Patents by Inventor Heinz-Hermann Letas

Heinz-Hermann Letas has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11018609
    Abstract: A method for controlling a wind turbine with a wind rotor (2), a doubly-fed induction generator (1) driven therewith, and a converter (4), which is electrically connected to feed electrical energy into an electrical grid (8) with at least one grid parameter, and having a controller with a memory in which rotation rate parameters are stored, characterized in that at least one variable characteristic curve is determined between at least one of the rotation rate parameters and the at least one grid parameter, the at least one characteristic is stored in the memory, the at least one grid parameter is measured, the grid parameter measurements are fed to the controller, the values of the at least one rotation rate parameter associated with the grid parameter measurements via the at least one characteristic curve are activated.
    Type: Grant
    Filed: January 11, 2019
    Date of Patent: May 25, 2021
    Assignee: Senvion GmbH
    Inventor: Heinz-Hermann Letas
  • Patent number: 10879783
    Abstract: A converter controller is provided, by which the current valves are controlled by means of a switching frequency. It is provided to alter the switching frequency in a step-wise manner between a first and at least one second integral multiple of the grid frequency. According to the invention, this is effected in that the switching frequency is switched over cyclically, and a frequency spacing between the switching frequencies is at least double the grid frequency, specifically in such a manner that none of the switching frequencies is an integral multiple of another of the switching frequencies. In this way, harmonics can be selectively reduced, no intermediate frequencies being produced, owing to the integrality in relation to the grid frequency.
    Type: Grant
    Filed: September 24, 2018
    Date of Patent: December 29, 2020
    Assignee: SENVION GmbH
    Inventor: Heinz-Hermann Letas
  • Patent number: 10637248
    Abstract: A wind turbine includes a wind rotor, a generator, and a converter. The generated electric power is fed from the converter by means of a feed to a turbine transformer for delivery to a grid. The feed is designed as a double branch including a power-branched power circuit breaker unit having a first feed line and a second feed line connected in parallel, wherein a separate low-voltage winding of the turbine transformer and a separate power circuit breaker at the connector of the converter is associated with each feed line.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: April 28, 2020
    Assignee: SENVION GmbH
    Inventor: Heinz-Hermann Letas
  • Patent number: 10389137
    Abstract: A wind turbine having a wind rotor, a generator powered therewith for generating electrical energy, and a connecting line for delivering the electrical energy, optionally via a system transformer. The wind turbine includes a voltage expander that expands the voltage range of the wind turbine by means of an auxiliary voltage source. The voltage expander comprises a small transformer of having a primary and a secondary winding, and a switching mechanism. The small transformer is looped into the connecting line with the secondary winding, and the switching mechanism is connected to the primary winding of the small transformer, actuating the primary winding in a switchable multi-stage manner. Thus, a multi-stage expansion of the voltage range of the wind turbine is achieved, wherein due to the arrangement of the small transformer lengthwise in the connecting line, the small transformer can have a fraction of the nominal power of the wind turbine.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: August 20, 2019
    Assignee: SENVION GMBH
    Inventor: Heinz-Hermann Letas
  • Publication number: 20190214927
    Abstract: A method for controlling a wind turbine with a wind rotor (2), a doubly-fed induction generator (1) driven therewith, and a converter (4), which is electrically connected to feed electrical energy into an electrical grid (8) with at least one grid parameter, and having a controller with a memory in which rotation rate parameters are stored, characterized in that at least one variable characteristic curve is determined between at least one of the rotation rate parameters and the at least one grid parameter, the at least one characteristic is stored in the memory, the at least one grid parameter is measured, the grid parameter measurements are fed to the controller, the values of the at least one rotation rate parameter associated with the grid parameter measurements via the at least one characteristic curve are activated.
    Type: Application
    Filed: January 11, 2019
    Publication date: July 11, 2019
    Inventor: Heinz-Hermann Letas
  • Publication number: 20190170117
    Abstract: A wind farm comprising wind energy installations, a farm-internal network and a collecting station, wherein a central transmission line is connected to the collecting station. The wind energy installations each have controllers for active/reactive power, which act on the respective converter depending on the phase angle. The wind farm has an autonomous reference angle generator, which generates a reference angle (?ext) for an artificial coordinate system defining an active and reactive axis in the farm network. The converters of the wind energy installations are thus externally controlled in terms of phase. The wind energy installation does not effect feeding with exactly the phase angle (?lcl) such as prevails at its connecting terminals, but rather with that predefined externally.
    Type: Application
    Filed: December 4, 2018
    Publication date: June 6, 2019
    Applicant: SENVION GmbH
    Inventor: Heinz-Hermann LETAS
  • Publication number: 20190097520
    Abstract: A converter controller is provided, by which the current valves are controlled by means of a switching frequency. It is provided to alter the switching frequency in a step-wise manner between a first and at least one second integral multiple of the grid frequency. According to the invention, this is effected in that the switching frequency is switched over cyclically, and a frequency spacing between the switching frequencies is at least double the grid frequency, specifically in such a manner that none of the switching frequencies is an integral multiple of another of the switching frequencies. In this way, harmonics can be selectively reduced, no intermediate frequencies being produced, owing to the integrality in relation to the grid frequency.
