Introduction; Operating Modes - Emerson Unidrive HS72 Control Getting Started Manual

2

Introduction

Universal AC and servo drive
This product delivers maximum machine performance.
• Universal high performance open and closed loop control for induction, servo, permanent
magnet and linear motors
• Automation and motion option module for direct migration of SyPTPro / SM-Applications
programs
• Onboard IEC 61131-3 programmable automation and motion control
• Flexibility with speed and position measurement, supporting multiple devices and all common
interfaces
• NV Media Card for parameter copying and data storage
Optional features
• Select up to three option modules including programmable automation and motion control.
• Ethernet fieldbus communications
• Dual channel Safe Torque Off (STO) input
2.1

Operating modes

The drive is designed to operate in any of the following modes:
1. Open loop mode
Open loop vector mode
Fixed V/F mode (V/Hz)
Quadratic V/F mode (V/Hz)
2. RFC - A
With position feedback sensor
Without position feedback sensor (Sensorless)
3. RFC - S
With position feedback sensor
Without position feedback sensor (Sensorless)
2.1.1 Open loop mode
The drive applies power to the motor at frequencies varied by the user. The motor speed is a result of
the output frequency of the drive and slip due to the mechanical load. The drive can improve the
speed control of the motor by applying slip compensation. The performance at low speed depends
on whether V/F mode or open loop vector mode is selected.
Open loop vector mode
The voltage applied to the motor is directly proportional to the frequency except at low speed where
the drive uses motor parameters to apply the correct voltage to keep the flux constant under varying
load conditions.
Typically 100 % torque is available down to 1 Hz for a 50 Hz motor.
Fixed V/F mode
The voltage applied to the motor is directly proportional to the frequency except at low speed where a
voltage boost is provided which is set by the user. This mode can be used for multi-motor
applications.
Typically 100 % torque is available down to 4 Hz for a 50 Hz motor.
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Unidrive M702 / HS72 Control Getting Started Guide
Issue Number: 2