US 4,180,853 A · Two-stage commutation circuit for an inverter

Abstract

A two-stage commutation circuit for an inverter, each having a different energy storage capability, commutates the main semiconductor switches by creating a commutation pulse suitable for the different levels of load current. This improves overall inverter efficiency by decreasing the circulating commutation current at light loads due to reduced size of the commutation and makeup pulses utilized at the lower load current levels. The control circuit for the dual commutation circuits includes a voltage detector for sensing the level of the DC input voltage and current detectors for sensing the times at which the load current is essentially zero so that the transistion between the commutation circuits will occur without perturbations in the cyclic operation of the inverter.

Claims12

Dependent claims

An inverter for converting DC electrical energy from a DC source into an output waveform having at least a fundamental sinusoidal component, said DC source having a voltage range which varies as a function of load current, comprising:

an input means for receiving electrical energy from a DC source, the voltage level of which varies within a range;
semiconductor switch means coupled to said input means which can be rendered conductive at a rate related to the fundamental sinusoidal component of the output waveforms;
commutation means connected to said semiconductor switch means including a first stage which is operable when the input parameters are within a first predetermined range and a second stage which is operable when the input parameters are within a second predetermined range;
and
discriminator means connected to said commutation means for enabling both said first stage at said commutation means and said second stage of said commutation means depending on the input voltage level within said voltage range of said DC source.

2 more elements

input means for receiving electrical energy from a DC source, the voltage level of which varies within a range;
semiconductor switch means coupled to said input means, which can be rendered conductive in a manner related to the fundamental sinusoidal component of the output voltage waveform;
and
commutation means connected to said semiconductor switch means including a means having a first stage which is operable when the input parameters are within a first predetermined range and a second stage which is operable when the input parameters are within a second predetermined range, depending on the input voltage level within said voltage range of said DC source.

1 more element

Dependencies are inferred from the claim text.

Two-stage commutation circuit for an inverter

Life of this patent

Two-stage commutation circuit for an inverter

Life of this patent

Abstract

Claims12