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Greater reliability and less maintenance effort
Three-phase motors are practically
maintenance-free because current is not transmitted via carbon brushes but electromagnetically and therefore without contact. Unlike direct current motors, the driving direction is not changed via direction contacts but electronically.
Therefore it is not necessary to replace worn carbon brushes and contactors or to overhaul the collectors. Moreover, because three-phase motors are generally more insensitive to dust and moisture, they are much more reliable
particularly under adverse operating conditions
Greater efficiency
Vehicles with a three-phase drive are generally more efficient and more agile because three-phase motors have a better torque characteristic at a
comparable capacity. The constant torque over a wide speed range facilitates for example starting on ramps or dynamic acceleration with large loads. Since the torque decrease characteristic of conventional direct current motors at high
speeds is also prevented, it is possible to achieve higher speeds.
Smoother maneuvering
Because three-phase motors can be controlled more precisely, they enable very smooth driving. Changes in driving direction can also
be performed more smoothly than with conventional direct current motors. This is especially important particularly when operating conditions require precise maneuvering in cramped spaces. A positive feature as to technical safety is the
fact that three-phase motors are speed-controlled and therefore the driving speed corresponds directly to the position of the accelerator pedal regardless of the respective route profile: accidental acceleration while driving downhill
is not possible.
Adequately low energy consumption
When three phase and direct current drives are compared, hardly any issue is as controversial as that of energy consumption. The fact is that the required conversion of
the direct current supplied by the drive batteries into three-phase current leads to energy loss. However, these efficiency disadvantages are compensated for by the higher efficiency of three-phase motors, resulting in a virtually
identical overall efficiency of both drive alternatives. The reason why these electro-technical results contradict to some degree customers’ experience, which attest vehicles with three-phase drive a somewhat smaller range, can be
explained easily: the greater performance potentials of a three-phase drive with regard to parameters such as pulling power, acceleration and speed are naturally tapped in practice. Therefore comparisons with nominally equally powerful
yet less efficient direct current vehicles are usually not very indicative.
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