| 摘要 |
A process is disclosed for controlling the speed of rotation of a single-phase or polyphase induction motor with N(N=1,2,3,...) phase windings by changing the frequency of N phase voltages that drive the phase windings and that are phase-shifted each by 2 pi /N. The phase voltages are formed by switching the tappable potentials of n(n=2,3,4,...) direct voltage sources connected in series with n different voltages Ej(j=1,2,...,n) through to output terminals in series of predeterminable intervals that is constantly repeated with a period duration T and in a predetermined sequence. Each switched through potential is associated to one of the time intervals. The frequency f1=1/t of the phase voltages is changed by increasing or reducing the duration of one or several predeterminable time intervals. |
