Research
- What is power electronics ?
Electrical power consumed by loads very often differs in form to what is available from different sources. e.g. Residential outlets provide ac power (230 V, 50 Hz), while consumer electronics products require dc power (say 19 V). Similarly, the output of a photovoltaic module is dc while most residential equipment like fans, pumps, freezers etc. run on ac power. Hence there is a need for converting power available from a source to a form compatible to its load. This is where power electronics comes in. Power electronics deals with the conversion and control of electrical power using electronic circuits. More specifically, such circuits consist of semiconductor switches along with passive elements like inductors, transformers and capacitors. If the circuit components are designed and operated appropriately, it is possible to realize power conversion with low losses, which is a key benefit of power electronics technology.
- Why power electronics matters ?
Power processing using “power electronic converters” offers several broad benefits like- Cleaner environment – by enabling the integration of non-polluting renewable energy sources like wind, solar and reducing automotive fuel emissions through adoption of electrified transportation.
- Energy savings – by enhancing energy-efficiency in applications like consumer electronics, data centers, variable-speed drives, lighting etc.
- Energy infrastructure development – by improving energy outreach to remote areas through adoption of renewable energy (e.g. solar-based standalone systems) and development of energy-efficient long-distance dc transmission systems.
These advantages have led to the steady proliferation of the field power electronics over the past decades to the extent that it has been estimated that by 2030, 80 % of all electricity in the U.S.A would be processed by some form of power electronics [1]. Globally, the power electronics market is expected to reach USD 44 billion by 2025 [2]. At a national level, recently-announced Govt. of India plans of realizing 500 GW of renewable energy capacity [3] and 30% penetration of private electric vehicles (EVs) [4] by 2030 and the rapid growth of data centers in the country [5] are just some of many examples which underscore the scope and importance of power electronics in India today.
- My research interests in power electronics
References
[1] M. Harrison, “The Future of Power Electronics Design,” APEC 2016 keynote presentation.
[2] “Power Electronics Market worth $44.2 billion by 2025,” available: https://www.marketsandmarkets.com/PressReleases/power-electronics.asp
[3] “India ups renewable energy target to 500GW by 2030,” available: https://ieefa.org/india-ups-renewable-energy-target-to-500 gw-by-2030/.
[4] “India turns to electric vehicles to beat pollution,” available: https://www.bbc.com/news/world-asia-india-48961525.
[5] “India’s data centers are set for growth,” available: https://www.datacenterdynamics.com/analysis/indias-data-centers-are-set-growth/.
- Sponsored projects
- Hardware development of power electronics building blocks (PEBB) with multiple wide-band-gap (WBG) device technologies
- Low-cost, high-reliability, quad-input solar microinverter featuring GaN devices and planar magnetics
- Consultancy projects
- Mitigation of Power Quality Problems in LV Power Distribution System
- Integration of On-board charger and Auxiliary DC-DC converter for Electric 2/3 wheeler Application
Research area : Packaging
- Extremely low loop inductances (Lpower < 2 nH ) due to compact wirebondless structure
- Thermo-electrical multi-functional components (MFCs), simultaneously serving as heat sinks and bus-bars enhance thermal performance by eliminating thermal interface material
- 3D-printed microchannel heat-sinks adaptable for air or liquid cooling
- Demonstrated operation in a 10 kW DAB converter with >97 % efficiency, 25 kW/litre power-density, >500 kHz switching frequency
Research area : Magnetics
- Leakage inductance–integrated & cooling-system-integrated planar transformer
- Electro-thermal co-design for optimal system-level performance
- Novel leakage inductance–integrated planar design with horizontal air-gap
- Asymmetrically distributed controllable leakage inductance
- Low Rac and Cpar
Research area : PV inverters, WBG devices
- Pareto-optimal selection of final topology and components based on loss and cost models
- Accurate modeling and efficiency optimization of high-frequency DAB
- Two prototypes – a 200 kHz, hybrid GaN (pri.)-Si (sec.) with film capacitors and a 1 MHz fully-GaN version with ceramic capacitors
- GaN-based parallel boost active power decoupling circuit for eliminating electrolytic capacitors
Research area : Dual-active-bridge – modulation
- Duty-ratio modulation of voltage-source & current-source Dual-Active-Half-Bridge (DAHB) converters to minimize transformer RMS current and increase ZVS range, thus optimizing efficiency
- Two modulation strategies investigated – 2D (D1 =D2) with and without ZVS & 3D (D1 ≠ D2); 3D leads to natural ZVS
- Look-up table-less, closed-loop strategies, simplifying implementation
Research area : Dual-active-bridge – topology
- ZVS of all switches over the entire ac line cycle
- Reliable operation due to elimination of electrolytic capacitors – inherent active power decoupling using film capacitors
- Uses same number of switches as comparable 2-stage or 1-stage solutions
- Topology variant proposed with a second dc-port (for battery integration)
Research area : Dual-active-bridge – topology
- Performs dc-ac (hf-isolated) conversion with only eight switches -lowest possible
- Like type 1, achieves ZVS of all switches over ac line cycle and film capacitor-based inherent active power decoupling
- Modular and universal topology
Research area : Phase-shifted resonant transition converters – modulation
- Use of ac-side phase-modulation as opposed to conventionally adopted dc-side phase-modulation
- Improves circuit efficiency by increasing ZVS range of primary switches (using novel extended dead-time control) and reducing circulating current
- Three-port version proposed with two dc ports and 1 ac port
Research area : Resonant converters
- Parallel-LLC high-gain boost topology for resonant tank, which has load-independent ZVS characteristics (Zi0 > Zi∞ in operation range)
- Fixed switching-frequency (200 kHz) operation with phase-shift; fully analog control
- Planar magnetics implementation of tank inductor, transformer
- Extended for automatic tracking of resonant frequency to ensure high-gain operation even for tank parameter drifts
