tirthasarathi lodh

Curriculum vitae  

Area of Expertise (11 Years in Power Electronics and Control): 

A. Data Center Power Delivery

  1. Multiphase Buck Point of Load Converters (Coupled Inductor, TLVR)

  2. Digital Controllers for Multiphase Buck with Current Mode Control, Constant On Time Control

  3. Intermediate Bus Converters 

      LLC Resonant (400 V to 48 V, 800 V to 48 V, 800 V to 12 V)

      Dual Active Bridge (400 V to 48 V)

      Phase Shifted Full Bridge (400 V to 48 V)

      Hybrid Switched Capacitor (48 V to 12 V) 

      Multiphase Buck (48 V to 12 V)

  4. Low High Voltage Hot Swap (48 V Bus)

  5. High Voltage Hot Swap Techniques (Single for 800 V Bus, Double for +-400 V Bus)

  6. Hot Swap Controllers

  7. 3-Phase Rectifiers (60 Hz 480 V Line to Line RMS to 800 V DC)

  8. Solid State Transformers for 3-Phase Rectifiers (60 Hz 13 kV Line to Line RMS to 800 V DC)

  9. PMBUS

B. Ultra High-Gain High-Voltage Converters for Mobile Soft Robots

C. Grid-connected and Standalone Solar PV Systems

 D. Modular Multilevel Converters for HVDC

 E. Mixed-Signal-Power-Management Integrated Circuits

 F. Microgrids

 G. Electric Vehicles 

-Technical Skills 

Testing and debugging of Power Electronic Hardware, Cadence Virtuoso, LTspice, Matlab/Simulink, Code Composer Studio, PLECS, PSim, PSCAD, Altium Designer, OrCAD, KiCad, TMS320F28379D, Arduino. 

SummAry

I am a highly competent and self-motivated individual with about a decade of intensive hands-on experience in hardware. I am looking for a job opportunity in Power Electronics. I am open to exploring exciting application areas of power electronics, including fields I have not adequately explored until now. I am nearing the completion of my Ph.D. thesis (advised by Prof. Hanh-Phuc Le), partially funded by the Office of Naval Research (ONR), USA. The actuation of underwater soft robotic fish formed by bipolar HASEL has been successfully demonstrated using the proposed and fabricated UHGHVH converter during my Ph.D. It converts an input voltage of 3.3 V to an output voltage of 9 kV at 50 W output with an efficiency of 75% and a power density of 10 W/in2. It has at least ∼8X higher output current capability than state of the art, ~2X higher power density, and potentially ∼4X the lower cost. More importantly, it is the only one that can have adjustable output voltage with simple pulse width modulation. It also achieves 4% higher efficiency, equivalent to a 16% loss reduction in the converter. Its meticulous circuit design made sure that the implemented prototypes operated at rated conditions reliably for a long time without failure due to high electric field due to over-voltage and high temperature due to overcurrent and power loss. Moreover, its minimal (3 pairs) wired outlets and careful packaging inside a transparent (4 In × 3 In. × 3 In.) box ensured safety from HV and ease of handling. I prepared the detailed bill of material, step-by-step instruction manual, and technical documentation to do the seamless technology transfer to the stakeholders within the deadline. Hence, the work met all the specifications set by the stakeholders and received high appreciation. 

Previously, I worked as an Associate R & D Engineer at ABB for two years, where I demonstrated leadership capability, team-work spirit, and innovative R and D potential in projects like gate unit design and its power supply design for high-power 4.5 kV, 3 kA ABB HiPack IGBTs, customer simulations for the power loss and temperature estimation of several power converters and PWM schemes in PSCAD and PLECS with ABB semiconductor device XML files used in HVDC, FACTS, electric vehicle applications. My master's thesis (advised by Prof. Vivek Agarwal, Fellow IEEE) was partially funded by the Tata Centre for Technology and Design (TCTD), IITB. I secured a GPA of 9.7/10, the highest among the 15 graduate students of the M. Tech—batch (Year: 2017) of PEPS specialization of the EE department of IITB. The single-stage grid-tied microinverter and its control proposed and demonstrated by me achieved grid current THD of less than 5.5%, the MPPT tracking efficiency of more than 95 %, and a disconnection time of less than 1.5 S after the detection of the islanding condition. These promising results validated the circuit as a strong candidate for grid-tied (230 Vrms, 50 Hz) solar PV (25 V, 10 A, 250 W) microinverter. My proposed and successfully demonstrated two-stage standalone microinverter with battery backup and its control was a promising candidate for powering a small household in rural areas where the utility grid is not available. It demonstrated maximum power point tracking from the 25 V, 10 A, 250 W Solar PV and created a 48 V regulated DC bus as well as a 230 Vrms regulated AC bus. It integrated a battery of 36 V, 72 Ah, which gets charged from solar PV during the day and supplies the load power during the absence of the sun.  It achieved a power conversion efficiency of 85.5% (95% for the boost converter stage × 90% for the high-gain inverter stage). It attained an MPPT efficiency of 95%. It provided an uninterrupted power supply to both the DC and AC loads. It achieved less than 5% ripple in the DC link voltage regulation and less than 5% THD in the AC link voltage regulation.