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shall be paid to the comparison between the rated currents of motor and
inverter. The overload capacity of the inverter only affects the startup and
brake process. In case short-time overload occurs during the running process,
variation of load speed may arise. If the requirement for the speed precision is
relatively high, it can consider increasing the level.
Constant torque load: Most of loads have constant toque characteristics, but
the requirements for rotation speed and dynamic performance are low.
Extruding machine, agitator, belt conveyer, transporting trolley in the factory,
and translational unit of crane are the examples. It can select MS V/F running
mode when performing prototyping test.
The controlled object has higher dynamic and static index requirements: It can
employ VC control mode in applications where the requirements for speed
adjustment precision and dynamic performance index are relatively high and
there is high precision synchronous control. Injection molding machine,elevator,
paper making and plastic thin film processing product line are the examples.
2.10 Guide to Prototyping of Brake Components
(*): Table 6 Driver Bake Components Prototyping Table provides data for
reference, and the user can select different resistance and power according to
the actual needs (but the resistance shall not be lower than the recommended
value, and the power may be higher than the recommened value). The
selection of brake resistor shall be determined in accordance with the power
generated by the motor in the actual application sytem and is associated with
the system inertia, speed-down time and energy of potential load. Thus, the
user needs to select based on the actual needs. The higher the system inertia,
the shorter the speed-down time required, and more frequent the brake is, and
then it needs to select higher power and lower resistance vlaue for the brake
resistor.
2.10.1Selection of resistance vlaue
Renewable electric energy consumption is almost the braking resistor when
braking.
Refer to the formula U*U/R=Pb,
In the formula, U refers to stable Braking system of Brake voltage. (Different
system has different brake voltage. The system 380VAC is 700V).Pb refers to
the Braking power.
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