Section Content

The simulator panel provides the test bench’s interactive interface, which includes access to settings, measurement device display and protection system status.
It allows users to manually control the bench, to start it and to regulate group speed by manipulating power, connecting various devices to the induction machine rotor, decoupling machine shafts to block the rotor or to reset the protection system in the event of a fault.
This section provides the complete reference for features located on the simulator panel.

3.1 Startup Panel

The main panel is shown in Fig. 3 at simulator startup.
Default setting values shown in Fig. 3 are applied, and control switches are grey, which means disabled.
Machines are stopped, all power output voltages are at 0 V.
The simulator is functioning, and the test bench can be used according to user needs, while maintaining the safe settings and making sure not to trip the protection system.

Figure 3: Panel at simulator startup

Observe, from left to right, in Fig 3, how the various settings and measurement display options are grouped according to the virtual test bench components, as described in Section 2:

DC machine: power settings, measurement display and protection status (fuses).
Shaft: for the detachable mechanical coupling of the shaft that connects the machines, displays torque and speed data.
Asynchronous Machine: electrical panel with fields to modify values, switches to control rotor winding connections and a rotary switch to modify external rotor resistances, measurement and protection (fuse) status displays.
Stator connections: command switches to activate or deactivate the induction machine’s stator connection with several devices.
AC Grid/Inverter/Measurement Resistors: three tabs that provide access to connect external devices to the induction machine’s stator (see Section 3.3).
AC Grid provides controls for an autotransformer connected to an infinite bus; Inverter provides controls for a battery powered, variable voltage and frequency PWM inverter, and Measurement Resistors provides measurements for the stator windings resistances.
Protections: protection system control panel allows users to simulate a fuse reset (Reset) in the event of a fault.

Blowing one fuse can cause machines to stop according to the dynamics of turning parts caused by inertia and friction.
Just like with a real test bench, the user must determine the causes of the fault before restoring power and resetting switches to ensure safe restart.
Failure to do so will result in triggering the protection system again, as would happen with a real test bench!

The tabs in the bottom panel of the screen of Fig.3 display the oscilloscopes connected to the bench, as described in Section 3.4.

3.2 Tables for Parameters Setup and Control Switches

Parameter setting	Default value	Variation range
SC1: Va DC Machine armature (Volt)	0	[0 ; 500] V
SC2: Vf DC Machine field (Volt)	0	[0 ; 500] V
SC3: Vdc external supply (Volt)	0	[0 ; 50] V
SA1: Autotransformer (Volt)	0	[0 ; 500] V
fs (Hz) AC grid frequency	60 Hz	[1 ; 100] Hz
Resistor value (Ω)	1.5 Ω	1.5 ; 2.5 Ω
Inverter frequency(Hz)	0	[1 ; 90] Hz

Table 3: User accessible setup parameters

Users can make precise adjustments using the controls to the right of the field.

FUNCTION	Icon	Description
Command Switches
K1: AC Grid		The grid is not connected to the induction machine's stator. Switch (K1) is open.
K1: AC Grid		The grid is connected to the induction machine's stator. Switch (K1) is closed
K2: Inverter		The inverter is not connected to the induction machine's stator. Switch (K2) is open.
K2: Inverter		The inverter is connected to the induction machine's stator. Switch (K2) is closed.
K3: Measurement Resistors		The DC voltage source SC3 is not connected to the machine's stator. Switch (K3) is open.
K3: Measurement Resistors		The DC voltage source SC3 is connected to the induction machine's stator. Switch (K3) is closed.
K4: Open Rotor		The induction machine's windings are short-circuited. Switch (K4) is closed.
K4: Open Rotor		The synchronous machine's rotor windings are in open circuit. Switch (K4) is open.
K5: Rotor Resistor		There is no external resistor connected to the induction machine's rotor. Switch (K5) is open.
K5: Rotor Resistor		External resistor, adjustable via dial on the induction machine's panel, are serially connected to the induction machine's rotor. Switch (K5) is closed.
K6: Decouple Shafts		The shaft of the induction machine is driven by the shaft of the DC machine
K6: Decouple Shafts		The shaft of the induction machine is decoupled from the shaft of the DC machine
K7: Phase inversion		The AC grid's phase sequence is positive.
K7: Phase inversion		The AC grid's phase sequence is negative (reverse).
K8: Reset		Reset push-button is inactive.
K8: Reset		Reset push-button is active and simulates a fuse replacement after a fault.
K10: Trig-Stator		Waveforms are not triggered, and signals are moving. The Oscilloscope1 group trigger is disabled.
K10: Trig-Stator		Waveforms are triggered. The stator voltage is acting as the reference signal.
K11: Trig-Rotor		Waveforms are not triggered, and signals are moving. The Oscilloscope1 group trigger is disabled.
K11: Trig-Rotor		Waveforms are triggered. The rotor voltage Is acting as the reference signal.
Fuses	LED indicators
Fia Fia		The DC machine's armature fuse is blown.
Fia Fia		The DC machine's armature fuse is intact.
Fif Fif		The DC machine's field fuse is blown.
Fif Fif		The DC machine's field fuse is intact.
Fi1 Fi1		The induction machine's stator phase 1 fuse is blown.
Fi1 Fi1		The induction machine's stator phase 1 fuse is intact.
Fi2 Fi2		The induction machine's stator phase 2 fuse is blown.
Fi2 Fi2		The induction machine's stator phase 2 fuse is intact.
Fi3 Fi3		The induction machine's stator phase 3 fuse is blown.
Fi3 Fi3		The induction machine's stator phase 3 fuse is intact.

