Adaptive control of power electronic drives for servomechanical systems

Abstract

This paper presents adaptive-control schemes that estimate load-model parameters and adaptively "tune" a digital controller for an inductively-coupled power delivery circuit. Estimation algorithms are presented that utilize specific recursive formulations, which provide adequate noise immunity in a powerelectronic environment. The techniques are demonstrated using a servomechanical system and a 1.5-kW prototype power electronic drive.

High-frequency digital PWM controller IC for DC-DC converters

“…For example (2) where , , and are constants, corresponds to the basic PID controller. Similar discrete-time control laws have been used in other applications of digital control for switching power converters [1], [7], [8], [19].…”

A digitally controlled amplifier with ripple cancellation

“…Also, we are engaged in studying the robustness of the multirate cascade controller in the face of load model errors or uncertainties, which may be of special concern in a field version of a battery charger, where significant deviations or drift in battery parameters may occur. The digital implementation of the charging current and voltage loops makes it easy to consider adaptive or scheduled control compensation for different loads in the field [19]. The favorable performance of the PP compensator makes it a likely candidate for use in many different digital control applications in power electronics [20].…”

“…This, of course, is subject to the limitations imposed by the maximum current command that can be followed by the inner current loop and by the discharge rate made possible by the loading conditions. Nevertheless, the achievable, practical performance appears to be more than adequate for high-performance battery charging and servomechanical applications [19].…”

“…The steady-state bus voltage at the input to the dc/dc stage can be described as (19) where is the nominal or dc level and is the 120-Hz ripple component. Under PWM control the output voltage of the dc/dc stage is linearly related to the duty-ratio command by (20) where is the duty ratio and is the effective transformer turns ratio.…”

Directional Tuning Control of Wireless/Contactless Power Pickup for Inductive Power Transfer (IPT) System

“…As IPT systems extend to more fields, better control methods are required to cope with various operating environments to satisfy users' needs. Difficulties in controlling the power flow in a wireless/contactless power pickup using IPT technologies can arise from several factors, which include but not limited to load and circuit parameter variations, magnetic field coupling variations between the primary and secondary coils, the operating frequency drift of the primary power supply, etc (Jackson et al, 2000;Chao et al, 2007). These factors can cause the output voltage of the secondary power pickup to deviate significantly from the original designed value, resulting in an undesirable characteristic for applications where a stable output voltage is required.…”