Reviewed by Lexie CornerNov 7 2024
Researchers at Purdue University-Indianapolis have made significant progress in solid-state filters for power electronics converters, as detailed in a study published in CES Transactions on Electrical Machines and Systems. They have introduced a new family of capacitorless solid-state power filters (SSPF) designed for use in DC-AC and DC-DC converters.
The consequences can be costly, ranging from production downtime to compromised equipment and even safety hazards. Certainly, capacitors are indeed responsible for 30% of power electronics failures, as illustrated in Fig. 1(a). This paper proposes a single-phase DC-AC converter designed for conditions where capacitors are not recommended for specific applications. The topology consists of two parts: a low-frequency H-bridge converter and a solid-state power filter (SSPF) capable of generating a sinusoidal voltage output for the load. The schematic representation in Fig. 1(b) illustrates the elimination of passive components, setting this design apart from existing literature. Image Credit: CES Transactions on Electrical Machines and Systems (CES TEMS)
The study, led by Dr. Haitham Kanakri and Dr. Euzeli Dos Santos, Jr., investigates the development of a novel capacitorless SSPF for single-phase DC-AC converters, utilizing a high-frequency planar transformer. This innovative design addresses the limitations of traditional power electronics by eliminating the need for both the LC filter and the DC-link capacitor. By removing these critical components, the proposed SSPF demonstrates significant potential to enhance system reliability and efficiency.
The H-bridge converter generates a sinusoidal output voltage by injecting voltage harmonics while operating at 30 kHz. Experiments, simulations, and theoretical analyses conducted on a 60 Hz, 120 V system showed an impressive total harmonic distortion of only 1.29 %, indicating compliance with IEEE 519 requirements, which is crucial for maintaining power quality.
The study also shows a notable decrease in three important components, highlighting the SSPF’s potential to improve the dependability and efficiency of power electronics systems.
Future Outlook: Expanding the Capacitorless Power Electronics Topologies
In the future, the power electronics research team aims to enhance the reliability of power converters by applying the concept of capacitorless topologies to a broader range of devices. Currently, the team is exploring innovative approaches, such as leveraging the stray capacitance naturally present in these converters to improve overall efficiency, reduce component count, and increase power density.
One of the primary objectives is to minimize or eliminate the reliance on external capacitors by integrating stray capacitance into the operation of various DC-DC converters. This advancement could lay the groundwork for the miniaturization of electric vehicle chargers.
To achieve these goals, the team is introducing calcium copper titanate (CCTO), a novel material expected to enhance stray capacitance and serve as a valuable component in diverse converter designs.
Journal Reference:
Kanakri, H. et al. (2024) Capacitorless Solid-State Power Filter for Single-Phase DC-AC Converters. CES Transactions on Electrical Machines and Systems. doi.org/10.30941/CESTEMS.2024.00033