Design considerations and laboratory testing of power circuits for parallel operation of silicon carbide MOSFETs
Paper i proceeding, 2015

In this paper, the impact of using parallel SiC MOSFETs as the switching device is investigated. Measurement considerations for a double pulse test are discussed, and the influence of the load inductor characteristic and the voltage measurement technique on the measurement results is demonstrated. It is shown that the inductor load can produce high frequency oscillations of up to 10 % of the load current in the switching current, which can wrongly be associated with the switching device. It is also shown that the standard earth connection of passive voltage probes can induce an extra stray inductance in the measurement loop, which can lead to a measurement of an extra overvoltage of up to 50 V, which is not due to the actual switching. Moreover, the dependency of turn-on and turn-off losses on the load current and the dc-link voltage is presented. It is shown that doubling the load current would increase the switching losses more than the double amount. Therefore, use of two parallel MOSFETs instead of a single one would decrease the total switching losses for a given load current. On the other hand, the parallel configuration is shown to have a higher overvoltage than one single MOSFET for a similar load current. This, however, can be reduced by a higher gate resistance which will eventually keep the total switching loss of parallel configuration equal to the single MOSFET configuration for a given load current. Finally, it is also shown that switching losses can be greatly decreased by decreasing the gate resistance, but this leads to a higher overvoltage on the device. Therefore, the final choice for design is a compromise between the switching losses and the overvoltage.

MOSFET devices

Parallel operation

Power electronics

Switching loss

Schottky diodes

Silicon carbides (SiC)

Silicon Carbide (SiC)

Electric inductors

Reconfigurable hardware

Parallel operations

Schottky barrier diodes

Schottky diode

Silicon carbide

Switching losses






S. Tiwari

Norges teknisk-naturvitenskapelige universitet

Ali Rabiei

Chalmers, Energi och miljö, Elkraftteknik

P. Shrestha

Norges teknisk-naturvitenskapelige universitet

O. M. Midtgard

Norges teknisk-naturvitenskapelige universitet

T. M. Undeland

Norges teknisk-naturvitenskapelige universitet

R. Lund

SmartMotor AS

A. Gytri

Norges teknisk-naturvitenskapelige universitet

17th European Conference on Power Electronics and Applications, EPE-ECCE Europe 2015, Geneva, Switzerland, 8-10 September



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