Investigation of spread spectrum techniques to reduce the electromagnetic interference in switch mode power supply

Title Investigation of spread spectrum techniques to reduce the electromagnetic interference in switch mode power supply
Summary The goal of the project is to investigate spread-spectrum-based PWM techniques to reduce the EMI in motor drivers caused by the SMPS
Keywords Spread-spectrum, electromagnetic interference, variable frequency drives, motors
References (1) Gamoudi, Rabiaa, Dhia Elhak Chariag, and Lassaad Sbita. "A review of spread-spectrum-based PWM techniques—A novel fast digital implementation." IEEE Transactions on Power Electronics 33.12 (2018): 10292-10307.

(2) Perotti, M., and F. Fiori. "Software based control of the EMI generated in BLDC motor drives." 2016 International Symposium on Electromagnetic Compatibility-EMC EUROPE. IEEE, 2016. (3) Blank, Mathias, et al. "Digital slew rate and s-shape control for smart power switches to reduce EMI generation." IEEE Transactions on Power Electronics 30.9 (2014): 5170-5180

Prerequisites Knowledge of electromagnetic compatibility, electric motors, basics in C-programming, Matlab
Supervisor Maria De Lauretis, Elena Haller
Level Master
Status Open

Background: A primary source of electromagnetic interference (EMI) in motor drivers is the switch-mode power supply (SMPS). Software strategies typically focus on pulse-width modulated (PWM) techniques. The most common band-aid approach to reduce EMI is to lower the slew rate of the switching voltages which, obviously, negatively impacts the power efficiency and nullifies the advantages that come from expensive high-frequency switching transistors. Spread-spectrum(SS)-based PWM techniques received a lot of attention in the past years because they leave the power efficiency untouched while reducing EMI. To apply SS techniques in the best way, it is necessary to precisely know the hardware and the application. In fact, different harmonic reduction schemes give different dB of reduction.

Research question: Reducing EMI in variable frequency drives is normally done at hardware level. However, once the product is finished, hardware solutions can be costly or even not possible to be implemented. Therefore, the question is if we can reduce EMI at software level without compromising the efficiency of the product.

Whether it’s more software or hardware related: Even thought the EMI reduction shall be achieved via software solutions, the software must be tailored to the specific application and it is essential to verify the results using a suitable hardware. Therefore, it is both software and hardware related.

A very brief description of work packages: - state of the art of software strategies for EMI reduction in SMPS, with focus on SS techniques - setting up the suitable test-bench for the tests - test 2 or 3 different SS techniques, first via software simulation, and then via hardware simulation

Deliverables/outcomes/results: Prove that the software technique adopted reduced the EMI without compromising the efficiency of the product under test.