Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
  • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
  • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters

Definitions

• the present invention relates to a multi-generator power plant arrangement, a power supply network comprising such a multi-generator power plant arrangement, and a method for distributing reactive power generation in a multi-generator power plant arrangement.
• Multi-generator power plants include multiple generators for generating electrical power.
• generators of different types can be combined.
• a multi-generator power plant assembly may include wind turbines, photovoltaic feeders with individual inverters, electrical storage systems such as batteries, flywheels, or super-caps with individual inverters, diesel generators, gas turbines, and / or other generators. All generators of such a multi-generator power plant arrangement are brought together at a common point, which is designed as an electrical interface of the multi- generator power plant ⁇ arrangement to form an electrical power grid. This electrical interface is called the point of common coupling (PCC).
• PCC point of common coupling
• the energy supply network in which the multi-generator power plant arrangement feeds the electrical power, it may be, for example, a transmission or distribution network or a stand-alone network.
• power plant arrangements distinguish between so-called grid-forming power plants and so-called grid-supporting power plants.
• Network forming power plants make it the electrical voltage clamping ⁇ provided with a predetermined amplitude and frequency.
• Examples of network-building power plants in the European Ver ⁇ Verbundnetz are nuclear or coal power plants.
• Power plants feed the active power and reactive power into the power grid depending on the frequency and amplitude of the voltage at the grid transfer point.
• the reactive power is in grid support alarm ⁇ collapsing power plants typically fits reasonable function of the amplitude of the voltage at the power transfer point relatively small variations in the amplitude of the mains voltage which can already result in a significant variation of the injected reactive power.
• An example of such grid supporting power plants are wind farms.
• a Derar ⁇ term control of the reactive power as a function of the voltage amplitude is not immediately at network forming power plants ⁇ due to the setting of the voltage amplitude on the power transfer point / directly possible. Rather, in the case of network-forming power plant arrangements, the reactive power fed in at the grid transfer point depends on the network configuration and the other producers and consumers in the grid.
• multi-generator power plant arrangements can or must be provided at the grid, the dummy ⁇ power be distributed to the plurality of generators of this power plant arrangement beyond.
• reactive power is distributed very un ⁇ evenly to the generators, and that walls ⁇ hand, flow within the multi-generator power plant arrangement reactive currents, while not contribute to the reactive power at the network transfer point, however, load the individual generators strong and optionally can lead to overloading of these generators.
• the present invention provides a multi-generator power plant arrangement with a grid feed point electrically coupled to a power grid; a plurality of generators, each electrically coupled to the grid feed point and configured to provide reactive power in response to a control variable, wherein at least one of the generators is a grid forming generator configured to provide an output voltage of a predetermined amplitude and to provide a predetermined frequency or phase based on another control quantity; and a controller configured to calculate the output voltage control values of each grid forming generator using a reactive power to be fed by the respective generator, and to provide the calculated control quantities to the respective generators.
• the present invention provides a method for distributing reactive power generation in a multi-generator power plant arrangement having a plurality of generators, wherein at least one of the generators is a grid-forming generator configured to provide an output voltage having a predetermined amplitude and a predetermined frequency or phase.
• the method comprises the steps of determining one of the
• Multi-generator power plant arrangement to be generated reactive power; splitting the reactive power to be generated into the generators of the multi-generator power plant assembly; the calculation of control variables for the output voltage of the network-forming generators of the multi-generator power plant arrangement, the respective control variable being calculated using a reactive power to be fed in by the respective generator. is expected; and transmitting the control variables to the Ge ⁇ generators.
• the present invention is based on the finding that in electric generators, in particular in netzbil ⁇ generating generators, only a default for frequency and amplitude of the output voltage of the generators can be specified. On the other hand, immediate adjustment of the active power and reactive power to be output is generally not possible. Therefore, the output from such a generator reactive power can be done only on the specification of a desired voltage.
• One idea on which the present invention is based is to divide the reactive power in a multi-generator power plant assembly for each generator of this multi-generator power plant assembly individual control variables, such as the setpoint values for the output voltages of the network forming generators and the setpoints for the reactive power to be fed in for the grid-supporting generators.
• Reactive power within the multi-generator power plant arrangement can be distributed selectively and to a desired extent to the individual generators. This reduces the risk that the individual generators are unintentionally loaded unevenly and that between the individual generators of Mehrgenera- tor power plant arrangement unnecessarily reactive power flows back and forth, although burdening the generators, but is not provided as reactive power at the grid transfer point.
