The pulse injection method from KOSTAL: Revolutionary control technology for variable frequency drives

A unique feature on the market is the fact that there is no overload limit. Whereas in the past motors had to be oversized in order to handle short-term overloads, the pulse injection method is no longer constrained by any overload limits. This means that the motor can also be smaller. Thanks to the second-generation pulse injection method, the rotor position can be precisely determined on the basis of the motor's anisotropy behaviour even at standstill – and performance levels remain high. In addition, the positional accuracy improves as the current increases, which is revolutionary compared with the methods currently on the market.

The new control method also comes with other advantages: by removing the encoder, the motor size is reduced and both shaft ends can be used. The reduced number of components and cable connections also increases the product's life expectancy and system's robustness. This is particularly interesting for applications that are not so well suited to using an encoder.

As the sensor is a very sensitive component in the drive train, problems or even failure may occur in environments with unfavourable ambient conditions, such as vibration, humidity, heat, cold or dust. 

Since both the costs of the encoder hardware and the work involved in mounting, adjusting and maintaining the encoder are eliminated, a significant cost saving can be achieved by using the new control process. This even allows the variable frequency drive to be used in harsh environmental situations that were previously not possible with encoder systems.

You also no longer have to worry about matching the variable frequency drive and motor perfectly. The adjustment takes place automatically with the aid of automatic configuration and motor recognition (Selfcom). This vastly simplifies commissioning and parameterisation.