Dunstano del Puerto-Flores

Passivity-Based Control by Series/Parallel Damping of Single-Phase PWM Voltage Source Converter

This paper describes a detailed design procedure for passivity-based controllers developed using the Brayton-Moser (BM) framework. Several passivity-based feedback designs are presented for the voltage-source converter, specifically for the H-bridge converter, since nowadays it is one of the preferred solutions to connect direct current (dc) loads or distributed sources to the alternating current (ac) grid. Independent of the operating mode, namely, the rectifier and regenerative operating mode, the achieved control aims are: high power factor correction in the ac-side and optimal dc voltage regulation capability in the dc-side. The proposed controllers can use series or parallel damping-based solutions for the error dynamics, naturally providing the conditions for stability and tuning of control parameters. In addition, the BM structure facilitates the addition of virtual resistance-inductance-capacitance (RLC) filter circuits to the control design for the rejection of low frequency harmonics. The effectiveness of series/parallel damping is investigated in case of abrupt changes in the load, using conductance estimators. Simulation and experimental results validate the analysis.

A cyclodissipativity characterization of power factor compensation of nonlinear loads under nonsinusoidal conditions

Recently, it has been established that power factor (PF) improvement for nonlinear loads with nonsinusoidal source voltage is equivalent to imposing the property of cyclodissipativity to the source terminals. Using this framework, the classical capacitor and inductor compensators were interpreted in terms of energy equalization. The purpose of this brief note is to extend this approach in three directions. In the result reported in the literature, the supply rate is a function of the load, which is usually unknown, stymieing the applicability of the technique for compensator synthesis. Our first contribution is a new cyclodissipativity condition, which is also equivalent to PF improvement, but whose supply rate is now function of the compensator. Second, we consider general lossless linear compensators, instead of only capacitive or inductive compensators. As a result, we show that the PF is improved if and only if a certain equalization condition between the weighted powers of inductors and capacitors of the load is ensured. Finally, we exhibit the gap between the ideal compensator, namely the one that achieves unitary PF, and the aforementioned equalization condition. This result naturally leads to the formulation of a problem of optimization of the parameters of the compensator. Copyright

Power factor compensation with lossless linear filters is equivalent to (weighted) power equalization and a new cyclo-dissipativity characterization

Recently, it has been established that the problem of power factor compensation for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclo-dissipativity. Using this framework the classical capacitor and inductor compensators can be interpreted in terms of energy equalization. Unfortunately, the supply rate is a function of the load, which is usually unknown, styming the applicability of this result for compensator synthesis. The purpose of this brief note is to extend this approach in three directions. First, power factor compensation is shown to be equivalent to a new cyclo-dissipativity condition, whose supply rate is now function of the compensator. Second, we consider general lossless linear filters as compensators and show that the power factor is improved if and only if a certain equalization condition between the weighted powers of inductors and capacitors of the load is ensured. Finally, we exhibit the gap between the ideal compensator, e.g., the one that achieves unitary power factor, and the aforementioned equalization condition. This result naturally leads to the formulation of a problem of optimization of the compensator topology and its parameters.

On power factor improvement by lossless linear filters in the nonlinear nonsinusoidal case

Recently, it has been established that the problem of power factor compensation (PFC) for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclodissipativity. Using this framework we study the PFC for nonlinear loads containing a memoryless nonlinearity. We show that the power factor is improved by lossless linear time invariant filter if and only if a certain equalization condition between the weighted powers of inductors and capacitors of the load is ensured.

On linear power factor compensation, power equalization and cyclo-dissipativity of nonlinear loads

The main contribution of this paper is an extension of the recently introduced result that recasts the problem of power factor compensation for nonlinear loads with non-sinusoidal source voltage in terms of the property of cyclo-dissipativity. Using the cyclo-dissipativity framework the classical capacitor and inductor compensators can be interpreted in terms of energy equalization. Unfortunately, the supply rate is a function of the load, which is usually unknown, styming the applicability of this result for compensator synthesis. We extend the result in three directions. First, power factor compensation is shown to be equivalent to a new cyclo-dissipativity condition, whose supply rate is now function of the compensator. Second, we consider general lossless linear filters as compensators and show that the power factor is improved if and only if a certain equalization condition between the weighted powers of inductors and capacitors of the load is ensured. Finally, we exhibit the gap between the ideal compensator, e.g., the one that achieves unitary power factor, and the aforementioned equalization condition. This result naturally leads to the formulation of a problem of optimization of the compensator topology and its parameters.

A cyclodissipativity condition for power factor improvement under nonsinusoidal source with significant impedance

The main contribution of this paper is an extension of a recent result that reformulates and solves the power factor compensation for nonlinear loads under nonsinusoidal regime in terms of cyclodissipativity. In the aforementioned result the generator was assumed to be ideal, that is, with negligible impedance. In this work, we formulate the power factor compensation problem in a way that explicitly accounts for the effects of a significant source impedance.