• the control device calculates the control quantities for the reactive power to be provided by a generator using an impedance between the respective generator and the grid feed-in point. By taking into account the impedance between generator and grid connection point, the voltage drops along the electrical connection between generator and
• the impedance between the generator and the grid feed the Lei ⁇ tung impedance between the generator and the grid feed.
• the multi-generator power plant arrangement further comprises a transformer which is arranged between the grid feed-in point and at least one generator. The impedance between generator and
• the grid connection point which in this case is used to calculate the control variable for the respective generator, in this case includes the reactances of the transformer.
• the grid-supporting generators of the plurality of generators include a droop regulator configured to adjust the reactive power provided by the respective generator in response to a voltage offset and / or a regulator slope, or a droop regulator configured therefor to adjust the voltage provided by the respective generator in dependence on a reactive power offset or reactive current offset and / or a regulator slope.
• control device is adapted to determine a control amount corresponding to the voltage offset ⁇ , adjusts the reactive power offset or the reactive current offset of a droop regulator of a generator.
• the control device is designed to determine a control variable which adapts the controller slope of the Droop controller of a generator.
• the regulator gradients can be adjusted such that a reactive power change at the grid transfer point after a pre-defined ratio divides the Ge ⁇ generators without the parameters of the droop controller needs to be set.
• the reactive power generated by the respective genei ⁇ term generators are adjusted individually. This applies both to constant reactive power purchases as well as for time-varying reactive power purchases from the grid.
• the distribution of a constant reactive power eg the average reactive power, is set via the voltage offset or reactive power / reactive current offset and the distribution of the deviation from this constant reactive power via the controller rates.
• the multi-generator power plant arrangement comprises a grid-forming power plant arrangement which is designed to provide a grid voltage with a predetermined amplitude and a predetermined frequency or phase at a grid feed-in point.
• a network-forming power plant arrangement also provides the reactive power which necessarily results from the configuration of the rest of the network.
• the Mehrgenera- tor power plant arrangement comprises a grid-supporting power plant arrangement in which the control device is adapted to be provided at the gridrise the reactive power in depen ⁇ dependence of a mains voltage at the grid represent ⁇ .
• the step of calculating the control quantity for the generators in the reactive power generation distribution method in a multi-generator power plant arrangement calculates the control quantities using the impedance between the grid connection point and the respective generator.
• the reactive power is divided among the individual generators using a predetermined ratio or predetermined rules.
• the division can be based on manually entered by a user rules.
• the division can also be made automatically based on a predetermined ratio and / or predetermined formulas or rules.
• the present OF INVENTION ⁇ dung relates to a power supply network with an inventive multi-generator power plant assembly.
• the power supply ⁇ network further comprises a further mains supply point and another generator, wherein the further generator is a netzbil- dender generator which is adapted to provide an output ⁇ voltage having a predetermined amplitude and a predetermined frequency or phase.
• the further generator can also be a further multi-generator power plant arrangement with at least one network-forming generator.
• the further generator is electrically coupled to the other power feed point.
• the white ⁇ tere generator is adapted to provide reactive power in response to a control parameter.
• the control apparatus of the multi-generator power plant arrangement is designed in this case further to determine a control variable for the other genes ⁇ rator and to transmit these control variable to the further generator.
• the power supply system further comprises a further, higher-level control apparatus which is adapted to a size for ready ⁇ presentation end reactive power and / or the preparatory adjusted to determine the output voltage of the other generator and to transmit this quantity to the control device of a multi-generator power plant arrangement.
• a multi-level, hierarchical At ⁇ adjustment of generated reactive power can be realized in larger power systems.
• FIG. 1 shows a schematic representation of a multi-generator power plant arrangement according to an embodiment
• FIG. 2 shows a schematic representation of a power supply network with a multi-generator
• FIG. 3 a schematic representation of a power supply network according to a further embodiment.
• Figure 4 is a schematic representation of a predominantlydiag ⁇ ram, as it is based on a method for distributing the reactive power generation in a multi-generator power plant arrangement.
• FIG. 1 shows a schematic representation of a multi-generator power plant arrangement 1 according to an embodiment.
• the multi-generator power plant arrangement 1 comprises a plurality of individual generators G1 to G-6.
• the generators G- i can be any generators for generating electrical act as a rival.
• the generators Gi can be wind turbines, photovoltaic systems with separate inverters, storage systems such as flywheels, compressed air storage, batteries or super-caps, which also each have a separate inverter, diesel generators, gas turbines, or any other generator for generating electrical power.
• the individual generators Gi can be of any different types. But also one or more generators of the same type are possible.
• the generators Gi are each connected via an electrical connection with Li ei ⁇ single power transfer point twentieth
• the outputs of several generators Gi are connected in parallel to the input of a transformer Ti, provided that the voltage levels of the parallel-connected generators are the same.
