The M2L product family is forced-air cooled, and spans a power range from 300hp to 10,000hp, operating at industry standard medium voltages up to 13.8 kVAC.
Key Features Include:
Compact Modular Design: Simplistic component arrangement with minimal total part count
Installation Flexibility: Optimal for retrofits
Arc Resistant: Safety by design — arc flash footprint inherently lower
Energy efficiency: Inverter efficiency losses >= 99.5%
Robust Control Architecture: High performance M2LC Control Architecture, reliability and immunity from EMI, through noise tolerant signaling & fiber optic communications
The Modular Multi-Level Converter (M2LC) combines the advantages of a rugged and
proven transformer-rectifier converter with a state-of-the-art multi-level inverter. The M2LC’s architecture differs radically from other multi-level systems in the market today. Gone are the days when an inverter had to rely on a common bank of capacitors for energy storage and filtering, or numerous rectifier-capacitor combinations located in individual inverter power modules. DC power is fed to the M2LC inverter from a standard transformer with bridge rectifiers, and can be located remotely from the inverter. Power is not individually fed to each module, but to the DC link as a whole via the DC voltage terminals. The link does not contain any capacitors for energy storage. Energy storage is distributed among identical power modules that comprise the M2LC inverter, which greatly reduces arc flash potential and substantially improves reliability.
Each module in the inverter contains two, 4th generation IGBT silicon switching devices and film capacitors. Embedded circuitry provides intelligence for control and communication in each module. In addition, each module inherently senses voltage and current, so separate voltage and current sensors are not needed on the motor leads.
A group of power modules connected in series forms an “arm,” and a pair of arms connected in series forms a switching “pole.” There are three poles in the inverter to form three phases. The outside points of the arms connect to the positive and negative terminals of the DC link, and their midpoints provide AC connections to the motor. The
DC link voltage is divided evenly among the modules in the arms. Pulse width modulation(PWM) converts the DC voltage into a low distortion AC waveform, which is applied to the motor. The output voltage can be finely set corresponding to the capacitor voltage of the individual modules.
The M2LC inverter features fine output voltage adjustment, low distortion, modularity and redundancy like the more popular multi-level inverters today; however, a complicated transformer and individual diode rectifiers are no longer needed. Unlike these systems,
it is possible to connect several M2LC inverters to the common DC link to form a fourquadrant drive or provide a solution for multi-motor systems.
The M2LC provides efficiency and reliability (MTBF) advantages over the popular Cascaded H-Bridge topology while providing equivalent low distortion input and output waveforms. Heat loss from both the M2LC inverter and converter are much lower than the Cascaded H-Bridge design and internal component operating stresses are lower, improving reliability and operating life.
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