System, apparatus and methods for controlling multiple output converters

摘要

An apparatus and method is presented for implementing and controlling a voltage converter with one input voltage and multiple output voltages. In the case of boost and buck-boost converters, a converter circuit with one inductor and a switched group of parallel connection capacitors is realized, one parallel connection for each output voltage. A duty ratio is monitored for the inductor and the switched group of capacitors to provide a set of duty ratios. The duty ratios form a control vector which describes the control inputs. The output voltages are the control outputs describing a MIMO system. A generalized Cuk-Middlebrook modeling approach is applied to the voltage converter, along with linearization and MIMO control methods to regulate all output voltages to desired levels.

主权项

1. A method for controlling a multiple output power converter, having a switched inductive circuit connected between a first polarity and a second polarity of a voltage source, and having a plurality of parallel capacitive circuits connected by a plurality of switches between a first node in the switched inductive circuit and the second polarity of the voltage source, the switched inductive circuit incorporating an inductor with inductance L having series resistance Rs, each capacitive circuit i of the plurality of parallel capacitive circuits incorporating a resistor Ri in parallel with a capacitor Ci having capacitive resistance RCi, the method using a PWM controller and comprising the steps of:
receiving into the PWM controller, a plurality of output voltages y, including at least one output voltage from each parallel capacitive circuit in the plurality of parallel capacitive circuits, a plurality of reference voltages y0 from a reference voltage source, a first current x1 through the inductor, and a supply voltage u0 from the voltage source; creating a plurality of difference voltages wherein each difference voltage represents the difference between an output voltage in y and a corresponding reference voltage in y0; conditioning the plurality of difference voltages in the PWM controller with a gain characterized by a gain matrix K; creating a plurality of control signals having a plurality of duty ratios d, each control signal associated to a switch in the plurality of switches, where the plurality of duty ratios d are set according to:
d=−β−1[K(y−y0)−α]; where d is a vector and the matrix β, its inverse matrix β−1 and the vector α are determined by Cuk-Middlebrook state space averaging of the equations of state for y and xi; constraining the plurality of control signals with a modulation condition and a linearization condition based on y, x1, y0, and u0; controlling the multiple output power converter using the plurality of control signals.