Sma Solar Technology Ag

Bsh Hausgerate Gmbh

Markus Hopf

Karl-Friedrich Laible

Marcel Kratochvil

Holger Behrends

Sebastian Bieniek

Gerd Bettenwort

Christopher Merz

Oliver Prior

Burkard Mueller

Jens Klein

Andreas Falk

Jens Friebe

Frank Greizer

Matthias Victor

Stephan Kempfle

Claus Allert

Joachim Ralf Laschinski

Hans Peter Werner

Michael Viotto

Gerald Schmidt

Thorsten Buelo

Alexander Heinrich

Bernhard Schropp

Thorsten Buleo

Felix Eger

Thorsten BÜLO

The disclosure relates to a method for determining a characteristic curve for a photovoltaic (PV) string of a photovoltaic system having an inverter which is connected to the photovoltaic string and to a power supply network. The photovoltaic string includes a series connection of a plurality of photovoltaic modules, in which series connection at least one of the photovoltaic modules is integrated into the series connection of the photovoltaic modules via a DC/DC converter. The at least one DC/DC converter operates the photovoltaic module assigned thereto in a first operating mode M1 at a maximum power point by varying, over time, a conversion ratio of output voltage (U) to input voltage (U), and operates the photovoltaic module in a second operating mode M2 with a conversion ratio of output voltage (U) to input voltage (U) that is constant over time. The method includes operating the at least one DC/DC converter in the second operating mode M2 in response to a current signature for the current (I) through the photovoltaic string, determining the characteristic curve by varying the current Ior the voltage Uof the photovoltaic string by the inverter, and detecting values assigned to one another for current Iand voltage Uof the photovoltaic string in the second operating mode M2 of the DC/DC converter.

Method for determining a characteristic curve of a photovoltaic (PV) string, DC/DC converter, and photovoltaic system suitable for carrying out the method

A method for detecting a contact fault in a photovoltaic system is disclosed. The photovoltaic system includes an inverter and a photovoltaic generator connected to the inverter via DC current lines. The inverter includes a transmitter for coupling a first AC voltage signal having communication frequencies in a first frequency range between 125 kHz and 150 kHz into the DC current lines. A receiver is configured to couple out the first AC voltage signal and is arranged at the photovoltaic generator. A decoupling circuit is configured to decouple the impedance of the photovoltaic generator is arranged between the inverter and the photovoltaic generator, such that the photovoltaic generator is AC decoupled from a transmission path between the inverter and the decoupling circuit. The inverter communicates with the receiver via the first AC voltage signal, and wherein AC currents are measured in the DC current lines and AC voltages are measured between the DC current lines to aid in detection of a contact fault condition.

Method for detecting a contact fault in a photovoltaic system

A solar module includes a safety circuit, and a series circuit of bypass diodes, which is arranged between solar module connections, wherein the bypass diodes have bypass connections at both ends and all connecting points of the series circuit of bypass diodes. The solar module also includes a series circuit of solar partial modules having partial module terminals at both ends and all connecting points of the series circuit of solar partial modules, wherein each bypass diode is associated with precisely one solar partial module, and a plurality of semiconductor switches configured to disconnect the solar module connections from voltage at an associated partial module terminal when a disconnection signal is received by the safety circuit. Each of the plurality of semiconductor switches is configured to switch a solar partial module associated therewith into a voltage-free or current-free state, and at least one bypass connection is directly connected to an associated partial module terminal and at least one bypass connection is connected to an associated partial module terminal by means of one of the semiconductor switches.

Solar module and energy-generating system

The disclosure relates to a protective circuit for a photovoltaic (PV) module that includes an input having two input terminals for connecting the PV module, an output having two output terminals for connecting further PV modules of a series circuit comprising PV modules, a first switch for connecting one of the input terminals to one of the output terminals, and a controller configured to control the first switch, wherein the protective circuit further includes a series circuit including a first diode and an energy store, wherein the series circuit is arranged in parallel with the input of the protective circuit. The protective circuit also includes a second diode, which connects an output terminal of the protective circuit to a midpoint of the series circuit including the first diode and the energy store, and wherein a series circuit including the second diode and the energy store is connected in parallel with the first switch. The disclosure also relates to a method for operating a protective circuit according to the disclosure, and to a photovoltaic (PV) system including a series circuit comprising PV modules.

