A new version of the Spice analogue simulator called Qspice can simplify the development of motor control for EV powertrains and other vehicle motors (writes Nick Flaherty).

The Qspice simulator has been written by Mike Englehardt, the creator of several versions of the Spice analogue simulator. It can integrate digital elements such as controllers with no performance penalties alongside the analogue power device simulation.

A key aspect of Qspice is that the digital models can be as detailed as the Verilog code of a microcontroller that is used to build the controllers in silicon. The simulator is written so that the digital elements are not run in an interpreter but as native object code on the Intel processor to avoid impacting on the Spice simulation, said Englehardt.

The simulator has been adopted by Qorvo as Qspice and runs on Windows PCs with GPU accelerators for high-quality real-time graphics.

“There is a collection of 62 circuits that are used as a torture test, and Qspice is the first one that can run all of these and in most cases is in first place,” said Jeff Strang, general manager of the power business at Qorvo, which has the sole distribution rights for Qspice.

It will be free and unrestricted for commercial use. Models of devices can be hosted by semiconductor companies, and Qorvo is working with microcontroller designers to make models available. The models can also be encrypted by the developers to run on the simulator, allowing a wider ecosystem of IP to be used securely.

Strang pointed to a three-phase traction 150kW inverter design using the Qorvo SiC cascode devices from UnitedSIC. “You can open the model in Qspice and run detailed simulations on each of the FETs as well as the whole design,” he said.

“A motor controller these days is not just the control signals; now there’s a complex microcontroller, and Qspice can simulate that entire digital simulation as a circuit block in a C++ behavioural model,” he added.