Real-time simulation is a familiar technique for testing hardware and software in the loop and for operator training. An important parameter of these simulations is the frame-time necessary to capture the dynamics of the system being simulated. Modern power electronic systems, using higher frequency pulse-width modulation (PWM) converter control demand frame times that are significantly shorter than those found in most real-time simulators. The paper describes an approach to real-time simulation that is capable of achieving the frame times of 10 ?S and less required for this application. It is a scalable technique that uses arrays of digital signal processors on commercially available boards plugged into a conventional desktop computer. Analog and digital interfaces provide for the connection of real hardware to the simulation. Although the technique has so far been applied only to power electronic systems, it is capable of being used in a wide range of applications in which frame times of less than 10 ?S are required.