I. Product Basic Information

Series: ABB Bailey Symphony Plus / Harmony DCS Rack (for thermal power plant turbine DEH system)

Model: SPHSS03 (out of production, replaced by SPHSS13)

Installation: Standard slot card type, compatible with Symphony control cabinet motherboard and INFI-NET redundant bus system

Net weight: ≈ 0.6kg; Dimensions: H35.6×W175×D297mm

Core Hardware & Electrical Parameters

Feedback Acquisition Channels: Multiple LVDT/RVDT differential displacement sensors for input (feedback of valve oil actuator displacement), integrated excitation + signal conditioning

Servo Drive Output: Direct drive of electro-hydraulic servo valve (MOOG/ABB servo valve), ±mA level servo control output, closed-loop valve position regulation

System Power Supply: Redundant 5VDC power supply on the cabinet backplane, internal voltage stabilizing circuit of the module

Communication Bus: INFI-NET high-speed redundant DCS bus, data interaction with the main control DPU

Environmental Conditions: Working temperature -20℃~+60℃, general for power plant high-temperature control room; resistant to electromagnetic interference for applications in turbine excitation, large-power frequency converter environment

Function Description (DEH Turbine-specific)

Closed-loop Valve Position Servo Control: Receives DCS valve position instructions, collects actual stroke of the oil actuator LVDT, PID closed-loop precise control of the regulating valve / main steam valve opening

Local Signal Preprocessing: On-board MCU local calculation, shortens servo response time, no need for external servo amplifier

Fault Self-Detection: LVDT open circuit detection, servo valve short circuit / open circuit alarm, power abnormality sending DCS alarm information

Application Closed-loop Logic: Full closed-loop control of turbine main steam valve, regulating valve, bypass valve hydraulic actuators

Main Application Scenarios

Thermal Power Industry (Main): DEH speed regulation system for thermal power plant turbine units, servo control of high and low pressure regulating valves of turbine (replacement parts for Symphony Bailey units)

Hydropower: Hydraulic servo control of water turbine guide vanes

Metallurgical heavy-duty hydraulic lowering, rolling mill AGC hydraulic servo closed-loop control (a small number of equipped with Symphony systems)