Controlling multiple motors utilizing a single DSP controller

Traditionally the cost sensitive motor drive market forced designers to avoid DSP controllers for their drive design. However, several factors are rapidly changing this scenario. The prices of DSPs have dropped from hundreds of dollars to approximately three dollars since their introduction in the early 1980s. Moreover, DSPs can now integrate a variety of sophisticated peripherals. This integration of DSP core with a set of useful peripherals significantly simplifies the design. At the same time, the cost sensitive drives like heating ventilating and air conditioning (HVAC), appliances are starting to utilize variable speed drives to maximize the efficiency and comfort for the user. Many of these applications have more than one motor. For example, a typical HVAC system usually utilizes two motors. Until now, these motors were mainly operated at a fixed speed or at a set number of multiple speeds to minimize cost. This paper shows the advantages of using DSP controllers for such applications. It will be shown that these controllers provide a true single chip solution for these drives.