Application of the Waveform Relaxation Technique to the Co-Simulation of Power Converter Controller and Electrical Circuit Models
For engineers co-simulating digital controllers with analog circuits, this method preserves each model's native time-stepping, but the contribution is incremental as it adapts an existing technique to a specific domain.
The paper applies waveform relaxation to co-simulate a PID power converter controller (fixed-step) and an electrical circuit (adaptive-step), enabling separate model handling. The approach is demonstrated on a PI controller and the LHC main dipole circuit, with mathematical analysis of iteration bounds.
In this paper we present the co-simulation of a PID class power converter controller and an electrical circuit by means of the waveform relaxation technique. The simulation of the controller model is characterized by a fixed-time stepping scheme reflecting its digital implementation, whereas a circuit simulation usually employs an adaptive time stepping scheme in order to account for a wide range of time constants within the circuit model. In order to maintain the characteristic of both models as well as to facilitate model replacement, we treat them separately by means of input/output relations and propose an application of a waveform relaxation algorithm. Furthermore, the maximum and minimum number of iterations of the proposed algorithm are mathematically analyzed. The concept of controller/circuit coupling is illustrated by an example of the co-simulation of a PI power converter controller and a model of the main dipole circuit of the Large Hadron Collider.