BENSHAW M2L 3000, Руководство пользователя

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M2L 3000 Series VFD
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Inverter
The role of the Inverter is to convert DC voltage produced by the Converter to variable voltage, variable frequency AC, to be
applied to the motor terminals. The Inverter utilizes a topology known as Modular Multi-Level Converter (M
2 LC), which offers
many benefits.
M
2
LC topology allows the Converter to be located remotely from the Inverter, for the ultimate in application flexibility. The
Inverter is a modular design enabling rapid drive repair by simple removal and replacement of a faulty module or “cell”. Re-
placing a cell can be done in a matter of minutes, minimizing downtime and process interruption.
IGBT Cell
The standard building block in the M2L 3000 Converter is the “cell”. A variety of cell
sizes are available, having different current ratings to configure drives at different
power levels.
A cell consists of Insulated Gate Bipolar Transistors (IGBTs), capacitors, associated
control, communication and gating circuitry, heatsinks, and sensors; all housed in a
metal enclosure. A depiction of the cell is shown below in Figure 9.
Figure 9: IGBT Cell
Each cell contains IGBT switching devices and film capacitors. These film capacitors
offer significant improvements over conventional electrolytic capacitor technologies.
This technology is more stable, and safer, than conventional capacitors that can ex-
plode from the buildup of high pressures within the capacitor if a failure should occur.
Embedded cell circuitry provides intelligence for control and communication. Communi-
cation with the central control system of the drive occurs over optical fiber, using an
Ethernet protocol that greatly improves speed and noise immunity. Each cell is de-
signed to sense voltage and current, eliminating the need to place external voltage and
current sensors on the motor leads.
The elimination of external sensors removes single points of failure, improving drive re-
liability.