eHS Solver

The FPGA-based Power Electronics Toolbox has, in its heart, an electric Hardware Solver (eHS).

The eHS solver is an FPGA-based technology developed by OPAL-RT for real-time power electronics simulation. Thanks to a convenient circuit schematic graphical user interface, the FPGA code is automatically generated, making FPGA-based simulation accessible to a large number of users.

The OPAL-RT electric Hardware Solver (eHS) is a powerful floating-point solver developed by OPAL-RT that enables users to simulate an electric circuit on an FPGA automatically, without having to write the mathematical equations. It combines the simplicity of building electric circuit models using either our OPAL-RT Schematic Editor or the Simscape Electrical Specialized Power Systems (SPS) Toolbox, PSIM, the PLECS Blockset, or NI Multisim software with the strength of OPAL-RT FPGA-based simulators to solve the currents and voltages within the circuit in real-time, with a sample time below 1μs.

The new 5th generation is based on state space method that allows higher order of discretization and offers better performances than the previous generation.

The 4th generation of eHS solver uses the modified nodal analysis. It solves a conductance matrix to find the voltage at each node of the circuit, and the current in each branch. The conductance matrix of the circuit is made independent of the switch control signals through the implementation of the Pejovic method representing the switch impedance. With this method, a conducting switch is represented as an inductance and an open switch is represented as a capacitance so the conductance matrix does not change during the simulation.