Experimental evaluation of iron loss minimization in automotive traction drives by increased disturbance rejection and precise flux control

Iron losses predominate in automotive traction applications at partial load and thus significantly in driving cycles. In this work, iron losses and overall drive losses of saturated salient pole synchronous machines are minimized by optimal control of flux linkage, in magnitude and waveform. Loss minimizing flux magnitude is calculated in real-time including copper-, inverter- and iron losses. By applying deadbeat-direct torque and flux control (DB-DTFC), flux linkage including harmonics is observed with a Gopinath observer and precisely closed-loop controlled with a bandwidth of 1400Hz. Increased disturbance rejection, as compared to current vector control (CVC), is achieved via simulation and experiment. Minimization of harmonics in current and reduction of total loss are measured on a 5.5kW synchronous reluctance machine (SynRM) testbench.