The concept of designing a high-speed, permanent magnet, brushless DC motor aircraft fuel pump drive using a cycloconverter link is examined. A combination of sinusoidal and DC steady-state analysis is used to produce a simple model of the system. A closed-loop control system with an outer loop based on speed and an inner loop based on current is postulated wherein a proportional-plus-integral controller is placed in the forward path to assure minimum speed error. Gains are then set to assure that the eigenvalues of the linearized control system lie within the left half s-plane over the entire full range.
A method of thyristor gating management to allow operation of a cycloconverter-link brushless DC motor drive from a variable-voltage variable-frequency (VV-VF) source is presented. Multiple microprocessors are utilized to assure that no compromise in signal processing priority is necessary as both motor and source frequency vary independently over a wide range. The architecture and logic of the de...
The control of a cascaded doubly fed machine (CDFM) to be used for aircraft power generation is investigated. The controller employs a resistance simulator in the generator exciter to provide machine damping. Excitation is provided by a six step inverter fed from a controlled rectifier. Delays due to the dc link time constant cause the resistance simulation to be nonideal. An investigation into the ability of resistance simulation to provide damping under these conditions is described. The study includes linearized analysis, simulation, and laboratory tests. Good correlation between these methods was obtained throughout the study. Three control strategies for providing machine damping were investigated, and it is concluded that resistance simulation can be used to provide machine damping under these conditions.
