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This paper presents a control method to eliminate the common mode voltage created by a three-phase, four-leg voltage source inverter. Wide band gap devices create an opportunity to use pulse density modulation instead of pulse width modulation, with two inverter poles switching high and two low at all times to eliminate common mode voltage without increasing losses. In this way the common mode voltage is always zero to the precision that the inverter legs can be simultaneously transitioned. The novel control strategy also produces balanced output voltage to meet the power quality requirements in MIL-STD-1399 when the load is unbalanced. Elimination of the common mode voltage removes the need for a large common mode choke to suppress circulating currents and to meet the conducted emission limits in MIL-STD-461G. A state space model is derived, used to compute the inverter reference voltages and to simulate the proposed control system. Experimental measurements on a laboratory prototype validate the model and verify the functionality of the novel control method.

In this paper we consider discrete time stochastic optimal control problems over infinite and finite time horizons. We show that for a large class of such problems the Taylor polynomials of the solutions to the associated Dynamic Programming Equations can be computed degree by degree.

We consider a rod that is heated/cooled and sensed at multiple point locations. To stabilize it to a constant temperature we set up a Linear Quadratic Regulator that we explicitly solve by the method of completing the square to find the optimal linear state feedback for the point actuators. But we don’t assume that the whole state is measurable so we construct an infinite dimensional Kalman filter to estimate the whole state from a finite number of noisy point measurements. These two components yield a Linear Quadratic Gaussian (LQG) Synthesis for the heat equation under point actuation and point sensing. AFOSR FA9550-20-1-0318