WO2014060065A2 - Onduleur électrique et son procédé de fonctionnement - Google Patents

Onduleur électrique et son procédé de fonctionnement Download PDF

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Publication number
WO2014060065A2
WO2014060065A2 PCT/EP2013/002908 EP2013002908W WO2014060065A2 WO 2014060065 A2 WO2014060065 A2 WO 2014060065A2 EP 2013002908 W EP2013002908 W EP 2013002908W WO 2014060065 A2 WO2014060065 A2 WO 2014060065A2
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WIPO (PCT)
Prior art keywords
momentary
power
rotated
frequency
inverter
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PCT/EP2013/002908
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English (en)
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WO2014060065A3 (fr
Inventor
Markus JOSTOCK
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Universite Du Luxembourg
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Priority to EP13780311.0A priority Critical patent/EP2907214A2/fr
Publication of WO2014060065A2 publication Critical patent/WO2014060065A2/fr
Publication of WO2014060065A3 publication Critical patent/WO2014060065A3/fr

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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
    • H02J3/381—Dispersed generators
    • 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
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin

Definitions

  • the present invention relates to means for adapting an power rotation angle of an electrical inverter to match the grid impedance angle at the point of interconnection.
  • the invention further relates to an electrical inverter comprising such means.
  • the present invention also relates to a method of adapting power rotation angle of an electrical inverter to match the grid impedance angle at the point of interconnection.
  • the classic droop control concept relates active power load to the grid frequency and the reactive power load to the grid voltage magnitude by a static head line as indicated in Fig 1 which illustrates the known static droop by relating Q with voltage and P with frequency.
  • the VSI droop control works with a characteristic head line.
  • the VSI adapts its injection frequency to the momentary rate of injected active power with
  • ⁇ vsi is the inverter output frequency
  • fo is the base frequency
  • P is the momentary active power
  • P ra ted is the inverter's rated power
  • droop is the maximum frequency deviation at Prated expressed in per cent.
  • the base frequency fo is a fixed reference value for the droop controller.
  • the working principle of the droop control of voltage source inverters assures that each inverter adapts its frequency independently, according to its actual power injection.
  • the injection frequency differs from the current grid frequency
  • the power angle ⁇ of the VSI voltage drifts with respect to the voltage angle at the end of the connected branch and induces a change in the power flow.
  • This changed power flow provokes frequency changes in the other VSIs in the grid - as these adapt their respective injection frequencies according to the changed power flow - and the whole system finds a new equilibrium point at a new frequency.
  • This concept allows for decoupled control of frequency and voltage in power grids with inductive line characteristics, i.e. generally the medium and high voltage grids.
  • Distributed renewable energy sources mostly inject their power in the low voltage grid. Due to the resistive nature of the low voltage lines, independent control of frequency and voltage is no longer possible with classic droop control. As a consequence, a change in the grid's active power load not only has an effect on frequency, but also on the grid voltage. Vice versa, a change in reactive power load not only influences the grid voltage, but also the grid frequency. This circumstance is illustrated in Fig 2 showing the known effect of rotated active and reactive power on frequency and voltage.
  • the very same load situation S ⁇ has a rotated effect on the low voltage grid and causes a change of f and w rot on frequency and voltage.
  • Fig 3 illustrates how the droop control is applied to the rotated values of active and reactive power.
  • the currently injected active power P and reactive power Q are measured and/or calculated.
  • the rotation block 31 rotates P and Q by an angle ⁇ into P mt and grot, on which the droop control block 32 for frequency / and the droop control block 33 for voltage u are exerted.
  • Frequency ⁇ si and voltage «vsi of the AC source are applied to the power grid 34, resulting in active and reactive power. Since the grid impedance angle ⁇ at the point of connection is not known, it has to be detected in order to find the optimal power rotation angle $ for the VSI, which ideally should match the grid impedance angle ⁇ .
  • the impedance angle could be estimated by general knowledge of the impedance relation R/X of low voltage grids. This assumed angle will most certainly be wrong, but the non-optimal control and the remaining coupling effect between frequency and voltage are accepted and might be considered "good enough”.
  • the grid utility company can provide the impedance angle at the point of connection. This value might be the result of calculations based on the grid model of the utility and thus deviate from the real value at the point of connection.
  • the utility might not have a possibility to measure or calculate values for every point of connection. Depending on the number of VSIs installed by different suppliers, inquiring the impedance angle from the utility might take long and be uneconomic.
  • the impedance can be measured at the PoC with a particular impedance measuring device. This approach is likely to be inefficient due to the necessary costly equipment and time and effort consumption.
