-Voltage Grid" [0010]
• 4. Supplement to the MSR 2008 with effect from January 2013 [0011]

Claims (13)

Renewable Energy Plant ( 10 ), comprising - a power generation unit ( 11 ), which can generate AC electrical power; - a plant transformer ( 12 ) with adjustable transmission ratio whose primary side to the power generation unit ( 11 ) and its secondary side to a power grid ( 20 ) can be connected; - a plant control system ( 13 ) connected to the plant transformer ( 12 ) is connected and designed such that it the transmission ratio of the plant transformer ( 12 ) as a function of a system reactive power and / or of a plant reactive power specification and / or of a primary-side plant voltage and / or of a primary-side plant voltage specification and / or of a secondary-side plant voltage and / or of a secondary-side plant voltage specification and / or of an operating point of the energy production unit ( 11 ) and / or from an operating point of the installation ( 10 ). Investment ( 10 ) according to claim 1, namely wind energy plant, wherein the power generation unit ( 11 ) comprises - a rotor ( 17 ); A generator ( 18 ) connected to the rotor ( 17 ) is coupled and can generate the electrical alternating current. Investment ( 10 ) according to one of the preceding claims, comprising a power converter ( 14 ), namely an inverter connected to the generator ( 18 ) and the primary side is connected. Investment ( 10 ) according to claim 1, namely photovoltaic system, wherein the energy generating unit ( 11 ) - a solar module ( 24 ); - a power converter ( 14 ), namely an inverter connected to the solar module ( 24 ) is connected and can generate the electrical alternating current. Investment ( 10 ) according to one of the preceding claims, comprising - a plant reactive power sensor ( 15 ), which can detect the system reactive power and generate a corresponding blind power signal; the asset control system ( 13 ) is designed such that it the transmission ratio of the plant transformer ( 12 ) depending on the plant blind power signal. Investment ( 10 ) according to the previous claim, comprising - a plant voltage sensor capable of detecting the primary-side plant voltage and generating a corresponding plant voltage signal; and / or a system voltage sensor capable of detecting the secondary side system voltage and generating a corresponding system voltage signal; the asset control system ( 13 ) is designed such that it the transmission ratio of the plant transformer ( 12 ) in response to at least one of these plant voltage signals. Investment ( 10 ) according to any one of the preceding claims, wherein the asset control system ( 13 ) to a remote control signal generating remote control system ( 27 ) and is designed such that it the transmission ratio of the plant transformer ( 12 ) depending on the remote control signals. Investment ( 10 ) according to one of the preceding claims, comprising an on-load tap-changer ( 16 ) for setting the transmission ratio of the plant transformer ( 12 ). Investment ( 10 ) according to one of the preceding claims, wherein - the power converter ( 14 ) is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it; - the plant control system ( 13 ) to the power converter ( 14 ) is connected and designed such that it the phase shift of the power converter ( 14 ) as a function of the reactive power of the plant and / or of the plant reactive power specification and / or of the primary-side plant voltage and / or the primary-side plant voltage specification and / or the secondary-side plant voltage and / or the secondary-side plant voltage specification and / or the operating point of the energy production unit ( 11 ) and / or from the operating point of the installation ( 10 ). Renewable Energy Park ( 25 ), comprising - a parking grid ( 20 ); - at least two renewable energy installations ( 10 ), each of which is designed according to one of the preceding claims and with the secondary side of its plant transformer ( 12 ) to the parking grid ( 20 ) connected; A parking transformer ( 26 ) with adjustable transmission ratio whose primary side is connected to the park power network ( 20 ) and its secondary side to a load current network ( 30 ) can be connected; A parking control system ( 27 ) connected to the parking transformer ( 26 ) and is designed such that it the gear ratio of the parking transformer ( 26 ) depending on one Park blind power and / or from a parking dummy power setting and / or from a primary-side parking voltage and / or from a primary-side parking voltage specification and / or from a secondary-side parking voltage and / or from a secondary-side parking voltage specification and / or from an operating point of the park ( 25 ). Park ( 25 ) according to the previous claim, wherein the parking control system ( 27 ) to the plant control systems ( 13 ) and is designed such that it the transmission ratio of each plant transformer ( 12 ) as a function of the parking blind power and / or the parking blind power setting and / or the primary side parking voltage and / or the primary-side parking voltage preset and / or the secondary-side parking voltage and / or the secondary-side parking voltage preset and / or the operating point of the park ( 25 ). Park ( 25 ) according to one of the preceding claims, wherein the parking control system ( 27 ) can be connected to a remote control signal generating remote control system and is designed such that it the gear ratio of the parking transformer ( 26 ) depending on the remote control signals. Park ( 25 ) according to one of the preceding claims, wherein - each power converter ( 14 ) is a power converter with adjustable phase shift between the current supplied by it and the voltage supplied by it; - the parking control system ( 27 ) to the power converters ( 14 ) is connected and designed such that it the phase shift of each power converter ( 14 ) as a function of the parking blind power and / or the parking blind power setting and / or the primary side parking voltage and / or the primary-side parking voltage preset and / or the secondary-side parking voltage and / or the secondary-side parking voltage preset and / or the operating point of the park ( 25 ).

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