Siemens SINAMICS PERFECT HARMONY GH180 - Summary of the Control Modes; Symbols Used in Figure Vector Control Algorithms

Table 4-1 Symbols used in Figure Vector Control Algorithms
Symbol Description
FluxDS D-component of motor 󹪞ux as referenced to the stator; also equal to the motor 󹪞ux, since Q-
component is zero. Motor Flux is de󹪝ned as: Motor_Voltage / Stator_Frequency (rad/s). Flux
(which has units of Volt-seconds) is also proportional (but not equal) to Volts-per-Hertz ratio.
r For an induction motor: Motor_Speed = Stator_Frequency / Pole_Pairs – Slip_Speed
This is the rotor (mechanical) frequency, which is equivalent to the motor speed.
For a synchronous motor: Motor _Speed = Stator_Frequency / Pole_Pairs
I
ds
Magnetizing component of motor current.
I
qs
Torque producing component of motor current.
V
ds,ref
Output of magnetizing current regulator used in the inverse D-Q transformation to produce
3-phase voltages.
V
qs,ref
Output of torque current regulator used in the inverse D-Q transformation to produce 3-phase
voltages.
ω
s
Stator frequency or output frequency of the drive. This is motorspeed (r) + Slip.
θ
s
Flux angle. This is the instantaneous position of the rotating 󹪞ux vector.
I
a
, I
b
, I
c
Motor phase currents.
Motor torque in newton-meters and shaft power can be calculated as:
Torque (Nm) = 3 * Pole_Pairs * Flux (V-secs) * Iqs (A)
≈ 3 * Pole_Pairs * Motor_Voltage (V) * Iqs (A) / (2 π * Frequency (Hz))
Shaft Power (W) = Torque (Nm) * Speed (rad/s) = Torque (Nm) * Speed (rpm) / 9.55
Rated Speed = 120 * rated frequency / number of pole pairs
Vector Control Modes
The control provides several control modes. The modes are described in the sections that follow.
4.7.3 Summary of the Control Modes
Summary of the Control Modes
Control Mode Vector Control Type of Motor Encoder Features
Open loop vector con‐
trol mode (OLVC)
Vector control Induction Without encoder
• Fast bypass option
• Spinning load op‐
tion
Open loop test mode
(OLTM)
N/a Not for motor control N/a Fast bypass and spin‐
ning load are disabled.
Synchronous motor
control mode (SMC)
Vector control Synchronous Without encoder
• Fast bypass option
• Spinning load op‐
tion
NXGPro+ Control Description
4.7 Control Modes
NXGPro+ Control Manual
Operating Manual, A5E50491925A 49