Protective circuit for a photovoltaic (PV) module, method for operating the protective circuit, and photovoltaic (PV) system having such a protective circuit

A description is given of an apparatus for disconnecting a connection between solar modules of a photovoltaic string. A circuit breaker, a band-stop filter and a supply circuit are arranged in a series circuit between a first and second terminal. The series circuit is configured to conduct a current that includes a DC string current flowing through the photovoltaic string and a high-frequency control signal modulated onto the DC string current. The supply circuit is configured to generate energy to power the apparatus from the DC string current. An AC bypass circuit bridges the circuit breaker in parallel and is configured to conduct the high-frequency control signal. A control unit is configured to operate the apparatus based on the high-frequency control signal. A reverse current diode oppositely polarized relative to an operating current flow is connected in parallel with the circuit breaker or the circuit breaker and the band-stop filter.

Disconnection apparatus for a photovoltaic string, solar installation and operating method for a solar installation with a photovoltaic string

A description is given of an apparatus for disconnecting an electrical connection between solar modules of a photovoltaic string, the apparatus including a first and a second terminal for a respectively assigned solar module of the photovoltaic string, also a circuit breaker, a band-stop filter and a supply circuit for supplying energy to the apparatus, which are arranged in a series circuit with respect to one another between the first and second terminals. A bandpass filter for coupling out a high-frequency control signal from the electrical connection bridges the circuit breaker and the band-stop filter in parallel. In this case, a reverse current diode that is oppositely polarized relative to an operating current flow direction is connected in parallel with the circuit breaker or the partial series circuit comprising the circuit breaker and the band-stop filter.

In a circuit arrangement for in-line supply of voltage to an electrical or electronic apparatus located in the region of a DC line, a parallel circuit of two diodes oriented in anti-parallel is arranged in the line. When a direct current is flowing between terminals of the circuit arrangement, the anti-parallel diodes permit a small voltage drop between the terminals, irrespective of the direction of flow of the current, which voltage drop is limited to the forward voltage of the diode that is currently forward biased. The voltage drop across the anti-parallel diodes is tapped by a supply subcircuit. A semiconductor switch can be connected in parallel with the anti-parallel diodes, which switch is controlled by a voltage-reduction subcircuit to minimize the power dissipation of the circuit arrangement.

Circuit arrangement for inline voltage supply, use of such a circuit arrangement and device having such a circuit arrangement

The invention relates to an inverter with at least one DC input for connecting to an energy producing device and/or an energy store and with a multiphase AC output for connecting to a local energy distribution network, which is coupled to a likewise multiphase master energy supply network via a switching device. The inverter is characterised in that it has a control terminal for connecting to the switching device such that individual phases of the local energy distribution network can be selectively connected to or disconnected from corresponding phases of the energy supply network via the control terminal, and is intended, in the event of a network error of at least one but not all phases of the energy supply network, to separate, via the control terminal, the at least one defective phase of the energy supply network from the corresponding phase of the local energy distribution network and to supply the at least one separated phase of the local energy distribution network with network-compatible alternating voltage. The invention also relates to a method for operating such an inverter and to an energy supply installation with an inverter.

Inverter, method for operating an inverter and energy supply installation with an inverter

The disclosure relates to methods for sequentially disconnecting at least two electrical current sources from a common load or for sequentially connecting the current sources to a load, wherein the current sources are each connected to the common load via a switching unit, each comprising a parallel circuit comprising an electromechanically actuated switch and an associated semiconductor switch. In the two methods, first semiconductor switches are closed if they are still not closed and the relevant electromechanical switches are opened. In the method for sequential disconnection, then at least two of the semiconductor switches that were actuated or that were already closed are opened sequentially. In the method for sequential connection, a plurality of the semiconductor switches are first opened, of which then at least two are closed sequentially. The disclosure also relates to a photovoltaic system comprising an apparatus that is suitable for implementing the method.

