RT-EVENTS is a Simulink toolbox for fixed-step simulations of hybrid systems involving dynamic and discrete events that are asynchronous with respect to the simulation clock. It allows the simulation of high frequency modulation signals of firing pulse units and power electronic controls.
The RT-EVENTS Blockset works with a fixed time-step, making it compatible with the Simulink Coder and Embedded Coder and RT-LAB, and can be used for real-time applications.
The use of variable-step solvers carries the disadvantage of significantly slowing the simulation of complex converter controls. The use of fixed-step solvers improves simulation speed, but often provides incorrect results due to delays for discrete events (asynchronous with the simulation step) to the next simulation cycle, causing an accumulation of errors and phase shifts.
Only fixed-step solvers are used for automatic code generation. Standard fixed-step solvers for Simulink yields errors, which are then applied to converter controls; this may accumulate and cause drift and significant phase shift. RT-EVENTS applies a compensation algorithm to discrete events in real-time, resulting in a greater precision.
When rapid prototyping power electronic systems, it can be challenging to convert controller outputs to switching signals sent to time-stamped digital outputs. The use of standard Simulink blocks causes high jitter, due to the lack of any timing information: when simulated at fixed-step in the order of 10us to 100us, the firing pulses cannot be generated precisely. RT-Event generates timing information about the switching and state transitions to each switching state, ensuring more precise results.