AC/DC/AC CONVERTER for teaching purpose UNS3

UNS3 is a didactic equipment developed to perform various kinds of exercises during the courses of POWER ELECTRONICS at the Faculty of Engineering of the Salerno University.

 

It allows the study of the design issues related to conversion of AC / DC with SCR, and the DC / AC conversion using IGBT; both converters are connected to a motor (DC motor in the first case, and three-phase induction motor in the second case), and should be controlled with TTL signals generated by external logic capable of providing the timing necessary to achieve the desired outputs from the converter .

 

In its typical use, the equipment thus operates as power interface among the controller and the motors, allowing to specify in safe conditions (for the operator, the engine, the mains, and for himself) various control strategies , and monitoring by external oscilloscopes, all electrical internal parameters.

 

The apparatus operates in total GALVANIC ISOLATION compared to the mains; this allows to connect without any problems measuring instrument or evaluation (including oscilloscopes with the cold pole to the frame), and to minimize the risks for the operator.

 

UNS3 makes available at its terminal 29 different waveforms, 19 of which are relative to the most significant currents, acquired by Hall effect isolated transducers, which are able to respond by 200KHz DCa.

 

The input signals (12 in total: 1 for each switch of each bridge) are subjected to a preconditioning aimed to eliminate interferences collected, and to prevent the implementation of commands improper or dangerous for the integrity of the apparatus; in any case, a generous size of the switch and protection devices, guarantee the survival of the apparatus in all the operating conditions.