SIEMENS
2/5
Siemens D 15.1 · 2017
SINAMICS PERFECT HARMONY GH180
Air-Cooled Drives
Introduction
2
■
Design
(continued)
A better approach is illustrated in the diagram on the right. This
method takes advantage of the fact that the star-point of the cells
is floating, and is not connected to the neutral of the motor.
Therefore the star-point can be shifted away from the motor neu-
tral, and the phase angles of the cell voltages can be adjusted,
so that a balanced set of motor voltages is obtained even though
the cell group voltages are not balanced.
Siemens calls this approach Neutral Shift. This approach is
equivalent to introducing a zero-sequence component into the
voltage command vectors for the cells. In the following diagram,
all intact cells are operational, and 80 % of the original voltage is
available. The phase angles of the cell voltages have been
adjusted so that phase A is displaced from phase B and from
phase C by 132.5°, instead of the normal 120°.
Drive output re-balanced by adjusting phase angles (Neutral Shift)
■
Function
Control, protection and monitoring functions
A
B
C
95°
A3
A2
A1
B1
B1
C1
B5
B4
C4
B3
C3
B2
C2
C5
15 cell drive after
bypass of 2 cells
in phase A only
and adjustment of
phase angles.
87% of the cells
are in use.
80% of full voltage
is available.
132.5°
132.5°
V
AC
V
BA
V
CB
G_D015_EN_00008
Closed-loop control
The drive can be controlled by means of vector control algorithm without an encoder (standard) or with it
(option).
Auto tuning
Auto tuning involves the estimation of motor parameters required for motor control. This is done in two
stages. In stage one, motor stator resistance and total leakage inductance are determined. This stage
does not require spinning the motor. In stage two, the motor no-load current and total inertia are esti-
mated. Estimation of these values requires the motor to be spun. Accuracy of the estimation is better if the
load is de-coupled from the motor.
Automatic restart
The automatic restart switches the drive on again when the power is restored after a power failure or a
general fault, and ramps up to the current speed setpoint.
Energy saver
Energy saver control allows the reduction of motor losses, and improves overall efficiency, when the
demanded motor load is low. The drive adapts the motor flux depending on the particular motor load.
Flying restart
The flying restart function permits smooth connection of the drive to a rotating motor.
Diagnostics functions
• Self-diagnosis of control hardware
• Non-volatile memory for reliable diagnosis when the power supply fails
• Monitoring of IGBTs with individual messages for each cell
• User-friendly local operator panel with plain text messages
• Fault log with first-in indication and time/date stamp
User configurable digital meters
The user can select indication of speed, voltage, current, input/output power, and efficiency on the
operator panel.
Process control system
The optional Process Tolerant Protection Strategy (ProToPS) is a groundbreaking process control system
available exclusively from Siemens. Instead of tripping the drive and automatically shutting down the sys-
tem due to a malfunction, ProToPS provides a hierarchical system of warnings. This control strategy pro-
vides the time needed to evaluate the situation and respond appropriately to avoid a system shutdown.
Operating hours and
switching cycle counter
The amount of the time that the drive was operational since it was commissioned can be displayed.
The switching cycle counter can be generated by means of an event log from the drive controller.
Detection of actual motor speed
The control algorithm calculates actual motor speed from currents and voltages measured at the drive
output.
Emergency Stop button
The drives are equipped as standard with an Emergency Stop button (red mushroom button with yellow
collar), which is fitted in the cabinet door. The contacts of the pushbutton are connected in parallel to the
terminal block so they can be integrated in a protection concept on the plant side.
Insulation monitoring
An output signal can be provided optionally to operate the customer protection.
I/O monitoring
I/O signals allow user-customization of the system and they can be monitored remotely or by using the
operator panel display.
Thermal overload protection
Based on the output signals of the drive the thermal motor model is calculated. The motor thermal over-
load protection algorithm prevents the motor from being exposed to excessive temperatures.
© Siemens AG 2017