What is the difference between Ehs et HSCS?

[PFA007]

eHS — electric Hardware Solver

eHS is OPAL-RT’s FPGA-based real-time solver for electric circuits. It automatically simulates power electronics and electrical networks on an FPGA without requiring users to write mathematical equations manually.

Solver type: Implicit (Pejovic method) — switches are modeled as L/C elements

Timestep: Typically 160 ns to 4 µs

Scope: General-purpose — supports large circuits, micro-grids, up to 144 switches (eHSx128)

Platform: Supported across multiple FPGA platforms (OP4510, OP5707, OP48xx…)

Tuning: Requires Gs/Rs snubber tuning to ensure stability

HSCS — High Speed Converter Solver
HSCS is OPAL-RT’s newer, specialized solver designed for ultra-high-speed power converter topologies (LLC resonant, DAB, T-type, ANPC, etc.). It was introduced with eFPGASIM 3.5 (2026.2).

Solver type: Explicit — no Gs/Rs tuning needed (much simpler for users)

Timestep: As low as 32–36 ns (with 4 ns internal oversampling)

Scope: Focused on small, high-frequency switching networks (up to ~13 switches per block), targeting GaN/SiC-based converters

Platform: OP48xx only (AMD Versal)

License: Requires High Performance eHS license

[Parija]

This comparison table is very helpful! Thanks

[TimoRoesch]

Small clarification: Please note that our eHS HP mode can go down to some 80-90ns time-step and has capturing of gate signals at 625ps.
eHS is also very relevant for high-switching frequencies of x-hundred kHz PWM…

[Fabien.Ducat]

The minimum time step for HSCS is indeed 32ns, and the official versions of eFPGASIM support up to 12 switches (13 remains custom for now).

Each HSCS model can be duplicated up to a maximum of 16 times.

All of this will be available for the OP4815 platform in RTLAB and HYPERSIM 2026.3, which is coming soon.

Thanks to HSCS, the maximum number of switches can now reach 256, and a new eHS x256 license will be introduced accordingly.