Figure 1: Allen-Bradley Powerflex 70 - Variable Frequency Drive

1 Description

The Powerflex 70 VFD.

The variable speed drive used in this lab is an Allen-Bradley Powerflex 70. This is a variable voltage variable frequency (VVVF) drive. The drive uses a three-phase diode rectifier input stage with a capacitor filter DC-link and a controlled 6-switch IGBT 3-phase inverter output to the motor. The 3-phase power input to the drive is the red, black and blue terminals labeled R, S and T. The power output of the drive is the red, black and blue terminals labeled U, V and W. The terminals labeled +DC and BRK are used for a DC-link break resistor which we will not be using in this lab. There is also a green input earth ground connection which should be connected to the ground of the power supply.

1.1 Topology

Figure 2: AC Drive Topology

2 Manual

Powerflex User Manual

3 Name Plate

figure 2. Allen-bradley Power-flex 70 Name Plate