  • the CPU or DSP of the VSI can be used to implement a measuring method. While numerous publications have proposed different schemes, not all methods can be implemented with the given limited capacities and capabilities of the VSI. Is has been proposed by D. Thomas, B. Palethorpe, M. Summer: "System impedance measurement for use with active filter control" in Power Electronics and Variable Speed Drives, volume 475, pages 24-28. IEE, September 2000, incorporated herein by reference in its entirety; and Frede Blaabjerg et al., loc. cit. that a measurement could be done e.g. by injection of harmonic currents. A. Luna et al., loc. cit. have suggested high precision voltage and current frequency measurement.
  • the impedance is calculated based on a measurement of voltage and current (transient or steady state) at a specific (inter)harmonic frequency. Some of these methods interpolate the impedance at fundamental frequency, calculating a value deviating from the real situation. Also, harmonic injection leads to waveform distortion during the measurement.
  • a first aspect of the present invention relates to means for adapting a power rotation angle ⁇ of an electrical inverter to an unknown grid impedance angle ⁇ of the electric grid or busbar at a point of connection of the electrical grid or busbar with the inverter output.
  • the power rotation angle adapting means comprise means for detecting a momentary active power of the inverter; means for detecting a momentary reactive power of the inverter; means for generating a rotated momentary active power and a rotated momentary reactive power by carrying out a rotation operation of the momentary active power and the momentary reactive power by a rotation angle; means for providing a reference frequency, means for controlling a momentary inverter output frequency in response to the rotated momentary active power and the reference frequency; and means for controlling a momentary inverter output voltage.
  • the reference frequency providing means further comprise means for providing a nominal frequency, wherein the nominal frequency corresponds to the nominal grid or busbar frequency, and means for applying a momentary jitter signal to the nominal frequency, so that the reference frequency varies in time.
  • the inverter further comprises means for adapting the power rotation angle in response to the rotated momentary active power and the rotated momentary reactive power.
  • the means for adapting the power rotation angle in response to the detected rotated momentary active power and the detected rotated momentary reactive power may further comprise means for detecting fluctuations in time in one or both of the rotated momentary active power and the rotated momentary reactive power.
  • the means for adapting the power rotation angle may further comprise means for adapting the power rotation angle & until it approaches, or optionally matches, the grid impedance angle ⁇ .
  • the means for adapting the power rotation angle may further comprise means for judging the quality of the match.
  • the means for judging the quality of the match may further comprise means for observing the rotated momentary active and reactive power which are altered through a jittering inverter frequency.
  • the means may further comprise meaiis for controlling a momentary inverter output frequency in response to the rotated momentary active power and the reference frequency.
  • the means for controlling the momentary inverter output frequency may comprise frequency droop control means.
  • the means of any one of the preceding claims may further comprise means for controlling a momentary inverter output voltage in response to the rotated momentary reactive power.
  • the means for controlling a momentary inverter output voltage may comprise voltage droop control means.
  • the means for manipulating the power angle may comprise a minimum correlation finding means in response to only the rotated momentary reactive power.
  • the minimum correlation finding means further may comprise means for calculating at least one harmonic coefficient.
  • the means for calculating at least one harmonic coefficient may further comprise means for performing a discrete Fourier transformation.
  • the minimum correlation finding means may further comprise means for performing an optimal control, optionally e.g. a linear quadratic controller or a H-infinity controller, such as known to the skilled person (http://en.wikipedia.org/wiki/Optimal_control).
  • the inverter also comprises means for adapting an power rotation angle ⁇ of the inverter to the unknown grid impedance angle ⁇ of the electric grid or busbar at a point of connection with the inverter output in accordance with one of the configurations of the first aspect.
  • the inverter may be of the voltage source or the current source type.
  • a third aspect of the present invention relates to a method for adapting the power angle of an electrical inverter, the method comprising the steps of: outputting an alternating current (AC) power to an electric grid or busbar, the electric grid or busbar representing at the inverter output an unknown impedance comprising a resistance and a reactance, wherein an unknown grid impedance angle ⁇ is determined by arctan R/X; detecting a momentary active power of the inverter; means for detecting a momentary reactive power of the inverter; generating a rotated momentary active power and a rotated momentary reactive power by carrying out a rotation operation of the momentary active power and the momentary reactive power by a rotation angle ⁇ ; providing a reference frequency, wherein the reference frequency corresponds to the nominal inverter output frequency.
  • AC alternating current
  • the step of providing a reference frequency further comprises applying a momentary jitter signal to a nominal frequency, so that the reference frequency applied to the inverter output frequency controlling means varies in time.
  • the method further comprises the step of adapting the power rotation angle ⁇ in response to the detected rotated momentary active power and the detected rotated momentary reactive power.
  • the method may further comprise means for detecting fluctuations in time in one or both of the rotated momentary active power and the rotated momentary reactive power.
