FAQ
Frequently asked questions about OverDrive, the inverter and CAN
The questions engineers ask us most often – answered briefly. Don’t see yours? Write to us.
OverDrive – simulation
What is OverDrive?
OverDrive is the Persystems real-time simulation software for electric drives. It computes motor, inverter and control as physical models with switching events and saturation – with structure-preserving integrators that conserve energy, momentum and charge. OverDrive is delivered as an FMU according to the FMI standard.
How much faster is OverDrive than conventional simulation tools?
Up to 32 times (Persystems benchmark, Graz Smart Vehicle Forum 2025). Validation of the inverter software runs twice as fast as real time – a SiL loop takes 15 minutes instead of 8 hours.
How accurate are the results?
Same circuit, same parameters, same excitation: the results agree with LTspice, PLECS and Simulink, down to the switching ripple of ±0.2 A. The validation examples are on the OverDrive page.
What are structure-preserving integrators?
Integration methods from geometric mechanics that preserve the structure of the physical system. They conserve energy, momentum and charge over the entire simulation – even with large time steps and over millions of steps. That makes OverDrive fast and exact at the same time.
In which environments does OverDrive run?
As an FMU according to the FMI standard in Simulink, IPG CarMaker and other co-simulation environments – on the development PC, without a compute cluster. Simulink is not required.
Can I keep using my existing motor and inverter parameters?
Yes. Parameters from your existing simulations are carried over – no rebuild, no duplicate model maintenance.
How do I get OverDrive?
As a license or for evaluation. Write to sales@persystems.org and tell us which drive you simulate and which toolchain you use.
INV-60V-120A inverter
What are the key data of the INV-60V-120A?
6 kW continuous power (6.5 kW for 180 s), voltage range 17 to 60 V, phase current 120 A rms continuous (135 A rms for 180 s), 50 kHz PWM. Three variants: case 100.4 × 77.2 × 32.9 mm at 337 g, embedded board 154 g, Aero variant 108 g. Air-cooled, IP-rated housing on request, CAN and PWM/PPM galvanically isolated (PersyCAN, DroneCAN), position sensor sin/cos, incremental encoder or sensorless.
Which motors is the inverter suitable for?
For permanent-magnet synchronous motors – including the outrunners marketed as “BLDC” – with field-oriented control. The rotor position comes sensorlessly from motor model and back-EMF, or from a sin/cos or incremental encoder.
Which protection functions does the inverter have?
Overcurrent, short circuit, overtemperature, undervoltage and sensor faults switch the drive into a safe state – Safe Torque Off or Active Short Circuit, configurable. The PWM/PPM inputs are monitored for invalid signals, timeout, inversion and noise. A fault log can be read over CAN, automatically on overcurrent.
How is the inverter controlled?
Over CAN with PersyCAN, over DroneCAN for flight controllers, or classically via PWM/PPM and analog. Arm and disarm work via CAN or input.
Can several inverters run on one bus?
Yes. Through the PersyCAN discovery mechanism, inverters with the same factory address are automatically assigned their own CAN IDs; known devices get their old address back after a restart. Over DroneCAN up to 20 ESC indices per bus are possible.
What is included?
The inverter with field-oriented control and Persystems firmware, the PC software for parameterization, firmware updates and fault diagnosis over CAN, and the protocol documentation for PersyCAN and DroneCAN. On request we adapt hardware and firmware to your application.
Is there a datasheet and are samples available?
Yes, both on request at sales@persystems.org – tell us voltage, power and interface of your drive.
PersyCAN and DroneCAN
What is PersyCAN?
The CAN protocol of the Persystems inverters for setpoints, parameters, telemetry and firmware updates. It uses 29-bit identifiers with a device address so that several inverters share one bus, and sends operating data cyclically without polling – every 100 ms currents, voltages, temperatures, speed, torque as well as controller and fault state. Details on the PersyCAN page.
What is DroneCAN?
The open CAN protocol of the ArduPilot and PX4 world (formerly UAVCAN v0). Flight controller, ESCs, sensors and servos exchange standardized messages over a shared bus. The INV-60V-120A reports esc.Status at 10 Hz and NodeStatus at 1 Hz, gets its node ID dynamically and supports up to 20 ESC indices per bus.
Can I use PersyCAN and DroneCAN at the same time?
Not at the same time: the inverter is configured either for PersyCAN or for DroneCAN, but can be switched during operation. The PC software reaches the inverter via PersyCAN even when it is configured for DroneCAN; the stored configuration is preserved.
Do I have to poll the telemetry?
No. The inverter sends cyclically: every 100 ms the operating data, every 10 ms the state of the setpoint signal. The host system only listens.
Where do I get the complete protocol description?
Pin assignment, signal paths, fault handling and firmware update are online in the technical documentation at esc.persystems.org. We send the complete protocol description as a PDF on request, together with the configuration tool for Windows – write to sales@persystems.org.
Working with Persystems
Does Persystems also develop custom drives?
Yes. We adapt hardware and firmware of the inverter to your application, and our engineering team supports sizing and system integration – up to production readiness.
Do you also measure drives on the test bench?
Yes. We measure inverters and motors on our test bench in Regensburg – with power analyzer, torque transducer and continuous CAN logging.
Where are the products developed and manufactured?
At the Persystems GmbH headquarters in Regensburg, Germany. Persystems was founded in 2022 as a spin-off of the University of Regensburg.
What is the best way to reach you?
By email at sales@persystems.org or by phone at +49 941 462 974 40. All contact details are on the contact page.
Contact
Didn’t find your question?
Write to us – you will get an answer straight from the engineering team, usually the same day.