How
Does An Inverter Work
The principle
of the Inverter is to produce a variable frequency supply
to the motor terminals. The supply to the Inverter is a
fixed supply, generally AC either 3 phase or single phase
of various voltages worldwide. To produce a variable frequency
from this fixed supply is complex.
Although Inverters have been around for many years (at least
since 1960) it has been the advances of modern power semi
conductor devices with micro electronics that has seen design
of Inverters reduced to more manageable and affordable proportions.
Inverters take the fixed AC supply and rectify to Dc. The
DC supply (called the DC bus) is then applied to a switching
circuit - an Inverter bridge. The Inverter bridge switches
the DC voltage to the motor in a sinusoidal manner. The
voltage pulses applied have a variable width generating
a synthetic sine wave. Obviously, the more voltage pulses
applied in each cycle, the better the current waveform and
less harmonics are generated.
Inverter drives automatically read the characteristics of
the motor and adjust the control software accordingly, further
assisting energy efficiency.
View
product PDF files
Siemens Inverters
- Variable Speed Drives Low Voltage Motors
Sirius Motor Management, p1-12
VA Tech
Frequency Inverters
brochure page 1-6
VA Tech Inverter Price
List
price list page 16-17