  • the method may further comprise adapting the power rotation angle & until it approaches, or optionally matches, the grid impedance angle ⁇ .
  • the method may further comprise judging the quality of the match.
  • the step of judging the quality of the match may further comprise observing the rotated momentary active and reactive power which are altered through a jittering inverter frequency.
  • the method may further comprise controlling a momentary inverter output frequency in response to the rotated momentary active power and the reference frequency.
  • the step of controlling the momentary inverter output frequency may further comprise applying a frequency droop control.
  • the method may further comprise controlling a momentary inverter output voltage in response to the rotated momentary reactive power.
  • the step of controlling a momentary inverter output voltage may further comprise applying a voltage droop control.
  • the step of manipulating the power rotation angle may further comprise finding a minimum correlation in response to only the rotated momentary reactive power.
  • the step of finding a minimum correlation further comprises calculating at least one harmonic coefficient.
  • the step of calculating at least one harmonic coefficient further comprises performing a discrete Fourier transformation.
  • the step of finding a minimum correlation further comprises performing an optimal control.
  • The may be applied to an inverter of the voltage source or the current source type.
  • Fig 1 is a diagram illustrating the known static droop by relating Q with voltage and P with frequency.
  • Fig 2 is a diagram showing the known effect of rotated active and reactive power on frequency and voltage.
  • Fig 3 is a diagram illustrating the known droop control applied to the rotated values of active and reactive power.
  • Fig 4 is a diagram showing the droop head line in accordance with the present invention.
  • Fig 5 is a block diagram of a control structure of an electrical inverter in accordance with the present invention.
  • Fig 5a is a block diagram of a control structure of an electrical inverter and angle quality evaluation and angle manipulation in accordance with the present invention.
  • Fig 6 is a flowchart illustrating a method in accordance with the present invention.
  • Fig 7 is a block diagram of an embodiment with an optimal controller to minimise jitter Q.
  • Fig 8 is a power over time diagram showing the reaction of P, P mt , Q and Q I0t .
  • a VSI can adjust its output frequency arbitrarily, which the present invention proposes to exploit for impedance detection.
  • the present invention proposes to combine an adaptive change of rotation angle until optimal adaptation to the impedance angle is reached, and a slowly jittering base frequency for the droop controller as an indicator of the rotation effect.
  • the exact signal form chosen for the jitter signal may be chosen from any suitable waveform, e.g. sinusoidal, sawtooth, triangle, binary, rectangular, or any other oscillating signal forms.
  • the present invention proposes to detect the optimal rotation angle 9, which is dependent on the grid impedance angle ⁇ , by the VSI applying a slowly oscillating base frequency fo + jitter(i) to the subordinate power or current controller.
  • a slowly oscillating base frequency fo + jitter(i) fo + jitter(i) to the subordinate power or current controller.
  • the head line swings vertically with an amplitude A around the base value in the grey band.
  • the jittering of the inverter's injection frequency is independent from the subordinate controller. It can be applied to droop controllers with different types of droops or other types of controllers, like e.g. maximum power point controllers.
  • the jitter will also be noticeable at the power measurement.
  • the measured active and reactive power are rotated by the rotation angle $ into rotated coordinates of active and reactive power ⁇ ⁇ and Q TOt With a non-optimal rotation angle the swing will be visible in both rotated active power rot and rotated reactive power Q rot .
  • This effect is exploited to adjust the rotation angle in accordance with the present invention: For detection, the power rotation angle ⁇ is changed until the jitter in P rot reaches its maximum and/or the jitter in Qrot reaches its minimum.
  • Fig 5 a is a block diagram of a control structure of an electrical inverter and angle quality evaluation and angle manipulation in accordance with the present invention.
  • the evaluation of the maximum jitter in rot or the minimum jitter in Q TOt may be separated from the adaptation of the rotation angle 9 ⁇ .
  • the evaluation of the rotation effect quality can be done automatically, e.g. in block 55a with a detection of the jitter signal in the rotated reactive power Q TO t(t) or e.g. by the calculation of harmonic Fourier coefficients, or it can be done manually by a human user.
  • the adaptation of the power rotation angle $ can be done e.g. in a linear sweep from 0 to ⁇ /2 (i.e.
  • the frequency jitters slowly around a base value fo with a swing period significantly larger than the grid period, i.e. T osc » 1/ f 0 , e.g. T osc ⁇ 0.5 seconds, and with an amplitude considerably smaller than the grid frequency A « f 0 , e.g. A ⁇ 0.00025 -fo .
  • the frequency set point is overlaid with a sinusoidal jitter signal, e.g.
  • the optimization can e.g. be done by detecting the exciter signal jitterif) in the measured reactive power signal Q(t) . Since the oscillation period T osc is known, only one complex Fourier coefficient needs to be calculated with very low computing resources from the measured (discrete) reactive power measurements Q[k]. With the sample time r sam pie the number of samples per oscillation is
  • the controller output is the rotation angle & which is fed into the rotation matrix. While the droop control is continuously enacted on the active and reactive power, the influence of the slow frequency oscillations on the reactive power will be influenced by the actual rotation angle
