DC/AC Converter Control Torque and Flux Control • Converter circuit + Motor • Control design – Design sliding surface for torque and flux denote – Lyapunov function

Torque and Flux Control (cont. ) – Calculate where and does not depend on control

Torque and Flux Control (cont. ) – Select control logic such that Control Logic tends to zero

Torque & Flux Control (approach 2) • Cascade Control – From torque and flux equations: where – Desired can be calculated – Sliding mode to provide desired current

Cascade Sliding Mode Control • Idea: Utilize extra degree of freedom • Sliding surface design

Lyapunov Approach • Select control logic based on Lyapunov function such that sliding mode is enforced • Advantage: simple Control Logic

Decoupling Approach to Enforce Sliding Mode • Idea: to decouple motions in • Method: non-singular transformation: • Advantage: allows frequency analysis performed for each surface individually Control Logic

Vn Control • Objective: optimality by changing • Example: switching frequency reduction

SMPWM Simulation Results • Current tracking and vn tracking

Experimental Setup • • Controller: TMS 320 F 2812 DSP Switching devices: 2 MBI 100 NC-12 IGBT 3 phase RL load 50 V DC supply

The first waveforms show the current tracking (and ), the second ones show tracking as a sinusoidal function by the average value of (after filtering out a high frequency component of discontinuous function ).