1. Exercise 1: System Setup – additional data for MS based on SC study files
• Source and Branch Parameters
Same as load flow and short-circuit studies.
• Switching Motor Data for Static MS Element Accel T No Load Accel T Full Load St Load* Final Load T Begin T Final Mtr 1 2 4 100 100 0 0 Mtr 2 1 2 100 100 0 0 Syn 1 2 4 25 90 1 5
* Set starting category data for Category 1, 2, and 3. * Check data for Mtr4 and Mtr5.
• Switching Motor Data for Dynamic Acceleration MS
Element Mtr Model * Load Model H
Mtr 1 Single 2, HV-HS-LT, MV500HP2P FAN 0.4
Mtr 2 Charac., LV-HS-HT, LV200HP2P a k**3 0.2
Syn 1 Single 2, HV-HS-HT, MV1000HP2P Recip. Comp .5
* In Motor Parameter Update Dialog, uncheck all boxes.
• Starting Category
Element Mtr Model
Normal Mtr 1, Mtr 4 Back Up Mtr 2, Mtr 3
2. Exercise 2: Motor Starting Case 1
• Set up Study Case: MSCase-1
• Using Design Load, No load diversity factor.
• Run simulation for 15 Seconds.
• Include XFMR LTC in Pre-starting Load Flow, not during simulation.
• Acceleration motor model based on Mechanical Load.
• Use default settings on Adjustment and Alert Pages. Check all alert options with minimum violation span = 0.2 second.
• Use Normal configuration.
• Action sequence:
Study Case: MSCase-1
Time Parameter Setting
0.2 second Start Mtr 5, at 60% load and ramp load from 60% to 100 % in 3 seconds. Switch on static load Load 2, Loading Category: Design
3 second Start all motors in the system belong to Normal Category
• Run Static Motor Starting
• Check results from OLV display, plot and report.
• Is system voltage ok? Is the problem real or is it related to user entered acceleration time and sequencing?
• Run Dynamic Motor Starting
• Check results from OLV display, plot and report.
• Is system voltage ok?
• Can all the motors be started?
• Solution to solve problem with motors failing to start (to increase acceleration torque):
• Change starting sequence
• Change pre-starting voltage
• Use XFMR LTC
• Use Starting device – What type of starter should be used here? (Cap)
• Use larger motor
• Try to change Mtr4 Starting Load from 60% to 40% -- Can Mtr 4 be started?
• Check for low voltage problem – Is there a voltage problem? How to solve it?
3. Exercise 3: Starting Devices
• Run Dynamic Motor Starting
• Configuration: Tie-Open, Study Case: MSCase-1 ( Change simulation duration to 15 seconds)
• Check bus voltage for starting motors. (Mtr1 V < 80%)
• How can you solve the problem? ( Re-sequencing, start at reduced load, using starter?)
• Try Using Starting Device
• What type of starting device to use?
• Try current control soft starter and Capacitor bank at motor terminal. Is it a good way of solving problem?
Starting Device
Current Control Capacitor at Bus/Terminal
Speed Setting Type Speed Setting Type
0 400% Fixed 0 1000 kvar Fixed
2 400% Fixed 95 Remove
2 200 or 250% Ramp
95 400% Fixed
95 Remove
4. Exercise 4: MOV Starting
• Set up MOV data
• Both MOVs have Hammer Blow.
• Both MOVs do not have Micro Switch.
• Both MOVs have Vlimit = 80.
• T = 0.5 second for Start, Full Speed, Seating/unseating, and Stall periods.
• 5 seconds for Travel period.
• Set up Study Case MSCase-2 and MSCase-3
• Using Design Load, No load diversity factor.
• Run simulation for 15 Seconds.
• Include XFMR LTC in Pre-starting Load Flow, not during simulation.
• Acceleration motor model based on Mechanical Load.
• Use default settings on Adjustment and Alert Pages. Check all alert options with minimum violation span = 0.2 second.
• Use Normal configuration.
• Action sequence:
Study Case: MSCase-2
Time Parameter Setting
0.2 second Start all motors in the system belongs to Backup Category Switch on static load Load 1, Design category
3 second Start OpenMOV and ClosedMOV
Study Case: MSCase-3
Time Parameter Setting
0.2 second Switch on static load Load 1, Design category 3 second Start OpenMOV and ClosedMOV
5 second Start all motors in the system belonging to Backup Category
• Run Dynamic Motor Starting with MSCase-2
• Check results from OLV display, plot and report.
• Check MOV starting process.
• Run Dynamic Motor Starting with MSCase-3
• Check results from OLV display, plot and report.
• Check MOV starting process.
5. Exercise 5: Load Transition
• Set up Load data
• All Motor: Design -- 100%, Normal – 90%, Winter -- 75.
• All Static Load: Design -- 100%, Normal – 80%, Winter -- 90.
• Mtr 1: Design -- 100%, Normal – 80%, Winter – 0%.
• Mtr 2 & 3: Design -- 100%, Normal – 0%, Winter – 90%.
• Set up Study Case MSCase-4
• Using Design Load, No load diversity factor.
• Run simulation for 10 Seconds.
• Include XFMR LTC in Pre-starting Load Flow, not during simulation.
• Acceleration motor model based on Mechanical Load.
• Use default settings on Adjustment and Alert Pages. Check all alert options
• Use Normal configuration.
• Action sequence:
Study Case: MSCase-4
Time Parameter Setting
0.2 second Switch to Normal Load Category Exclude MV loads >= 5000 kVA 3 second Switch to Winter Load Category
Exclude MV loads >= 1200 kVA Exclude MV loads >= 1000 kVA
• Run Dynamic Motor Starting with MSCase-4
• Check results from OLV display, plot and report.
• Check bus load change.