Opal-RT DriveLab kit is a fully integrated motor drive kit, designed to enable the user to perform a variety of experiments on AC and DC machines. The system was specifically designed for teaching, experimentation, and research.

The system consists of four major components:

• motors
• power electronics
• control hardware
• control software

This document provides information, instructions, and details about those components.

Drivelab Kit Contents

• 1 real-time simulator (target computer)
• 1 TestDrive pack (model) with a user interface
• 4 motors:
  
  • 1 PM-DC (DC motor, see DC Motor)
  • 1 PM-DC Gen (DC generator with encoder, see DC Generator)
  • 1 BLDC (BLDC motor with encoder, see BLDC Motor)
  • 1 Async (AC Induction motor with encoder, see AC Induction Motor)
• 1 DriveLab box
• 1 external DC power supply
• 2 I/O cables (one for digital control signals and one for analog input signals)
• 2 encoder cables (5-pin and 8-pin)
• 8 banana plug cables (3 for inverter #1, 3 for inverter #2 and 2 for external power supply)
• Other interface cables (power cord, ethernet cable, etc)

How the Kit Works

The DriveLab kit consists of two electric motors fixed on a base plate. Since the motors can be physically coupled, this document assumes that one of the motors is used as a motor and that the other is used as a generator (load of the motor).

Each motor is driven by a separate power converter connected to a common 36 VDC bus. This DC bus is powered by an external power supply (provided with the kit). The power converters have all the drivers and circuit accessories needed to be controlled by PWM logical signals. Current, voltage and mechanical angle/speed sensors give the required feedback to the real-time control prototyping system.

The image shows the four major DriveLab kit components (motors, power electronics, control hardware (real-time simulator) and control software in relation to the function diagram.

How the DriveLab Box Works

The DriveLab box is a motor drive system in which the PWM pulses generated by the real-time simulator dictate the modulation of a voltage-source converter, and then control the motor.

It consists of two identical, independent 3-phase PWM inverter circuits, each one with 3 MOSFETs that can drive two motors simultaneously.

Both circuits provide current feedback for the first two phases (A & B). A 36 VDC-bus voltage is provided to reduce electrical hazards. Feedback of this bus voltage level is also provided. The DriveLab box passes the encoder feedback to the real-time simulator. The box also provides fault detection and clearance.

Power Electronics

The DriveLab box circuit board manages inputs and outputs (see schematic) using MOSFET switching devices, converters, inverters, and sensors, among numerous other components. These components are linked to interfaces provided on the DriveLab box.

Each interface provides a connection to another component, such as a host computer, simulator or motors.

The PCB housed within the DriveLab box also offers additional connector components and switches and should only be accessed by qualified technicians and, in certain cases, advanced users. Additional details are provided in “Appendix B” on page 39.

Fault Detection and Fault Clearance

The DriveLab box is physically protected against overcurrents.

When an overcurrent occurs, it generates a fault, which is indicated in two ways:

1. The front LED indicates a fault status (Motor 1 or Motor 2, depending on which inverter is in fault) status of the front associated with that inverter circuit. If the LED is on, it means a fault has occurred on this inverter. The protection ensures the circuit is not damaged and will stop any activity on that circuit.
2. The real-time model also offers the fault detection option using a digital input line. When a fault occurs, the input status changes from 0 (normal operation) to 1 in the real-time model.

The DriveLab box lets users clear the fault using one of two options and continue with the activity:

1. Press the “Clear” button on the front of the DriveLab box to clear the fault.
2. The real-time model also provides a fault clearance option, which will change the status of a digital signal (from low to high). This signal, sent from the real-time simulator to the DriveLab box, has the same effect as pushing the “Clear” button on the box. After clearing the fault, the fault trigger should be returned to its initial position to ensure the “clear fault” signal does not stay on indefinitely. The fault LED will turn off.

Here is a simplified schematic to illustrate how the board (within the DriveLab box) channels signals: