Sma Solar Technology Ag

Henrik Wolf

Sven Bremicker

Oliver Prior

Marek Rylko

Milosz Handzel

Thomas Schroeder

Milosz Szarek

Adrian Haering

Marcin Kacki

Benedikt Kuenzel

Artur Mulawa

Piotr Otwinowski

Frank Greizer

Joachim Ralf Laschinski

Tobias Mueller

Stefan Buchhold

Pablo Ignacio Correa Vasquez

Uwe Stickelmann

Harald Drangmeister

Niels Berger

Torben Westphal

Thomas Wegener

Andreas Jeppe

Christian Bode

Daniel Clemens

Carsten Ewig

Tobias Müller

Tomasz Napierala

Frank Rueckmann

Julia Pinne

Matthias Walter

Frank RÜCKMANN

Sven Bremiker

Adrian Häring

Thomas SCHRÖDER

Benedikt Künzel

Uwe Stickelman

A power generation system for feeding electrical power from a generation unit into a three-phase grid via three AC terminals is disclosed. The system includes a relay arrangement for disconnecting the system from the grid having at least three relays. Each of the three relays includes a control coil and two switching contacts operated by the corresponding control coil. Each of the AC terminals is connectable to the grid via a first and a second switching contact, each of which is assigned to a different one of the relays. Further disclosed are a relay arrangement and an inverter with a relay arrangement.

Power generation system and inverter for feeding power into a three-phase grid

An inductor assembly is disclosed that includes a magnetic core with a center leg and a number n of phase legs, wherein n is an integer and n&#x3e;1. Each phase leg is magnetically connected to the center leg by an upper bridge and a lower bridge to form a magnetic main loop, a midpoint of the phase leg being magnetically connected to a center point of the center leg by a shunt element including a gap. Each phase leg further includes an upper inductor coil disposed on an upper phase leg section located between the midpoint and the upper bridge and a lower inductor coil disposed on a lower phase leg section located between the midpoint and the lower bridge. Alternatively, the upper and lower inductor coils are disposed on respective upper and lower bridges.

Inductor assembly and power supply system using the same

Power supply system using an inductor assembly

In order to protect reverse currents, several strings of a photovoltaic generator, which are connected in small groups respectively via a DC/DC-converter, parallel to a common DC voltage intermediate circuit, the current which flows over each of the DC/DC-converter is detected and if a reverse current is detected flowing through one of the DC/DC converters, the converter is stopped by controlling the DC/DC-converter.

Method and device for protecting several strings of a photovoltaic generator from reverse currents

The disclosure relates to a method for operating an inverter that includes at least one bridge assembly that is actuated in a modulated manner for supplying electrical power to an energy supply network. Initially, the inverter is operated by the unipolar actuation of the at least one bridge assembly and the energy supply network is monitored for the presence of a network fault. If a network fault is detected, the inverter is operated at least at intervals by the bipolar actuation of the at least one bridge assembly. The disclosure further relates to a network fault-tolerant inverter which is equipped for carrying out the method.

Operating method for an inverter and grid fault tolerant inverter

An inverter includes a DC/AC converter, a DC intermediate circuit on the direct current input side of the DC/AC converter, multiple DC/DC converters connected in parallel to one another on the output side to the DC intermediate circuit, multiple inputs each coupled to one of the DC/DC converters, and an EMC filter connected between the inputs and the DC/DC converters. The EMC filter includes chokes in all current-carrying lines between the inputs and the DC/DC converters and filter capacitors between the inputs and the DC/DC converters leading from all the current-carrying lines to ground. The chokes in all current-carrying lines from the at least two inputs are formed by means of choke windings on a common core of a current-compensated choke.

Multi-string inverter having input-side EMC filter

A method and device to discharge a filter capacitance at the output of an inverter for feeding electrical power from a generation unit into a grid via a grid connect switch is disclosed. The grid connect switch has a generation unit side and a grid side, and via AC grid terminals on the grid side of the grid connect switch, the filter capacitance is connected to at least one of the AC grid terminals. A voltage applied across the filter capacitance is rectified independent of a polarity thereof, and a rectified voltage of a fixed polarity is provided, and a DC voltage link of a power supply unit for supplying power to circuitry of the inverter is charged with this rectified voltage.

Discharging a capacitance provided at the output of an inverter

An inverter device for feeding electrical energy from a DC-power source into a power grid includes a pair of bus lines to be connected to the DC-power source; a plurality of capacitors connected in series between the bus lines; a surveying topology surveying an integrity of the plurality of capacitors, and to provide a signal indicating a loss of integrity of one capacitor of the plurality of capacitors; a voltmeter measuring a voltage drop over the plurality of capacitors; a DC/AC-inverter; and a controller. in case of the signal indicating a loss of integrity of one capacitor of the plurality of capacitors, the controller compares the voltage drop over the plurality of capacitors to a lost integrity threshold voltage value, and reduces a current load to the plurality of capacitors by reducing the power uptake of the DC/AC-inverter, when the voltage drop exceeds the lost integrity threshold voltage value.

Inverter device comprising a topology surveying a series of capacitors

A wiring testing device configured to test the wiring correctness of an inverter is disclosed. The inverter is configured to be connected to a low-voltage three-phase system with a neutral conductor serving as a reference point for grid-side conductor voltages. The wiring testing device includes a test circuit configured to measure the grid-side conductor voltages and determine an average value from the sum of the instantaneous values of the grid-side conductor voltages, and a display unit configured to display an error message if the average value exceeds a threshold voltage for a defined time period. The wiring testing device further includes a capacitor connected between a phase of the three-phase system and the neutral conductor configured to generate a voltage imbalance if the neutral conductor connection is missing, wherein the test circuit is configured to measure the conductor voltages and determine the voltage imbalance.

Wiring testing device

In an overvoltage protection apparatus before an inverter configured to feed electric energy from a DC voltage source into an AC power grid, the overvoltage protection apparatus includes a DC voltage input stage. The DC voltage input stage includes at least two current-carrying lines and an EMC filter including interference suppressing capacitors and interference suppressing inductors, and surge arrestors configured to divert overvoltages with respect to ground are connected to the current-carrying lines after the EMC filter, from a point of view of the DC voltage source.

Overvoltage protection for inverters that comprise an EMC filter at their input end

Growing community of inventors

Kassel, Germany

Henrik Wolf