Outline Of Control Methods; Functions; Control Method Characteristics; Autotuning - YASKAWA VARISPEED-616G5 Instruction Manual

Introduction

1.1.2 Outline of Control Methods

1.1.2 Outline of Control Methods
1

1.1.3 Functions

The VS-616G5 uses four control methods.
Open-loop vector control (factory setting)
D
Flux vector control
D
V/f control without PG
D
V/f control with PG feedback
D
PG stands for pulse generator (encoder).
Vector control is a method for removing interference with magnetic flux and torque, and controlling torque
according to references.
Current vector control independently controls magnetic flux current and torque current by simultaneously
controlling the motor primary current and phases. This ensures smooth rotation, high torque, and accurate
speed/torque control at low speeds.
Vector control can be replaced by the conventional V/f control system. If the motor constants required for
vector control are not known, the motor constants can be automatically set with autotuning.
The control methods are effective for the following applications:
Open-loop vector control:
D
Flux vector control:
D
V/f control without PG:
D
V/f control with PG feedback: Simple speed feedback control. (For applications with the PG
D
The control characteristics for each mode are shown in Table 1.2.
Table 1.2

Control Method Characteristics

Characteristic
Speed Control
Range
Speed Control
Precision
Initial Drive

Autotuning

J
Autotuning is effective for vector control. It solves problems in applicable motor restrictions and difficult
constant settings. The motor constants are automatically set by entering a value from the motor's rating
nameplate.
Autotuning allows flux vector control to operate accurately with virtually any normal AC induction motor,
regardless of the supplier.
Always autotune the motor separately before operating using vector control. Refer to 5.2.5 Autotuning and
6.4.3 Autotuning for details.
Torque Control
J
Torque control is effective for flux vector control with PG. Torque is controlled by taking multi-function
analog input signals as torque references. Torque control accuracy is ±5%. Switching is possible between
torque control and speed control.
V/f Pattern Settings
J
V/f pattern settings are effective for V/f control. Select a V/f pattern according to the application from
among the 15 preset V/f patterns. Custom V/f patterns can also be set.
Frequency References
J
The following five types of frequency references can be used to control the output frequency of the Invert-
er.
Numeric input from the Digital Operator
D
Voltage input within a range from 0 to 10 V
D
Voltage input within a range from 0 to ±10 V (with negative voltages, rotation is in the opposite direc-
D
tion from the run command.)
General variable-speed drive.
Simple servodrive, high-precision speed control/torque control.
Conventional Inverter control mode. Used for multi-drive operation
(connecting multiple motors to one Inverter).
connected to the machine shaft rather than the motor shaft.)
Vector Control
Open-loop Flux Vector
1:100 1:1000
± 0.2 % ± 0.02 %
150% at 1 Hz 150% at 0 r/min
1 - 4
V/f Control
Without PG With PG feedback
1:40 1:40
± 2 to 3 % ± 0.03 %
150% at 3 Hz