Scale back dimension, weight and value via upper switching frequencies and decrease losses

Throughout the analysis undertaking PV-MoVe, researchers at Fraunhofer IEE investigated how energetic switching loss aid networks of energy semiconductors can be utilized to permit smaller, extra light-weight and cheaper photovoltaic inverters. The use of newly evolved further circuits, the switching frequencies of a 50 kW PV inverter may also be greater by means of an element of two.5-3 for the DC enter degree and by means of an element of 10-12.5 for the inverter output degree.

The undertaking used to be labored on in cooperation with undertaking companions Infineon Applied sciences AG and SUMIDA Parts & Modules GmbH from 2019 to 2023.

The primary purpose of the undertaking, titled “Strategies, procedures and elements to cut back switching losses in fast-switching photovoltaic inverters for centered weight and value aid,” used to be to cut back switching losses in energy semiconductors to permit upper switching frequencies. This opens up alternatives to fabricate smaller, extra light-weight and cheaper PV inverters with out considerably hampering their potency.

“The upper switching frequencies of energy semiconductors can be utilized to cut back the dominant participants in relation to weight and dimension, i.e. energy inductors and capacitors, with decreased uncooked fabrics and provides. This reduces subject matter intake and part prices, leading to further advantages in relation to cooler and enclosure.” Design, says Prof. Dr. Marco Jung, knowledgeable in energy electronics, who’s Head of the Division of Converters and Force Era at Fraunhofer IEE in addition to a complete professor on the Bonn-Rhein-Sieg College of Implemented Sciences.

The PV-MoVe undertaking desirous about the use of further circuits to cut back switching losses, as those applied sciences may also be implemented independently of the facility semiconductor base subject matter.

“They may be able to be used for well-established silicon (Si) applied sciences to permit prime switching frequencies which are usually handiest achievable with wide-bandwidth (WBG) semiconductors, reminiscent of silicon carbide (SiC) or gallium nitride (GaN), then again they are able to even be used” To extend the already prime switching frequencies even additional,” explains Fraunhofer IEE undertaking coordinator, Dr. Sebastian Spronk.

Those further circuits consist of specialised assemblies of auxiliary energy semiconductors, resonant capacitors, and inductors. They cut back voltage and/or present stresses at the major energy semiconductors all over switching transitions, leading to “comfortable” switching off and on with considerably decreased switching losses.

To display the effectiveness of this means, circuits appropriate for partial techniques of a 50 kW photovoltaic inverter, i.e. a DC/DC enter spice up converter and an output inverter, have been evolved, constructed and carefully examined in a laboratory surroundings.

“The effects obviously display the opportunity of an important aid in switching losses of key energy semiconductors: for the Si-based IGBT of the spice up converter as much as -70% and for the SiC-based MOSFET of the inverter as much as -92%,” says Spronk.

The essential further circuits introduce losses themselves, however will have to no longer exceed the losses which are minimized in the principle energy semiconductors. For those, loss aid can be utilized to noticeably building up switching frequencies with out risking thermal overload.

“In accordance with our calculations, the switching frequency of the investigated 50 kW IGBT PV spice up converter may also be greater from 6.6 kHz by means of an element of two.5–3. For the corresponding SiC ANPC PV inverter, an building up from 36.6 kHz by means of an element of 10–12.5 turns out conceivable,” the mavens conclude. .

Fraunhofer scientists at the moment are operating to combine the newly evolved applied sciences into a whole gadget demonstration to make sure their effectiveness below real-life stipulations in addition to to switch them to different programs, reminiscent of battery and gasoline cellular inverter drives.

Supplied by means of Fraunhofer-Institut für Energiewirtschaft und Energiesystemtechnik IEE