  • Fig 5 is a block diagram depicting a control structure of an electrical inverter in accordance with the present invention.
  • the adaptation of the rotation angle 3 through a minimum correlation finder 56, is based on the measurement of the reactive power Q.
  • the currently injected active power P and reactive power Q are measured and/or calculated.
  • the rotation block 51 rotates P and Q by an angle ⁇ into P I0t and Q mt .
  • a jitter signal jitterif is added to the reference frequency fo.
  • the droop control block 52 therefore applies a modulated headline corresponding to fo + jitterif) for droop control of frequency Jvsi-
  • the droop control block 53 applies a non-modulated headline for droop control of voltage «vsi-
  • Frequency J si and voltage MVSI of the AC source are applied to the power grid 54, resulting in active and reactive power.
  • the jitter signal jitterif) which has been applied to the reference frequency f becomes detectable in the measured values of P(t) and Q(t), and in the rotated values P ro t(t) and Q TO t(t).
  • a minimum correlation finder 56 the rotation angle ⁇ is changed, until correlation coefficient reaches its minimum in Q mt .
  • the frequency variation reaches a minimum influence on Q, and simultaneously reaches a maximum influence on active power P when the rotation angle ⁇ matches the grid impedance angle at the point of connection.
  • the optimum power rotation angle & 0 p t is determined as the grid impedance angle ⁇ .
  • the droop control can be applied to the rotated values of P and Q for independent control of frequency and voltage.
  • step 61 When, e.g. in normal operation of the inverter, an adaptation of the power rotation angle 9 is requested, see step 61 , step 62 foresees that a jitter signal jitterif) is applied to the reference frequency fo.
  • step 63 the power rotation angle & is changed, and reactive power is monitored for a decrease in Q m and/or active power is monitored for an increase in rot . If this is the case, step 64 foresees a further change of the power rotation angle 9 ⁇ , and step 63 is executed again. If no further change in reactive power Q mX and/or active power P mt is observed, step 65 provides that the output power rotation angle 9 is stored. Finally, in step 66 the jitter signal is stopped and normal operation is resumed.
  • the search of the optimal rotation angle can be done arbitrarily in the range of 9 from 0 to ⁇ /2.
  • the search can done e.g. linearly in a single sweep or e.g. in a circular search or e.g. in a non-linear binary search.
  • the increment of the power rotation angle ⁇ depends on the sample rate, i.e. on the clock rate of execution of the program, respectively how fast the power can be measured and calculated, as well as on setting of the minimum finder control.
  • the person skilled in the art is aware of the classical control problem to tune a controller so that it quickly reaches its set point, perhaps including an overshoot, but without becoming instable.
  • the increment thus depends strongly on the implementation chosen.
  • the step size was variable due to the type of controllers used: the bigger the DFT coefficient, the bigger the step size.
  • Fig 7 shows a block diagram of an implementation with an optimal controller to minimise jitter in Q TOt . Fig.
  • FIG. 7 shows the adaptation of the rotation angle through a minimum correlation finder, based on the measurement of the reactive power Q mt .
  • the currently injected active power P and reactive power Q are measured and/or calculated.
  • the rotation block 71 rotates P and Q by an angle $ into P mt and Q mX .
  • a jitter signal jitterif is added to the reference frequency fo.
  • the droop control block 72 therefore applies a modulated headline corresponding to fo + jitter ⁇ f) for droop control of frequency f s ⁇ -
  • the droop control block 73 applies a non-modulated headline for droop control of voltage wvsi-
  • Frequency ⁇ vsi and voltage wvsi of the AC source are applied to the power grid 74, resulting in active and reactive power.
  • the jitter signal jitterif) which has been applied to the reference frequency f becomes detectable in the measured values of Pit) and Qif), and in the rotated values P ro t( and Q TO iif)-
  • the jitter signal jitterif) may Y be chosen sinusoidal, sawtooth, triangle, binary or any other oscillating signal forms, in the present embodiment it is preferred that the jitter signal jitterif) be a sine wave, hence the minimum correlation finder 76 comprises a Digital Fourier Transformation (DFT) 77 and an optimal controller 78.
  • the DFT 77 calculates preferably the coefficient of first sine fundamental of the jitter signal jitter ⁇ t) from the value of £? ro t( - Of course, one or more alternative fundamentals might also be used.
  • Via a controller 78 the power rotation angle & is changed, until the DFT coefficient reaches its minimum in Q l0t .
  • the frequency variation reaches a minimum influence on Q, and simultaneously reaches a maximum influence on active power P when the power rotation angle & matches the grid impedance angle ⁇ at the point of connection.
  • the impedance angle is determined as $ opt .
  • $ opt the optimal angle $ opt the droop control can be applied to the rotated values of P and Q for independent control of frequency and voltage.
  • the swing in Q minimises only two seconds after the algorithm was started.
  • a subordinate droop control is not mandatory for the present invention to work.
  • the power angle detection can be performed in inverters with different control concepts.
  • the present invention works also for other droop modes like Q(P) or ⁇ ( ⁇ /) on a stiff grid, such as those mentioned in J. Van den Keybus, loc. cit.
  • VSI equipped with the present invention are able to control voltage and frequency in an independent manner at any point of connection.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)
  • Control Of Electric Motors In General (AREA)