• Each of the generators Ti has a reactance jX T i.
• the ohmic resistances R T i of the respective transformers Ti are relatively small compared to the respective reactance X T i and can therefore be neglected.
• the configuration shown here consists of six generators G-1 to G-6 and three transformers Tl to T3 is selected only ⁇ example and serves to explain the better understanding of the invention, without limiting the invention to this configuration.
• active power and reactive power are respectively generated by the generators Gi, which via the lines Li and optionally via the transformers Ti on the Grid transfer point 20 are fed into the power grid N ⁇ .
• the voltage-dependent READY ⁇ development of reactive power on a grid-forming generator Gi is realized by a so-called droop controller.
• the output voltage U ⁇ can be set as follows at the output of a grid-forming generator Gi.
• Uo is the reference voltage
• k Q i the slope of the controller i
• I Q i of the reactive current emitted by the generator i and IQ OI the setpoint of the reactive current.
• the reference voltage clamping ⁇ Uo is the same for all generators Gi usually bezo ⁇ gen to their nominal voltage U N i.
• AUio k Q -I Q oi results as an alternative controller form thus
• the two controller regulators can also be implemented in the following form depending on the reactive power.
• the voltage dependent provision of reactive power to a grid supporting generator Gi is realized by another Droop controller.
• the injected reactive power Qi of a generator Gi can be set as follows.
• AI L (YU N1 + Y 2 U N2 ) AU
• the control device 10 can detect the voltage at the grid transfer point 20 for this purpose. Detects the Steuerervor ⁇ direction 10 that the detected voltage at the grid transfer point 20 deviates from the predetermined reference voltage, then the control device 10 then for the reference voltage Uo of all generators Gi calculated (based on the rated voltages U N i) identical voltage difference AU to compensate for the voltage fluctuation at the grid transfer point 20 and thus the voltage at the grid transfer point 20 again to the pre ⁇ given setpoint, for example, the rated voltage to set.
• the adaptation of the voltage and the calculation of the required voltage value required for this purpose can be done by an integral controller (I controller) or a proportional integral controller (PI controller). In this way, in a multi-generator power plant arrangement 1 by targeted, individual and simultaneous adjustment of the setpoint voltages Uo of the generators Gi, the voltage U Ne tz am
• Power transfer point 20 provided a ⁇ to a predetermined reference value.
• a single generator Gi is connected to the grid transfer point 20 via a transformer Ti, as is the case, for example, for the generator G-5 in FIG. 1, it can be assumed in this case that the reactance X T i of the respective transformer Ti is substantially larger than the impedance Z ⁇ the electrical line Li between the generator Gi and the grid transfer point 20. In the case that is so a transformer Ti between a generator Gi and the
• the reactive current I Q os to be set at the generator G-5 is set as follows where i Q oi is the required reactive current that is to be provided by the generator ⁇ Gi.
• i Q oi is the required reactive current that is to be provided by the generator ⁇ Gi.
• the reactive current I QO i can be selected as follows: where l Q oi is the required reactive current from the generator Gi and in the measured or estimated active current of the genera ⁇ gate Gi is. If the active current I P ⁇ is to be estimated, then this can be calculated, for example, by the control device 10 or another device. If k Q i is much larger than the maximum of Xi and Ri, the above formula can be simplified as follows:
• i Q oi is the required reactive current from the generator Gi and ipi is a measured or calculated actual injected active current.
• the index n is the summation of the reactive currents running through all the indices is ⁇ closed to the transformer generators Gi.
• Equation (5) can be transformed by (3) to give (4).
• network AU U ⁇ network Uo
• 1 and 1 is a vector or a square matrix is of the appropriate size having at al ⁇ len provide 1, and 0 is analogous to a zero matrix of appropriate size.
• the distribution of the static part Q i Netzo which is provided by a ⁇ individual generators Gi, the reactive current instruction IQ values OI may be used.
• the distribution of the variable component AI QNe tz can be calculated using the slopes k Q i of the individual controllers are adapted to the generators Gi accordingly. Analogous to the distribution of the variable component of the reactive currents, it is also possible to divide the variable component of the reactive power.
• the desired ratio of reactive currents ⁇ ⁇ is referred to with the vector AI * Q, where it is assumed at ⁇ that the elements of the vector ⁇ ⁇ * add up to one. This results in:
• the scalar parameter ⁇ (AU network / AI Q network ) is a freely selectable design parameter that shows the correlation between the deviation of the reactive current i Q network from its static component iQNetzo, ie ⁇ ⁇ network / and the voltage difference between Mains voltage U Ne tz and Uo indicates.
