GE DS200SDCIG2AHB Power Supply and Instrumentation Board

الوصف

The GE DS200SDCIG2AHB is a critical DC Power Supply and Instrumentation Board (SDCI) designed for the GE Mark V Speedtronic Turbine Control System and the DC2000 Drive Series.¹

Its fundamental role is to perform two essential functions within the control cabinet: regulate power for the control electronics and act as a measurement interface for high-voltage and high-current motor signals.

The “G2” designation in the part number is key, indicating that this board is engineered for use in high-power DC drive systems that rely on an External Field Exciter (such as a GE EX2000) for the motor’s field current.

Core Functions and Technical Specifications

The DS200SDCIG2AHB integrates essential power regulation, sophisticated instrumentation, and critical protection features.

1. Power Supply and Regulation

The board is the primary source of clean, regulated DC and AC power for the sensitive control cards in the drive system, converting raw input power into the precise voltages needed for logic operations.

• DC Logic Power: Provides highly stable voltages, typically including ²$+5 \text{ VDC}$ (for logic), ³$\pm 15 \text{ VDC}$ (for analog circuits), and ⁴$\pm 24 \text{ VDC}$ (for interfaces and drivers).⁵

   

• AC Power: Supplies regulated ⁶$115 \text{ VAC}$ for various system relays and components.⁷

   

2. Instrumentation and Signal Interface

The board acts as the central hub for measuring and isolating critical electrical signals from the drive components, providing feedback data to the main Drive Control Card (SDCC).

• AC Line Instrumentation: It processes signals from the AC Current Transformers (CTs) on the main power lines. This allows the system to monitor the AC input, check for phase imbalances, and detect conditions that could lead to commutation failure in the SCR bridge.
• SCR Gating Drivers: The board includes the necessary driver circuits to generate the firing pulses for the main Armature Silicon Controlled Rectifiers (SCRs), which directly control the flow of current to the DC motor armature.⁸

   

• Voltage and Current Feedback: It conditions high-level analog signals (from shunts and transducers) representing Armature Voltage, Armature Current, and Field Current, isolating them and converting them into reliable frequency signals (using VCOs) for the digital controller.

3. Protection and Configuration

The design includes several features that aid in system protection and field configuration:

• Fuses and LED Indicators: The board is equipped with multiple fuses (FU1, FU2, FU3, FU5, FU6, etc.) to protect the various power circuits.⁹ Crucially, these fuses are linked to LED indicators; when a fuse blows, the corresponding LED lights up, allowing for immediate fault diagnosis and minimizing downtime.¹⁰

   

• Configurable Jumpers (JP1, JP2):
  • JP1 (MD Control Source): Selects the control source for the Motor Field contactor.
  • JP2 (MA AC Contactor Drop-out Time): Adjusts the delay time for opening the Motor Armature (MA) AC contactor, ensuring that all load current has dropped to zero before the contactor physically opens to prevent arcing and damage.
• DIP Switch (SW1): Used to select the burden resistance for the AC line CTs based on the nominal DC output current of the drive, ensuring accurate current measurement.

Part Number Breakdown (DS200SDCIG2AHB)

Application and Context

As a G2 board, the DS200SDCIG2AHB is primarily installed in drive systems for large DC motors (e.g., in steel mills, paper machines, or large industrial pumps) where the high field current demand necessitates a powerful, standalone external exciter. Its high degree of instrumentation also makes it invaluable in GE Speedtronic Mark V systems for gas and steam turbine control, where precise power regulation and signal monitoring are non-negotiable for safe and efficient operation.¹¹