| The research described herein documents the efforts to design and characterize the behavior of 5-phase diode rectifier systems. The motivation behind this research began with a project whose goal was to establish the source (and subsequently mitigate) the acoustic noise produced by an automotive alternator. Based upon the finding that torque ripple is a dominant noise source, effort has been focused upon creating a machine-rectifier system that has maximum output power and minimal acoustic noise. Herein, analytical and experimental results are used to show that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines are a superior alternative to 3- and 6-phase machines of identical volume.; To provide analytical tools for the design of 5-phase diode rectifier systems, their steady-state behavior has been investigated starting with a light load and ending with a short circuit on the DC bus. Analysis has been performed on systems in which the rectifier is connected to both a 5-phase idealized inductive voltage source and a 5-phase permanent magnet synchronous machine. For an inductive voltage source system, seven operational modes are identified and are grouped into four regulation regions; three that are linear and one that is nonlinear. Interestingly, in the case that a machine is the source, the same seven modes are observed. However, the operating boundaries of each mode are altered, leading to a much different regulation characteristic. Average-value models relating output current and voltage have been derived for both the source- and machine-rectifier systems in all modes of operation. |