• ⁇ in the range from a few percent selected so that large variations in the ready ⁇ provided at the grid transfer point 20 reactive power result in only a small variation of the adjusted voltage Uo. This also means that the slope of the controller is very low.
• the control device 10 can determine control variables for the setpoint voltage to be set on all generators Gi and transmit these to the respective generators Gi. Is also the regulator slope on the individual generators In addition, the control device 10 can also determine the respective slope of the controller k Q i and transmit it to the generators Gi. In this case, the division of the reactive power to be generated on the available generators Gi by a user or automatically by a suitable algorithm or the like in the control device 10 can be specified. The control device 10 then determines all required control parameters for the generators Gi and thus controls the reactive power generated by the individual generators Gi such that at the grid transfer point 20 in sum, the required reactive power can be provided and thereby the voltage at the grid transfer point 20 the required Reference value corresponds.
• the STEU ⁇ ervorges 10 may reactive power generated by the Mehrgenerator- power plant arrangement 1 can also be varied in dependence on a voltage variation at the power transfer point twentieth
• FIG. 2 shows a schematic illustration of an embodiment for a power supply network with a multi-generator power plant arrangement 1.
• the power supply network in this embodiment comprises at least one further generator G-z.
• this generator G-z can also feed a variable reactive power component into the energy supply network N.
• the control apparatus 10 can also determine control parameters for this further generator G-z and transmit these to the further generator G-z.
• FIG. 3 shows a further embodiment for a power supply network N with a multi-generator power plant arrangement 1.
• this power supply network also comprises N other generators Gz.
• the further generators Gz can also be generators of a further multi-generator power plant arrangement in which the active electrical power and reactive power are generated by more than one generator and fed into the energy supply network N. becomes.
• the energy supply network N has a higher-level further control device 11, which in turn divides the reactive power to be fed into the energy supply network N and transmits information about the reactive power components to be injected to the control devices arranged hierarchically thereunder, such as the control device 10.
• Darue ⁇ via addition also multilevel hierarchical arrange- are gen possible to divide the distribution of reactive power.
• Figure 4 shows a schematic representation of a Medicarediag ⁇ ramms, as it is based on a method for distributing the reactive power generation in a multi-generator power plant assembly 1.
• a step S1 first of all a generator to be generated by a multi-generator power plant arrangement 1
• step S2 the reactive power to be generated is divided among the generators G-i of the multi-generator power plant arrangement 1.
• the division of the reactive power to be generated on the individual generators G-i can either be specified by a user or automatically determined by an algorithm or the like.
• the distribution of an expected or unexpected reactive power change to the generators can be divided.
• step S3 the control variables for the output voltage of the network-forming generators Gi of the multiple nerator power plant assembly 1 calculated.
• the control quantities for the output voltages of the respective generators are calculated using a reactive power to be fed by the respective generator.
• the calculated control variables for a generator Gi correspond in each case to the reactive power to be generated by the respective generator Gi.
• the calculation of the control variables for the generators Gi can be carried out in particular taking into account the impedances between the generator and the grid feed point. Is between generator Gi and feed-in point 20 a
• Transformer T-i arranged, so the calculation can be made in particular taking into account the reactances of the respective transformer T-i.
• a voltage offset and / or possibly also a slope of a regulator in the generator G-i are calculated.
• step S4 the calculated control quantities are transmitted to the respective generators G-i.
• the present invention relates to a multi-generator power plant arrangement and a method for distributing reactive power generation in a multi-generator power plant arrangement.
• the control parameters for the controller of the individual generators of a multi-generator power plant arrangement are individually calculated based on predetermined parameters and transmitted to the controller of the individual generators.
• the respective reactive power component to be generated can be specified individually.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Supply And Distribution Of Alternating Current (AREA)
• Control Of Eletrric Generators (AREA)

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• 2014
  • 2014-07-21 DE DE102014214151.6A patent/DE102014214151A1/de not_active Withdrawn
• 2015
  • 2015-06-30 EP EP15733701.5A patent/EP3146609A1/de active Pending
  • 2015-06-30 US US15/327,390 patent/US10559959B2/en active Active
  • 2015-06-30 BR BR112017001068A patent/BR112017001068A2/pt not_active Application Discontinuation
  • 2015-06-30 WO PCT/EP2015/064788 patent/WO2016012201A1/de active Application Filing
• 2017
  • 2017-01-13 CO CONC2017/0000334A patent/CO2017000334A2/es unknown
  • 2017-01-18 CL CL2017000144A patent/CL2017000144A1/es unknown

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