A new control algorithm for Danfoss VLT frequency converters now opens up for synchronous reluctance motors. High efficiency synchronous reluctance is one of the newly-emerged motor technologies offering optimum energy utilisation. 
Furthermore, it is a robust technology and maintenance requires little effort; so overall it demonstrates an impressively short payback period in terms of return on investment. 
When the diverse motor technologies within one plant are controlled by a single drive platform, the designer has full liberty to install the best value motor for each application. At the same time, costs are reduced for both storage and training in operation of the frequency converter. Updating the system with the new motor technology is an easy retrofit, as no exchange of the drive is required. 
These advantages are precisely the benefits that Danfoss VLT frequency converters offer. The VLT AutomationDrive is able to control a wide variety of motor types, now including synchronous reluctance. Control not only involves operating the motors using advanced Voltage Vector Control, but also the full realisation of the efficiency advantages. This realisation is possible due to specially adapted algorithms for operation at the optimum operating point. 
The new Danfoss firmware for synchronous reluctance means that commissioning is as easy as for a standard AC asynchronous motor. The installer has to enter only four motor parameters. The automatic motor adaptation for synchronous reluctance motors takes only 2.7 seconds to measure the motor characteristics and optimise the motor parameters. The motor then operates at the highest possible energy efficiency, for lower energy consumption and reduced running costs. Danfoss’ “One VLT for all motors” approach is different to that of competitors, because it enables motor independence including synchronous reluctance at no extra cost; whilst still ensuring optimal performance. The same frequency converter can be configured for operation of standard asynchronous machines, permanent magnet and synchronous reluctance motors; even existing installations can be upgraded with the new software.