Functional Extension:
Sensorless Control for Synchronous Motors (SLSM-PSM)
Sensorless control for synchronous motors is based on the implementation of the BitFlux method, which actively controls the flux and the torque-generating current in the motor independently of one another.
Thanks to the anisotropy of the motors, the rotor position is reliably determined even at standstill and low speeds using an HF injection method.
Compared to the "SL-PSM" sensorless control, the "SLSM-PSM" control offers the following
advantages:
- Standstill at the motor’s rated torque is possible
- The precise adjustment of the torque-generating current starting from a standstill saves energy and prevents unnecessary heating of the motor
- Better positioning capability (regulated rather than controlled)
- Optimal torque efficiency.
- Up to 3 times the acceleration torque with Lenze synchronous motors m550/m650 from a standstill
- Easy commissioning of the m550/m650, as selecting the motors via the C86 reference requires virtually no further optimization, except, of course, for the application-specific configuration.
Included in the following products:
- i950 B starting with firmware V02.00.03
- Easy Starter starting with V1.31
The implementation is comparable to (and compatible with) that in the i510, i550, and i650 inverters.
Application:
Unlike conventional servo control with motor feedback, position and speed are only available when the drive is enabled. The position reference is lost with every interruption in operation (OperationDisabled, STO, error, etc.).
Applications involving relative positioning, load-dependent constant speed, and even simple electric shaft applications with speed synchronization can be implemented. Torque control with a moderate control range is also possible.
Due to the elimination of the encoder and, above all, the cabling, the system costs are significantly lower than those of a solution using servomotors.
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