Abstract

La présente invention concerne des moyens d'adaptation d'un angle de rotation de puissance d'un onduleur électrique pour qu'il corresponde à l'impédance de grille inconnue au point de connexion. L'invention concerne en outre un onduleur électrique comprenant de tels moyens. La présente invention concerne également un procédé d'adaptation de l'angle de rotation de puissance d'un onduleur électrique pour qu'il corresponde à l'impédance de grille inconnue au point de connexion.
PCT/EP2013/002908 2012-10-15 2013-09-27 Onduleur électrique et son procédé de fonctionnement WO2014060065A2 (fr)

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EP13780311.0A EP2907214A2 (fr) 2012-10-15 2013-09-27 Onduleur électrique et son procédé de fonctionnement

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LU92083 2012-10-15
LU92083A LU92083B1 (en) 2012-10-15 2012-10-15 Electrical inverter and method of operation

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WO2014060065A2 true WO2014060065A2 (fr) 2014-04-24
WO2014060065A3 WO2014060065A3 (fr) 2015-04-09

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3098930A1 (fr) * 2015-05-29 2016-11-30 Delta Electronics, Inc. Dispositif et methode de detection de l'argument de l'impedance de sortie d'un onduleur
EP3347960A4 (fr) * 2015-09-11 2019-03-20 Enphase Energy, Inc. Procédé et appareil d'adaptation d'impédance dans des unités de conditionnement d'énergie commandées par chute d'impédance virtuelle
CN109787280A (zh) * 2019-01-17 2019-05-21 合肥工业大学 基于起始阻抗角的逆变器系统线路阻抗模拟方法
WO2019145376A1 (fr) 2018-01-25 2019-08-01 Universite Du Luxembourg Estimation de conductance et de susceptance de réseau pour la commande de puissance dans des onduleurs connectés à un réseau
CN110808602A (zh) * 2019-11-15 2020-02-18 华北电力大学 一种多端柔性直流输电系统改进附加频率控制方法及系统
NL2026118B1 (en) * 2020-05-07 2021-11-23 Univ Central South Method and system of general decentralized control for cascaded inverters
EP4007106A4 (fr) * 2019-07-23 2023-05-03 Toshiba Mitsubishi-Electric Industrial Systems Corporation Dispositif de conversion de puissance et système de source d'alimentation distribuée

