US 6,472,844 B2 · Single-phased powered drive system

Abstract

A drive system including a rectifier, a high-frequency filter, a static inverter and an induction motor is driven without energy stores and fed by the single-phase mains, in which the use of an envelope generator with a mains-synchronous, preferably sinusoidal signal causes a preferably sinusoidal envelope to be sign-superimposed on the static inverter output signal, thus preventing inadmissible current overshoots in the single-phase mains. Possible fluctuations of the intermediate circuit voltage are thereby compensated. The advantageous operating frequency of the static inverter may be adjusted automatically by a PLL control circuit in that the phase shift between intermediate current and the envelope signal is evaluated. The advantageous operating frequency may be gained by adding a given frequency difference to the rotational speed of the motor. The envelope directly represents a projection of the variation of the voltage of the single-phase mains.

Claims19

Dependent claims

A the drive system powered by a single-phase alternating current source, comprising

at least a rectifier,
a preceding or succeeding filter coil,
a filter capacitor,
a static inverter having a variable frequency and an adjustable output voltage amplitude, and
an induction motor which is fed by the static inverter,
characterized in that a mains-synchronous envelope generator generates a bipolar signal with which the amplitude of the output voltage of the static inverter is modified in the sense of a sign-multiplication of the original signal, such that the envelope of the voltage at the motor is essentially equal to the signal of the envelope generator, independent of the variation of the actual intermediate circuit voltage.

3 more elements

Dependencies are inferred from the claim text.

Single-phased powered drive system

Life of this patent

Single-phased powered drive system

Life of this patent

Abstract

Claims19