4 Phase IGBT Inverter Test Set (ULK-INV4)


The ULK-INV4 is a flexible 4-phase leg inverter system developed for the Power Electronics teaching environment. It provides both undergraduate and postgraduate students with a complete digitally controlled (up to) 2kW inverter platform.

The system has at its core a standalone inverter controller that interfaces to a 2kW rated four-phase leg IGBT based power stage.

The ULK-INV4 controller is powered from a universal single-phase input (85 - 265VAC), which is separate to the power stage connections.

External interfaces provide expansion capability for user programmed applications.

The ULK-INV4 is controlled via an isolated USB Serial Port interface. The PC user interface can be accessed via the dedicated ULK-INV4 graphical interface software, or alternatively through a standard terminal serial program.

Key Features

Configurable AC Modes Configurable DC Modes
  • Single-Phase Voltage Source Inverter (VSI)
  • Three-Phase Voltage Source Inverter(VSI)
  • Four-Phase leg Voltage Source Inverter(VSI)
  • Two independent Single-Phase Voltage Source Inverters
  • Buck Converter (low and high side switching)
  • Boost Converter (with in-built boost inductor)
  • H-Bridge (Phase Angle Controlled)
  • Phase Shifted Square Waves (PSSW)
Available Detailed Functionality Selections
Three-Phase AC Reference Definition
  • Normal (simple sinusoid)
  • 3rd Harmonic Injection
  • Centred Switching
  • 30° Discontinuous Switching
  • 60° Discontinuous Switching
  • 120° Discontinuous Switching
Switching Levels (single-phase AC or DC only)
  • Two Level Switching
  • Three Level Switching
Voltage vs. Frequency Operation
  • Independent Voltage & Frequency Control
  • Constant Volts-per-Hertz (V/f) Control
Fundamental Angle Control Type
  • Phase Angle
  • Frequency
Switching Sampling Strategy
  • Asymmetrical
  • Symmetrical
Buck Converter
  • High Side Switch
  • Low Side Switch
Boost Converter
  • Low Side Switch
Closed Loop Regulation
  • PI Control (Proportional + Integral)
  • PR Control (Proportional + Resonant)
  • PI for DC Systems
  • Support for in-line clamp-on current meters
  • Built-in protection, with relay disconnect
  • Fuse Protected Power Stage input
  • Isolated logic interfaces
  • Simple Interface
  • Safety Shrouded Power Connectors
  • User Programmable
  • Built-in software supporting all Inverter Laboratory Experiments
  • MCU Controller is upgradable



    Power Stage
    Configuration4 phase leg, TO-247 IGBT’s
    Input Voltage0 - 265VAC single-phase; 0 - 400VDC
    DC Bus Voltage Range0 - 400V maximum
    Input Current15A (maximum)
    Switching Frequency500Hz - 10kHz (maximum)
    Power2kW, with either single or 3/4-Phase operation
    Bus Capacitance:DC Bus 1 (1320μF), DC Bus 2 (2970μF)
    CoolingFan Forced
    Ambient Temperature -5°C to 55°C
    Control Supply
    ConfigurationIndependent isolated Control logic power
    Input Voltage85-265V /50-60 Hz AC input.
    Control Interfaces
    Start/StopButtons available on Top Panel
    Communications Isolated USB serial interface
    Isolated Clocked Serial Interface Port (user programmable)
    Position EncoderIsolated Digital Quadrature Encoder Input (user programmable)
    User ProgrammableYes - Isolated JTAG Interface (requires JTAG Programmer)
    MCU ProcessorTexas Instruments TMS320F2810 (CPT-DA2810)
    Digital Output Interfaces
    RelaysTwo off Changeover Contacts (user programmable)
    MOSFETOne off Digital Output (user programmable)
    Analog Measurements
    Currents (internal) DC Input Current (when operated from a DC input)
    Switched phase leg A, B and C.
    Voltages (internal) DC Bus 1 Voltage
    DC Bus 2 Voltage
    Voltages (external) DC Voltage
    2 off AC Voltages (common neutral).
    Control Signal IsolationYes
    Power Stage IsolationYes - from all control interfaces
    Power Stage ConnectorsSafety Shrouded 4mm Socket
    Protection DC Bus Over Voltage
    IGBT Desat
    Over Current
    Fuse Protection - Power Stage
    Fuse Protection - Controller
    Dimensions (WxLxH) mm390 x 495 x 275
  • Optional:
    • Isolated Bi-directional SPI Interface - +SPI-BI
    • side panel



  • ULK-INV4 provided with built-in MCU software that supports operation of the Inverter in many different configurations.
  • PC based user program for Laboratory Use
  • Default MCU Software image provided on support CD
  • Creative Power can produce custom software variations to suit specific customer requirements.

To simplify the use of the inverter within the teaching laboratory Creative Power has developed a GUI that allows the focus to remain on the teaching of power electronic concepts, rather than the configuration of the inverter. When an operating mode is selected the Inverter Status box displays the appropriate phase legs to be used for the output.

The graphical user interface software is available as standard with the ULK-INV4. It provides a consolidated display showing the Inverter Status, selected operating mode and the value of the PWM parameters relevant to that mode. The user can modify these settings, as appropriate, through the graphical interface.


The following pictures provides an example of the mode selection process within the ULK-INV4 graphical interface. In this instance the mode of operation to be selected is Three Phase PWM, with Sinusoidal PWM and Phase Control.


In addition, there is a detailed Analog Measurements mode which displays the value of all available analog quantities. Note that this display should be used in conjunction with appropriate external measurement equipment, such as oscilloscopes and multimeters.


GUI Software compatible with Windows 7 and above