Portable power supply incorporating a generator driven by an engine

DETAILED DESCRIPTION Features of the present invention improve conventional engine-driven generators in portable power supplies, and, in particular, enable an improved generator to operate quietly and to provide power to relatively large loads.
Exemplary applications and configurations of the improved engine-driven generator are discussed below.
It should be noted that the following discussion relates to several distinct features of the present invention, and not all of the features need to be present in any single embodiment of the present invention.
Thus, some of the features may be used with other features in some applications while other applications will only reflect one of the features.
Moreover, the features, aspects and advantages can be applied to portable engine-driven generators in the narrow sense, but can be also applied to other power supplies, as will become apparent to those of ordinary skill in the art.
Accordingly, one aspect of the invention involves a power supply that comprises an internal combustion engine.
The engine drives a generator that generates a first AC power.
A rectifier rectifies the first AC power to produce a first DC power.
An inverter converts the first DC power to a second AC power.
An electrical energy storage device accumulates electrical energy to supply a second DC power.
A DC-to-DC converter converts the second DC power to a third DC power.
The third DC power is selectively provided as an additional input to the inverter.
When the third DC power is provided as an input to the inverter, the inverter converts the third DC power to the second AC power.
A controller controls at least the rectifier and the DC/DC converter.
The controller selectively enables one of the rectifier and the DC/DC converter to provide either the first DC power or the third DC power as the input power to the inverter.
The controller also selectively enables both the rectifier and the DC/DC converter to provide both the first DC power and the third DC power as input powers to the inverter