    Type: Application
    Filed: September 24, 2018
    Publication date: March 28, 2019
    Applicant: SENVION GmbH
    Inventor: Heinz-Hermann LETAS
  • Publication number: 20180287369
    Abstract: A wind turbine includes a wind rotor, a generator, and a converter. The generated electric power is fed from the converter by means of a feed to a turbine transformer for delivery to a grid. The feed is designed as a double branch including a power-branched power circuit breaker unit having a first feed line and a second feed line connected in parallel, wherein a separate low-voltage winding of the turbine transformer and a separate power circuit breaker at the connector of the converter is associated with each feed line.
    Type: Application
    Filed: March 22, 2018
    Publication date: October 4, 2018
    Applicant: SENVION GmbH
    Inventor: Heinz-Hermann LETAS
  • Patent number: 9787174
    Abstract: A converter including a converter control for a wind turbine and a chopper, wherein the converter control includes a dynamic limit value which is allowable for a first tolerance time and a static limit value of the converter. Furthermore, an overcurrent module is provided which includes a limit value expander which is designed to increase the static limit value by a portion of the difference from the dynamic limit value as additional current, and a dynamic module which interacts with the limit value expander in such a way that overcurrents between the static limit value which is increased by the additional current and the dynamic limit value are routed in a first stage to the converter and in a second stage at least partially to the chopper, wherein a switch is made to the second stage after a second tolerance time.
    Type: Grant
    Filed: March 27, 2013
    Date of Patent: October 10, 2017
    Assignee: SENVION SE
    Inventors: Heinz-Hermann Letas, Malte Mohr
  • Patent number: 9515594
    Abstract: A wind turbine comprises a wind rotor, a generator driven by the wind rotor, a converter, wherein the generator and the converter generate electrical energy output via a connecting line with an inductively acting line reactor to a grid, and an overvoltage protection device comprising a plurality of different active modules, which are designed in such a way that they each effect, in different ways, a reduction in the voltage at the output of the converter, a switching matrix, which connects and disconnects the different active modules, and a selector comprising an overvoltage classifier, which is designed to select a predetermined stage depending on the overvoltage and to actuate the switching matrix in such a way that successive ones of the active modules are disconnected, wherein the overvoltage classifier defines a plurality of overvoltage ranges by virtue of in each case the selector setting different switching groups.
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: December 6, 2016
    Assignee: SENVION SE
    Inventors: Heinz-Hermann Letas, Steffen Pingel
  • Publication number: 20160308368
    Abstract: A wind turbine having a wind rotor, a generator powered therewith for generating electrical energy, and a connecting line for delivering the electrical energy, optionally via a system transformer. The wind turbine includes a voltage expander that expands the voltage range of the wind turbine by means of an auxiliary voltage source. The voltage expander comprises a small transformer of having a primary and a secondary winding, and a switching mechanism. The small transformer is looped into the connecting line with the secondary winding, and the switching mechanism is connected to the primary winding of the small transformer, actuating the primary winding in a switchable multi-stage manner. Thus, a multi-stage expansion of the voltage range of the wind turbine is achieved, wherein due to the arrangement of the small transformer lengthwise in the connecting line, the small transformer can have a fraction of the nominal power of the wind turbine.
    Type: Application
    Filed: March 13, 2014
    Publication date: October 20, 2016
    Applicant: SENVION GMBH
    Inventor: Heinz-Hermann LETAS
  • Patent number: 9416772
    Abstract: A wind power plant is characterized in that a measurement device (18) is provided for the determination of the load on an electric motor (13, 14), wherein the control device (16, 17) reduces the load on the motor (13, 14) by reducing the rotational speed of the rotor (11), by changing the blade angle of the at least one rotor blade (12, 12?) and/or by reducing the output of the wind power plant (10) when a preselectable first load limit of the electric motor (13, 14) is exceeded.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: August 16, 2016
    Assignee: SENVION SE
    Inventors: Jens Altemark, Heinz-Hermann Letas, Eckart Hopp, Thomas Kruger
  • Patent number: 9397599
    Abstract: A harmonic predictor for a wind farm comprising at least two wind turbines, each having a generator with a converter for generating electrical energy. The harmonic predictor determines the harmonic component expected from the wind farm in order to limit the harmonic component to a harmonic limit. The harmonic predictor comprises a calculation module, an iteration module and a summing module. The calculation module calculates a complex mean value over at least one period of the harmonic component of one of the wind turbines and determines a first equivalent vector therefrom. The iteration module successively connects the calculation module to at least one other of the wind turbines to form at least one second equivalent vector. The summing module sums the equivalent vectors to form a total vector and compares the total vector with the harmonic limit.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: July 19, 2016
    Assignee: Senvion SE
    Inventor: Heinz-Hermann Letas
  • Publication number: 20150333677
    Abstract: A wind turbine comprises a wind rotor, a generator driven by the wind rotor, a converter, wherein the generator and the converter generate electrical energy output via a connecting line with an inductively acting line reactor to a grid, and an overvoltage protection device comprising a plurality of different active modules, which are designed in such a way that they each effect, in different ways, a reduction in the voltage at the output of the converter, a switching matrix, which connects and disconnects the different active modules, and a selector comprising an overvoltage classifier, which is designed to select a predetermined stage depending on the overvoltage and to actuate the switching matrix in such a way that successive ones of the active modules are disconnected, wherein the overvoltage classifier defines a plurality of overvoltage ranges by virtue of in each case the selector setting different switching groups.
    Type: Application
    Filed: May 15, 2015
    Publication date: November 19, 2015
    Applicant: SENVION SE
    Inventors: Heinz-Hermann LETAS, Steffen PINGEL
  • Patent number: 9121882
    Abstract: A wind energy installation test device for defined production of grid system faults, and a method thereof. The test device can include an output configured to connect to a wind energy installation, an input configured to connect to a grid system, and a switching device for connection of an electrical disturbance component relating to a grid system parameter. An autotransformer can be used for the electrical disturbance component. The grid system in a sound state can be connected to a primary winding connection and the grid system in a disturbed state with respect to the grid system parameter can be output at a secondary winding connection.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: September 1, 2015
    Assignee: SENVION SE
    Inventor: Heinz-Hermann Letas
  • Publication number: 20150048683
    Abstract: A converter including a converter control for a wind turbine and a chopper, wherein the converter control includes a dynamic limit value which is allowable for a first tolerance time and a static limit value of the converter. Furthermore, an overcurrent module is provided which includes a limit value expander which is designed to increase the static limit value by a portion of the difference from the dynamic limit value as additional current, and a dynamic module which interacts with the limit value expander in such a way that overcurrents between the static limit value which is increased by the additional current and the dynamic limit value are routed in a first stage to the converter and in a second stage at least partially to the chopper, wherein a switch is made to the second stage after a second tolerance time.
    Type: Application
    Filed: March 27, 2013
    Publication date: February 19, 2015
    Applicant: SENVION SE
    Inventors: Heinz-Hermann Letas, Malte Mohr
  • Patent number: 8934270
    Abstract: Controlling a converter of a wind turbine is disclosed. The converter is connected to a rotor of a doubly fed asynchronous generator in order to feed electrical energy into an electric network. The converter comprises a network-side inverter, a generator-side inverter, and a controller, which outputs target values for demanded reactive power to at least one of the inverters. A reactive power target signal is determined for the portion that the network-side inverter contributes to the demanded reactive power QT, a slip signal is determined from the frequency of the network and the rotational speed of the generator, a gain value is calculated according to the slip signal, and the gain value is modified according to the reactive power target signal for the network-side inverter. The distribution of the reactive power between the two inverters is thus optimized over a wide operating range, not only at individual predetermined operating points.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: January 13, 2015
    Assignee: Senvion SE
    Inventor: Heinz-Hermann Letas
  • Patent number: 8749082
    Abstract: A wind energy installation, monitoring device, and method. An exemplary wind energy installation includes a rotor including at least one blade and a generator configured to be driven by the rotor to produce electrical energy. The installation also includes a pitch device configured to vary the at least one blade of the rotor. The pitch device includes a power supply unit with a battery, an actuating drive, a monitoring unit, and a load module configured to switch the actuating drive between an operating mode and a test mode. In the test mode, the actuating drive forms a preselectable defined load for the battery. Accordingly, a high and reproducible load not dependent upon environmental conditions may be applied to conduct a stress test, even during ongoing operation.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: June 10, 2014
    Assignee: Senvion SE
    Inventors: Heinz-Hermann Letas, Matthias Peters
  • Patent number: 8710689
    Abstract: A wind energy installation includes a rotor, a generator driven by the rotor, and a converter for generating electrical power which is output into a power supply system via a transformer. The installation also includes an open-loop control system having an open-loop converter control unit. The open-loop control system supplies an actuating signal for a reactive component to the converter. The installation further includes a voltage measurement device arranged on the transformer. The voltage signal of the voltage measurement device is applied to an input of a state-dependent setpoint value shifter, whose output signal is applied to a limitation module for the reactive component acting on the converter. With this configuration, the installation can be better protected and the transformer can be better utilized.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: April 29, 2014
    Assignee: Senvion SE
    Inventor: Heinz-Hermann Letas
  • Patent number: 8692419
    Abstract: A method is provided for operating a wind power plant (15-19) with a rotor-driven (25-29) electric generator (30) for delivering electric power to an electric grid (31) which provides a grid voltage in which, when excess voltage prevails in the grid (31), idle power from the wind power plant (15-19) is fed to the grid (31) in order to lower the voltage. A wind power plant is provided (15-19) with a rotor-driven electric generator (30) for delivering electric power to an electric grid (31) in which when excess voltage prevails in the grid idle power from the wind power plant (15-19) is fed to the grid (31) in order to lower the voltage. Monitoring occurs to determine whether within a predeterminable time a voltage was lowered to a predeterminable reference value and/or an idle current is delivered which is greater than or equal to a predeterminable idle current reference value.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: April 8, 2014
    Assignee: Repower Systems SE
    Inventors: Jens Fortmann, Heinz-Hermann Letas