METODO E RELATIVO DISPOSITIVO DI CONTROLLO DI UN MOTORE SINCRONO MONOFASE A MAGNETI PERMANENTI ATTO AD OTTIMIZZARE I PARAMETRI DI FUNZIONAMENTO ANCHE IN PRESENZA DI OSCILLAZIONI DELLA TENSIONE DI ALIMENTAZIONE O DEL CARICO APPLICATO

摘要

A system for controlling the performance of a mains supplied single phase synchronous motor (1) having a permanent magnet rotor energises the stator via a semiconductor switch (5) e.g. a triac or silicon controlled rectifier, signalled (11) by a controller (4). The system references (a) the supply voltage (U(t) across the switch (5) in the open condition and (b) the rotor position w.r.t. the stator field via a Hall-effect sensor (6) which latter is an index of the motor EMF. As a result of the measurements (a,b) the firing angle of the semiconductor switch (5) is adjusted by the controller (4) when a zero phase difference between the EMF and first harmonic of stator current affords maximum motor output and minimum load currents.