Method for sequentially disconnecting/connecting electrical current sources from/to a common load

A protective device for a photovoltaic system includes at least one input for connection to a photovoltaic generator and at least one output for delivery of an electric power supplied from the photovoltaic generator. The protective device includes a detection device for a signal applied via the at least one output, and is configured to provide a low level-limited voltage at the at least one output if an applied signal does not meet a predetermined criteria, and is further configured to connect the at least one output with low resistance to the at least one input via a switching device if the applied signal meets the predetermined criteria.

Protective device for a photovoltaic system

A method for leakage current compensation in a photovoltaic system includes determining a reference current flowing from at least one current-carrying line under voltage via a capacitor to earth, and generating a compensation current, having a phase and a frequency of the reference current, and having an amplitude adjusted by a negative scaling factor based on the reference current. The method further includes determining a current sum using a differential current sensor for at least a portion thereof, wherein the addends of the current sum are the currents through a complete set of current-carrying lines and the compensation current, minimizing the determined current sum by adjusting the scaling factor, and routing the compensation current through at least one other differential current sensor, such that the compensation current compensates a leakage current component of a differential current monitored by the other differential current sensor. A related device and system is also disclosed.

Method and circuit arrangement with means for a leakage current compensation in a photovoltaic system with multiple differential current sensors

The apparatus for monitoring a photovoltaic system includes an incoupling circuit configured to couple an AC voltage test signal into the photovoltaic system, and an outcoupling circuit configured to outcouple a response signal, which is associated with the test signal, from the photovoltaic system, and an evaluation device, which is connected to the outcoupling circuit. The evaluation device is configured to identify events which adversely affect correct operation of the photovoltaic system. The apparatus is distinguished in that the outcoupling circuit includes a first transformer and a second transformer, each having a respective primary winding and each having a respective secondary winding which is connected to the evaluation device, with the primary windings of the first and second transformers being arranged in different electrical lines between a generator and an inverter in the photovoltaic system. The disclosure also relates to a corresponding method for monitoring a photovoltaic system.

Apparatus and method for monitoring a photovoltaic system

A device and corresponding method for monitoring a photovoltaic system to detect an occurrence of events impairing normal operation of the photovoltaic system is provide. The photovoltaic system includes a photovoltaic generator including a first group of photovoltaic modules and a second group of photovoltaic modules being different from the first group. The device includes a first and a second pair of coupling means, both pairs including signal coupling-in means for coupling a test signal into the photovoltaic generator, and a signal coupling-out means for coupling out a response signal from the photovoltaic generator, the first pair of coupling means configured to selectively detect the occurrence of the events in the first group of photovoltaic modules, and the second pair of coupling means configured to selectively detect the occurrence of the events in the second group of photovoltaic modules.

Device and method for monitoring a photovoltaic system

The disclosure relates to a method for signaling partial shadowing within a PV generator including at least two partial PV generators connected in parallel. The method includes performing a reference impedance measurement on each of the at least two partial PV generators in a state of uniform irradiation of the PV generator, and determining at least one reference resonant property of each of the at least two partial PV generators from the reference impedance measurement. Furthermore, impedance measurements are carried out on the at least two partial PV generators at a first operating point of the PV generator during operation of the PV generator. Resonant properties of the partial PV generators are determined from the impedance measurements. Partial shadowing within the PV generator is detected and signaled if a difference between the resonant properties of the partial PV generators at the first operating point differs from a difference between the reference resonant properties of the partial PV generators. The disclosure also relates to an apparatus suitable for carrying out the method.

Method and apparatus for signaling partial shadowing of a photovoltaic generator

The disclosure relates to a circuit arrangement for suppressing an arc occurring during a switching process, wherein a current bypass path comprises a PTC resistor connected in series with a fuse. The current bypass path is provided in parallel with a switch. The disclosure also relates to a photovoltaic power plant with a photovoltaic generator which is connected to an inverter via DC lines. In this arrangement, such a circuit arrangement is arranged in at least one of the DC lines.

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Espenau, Germany

Markus Hopf