GE DS200SDCIG2AGB DC Power Supply and Instrumentation Board

الوصف

The GE DS200SDCIG2AGB is a crucial DC Power Supply and Instrumentation Board (SDCI) designed for the GE Mark V Speedtronic Turbine Control System and DC2000 Drive Series.¹

Its primary function is twofold: to provide regulated logic power to other sensitive control cards and to act as a central interface and measurement hub for critical drive signals.²

The “G2” in the part number signifies that this board is designed for External Field Excitation, meaning it is used in high-power DC drive systems where the field current is supplied and regulated by a separate, powerful external exciter (like a GE EX2000), rather than a small internal circuit on the board itself (as is the case with G1 boards).

Core Functions and Design Features

The DS200SDCIG2AGB is a highly complex Printed Circuit Board (PCB) that serves as the foundation for the digital control system’s power and data integrity.

1. Regulated Power Supply

The board receives unregulated input power and converts it to the various clean, regulated DC and AC voltages required by the sensitive digital circuitry in the control rack. This includes:

• $+5 \text{ VDC}$ (for digital logic and microprocessors).³

   

• $\pm 15 \text{ VDC}$ (for analog signal conditioning and operational amplifiers).⁴

   

• $\pm 24 \text{ VDC}$ (for driver circuits and digital interfaces).⁵

   

• $115 \text{ VAC}$ (for certain system components or interface relays).

2. Instrumentation and Measurement Interface

The board translates critical high-voltage and high-current analog signals into clean, isolated digital signals for the main drive control board (SDCC). Key measurements processed include:

• AC Line Currents (⁶$I_{L1}, I_{L3}$): Monitored via current transformers (CTs) for functions like checking for commutation failure and AC input monitoring.⁷ The DIP switch SW1 on the board is used to select the correct burden resistance for the CTs based on the nominal DC output current of the drive.⁸

   

• Armature Current and Voltage: Essential for precise motor torque and speed control.

3. Diagnostic and Protection Features

The board includes several components designed for protection and simplified troubleshooting:

• Fuses (FU1, FU2, FU3, etc.): The board is equipped with several fuses to protect the various power circuits.⁹ For example, Fuse FU3 specifically safeguards the ¹⁰$-24 \text{ VDC}$ and ¹¹$-5 \text{ VDC}$ signal-level power supplies.¹²

   

• LED Indicators: Each fuse is typically associated with a diagnostic LED.¹³ If a fuse blows, the corresponding LED illuminates, allowing maintenance personnel to quickly pinpoint the failure without needing to manually test every fuse.¹⁴

   

• Relay K2: This relay often serves as a pilot relay for the MA (Motor Armature) or MD (Motor Field) contactor within the DC2000 drive system, playing a critical role in sequencing the main power components.¹⁵

   

Part Number Breakdown (DS200SDCIG2AGB)

Comparison to Related Boards

The DS200SDCIG2AGB is a refinement of the base G2 design. While the core function remains the same across all G2 boards (no internal field supply), the revision codes indicate specific changes over time.

In short: The DS200SDCIG2AGB is a reliable, high-specification board that acts as the power and data hub for GE’s large DC drive systems, designed specifically to interface with powerful external field exciters.