Frequency inverters

Revolution of the encoderless motor control

Revolution of the encoderless motor control

Kostal frequency inverters are now also equipped with Kostal -ISP. The Integrated Sensorless Position Control function is made possible by the patented sensorless control method. This means that it is now possible to carry out positioning applications entirely without the use of a rotor position encoder.

The Kostal pulse injection method calculates the exact rotor position based on the anisotropy of the motor completely without an encoder. In other words, it uses the motor itself as a sensor, which works with high performance for all PM synchronous and synchronous reluctance motors. The reluctance motor in particular offers customers a very efficient and future-proof alternative to the asynchronous motor.

When it comes to encoderless positioning, many parameters play a role that must be considered, such as the controlled motor type and the suitability of the motor as a sensor. However, other systems available on the market quickly reach their limits when it comes to this topic, because positioning can only be as good as the signal that the control system is able to draw from the motor.

In this respect, the Kostal ISP certainly leads the market comparison, because once calibrated, the Kostal system is able to maintain the position even after an infinite number of repetitions. In terms of repeat accuracy, the system is thus comparable to encoder-based systems. Other systems either lose accuracy after multiple runs (drift) and end up needing a sensor again to find the zero position, or cannot meet requirements for dynamics and speed control range without a sensor.

In terms of resolution for speed control, Kostal's encoderless control is high-resolution and comparable to the performance of an incremental encoder.The method is superior in all these respects and thus represents a real revolution in the field of encoderless positioning. In practice, the ISP in Inveor frequency inverters enables many positioning applications that would otherwise require an encoder. This offers real added value and is particularly interesting for applications where the use of an encoder is not possible without restrictions.

Since the sensor is a very sensitive component in the drive train, it can lead to problems or even failure in environments with unfavorable ambient conditions such as vibration, humidity, heat, cold, dust or radiation. With Kostal motor control, you don't have these problems, which makes the area of application extremely flexible. At the same time, encoderless positioning means considerable cost savings for the user, since the acquisition costs for encoders and connection become superfluous, as do the interface hardware and the setup and maintenance of the encoder.