Description
Product Overview
The Woodward 9907-135 is a high-performance GS3/LQ servo valve driver module, designed to drive Woodward LQ-series hydraulic actuators for steam and gas turbine fuel / steam valve position control. It receives 4–20mA setpoint commands from turbine governors (such as 505, 505D, 723 controls) and provides closed-loop position control via resolver feedback. This unit converts low-level control signals into high-current drive output for hydraulic servo actuators, widely used in power generation turbine governing systems.
Technical Specifications
| Item | Parameter |
|---|---|
| Part Number | 9907-135 |
| Manufacturer | Woodward |
| Product Family | GS3/LQ Valve Driver |
| Supply Voltage | 10–32 VDC, nominal 24 VDC |
| Max Drive Current | 24 A peak |
| Control Setpoint | 4–20 mA analog command |
| Position Feedback | Single-speed resolver |
| Compatible Actuators | LQ3, LQ25, LQ25T and LQ bypass liquid fuel/steam valves |
| Diagnostics | Resolver fault, overcurrent, short circuit, power monitor, status LED indicators |
| Operating Temp | -40 °C ~ +70 °C |
| Mounting | Panel / rack mount in control cabinet |
| Enclosure | Metal chassis, IP20 internal cabinet mounting |
Key Features
- Closed-loop position regulation using resolver feedback for precise valve positioning
- Accepts standard 4–20mA command signal from turbine governor controllers
- High-current output stage to directly power LQ hydraulic servo actuators
- Comprehensive fault diagnostics with fault flagging for control system alarms
- Over-current, short-circuit and over-temperature protection to safeguard actuator and driver hardware
- Fast response for turbine load and speed regulation during transients, startup and trip events
- Works seamlessly with Woodward 505, 505D, 723 and other Woodward turbine control platforms
Application
Primary application for gas turbine fuel valves, steam turbine throttle / governor valves and bypass valve control in thermal power plants, combined cycle units and mechanical drive turbine packages. It sits between the turbine governor and hydraulic LQ actuator, performing the power amplification and position closed loop control.
Installation & Maintenance Notes
- ESD precautions required during handling and replacement
- Separate low-level command wiring from high-current actuator cabling to reduce noise interference
- Verify resolver wiring polarity and shield grounding during commissioning
- Check DC supply voltage before power-up; unstable 24V supply can trigger drive faults
- Perform stroke calibration after module replacement to match valve full travel
- Review fault LED status and governor diagnostic logs for troubleshooting
FAQ
Q: What actuator does 9907-135 drive? A: It is built exclusively for Woodward LQ series hydraulic servo actuators including LQ3, LQ25, LQ25T.
Q: What signal comes from the turbine governor to this driver? A: A standard 4–20mA analog position command signal.
Q: Does this module include resolver feedback? A: Yes, it reads resolver signal from the LQ actuator for closed valve position control.
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