S. Yadav
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13 records found
1
Diamond
The DC Motor Drive Module in the GEMS Erasmus+ Project
Mechatronics is an interdisciplinary field that requires students to possess knowledge and skills from multiple domains. Theoretical learning can provide students with basic knowledge. However, it is not sufficient for applied engineering knowledge. It is essential for students to learn with a suitable platform, including hardware and software. Moreover, the platform should also be equally accessible to all students. This paper describes the DC motor drive module developed in the context of the GEMS (Graceful Equalising of Mechatronics Students) Erasmus+ project. The designed module is open access and a part of a mechatronics platform, which allows students who are interested in mechatronics to learn from scratch.
Triangular current mode (TCM) zero-voltage switching (ZVS) modulation method is widely adopted in power electronic converters to achieve acceptable efficiency in high switching frequency operations. For bidirectional dc-dc converters, in order to realize ZVS turn-on, a reverse inductor current can be utilized for this purpose through variable frequency control. In this article, this reverse switched current is revisited considering the parasitic resistances presented in the mosfet switches and the inductor for three common types of dc-dc converters, i.e., buck, boost, and buck-boost converters, which study was normally neglected in the previous research. Universal closed-form equations of the modified duty cycle and switched current are derived, which can be utilized to calculate the reverse current under different operating conditions. It is found that the parasitic resistances can have a negative impact on the switched current value, and this may lead to an unexpected loss of ZVS turn-on. A laboratory prototype of a four-switch buck+boost converter featuring TCM-ZVS buck, boost, and buck-boost operation capability was built to investigate and verify the proposed concepts. The operating voltage and power range are from 100 V to 400 V, and 300 W to 1 kW, respectively.
Balancing converters play a pivotal role in bipolar dc grids, and while numerous topologies have been explored, many suffer from drawbacks, such as reliance on bulky passive components, limited soft-switching capabilities, or complex control mechanisms. This article introduces an LC series-resonant balancing converter topology that addresses these issues, featuring smaller passive components, the ability to achieve soft switching across its entire operational range, and simplified control with proper design. By operating in the capacitive region, the converter ensures soft switching for the complete load range, enabling all switches to achieve zero voltage switching (ZVS) turn on. The study reveals that the converter's power flow depends on both the switching frequency (fsw) and the phase shift angle (φ), but notably, when the resonant inductor value is kept sufficiently low, fsw and φ become decoupled, simplifying power flow control. In addition, this article provides detailed design guidelines for the converter's resonant tank and validates the operation and control of the converter through an experimental setup.
Preliminary Design of LUCID
The Lunar Unidentified Celestial Identification & Detection Satellite
This work outlines the Phase 0 design of the Lunar Unidentified Celestial Identification & Detection (LUCID) mission, a sub 200 kg micro-spacecraft developed to observe and track objects larger than 3 metres in diameter at the average distance of the lunar orbit. The mission, planned for launch on a Vega-C rocket into a Sun-synchronous orbit at 500 km, aims to enhance space situational awareness in the cislunar region. The spacecraft's optical payload will survey a defined area at least once daily, contributing to the tracking of space debris as space exploration and cislunar activities expand. The LUCID mission concept was developed by 40 students over one week during the 2023 European Space Agency (ESA) Academy Concurrent Engineering Workshop (CEW), using the COMET tool to achieve a concurrent design of both the space and ground segments. This paper details the preliminary design outcomes and subsystem analyses of the LUCID mission.
This article introduces an auxiliary power supply (APS) designed explicitly for bipolar DC grids, utilizing a flyback topology for robust and efficient operation. Central to our design is a high-voltage 3300 V silicon carbide (SiC) MOSFET and a planar transformer comprising one primary, one auxiliary, and two secondary windings. This APS uniquely addresses the resilience requirements of bipolar grids by enabling seamless switching between poles in the event of a pole failure, thus maintaining continuous power supply. Control is achieved through the UC3844A integrated circuit from Texas Instruments. The converter's effectiveness is demonstrated through experimental validations, confirming its suitability for advanced bipolar DC grid applications.
This article provides the design procedure of a ±350 V series resonant balancing converter for bipolar DC grids. The process creates a η-ρ Pareto front to design a 3 kW converter with natural convection cooling.
This paper presents a control strategy for active power decoupling in a Solid State Transformer (SST) using a cascaded H-bridge (CHB) converter, dual active bridge (DAB) converters, and a high-frequency link (HFL). The strategy balances capacitor voltage and decouples power flow, significantly reducing second harmonic voltage ripple in DC link capacitors and potentially reducing their size.
Balancing converters are an integral part of a bipolar dc grid. Resonant converter topologies are interesting for power electronics engineers due to their soft switching capabilities. A series resonant converter topology is promising as a balancing converter in a bipolar dc grid. The series resonant converter is usually a non-inverting topology. However, in the balancing converter application, the converter is used as an inverting type, like a buck-boost converter topology. In this paper, the soft switching capabilities of this converter are shown and analyzed for four distinct converter modulation schemes.
Electrification of ships is one of the hot topics in the marine industry. This is due to the stringent guidelines by the International Maritime Organisation (IMO) for curbing the green house gas emissions from the marine sector. In this paper, the state-space modeling approach is used to model bipolar dc grids on ships. A ferry is used as a test case. The modeling is done for the radial and zonal architecture with similar components. The dynamic simulation and stability analysis of the two architectures reveal that zonal architecture is potentially more stable than the radial architecture.