4-2 Function Mode Overvoltage Control Function During Deceleration This function helps avoid an overvoltage trip during deceleration. Note that the actual deceleration time may be longer than the set value. This function automatically keeps DC voltage at the set level during deceleration. The aim of this function is the same as the overvoltage LAD stop function, de- scribed in b130 and b131. However, these functions have different deceleration characteristics and you can select either function according to your system.
4 Functions Internal DC voltage Set level (B134) Output frequency t t Normal Overvoltage protection during deceleration With this function activated, PI control works to keep the internal DC voltage constant. •Though quicker response is expected with a larger proportional gain, control tends to be divergent and may easily lead to a trip. •Response also becomes quicker with a shorter integral time, but if too short, it may lead to a trip as well. AM Adjustment You can adjust the calibration of the analog voltage (0 to 10 V DC) from the AM terminal on the con- trol terminal block by using the Inverter setting. 4-35 Parameter No.
Function name Data Default setting Unit b055 Overvoltage protection proportional gain during deceleration 0.2 to 5.0 0.2 ⎯ b056 Overvoltage protection integral time during deceleration 0.0 to 150.0 0.2 s b133 Overvoltage protection function selection during deceleration 00: Disabled 01: Enabled 00 ⎯ b134 Overvoltage protection level setting during deceleration 200-V class: 330 to 395 400-V class: 660 to 790 380/ 760 V Parameter No. Function name Data Default setting Unit b080 AM adjustment 0. to 255. 100 ⎯ C028 AM selection 00: Output frequency 01: Output current 00 ⎯ C086 AM offset adjustment 0.0 to 10.0 0.0 V