4-2 Function Mode •If 0-Hz sensorless vector control cannot provide the desired characteristics, adjust the motor parameters depending on the phenomena, as shown in the table below. 4 Functions Note 1: Make sure that the carrier frequency (b083) is not lower than 2.1 kHz. If the carrier frequency is at 2.1 Hz or lower, the Inverter does not operate normally. Note 2: Set a torque limit value (b041 to b044), while keeping the value α , calculated with the following formula, at 200% or lower. Otherwise, the motor may burn out.
α = Torque limit set value Ч (Inverter capacity) / (Motor capacity) (Example) If the Inverter capacity is 0.75 kW and the motor capacity is 0.4 kW, the torque limit set value for α = 200%, calculated with the above formula, is as follows: Torque limit set value (b041 to b044) = α Ч (Motor capacity) / (Inverter capacity) = 200% Ч (0.4 kW)/(0.75 kW) = 106% 4-113 Operation status Phenomenon Adjusting method Adjustment item Power running Speed change ratio is a negative value. Increase motor parameter R2 gradually (up to set parameter × 1.2). H021/H221/H031 Speed change ratio is a positive value. Reduce motor parameter R2 gradually (down to set parameter × 0.8).
H021/H221/H031 Regeneration Insufficient torque at low frequency (several Hz) Increase motor parameter R1 gradually (up to set parameter × 1.2). H020/H220/H030 Increase motor parameter Io gradually (up to set parameter × 1.2). H023/H223/H033 During startup Shock occurs during startup. Reduce motor parameter J from the set parameter. H024/H224/H034 During deceleration Motor hunting Reduce the speed response. H005/H205 Reduce motor parameter J from the set parameter. H024/H224/H034 Immediately after deceleration Overcurrent or overvoltage protection is activated. Reduce motor parameter Io gradually (down to set parameter × 0.8).
H023/H223/H033 Set AVR selection A081 to "00" (always ON) or "01" (always OFF). A081 Low- frequency operation Rotation is not constant. Increase motor parameter J from the set parameter. H024/H224/H034 Related functions A001, A044/A244, F001, b040, b041 to b044, H002/H202, H003/H203, H004/H204, H005/H205, H020/H220, H021/H221, H022/H222, H023/ H223, H024/H224, H050/H250, H051/H251, H052/H252, H060/H260, H061/H261