The IS200IGPAG2A is a Gate Driver Power Supply Board designed by General Electric (GE) for its Innovation Series™ Drive Systems. This board is the Group 2 version within the IGPA series, primarily used to provide the necessary DC gate driver power for each Integrated Gate Commutated Thyristor (IGCT). One IGPA board is mounted directly on each IGCT.
The core function of the IS200IGPAG2A board is to convert the AC square wave power provided by an external isolation transformer into the stable DC voltages required for IGCT gate driving. Unlike the Group 1 version, which incorporates two power supplies on each board, the Group 2 version IGPAG2A contains only one power supply per board, suitable for IGCT configurations requiring a single power supply.
Key features of the IS200IGPAG2A include:
Designed Specifically for IGCTs: Mounts directly on the IGCT, providing precise power for gate driving.
High-Voltage Isolation: Floats at the IGCT cathode potential (3300-6600 V ac), requiring strict attention to high-voltage safety.
Dual Outputs: Provides +5 V dc turn-on supply and -20 V dc turn-off supply.
Comprehensive Protection: Two input fuses (6A and 7A) provide overcurrent protection.
Status Indication: 8 LED indicators show gate signal and voltage status.
Test Points: 8 test points for commissioning and fault diagnosis.
Soft Start Function: Positive supply soft start time 200 ms, negative supply soft start time 20 ms.
Energy Storage: Minimum 1.0 ms of regulated energy storage, maintaining output during brief power interruptions.
The board uses current mode control with an outer voltage loop, offering fast dynamic response and stable output voltage. The positive supply outputs 5 V dc ±0.25 with a maximum continuous current of 15 A; the negative supply outputs 20 V dc ±0.8 with a maximum continuous current of 6 A. The board dissipates approximately 10 W and requires at least 80 LFPM of airflow for cooling.
II. Main Functions
The primary functions of the IS200IGPAG2A include, but are not limited to, the following:
1. Power Conversion
The IS200IGPAG2A board receives an AC square wave input from an external isolation transformer and converts it internally to the DC voltages required for IGCT gate driving. The input power specification is 50 V ac square wave (±1%), 27 kHz (±1%), connected via the 5-pin P1 connector. Two internal fuses (FU1 and FU2) provide overcurrent protection.
2. Positive Supply Output
The positive supply output is +5 V dc ±0.25, used for IGCT turn-on driving. Key characteristics include:
3. Negative Supply Output
The negative supply output is -20 V dc ±0.8, used for IGCT turn-off driving. Key characteristics include:
4. Control Method
Both positive and negative supplies use current mode control with an outer voltage loop. This control method offers:
Fast dynamic response
Excellent output voltage stability
Built-in current limiting protection
Good immunity to input voltage fluctuations
5. Status Indication
The board features 8 LED indicators providing visual status of gate signals and voltages:
DS1, DS2: Green and yellow LEDs, indicate gate signal status when 5 V output current > 4 A.
DS3, DS4: Indicate 5 V voltage OK.
DS5, DS6: Indicate 20 V output current status (DS5 on when current > 2 A, DS6 on when current < 2 A).
DS7, DS8: Indicate 20 V voltage OK.
6. Test Points
The board features 8 test points for commissioning and fault diagnosis. The test points allow measurement of:
Signal common for positive and negative supplies
Average current feedback for positive and negative supplies
Power common for positive and negative supplies
Inductor input voltage for positive and negative supplies
Important Safety Warning: When the drive is operating, these test points float at bridge potential. DO NOT TOUCH!
7. Common Mode Current Rejection
The board design considers the effect of high du/dt (6 kV/μs) generated by fast IGCT switching on common mode current. The common mode current I = c × 6 kV/μs, where c is the isolation transformer capacitance. The board is designed to operate correctly under these conditions.
III. System Applications
1. Application in Innovation Series Drive Systems
The IS200IGPAG2A is a critical board providing gate driver power for IGCTs within the Innovation Series drive system. Its roles within the system include:
IGCT Gate Driving: Provides precise turn-on and turn-off power for each IGCT, ensuring reliable switching.
Electrical Isolation: Achieves electrical isolation between the control circuit and the high-voltage main circuit via an external isolation transformer, ensuring personnel and equipment safety.
Status Monitoring: Provides status information and diagnostic means for field operation and maintenance personnel via LED indicators and test points.
2. Differences Between Group 1 and Group 2
The IGPA series has Group 1 and Group 2 versions, with the main differences being:
| Feature | Group 1 | Group 2 |
| Number of Power Supplies per Board | 2 | 1 |
| Applicable Scenario | IGCTs requiring dual supplies | IGCTs requiring a single supply |
| Board Layout | See Figure 3 | See Figure 4 |
When selecting an IGPA board, users must choose the appropriate version based on the specific IGCT's power requirements.
3. High-Voltage Safety Precautions
The IGPAG2A board mounts directly on the IGCT and floats at the IGCT cathode potential (3300-6600 V ac) during operation. Therefore, DO NOT TOUCH OR PROBE any part of the board while the system is energized. Installation, replacement, or measurement should only be performed after the system is completely de-energized and verified safe.
