Universal Inverter

Testing of traction inverter control algorithms with production E-Motor or E-Motor Emulator, charactering production E-Motors, and development testing of E-motor, E-drive and E-Axle designs and power ratings.

Unico’s Universal Inverter works with all of the most-common types of AC motors (Asynchronous Induction, Synchronous Permanent Magnet, and IPM – Internal Permanent Magnet) without changing hardware or loading different software. Switching frequency is user-adjustable up to 24kHz. The inverter contains a dynamic protection curve that automatically adjusts based on operating conditions including DC input voltage, switching frequency, overload, output frequency, and ambient temperature.

Operate in closed-loop vector control, open-loop vector control (transducerless), or volts/hertz frequency mode. For closed-loop control, the inverter accepts feedback from most feedback devices through add-on modules. Unico’s Universal Programmable Resolver Interface module works with almost any resolver. The excitation voltage, excitation frequency, and turns ratio are all configurable through simple drive setup parameters to match the specific type of resolver being used.

The Unico Universal Inverter includes automated test routines that characterize an IPM motor and generate its flux maps. Separate maps are generated for d and q-axis flux and for motoring and absorbing. This flux map data alone is invaluable for a motor designer. The inverter uses this data and generates the ideal current vectors for any combination or speed and torque. All of this data can be exported for additional external analysis if desired. Unico provides additional tools for analyzing this data to help validate the motor design.

Once the IPM motor has been mapped, the Universal Inverter can control the motor in velocity or torque mode, much like any other motor. For those who would rather use their own external motor control, the Unico Universal Inverter can also be configured to operate in Direct Current Control Mode. In this mode the inverter can accept external commands for d-axis and q-axis current. Or, the inverter can be set to instead accept a current magnitude and phase angle. In this case, the external controller would be responsible for any velocity control and/or torque control.

Supports most industry standard communication protocol, making it versatile to work with any available automation system platform. A high-speed communications interface is optionally available to accept commands from existing customer controllers that are used to generate test profiles. Wired and fiber-optic options are available. Supported protocols include:
CANopen, CC-Link, ControlNet, DeviceNet, Ethernet, EtherCAT (async), Interbus, LonWorks, Modbus Plus, Profibus DPV1, Profibus Master, EtherCat (sync)

Motors used in EV applications often operate at high speeds, with 20-30,000 rpm being fairly common. These motors are often high pole-count as well, meaning the motor fundamental frequency can get quite high (often 1000 – 2000Hz at maximum speed). Unico inverters do not impose a hard limit on output frequency, but it is recommended that the switching frequency be at least twelve times the motor fundamental frequency for proper control.

Built-in safety and control interlocks are hardwired, opto-isolated, and software configurable, so you can match the demands of your EV propulsion system under test.