With the rapid development of semiconductor technologies over the past few decades, increasingly DC engines are being replaced by an adjustable asynchronous engine drive. The advantage of asynchronous engines is their simple design and longevity because they don't have brushes and a collector that dilves and complicates the design of a engine. Speed adjustment is provided by frequency drives using different speed or moment adjustment methods. Frequency drives also generally allow different additional functionality – protecting the engine from damage, braking it, creating different speed and power profiles.
It is important for students in high-school electrical engineering programs not only to learn the theory about the principles of the asynchronous engine and frequency drive, but also to strengthen knowledge in practice, to have the ability to change the settings of the frequency drive, to measure the output voltage and current shapes of the frequency drive to capture electromechanical curves of the load and then to perform calculations and construct curves, and draw conclusions on the results obtained.
For this purpose, a stand consisting of an asynchronous motor with a mechanical braking device has been created at Riga Technical University, supplemented with measuring equipment and a modern frequency drive, which has been received as a gift from the SIA “ZTF LĀSMA”. It is planned to replenish the bench with a speed feedback loop, allowing students to also learn the choice of coefficients for the integrated proportionally integrated controller in the frequency drive. Such knowledge is very useful because more and more technological processes are automated and robotised and require accurate speed or moment management.
A stand equipped with this frequency drive is intended to be used for the acquisition of the "Electrical Control" object of the students of ''Computer Control of Electrical Technologies" and "Mehatronics" program.