Table 4: Command switches and LED fuse status indicators

3.3 Tabs Description

The simulator interface, shown in Fig.3 contains several additional tabs selectable by the user:

Electrical panel for devices that can be connected to the induction machine's stator: “AC Grid”, “Inverter” and “Measurement Resistors”. The user can select devices according to the desired test.
“Help" tab: in the upper left Section of the interface, the "Help" tab contains information of the basic tests and their associated wiring diagrams.

3.4 Measurement Device Display and Oscilloscope Waveforms

Device display modules shown in the main screen of the virtual simulator are shown in Fig.3. The sign convention by devise is also provided.

Sections	Display	Label	Displays Content
DC Machine	Display₁	V_a	Voltage at machine armature terminals.
	Display₂	I_a	Current in the armature (positive for operation in a generator rotating in N positive direction). The power label convention V_a. I_a is generator-type: V_a. I_a is positive in generator operation and negative in motor operation.
	Display₃	V_f	Voltage at field terminal.
	Display₄	I_f	Current in the field.
Shaft	Display₁	N	Drive rotation speed [rpm] (according to convention N is positive when the phase voltage sequences applied to the induction motor stator is direct)
Shaft	Display₂	T_u	DC machine resistive torque (according to convention, it is positive when operating in a generator rotating in N positive direction).
Asynchronous Machine	Display₁	U_s	RMS line-line voltage at stator terminals.
	Display₂	I_s	RMS line current in stator.
	Display₅	P	Induction machine active power. The sign convention is receptor-type: P is positive in motor mode operation.
	Display₆	Q	Induction machine reactive power. The sign convention is receptor-type: Q is positive if it is absorbed by the induction machine.
AC Grid	Display₁	U	RMS line-line voltage at the autotransformer’s SA1 output.
AC Grid	Display₂	I	RMS line current at the autotransformer’s SA1 output.
Inverter	Display₁	V_s/f_s	Ratio between Vs/fs and [V/Hz].
Inverter	Display₂	I_bat	Mean current supplied by the battery to the inverter [A]. According to convention, it is positive when the inverter supplies active power to the induction motor.
Measurement Resistors	Display₁	U_dc	DC current between two induction machine stator terminals to measure resistances.
Measurement Resistors	Display₂	I_dc	DC current flowing through the stator during resistance measurement.

Table 5: Display modules for measurement devices and sign convention for parameters displayed

All physical measurements listed in Table 5 are represented in test setup schematics.

Waveforms for electrical and mechanical signals displayed on the oscilloscopes are listed in Table 6.
Each oscilloscope allows users to view one or two signals.
Voltage and/or current range settings and time settings are also provided in this table.

Tabs	Oscilloscopes	Waveforms displayed
Oscilloscope 1	Oscilloscope 1	Induction machine stator line-line voltages [U_s]. Induction machine rotor line-line voltages [U_r].
	Oscilloscope 2	Induction machine stator currents [Is].
	Y axis scale 1	Oscilloscope1 voltage range settings.
	Y axis scale 2	Oscilloscope2 current range settings.
	Y axis offset 1	Oscilloscope1 zero calibration

Table 6: Waveforms displayed and oscilloscope settings

While both oscilloscopes may display the same signal, they are not used to view the same phenomena.

Using exercise 1 as an example:

To test shifting transformer performance, the rotor voltage must be synchronized to the stator voltage frequency.
This test is displayed when Trig-Stator is activated.
On the other hand, to test frequency converter performance, the rotor voltage must be synchronized to its own frequency.
This test is displayed when Trig-Rotor is activated.

Courseware

Induction Machines - 3. Description of the Panel

Section Content

3.1 Startup Panel

3.2 Tables for Parameters Setup and Control Switches

3.3 Tabs Description

3.4 Measurement Device Display and Oscilloscope Waveforms