Transcription of บทที่ 8 การป้องกันมอเตอร์ (Motor Protection)
1 1 8 ( motor Protection) 2 3 3 Three-Phase AC motor 3 1. Asynchronous motor or induction motor 2. Synchronous motor 4 4 induction motor (Asynchronous motor ) induction motor 5 5 induction motor Stator 3 Rotor 2 - (Squirrel Cage induction motor ) - (Wound Rotor induction Motors)
2 3 ( slip ring) 6 6 induction motor - - - - 7 7 Synchronous motor Synchronous motor 2 - Permanent-Magnet Synchronous motor - Electronically Commutated motor / Wound rotor field 1 HP slip Rings , , power factor.
3 , pump-storage hydro power plant 8 8 Synchronous motor Stator 3 3 Rotor 9 Synchronous motor - - - (variable-frequency drives , amortisseur winding, separate motor ) - 10 - - - 11 3 1.
4 ( Squirrel Cage induction motor ) 2. slip Ring ( slip Ring induction motor ) 3. Synchronous ( Synchronous motor ) 12 1. ( Squirrel Cage induction motor ) - - 10 MW - ( Line Voltage ) 3 - 10 kV - Direct On Line Reduce Voltage Starting 13 2. slip Ring ( slip Ring induction motor ) - - 10 MW - ( Line Voltage ) 3 - 10 kV - Rotor Start 14 3. Synchronous ( Synchronous motor ) - 1 - 20 MW - Direct On Line Start , induction Start Transformer Start 15 motor 1000 kW, kV motor 1200 kW, kV 16 motor 1000 kW, kV High-Voltage AC motor With Slipring Rotor 17 3 1.
5 ( Faults Related to Driven Load ) 2. ( Power Supply Faults ) 3. ( Internal motor Faults ) 18 1) ( Overload ) 2) Start ( Too Long Too Frequent Start-Up ) 3) ( Jamming ) 4) ( Pump De-energizing ) 5) ( Reverse Power ) 19 1) ( Drop In Voltage ) 2) ( Unbalance ) Negative Sequence Current 20 1) ( Phase-to-Phase Short Circuit ) 2)
6 ( Frame Faults ) 3) ( Loss of Synchronism ) 21 1) motor Characteristics 2) motor Starting Condition 3) Ambient Conditions 4) Driven Equipment 5) Power System 6) motor Importance 7) Load Side Faults For motor Controllers 22 - ( Undervoltage Protection ) - ( Phase Unbalance Protection ) - ( Instantaneous Phase Overcurrent Protection ) - ( Time-Delay Phase Overcurrent Protection ) - ( Overload Phase Overcurrent Protection ) 23 ( ) - ( Instantaneous Ground Overcurrent Protection ) - ( Time-Delay Ground Overcurrent Protection ) - ( Phase Current Differential Protection ) 24 ( ) - ( Split Winding Current Unbalance Protection ) - ( Stator Winding Overtemperature Protection ) - ( Rotor Overtemperature Protection ) - ( Synchronous motor Protection ) 25 ( ) - ( induction motor Incomplete Starting Sequence Protection )
7 - ( Protection Against Too Frequent Starting ) 26 ( ) - (Rotor Winding Ground Fault Protection) - (Lightning and Surge Protection) - (Protection Against Failure to Rotate or Reverse Rotation Protection) - (Mechanical and Other Protections) 27 1. (Undervoltage Protection) 2. , (Voltage Drop), ( Voltage Dip ) 28 Undervoltage Protection -Instantaneous -Time-Delay Trip Voltage Drop ( Undervoltage Protection ) 29 (Overheating) 2 1.
8 ( Phase Unbalance Protection ) 30 2. Negative-Sequence Negative Sequence Impedance Locked Rotor Impedance Negative-Sequence Negative-Sequence 31 ( Phase Unbalance ) 1) 2) 2 Single Phasing 32 Single-Phasing - Phase Current Balance Relay - Negative-Sequence Voltage Relay - Negative-Sequence Current Relay 33 ( Instantaneous Phase Overcurrent Protection )
9 ( Phase Short Circuits ) 1. 2. ( Voltage Dip ) 34 ( Instantaneous Phase Overcurrent Protection ) 3. Instantaneous Pick up 175% Maximum Symmetrical Starting Current 35 ( Time Phase Overcurrent Protection ) 1. 2. (Stalled Condition ) 3.
10 36 Time-delay Overcurrent Thermal Overcurrent Relays Thermal Overcurrent Relays 1. Pickup 5-25% 2. Pickup 200-350 % Trip Overload 37 Thermal Overcurrent Relays ( ) 3. Pick up Symmetrical Starting Current Time Delay 38 Trip Overload Protection 2 1) Alarm 2) Higher Pickup ( Overload Protection ) 39 ( Ground-Fault ) 1) Zero-Sequence Current Transformer or Sensor and Ground Relay-Device (50G)
