Lenze three-phase AC motors - MEYLE - Meyer Industrie Electronic ...

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Inverter operation Limit values for operation with IGBT inverters The insulation system of Lenze three-phase AC motors has been dimensioned for thermal class F (�max. = 155°C). Dielectric and thermal stress has a major effect on the ageing/weakening of windings. Operation with high-speed IGBT inverters actually increases dielectric stress. The following limit values have been set for the motor winding based on current data without assuming a significant reduction in service life: du/dt < 5 kV/μs U < 1500 V These values are not exceeded in motive mode on IGBTs currently used on Lenze products and at cable lengths of less than 50 m. In operation in generator mode, these values may be exceeded. In applications in which an external brake resistor is required to convert the generator power fed into the DC bus, a motor choke must be provided to reduce insulation stresses. Operation at 50/60 Hz Three-phase AC standard motors are designed for operation at 50 Hz. The motors can be connected to a 230 V power Speed/torque characteristic for inverter operation U = Motor voltage M stall = Stalling torque M A = Starting torque supply in a Δ-connection or a 400 V power supply in a Yconnection. Frequency inverters can be used to vary the rotating field frequency and therefore the speed of the motor. In the inverter output frequency range up to 50 Hz (known as the armature speed range), the inverter keeps the voltage/frequency (V/f) range constant. This creates constant magnetic flux in the machine, i.e. the torque remains constant up to 50 Hz. In contrast, the power increases in a linear fashion until it reaches the rated power. At 50 Hz and above (known as the base frequency), the field weakening range begins. Although the voltage cannot be increased any further due to the preset mains voltage, the output frequency continues to increase. The torque decreases in proportion with the reduction in the magnetic flux. As the speed increases in proportion with the frequency, operation with constant power is possible above the base frequency. The diagram below illustrates the resulting speed/torque characteristic. The data provided for operation at 50 Hz can be applied to operation at 60 Hz by taking into account the affect of the operating frequency on the rated data as shown in the table at the bottom of page 22. Rated value 26 Three-phase AC motors en 1/2006
Operation at 87 Hz Setting the V/f break point to 87 Hz and 400 V in a Δ-connection for inverter operation enables the motor to be operated at up to 87 Hz with its rated torque without exceeding the thermal limit values of the motor. In comparison with operation at 50 Hz, this type of operation enables the permanent power of the motor to be increased by approximately 73%. However, throughout the range, the motor runs with the delta current increased by a factor of 400/230 = √3. Do not forget to dimension the inverter for the corresponding current. Torque reduction based on motor frame size with self-ventilation A motor protection relay is no longer sufficient to protect the motor as at operation at f
Page 1 and 2: Three-phase AC motors Carl-Bosch-St
Page 3 and 4: Product code Three-phase AC motors
Page 5 and 6: Lenze is the competent partner for
Page 7: 9300 servo inverter 9300 vector fre
Page 10 and 11: 10 Three-phase AC motors en 1/2006
Page 12 and 13: Overview General Robust three-phase
Page 14 and 15: Overview Designs Three-phase AC mot
Page 16 and 17: Control modes Overview Dimensioning
Page 18 and 19: Overview Dimensioning motors Radial
Page 20 and 21: Overview Motor connection Terminal
Page 22 and 23: Technical data, motors Rated data f
Page 24 and 25: Blower Brake BFK458 - __ E Options
Page 28 and 29: Inverter operation KTY 83-110 detec
Page 30 and 31: Sizing Inverter operation Maximum t
Page 36 and 37: Maximum torques MDòMAòò 100-12,
Page 46 and 47: Motor dimensions Design IM B3 (with
Page 48 and 49: Motor dimensions Design IM B5 (with
Page 50 and 51: Motor dimensions Design IM B14 (wit
Page 52 and 53: items Fax order form Preferred moto
Page 54 and 55: 8200 motec frequency inverters Func

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