A poly-phase electrical system having a 90° phase separation is classified as which type?

A poly-phase electrical system with a 90° phase separation is classified as a 4-phase system. This classification stems from the fact that phase separation cannot be achieved with a standard three-phase system, which typically has phase separations of 120° between the phases. In the case of a 4-phase system, four voltage waveforms are generated, each separated by 90°, allowing for better performance in certain applications, such as in stepper motors and other specialized equipment.

In a 2-phase system, for instance, the phase separation is typically 90° or 180°, but only two phases are utilized; thus, it does not encompass the characteristics of a 4-phase system. Similarly, a 3-phase system consists of three phases separated by 120°, and a 5-phase system would have a separation of 72° for each phase. Therefore, the specific characteristic of having four distinct phases each separated by 90° categorizes the poly-phase electrical system as a 4-phase system.