Fuji Electric frenic mini series, User Manual

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7.2 Selecting a Braking Resistor
7-13
Chap. 7
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7.2 Selecting a Braking Resistor
7.2.1 Selection Procedure
The following three requirements must be satisfied simultaneously:
1) The maximum braking torque should not exceed values listed in Tables 6.7 to 6.9 in Chapter 6,
Section 6.4.1 [1] "Braking Resistor." To use the maximum braking torque exceeding values in
those tables, select the braking resistor having one class larger capacity.
2) The discharge energy for a single braking action should not exceed the discharging capability
(kWs) listed in Tables 6.7 to 6.9 in Chapter 6, Section 6.4.1 [1] "Braking Resistor." For detailed
calculation, refer to Section 7.1.3.3 "Heat energy calculation of braking resistor."
3) The average loss that is calculated by dividing the discharge energy by the cyclic period must not
exceed the average loss (kW) listed in Tables 6.7 to 6.9 in Chapter 6, Section 6.4.1 [1] "Braking
Resistor."
7.2.2 Notes on Selection
The braking time T
1
, cyclic period T
0
, and duty cycle %ED are converted under deceleration braking
conditions based on the rated torque as shown below. However, you do not need to consider these
values when selecting the braking resistor capacity.
Figure 7.11 Duty Cycle