Last update : 1st September 2014

Design and Implementation of Digital Current Mode Controllers For DC-DC Converters in Eletromobility Applications

Summary

The dc-dc converters are extensively used in electrical vehicles. They are mainly utilized in battery chargers or in step-up converters to boost the battery voltage for the motor drivers. In order to keep the output voltage (or current) of the converter equal to the reference value regardless of the changes in the system, implementation of the control mechanism for a converter is required.

In one part of this work package, design and implementation of digital current mode controllers for dc-dc converters is targeted. The term of digital controller here means that the controller is implemented inside of a digital processor (in this case an FPGA). The digital controllers are more immune to noises, more flexible, and less sensitive to environmental conditions compared to traditional analog controllers.

Background

The current mode (CM) controller has faster response compared to voltage mode (VM) controllers, but it is more sensitive to noises and the implementation is more challenging. Many CM controllers are developed in analog or hybrid domain. The digital implementation of CM controller is a difficult task; because the analog signal must be converted to digital signal with an extremely fast analog to digital converter (ADC).

The aim of this project is to develop a digital CM controller which retains the advantages of analog CM controllers while covering the disadvantages of analog CM controllers.

Activity

 The research work is defined for a 3 years PhD study. The research work is divided into three milestones. In the first step, the dc-dc converter is modeled in order to determine the behavior of the converter. In the next step, a VM controller is implemented in FPGA and  modeling results are verified by experimental measurements.

 In the final stage, a novel digital CM method is proposed which is fast, simple and has high performance.

LabLab2

Publications

- F. Taeed, M. Nymand, "Modeling and control of isolated full bridge boost DC-DC converter implemented in FPGA," Power Electronics and Drive Systems (PEDS), 2013 IEEE 10th International Conference on, pp. 119-124, 22-25 April 2013.

DOI: http://dx.doi.org/10.1109/PEDS.2013.6527000

- F. Taeed, M. Nymand, "A new simple and high performance digital peak current mode controller for DC-DC converters," Applied Power Electronics Conference and Exposition (APEC), 2014 Twenty-Ninth Annual IEEE ,  pp. 1213-1218, 16-20 March 2014

DOI: http://dx.doi.org/10.1109/APEC.2014.6803461

-F. Taeed, M. Nymand, "A novel high performance and robust digital peak current mode controller for DC-DC converters in CCM",  IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), pp. 1-5, June 2014.
DOI: http://dx.doi.org/10.1109/COMPEL.2014.6877160

- F. Taeed, Z. Ouyang, M. Nymand, Michael A.E Andersen, "Design and implementation of power flow control for a novel dual input DC-DC converter", IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), pp. 1-5, June 2014.

DOI: http://dx.doi.org/10.1109/COMPEL.2014.6877201

Conclusion

The outcome of this research presents a high performance and low cost solution for implementation of digital CM controllers. The proposed digital CM controller is applicable to any dc-dc converter regardless of topology.

      Perspectives and Applications

The research results can be used in battery charger controllers for electrical vehicles. The digital controller can easily communicate with other control units to share the charging data or display the possible faults in the system. The proposed controller can be used in other part of electrical vehicles which are using dc-dc converters (e.g. dc voltage booster for inverter’s input side).


Electromagnetic Interference (EMI) Filter Design for Isolated DC-DC Converters

Summary

 

 

 

Background

Responsible partner:

Syddansk Universitet
Mærsk Mc-Kinney Møller Instituttet (SDU-MMMI)
Niels Bohrs Allé 1, 5230 Odense M
Associate Professor

Morten Nymand

mny@iti.sdu.dk
+45 6550 7427