Minimum-Time Transient Recovery for DC–DC Converters Using Raster Control Surfaces

Abstract

Fast power converters are desired in microprocessors, audio, and servomotor power supplies. Fixed-topology dc-dc converters have a minimum time in which to respond to line, load, and control change. This response depends on converter control, topology, and circuit parameters. Minimum-time control (MTC) considers these three items when it predicts postdisturbance steady-state points and directs capacitor voltage and inductor current in the shortest time. In this paper a nonlinear model-predictive control steers energy using geometrical curved control surfaces derived from piecewise linear (PWL) and bilinear models. The MTC differs from previous work on the topic in that it considers lossy com- ponents (a cause for nontriangular ripple) and is an open-form solution (as originally proposed by LaSalle in 1959). The different approach revealed a quantitative link between the needed control surface memory and state/parameter resolution. Results are generalized for two-state dc-dc converters and all parameter/controldisturbances. An unconventional digital method was devised to accommodate the open-form solutions. It involved a priori control surface calculations, A/D scaling, surface quantizing, and image compression. The final control executed no real-time arithmetic operations. MTC performance was compared with other pulsewidth modulation controls and time-optimal control in simulations, and tests were performed in hardware using synchronous buck and boost converters.

Design of envelope amplifier based on interleaved multiphase buck converter with minimum time control for RF application

“…The principle of Minimum Time Control (MTC) is explained in [6][7]. In order to simply the problem, the buck converter is considered as linear system.…”

Digital memory look-up based implementation of sliding mode control for dc–dc converters

“…The use of digital control in switching power converters has increased due to the decreased cost and increased computational capability of digital ICs (König, Gregorĉiĉ, & Jakubek, 2013;Liu & Jia, 2010;Marwali & Keyhani, 2004). Some work has been done with the digital implementation of a control strategy by using a predetermined surface inside a digital controller (Banerjee & Weaver, 2014;Pitel & Krein, 2009).…”

“…The stability analysis of various reference surfaces chosen for the controller is performed in this work. This work uses (Pitel & Krein, 2009) as the starting point and implements a digital slidingmode hysteretic control method in a dc-dc boost converter where the sliding surfaces are predetermined and stored in a low-cost memory circuit, instead of using any form of software component, such as a Digital Signal Processor (DSP), in the design. The use of this control strategy eliminates the necessity of any analog tuning and communication.…”

Minimum Time Control for Multiphase Buck Converter: Analysis and Application

“…However, the demands for power supplies with very fast dynamic response in modern electronic applications require complex control algorithms [1]. For example, in power supplies for microprocessors, dynamic voltage scaling (DVS) technique is applied in order to reduce the energy consumption.…”

“…For fast load transient responses, in [1], minimum time control is derived from a piecewise linear model and implemented as a pre-calculated solution in a look-up table [2]. But it requires an accurate model of the actual converter.…”