4. Typical Application Scenarios
Medium-Voltage Variable Frequency Drives: Provides gate driver power for IGCTs in motor control applications.
High-Power Power Conversion Systems: Used in various power conversion equipment requiring IGCTs.
Rail Transit Traction Systems: Provides driver power for IGCTs in traction converters.
Industrial High-Power Drives: Used in heavy industries such as mining and metallurgy for high-power motor drives.
IV. Detailed Interface Description
1. Power Input Connector P1
P1 is a 5-pin connector for connecting the AC square wave power from the external isolation transformer:
| Pin | Signal | Description |
| 1 | AC1P | +20 V ac, 27 kHz |
| 2 | AC1N | +20 V ac return |
| 3 | AC2P | 40 V ac, 27 kHz |
| 4 | AC2N | 40 V ac return |
| 5 | Cathode | External isolation transformer shield, connect to IGCT cathode |
2. Power Output Connector PXPL
PXPL is a 9-pin connector for outputting IGCT gate driver power:
| Pin | Signal | Description |
| 1 | P5 | +5 V turn-on supply |
| 2 | P5 | +5 V turn-on supply |
| 3 | P5COM | 5 V return |
| 4 | P5COM | 5 V return |
| 5 | - | Not connected |
| 6 | N20 | -20 V turn-off supply |
| 7 | N20 | -20 V turn-off supply |
| 8 | N20COM | -20 V return |
| 9 | N20COM | -20 V return |
Multiple pins are paralleled to carry higher current.
3. LED Indicators
| LED | Color | Indication Function |
| DS1 | Green | Lights when 5 V output current > 4 A (gate signal indication) |
| DS2 | Yellow | Lights when 5 V output current > 4 A (gate signal indication) |
| DS3 | - | Indicates 5 V voltage OK |
| DS4 | - | Indicates 5 V voltage OK |
| DS5 | - | Lights when 20 V output current > 2 A |
| DS6 | - | Lights when 20 V output current < 2 A |
| DS7 | - | Indicates 20 V voltage OK |
| DS8 | - | Indicates 20 V voltage OK |
4. Test Points
| Test Point | Description |
| TP1 | Signal common for positive supply |
| TP2 | Average current feedback for positive supply |
| TP3 | Power common for positive supply |
| TP4 | Inductor input voltage for positive supply |
| TP5 | Average current feedback for negative supply |
| TP6 | Signal common for negative supply |
| TP7 | Power common for negative supply |
| TP8 | Inductor input voltage for negative supply |
Important Safety Warning: When the drive is operating, these test points float at bridge potential. DO NOT TOUCH!
5. Fuses
| Fuse | Rating | Protected Circuit |
| FU1 | 7 A, 250 V, Fast-acting | Input power protection |
| FU2 | 6 A, 250 V, Fast-acting | Input power protection |
V. Installation and Replacement
1. Mounting Location
The IS200IGPAG2A board mounts directly on the IGCT, with one board per IGCT. During installation, ensure good contact between the board and the IGCT, and tighten the mounting screws securely.
2. Installation Precautions
High-Voltage Safety: The IGPA board operates at high voltage potential. Installation and replacement must only be performed after the system is completely de-energized.
Star Washers: Metal star washers must contact the metal surface, not the plastic board. These metal washers and standoffs form a protective circuit, shunting accidental high voltage to ground.
Cooling Requirements: Ensure at least 80 LFPM of airflow across the board for proper cooling.
ESD Protection: Handle the board following ESD precautions.
3. Replacement Procedure
Safety Warnings:
WARNING: To prevent electric shock, turn off power to the drive system and use high-voltage test equipment to verify circuits are de-energized before touching.
CAUTION: To prevent component damage caused by static electricity, treat all boards with static sensitive handling techniques. Wear a grounding strap and store boards in anti-static bags.
Removing the Old Board:
Verify Power Off: Ensure the drive system is completely de-energized.
Open Cabinet Door: Open the drive cabinet door. Use high-voltage test equipment to verify circuits are de-energized.
Disconnect Connections: Disconnect all electrical connections.
Remove Screws: Loosen the six mounting screws using a ratchet and socket/screwdriver.
Collect Hardware: As the screws are removed, catch the standoffs and star washers. Note that the star washers are paired with the metal standoffs.
Remove Board: Carefully remove the old board.
Installing the New Board:
Position New Board: Place the new board in the correct orientation on the IGCT.
Install Screws: Secure the board using the 6 screws, standoffs, and star washers.
Tighten Screws: Tighten the screws to hold the board securely in place.
Check Washers: Ensure the metal star washers are seated against the metal surface, not the plastic board. The metal standoffs and star washers make a protective circuit, shunting accidental high voltage to ground.
Reconnect Connections: Reconnect all electrical connections.
Restore Power: Close the cabinet door and restore power to the system.
