Hitachi SJ Series, User Manual

Page: 304 / 786

12-12-1
Chapter 12
Inverter Function
12.12 Adjusting Motor Noise, Noise,
and Inverter Heat Generation
12.12.1 Adjusting carrier frequency
• I want to reduce the electromagnetic noise from the
motor.
• I want to reduce the noise from the inverter.
• I want to suppress the heat generated in the
inverter.
• I want to suppress the leakage current.
• The carrier frequency is the frequency at which the
element that controls the inverter output changes.
• The carrier frequency can be changed using the
[bb101] setting.
• It is also effective in avoiding resonance of
mechanical systems and motors.
Carrier frequency and its extent of the effect
Parameters
*1) The following constraints will be applied internally.
Maximum 12.0 kHz at rated LD, maximum 10.0 kHz at rated
VLD
• With the selection using [Ub-03] Load
specifications, the carrier frequency setting will be
automatically restrained.
• The relation between allowable output current and
carrier frequency depends on the inverter type.
Derate the output current as shown in the table on
the next page when increasing the carrier
frequency.
• If the [AA121] control method selection when
driven by induction motor (IM) is automatic torque
boost (03), sensorless vector control (08), or zero
speed area sensorless vector control (09), set the
carrier frequency to 2.0 kHz or higher.
• If the [AA121] control method selection is the
synchronous motor/permanent magnet motor
(SM/PMM) sensorless vector control (11), set the
carrier frequency to 8.0 kHz or higher.
• The carrier frequency should be set to 10 times or
higher of the [Hb105] IM highest frequency or
[Hd105] SM (PMM) highest frequency.
(Ex.) When [Hb105] = 60 Hz, [bb101] = 0.6 kHz
(600 Hz) or higher
• When using the carrier frequency of 2.1 kHz or
higher, see the derating characteristics described
in "Chapter 20 Specifications".
Carrier frequency Low High
Motor electromagnetic
noise
Loud Quiet
Noise Quiet Loud
Inverter heat generation Little Much
Leakage current Low High
Inverter
output voltage waveform
example
(PWM output)
Carrier frequency: Low Carrier frequency: High
Item Parameter Data Description
Carrier
frequency
[bb101] 0.5~16.0(kHz) *1) Changes the carrier frequency.
Ｑ
Ａ
！