Fuji Electric frenic mini series, Руководство пользователя

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7.1 Selecting Motors and Inverters
7-3
Chap. 7
SEL
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IMAL I
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(4) Braking torque (Curves (d), (e), and (f) in Figures 7.1 and 7.2)
In braking the motor, kinetic energy is converted to electrical energy and regenerated to the
smoothing capacitor on the DC link circuit of the inverter. Discharging this electrical energy to the
braking resistor produces a large braking torque as shown in curve (e). If no braking resistor is
provided, however, only the motor and inverter losses consume the regenerated braking energy so
that the torque becomes smaller as shown in curve (d).
Models of 1.5 kW to 3.7 kW, 3-phase 200/400 V are each available in a braking resistor built-in type
in which the braking torque equivalent to that of the optional braking resistor can be obtained
without an optional resistor.
For more information, refer to Chapter 8, Section 8.2.2 "Braking Resistor Built-in Type."
When an optional braking resistor is used, the braking torque is allowable only for a short time. Its
time ratings are mainly determined by the braking resistor ratings. This manual and associated
catalogs list the allowable values (kW) obtained from the average discharging loss and allowable
values (kWs) obtained from the discharging capability that can be discharged at one time.
Note that the torque % value varies according to the inverter capacity.
Selecting an optimal braking unit enables a braking torque value to be selected comparatively freely
in the range below the short-time maximum torque in the driving mode, as shown in curve (f).
For braking-related values when the inverter and braking resistor are normally combined, refer
to Chapter 6, Section 6.4.1 [1] "Braking Resistor."