By default, a real time digital simulator will execute a simulation case and provide the solution for the controls and power system every time-step (typically 50 musec). The length of the time step is decided by the time taken to execute the longest component algorithm. The component in question may be that for a protective relay which takes in new data only every 1 or 2 milliseconds. The idea behind a multithreaded component is that a protection algorithm does not need to be executed every time-step. A component algorithm can be separated into individual blocks of code processed independently of each other to create a multi-threaded component running within the main simulation. Details are given of this process and how it is applied to several relay models.
D. S. Ouellette, R. P. Wierckx and P. G. McLaren, "Using a Multi-Threaded Time-Step To Model a Multi-Function Relay in a Real Time Digital Simulator," 2008 IET 9th International Conference on Developments in Power System Protection (DPSP 2008), Glasgow, 2008, pp. 162-167, doi: 10.1049/cp:20080029.
KEYWORDS: Time-step, Multi-threaded, Multi-function, Protective Relay, Power System Simulation