WOODWARD 3522‑1004 High‑Performance Servo Drive Module

Product Description

3522‑1004 is a rugged industrial servo drive module manufactured by Woodward. It is specially designed to drive electro‑hydraulic servo valves and precision actuators for turbine and engine governing systems. The unit accepts 24V DC power supply, supports 4‑20mA setpoint commands and LVDT position feedback, and realizes high‑speed closed‑loop position control. Built with wide temperature tolerance and strong electromagnetic interference resistance, it is panel‑mounted inside control cabinets and widely integrated into steam turbine, gas turbine and diesel generator control systems.

Product Functions

• High‑precision closed‑loop position control for hydraulic servo valves and fuel actuators
• Receive 4‑20mA analog control command from main turbine governor controller
• LVDT feedback signal acquisition and real‑time actuator position correction
• Built‑in over‑current, over‑voltage, short‑circuit and stall fault protection
• Automatic zero‑point calibration to compensate long‑term servo valve drift
• Status and fault alarm output for upper DCS or local monitoring panel

Application Scenarios

• Steam turbine and gas turbine governing valve electro‑hydraulic control cabinets
• Diesel and gas generator set speed regulation actuator drive systems
• Oil & gas pipeline compressor and power plant auxiliary turbine control
• Marine main engine and auxiliary generator governing retrofitting projects
• UG mechanical governor digital upgrading and electro‑hydraulic conversion systems

Common Problems

• Actuator fails to respond: Loss of 4‑20mA command signal, loose LVDT wiring or internal drive circuit damage.
• Position drifting and unstable hunting: LVDT sensor aging, servo valve zero drift or poor grounding causing signal noise.
• Over‑current alarm frequently triggered: Hydraulic valve mechanical jamming, actuator short circuit or internal power stage failure.
• No fault indication but control output abnormal: Incorrect gain parameter configuration or firmware corruption.
• Intermittent operation failure: Cabinet overheating, loose terminal connectors or vibration‑induced contact degradation.