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10008854B2 (en) 2015-02-19 2018-06-26 Enphase Energy, Inc. Method and apparatus for time-domain droop control with integrated phasor current control

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2483879A (en) * 2010-09-22 2012-03-28 Qingchang Zhong Proportional load sharing for inverters

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2483879A (en) * 2010-09-22 2012-03-28 Qingchang Zhong Proportional load sharing for inverters

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
ADRIAN V TIMBUS ET AL: "Grid Impedance Identification Based on Active Power Variations and Grid Voltage Control", INDUSTRY APPLICATIONS CONFERENCE, 2007. 42ND IAS ANNUAL MEETING. CONFE RENCE RECORD OF THE 2007 IEEE, IEEE, PI, 1 September 2007 (2007-09-01), pages 949-954, XP031146038, ISBN: 978-1-4244-1259-4 *
CIOBOTARU M ET AL: "Online grid impedance estimation for single-phase grid-connected systems using PQ variations", POWER ELECTRONICS SPECIALISTS CONFERENCE, 2007. PESC 2007. IEEE, IEEE, PISCATAWAY, NJ, USA, 17 June 2007 (2007-06-17), pages 2306-2312, XP031218627, ISBN: 978-1-4244-0654-8 *
IOV F ET AL: "Power Electronics and Control of Renewable Energy Systems", POWER ELECTRONICS AND DRIVE SYSTEMS, 2007. PEDS '07. 7TH INTERNATIONAL CONFERENCE ON, IEEE, PISCATAWAY, NJ, USA, 27 November 2007 (2007-11-27), pages P-6, XP031242478, ISBN: 978-1-4244-0644-9 *
JOSEP M GUERRERO ET AL: "Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output Impedance", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, IEEE SERVICE CENTER, PISCATAWAY, NJ, USA, vol. 54, no. 2, 1 April 2007 (2007-04-01), pages 994-1004, XP011175314, ISSN: 0278-0046, DOI: 10.1109/TIE.2007.892621 *
VASQUEZ J C ET AL: "Adaptive Droop Control Applied to Voltage-Source Inverters Operating in Grid-Connected and Islanded Modes", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, IEEE SERVICE CENTER, PISCATAWAY, NJ, USA, vol. 56, no. 10, 1 October 2009 (2009-10-01), pages 4088-4096, XP011271188, ISSN: 0278-0046, DOI: 10.1109/TIE.2009.2027921 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3098930A1 (fr) * 2015-05-29 2016-11-30 Delta Electronics, Inc. Dispositif et methode de detection de l'argument de l'impedance de sortie d'un onduleur
US20160349299A1 (en) * 2015-05-29 2016-12-01 Delta Electronics, Inc. Detecting device and detecting method for detecting output impedance angle of inverter
CN106291108A (zh) * 2015-05-29 2017-01-04 台达电子工业股份有限公司 逆变器的输出阻抗角检测装置及检测方法
US9933468B2 (en) 2015-05-29 2018-04-03 Delta Electronics, Inc. Detecting device and detecting method for detecting output impedance angle of inverter
EP3347960A4 (fr) * 2015-09-11 2019-03-20 Enphase Energy, Inc. Procédé et appareil d'adaptation d'impédance dans des unités de conditionnement d'énergie commandées par chute d'impédance virtuelle
US10707681B2 (en) 2015-09-11 2020-07-07 Enphase Energy, Inc. Method and apparatus for impedance matching in virtual impedance droop controlled power conditioning units
US11289910B2 (en) 2015-09-11 2022-03-29 Enphase Energy, Inc. Method and apparatus for impedance matching in virtual impedance droop controlled power conditioning units
WO2019145376A1 (fr) 2018-01-25 2019-08-01 Universite Du Luxembourg Estimation de conductance et de susceptance de réseau pour la commande de puissance dans des onduleurs connectés à un réseau
CN109787280A (zh) * 2019-01-17 2019-05-21 合肥工业大学 基于起始阻抗角的逆变器系统线路阻抗模拟方法
EP4007106A4 (fr) * 2019-07-23 2023-05-03 Toshiba Mitsubishi-Electric Industrial Systems Corporation Dispositif de conversion de puissance et système de source d'alimentation distribuée
CN110808602A (zh) * 2019-11-15 2020-02-18 华北电力大学 一种多端柔性直流输电系统改进附加频率控制方法及系统
NL2026118B1 (en) * 2020-05-07 2021-11-23 Univ Central South Method and system of general decentralized control for cascaded inverters

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