Product Description
The Woodward 9907-1199 CPC-II (Generation II) is an electrohydraulic current-to-pressure conversion module engineered for precision control of steam turbine governing systems. The unit translates a standard 4–20 mA control signal into a stable hydraulic pressure output used to actuate turbine governor valves and servo mechanisms.
Developed for demanding turbine environments, the CPC-II design delivers extremely fast dynamic response and high control accuracy while maintaining reliable operation in hydraulic systems where oil contamination and harsh temperatures are common. The module integrates advanced valve algorithms that help maintain stable pressure regulation even when fluid cleanliness conditions fluctuate.
The 9907-1199 is widely used in modern turbine control platforms and is commonly installed as a direct replacement for earlier converter generations, including CPC-I and comparable electrohydraulic interfaces used in legacy turbine systems.
Key Functional Characteristics
The CPC-II architecture improves response speed and reliability compared with earlier electrohydraulic converters. Its internal digital control algorithm continuously adjusts the hydraulic valve position to maintain accurate pressure output corresponding to the incoming current signal.
The device also supports redundant input signals and power connections, allowing integration into safety-critical turbine control loops where system availability is essential.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 9907-1199 |
| Product Series | CPC-II (Generation II) |
| Manufacturer | Woodward |
| Device Type | Electrohydraulic Current-to-Pressure Converter |
| Control Input | 4–20 mA analog signal |
| Output Pressure | 0–25 bar (0–363 psi) hydraulic output |
| Supply Voltage | 24 VDC nominal |
| Operating Voltage Range | 18–32 VDC |
| Typical Current Consumption | 1 A |
| Dynamic Response | 2.5 ms (10–90% step response) |
| Linearity | Better than ±0.2% full scale |
| Repeatability | ±0.1% |
| Operating Temperature | –40 °C to +70 °C |
| Optional Extended Rating | Up to +85 °C depending on configuration |
| Oil Cleanliness Requirement | ISO 20/16 compatible |
| Environmental Certifications | ATEX, IECEx, UL (variant dependent) |
| Control Architecture | Supports redundant signal inputs and dual power interfaces |
| Mechanical Compatibility | Mounting compatible with CPC-I and Voith E360 converters |
Design and Reliability Features
High-speed electrohydraulic control is one of the defining characteristics of the CPC-II platform. The internal actuator valve and electronic control loop allow the converter to react within milliseconds to load or speed changes in turbine systems.
The hydraulic stage incorporates contamination-tolerant valve geometry and a self-cleaning control algorithm. This significantly reduces sensitivity to oil particle contamination compared with conventional electrohydraulic interfaces.
In turbine installations requiring uninterrupted operation, the unit supports redundant control configurations where two converters operate in master-slave mode or parallel monitoring architectures.
Typical Application Scenarios
Power generation facilities commonly install the 9907-1199 within steam turbine governing systems where precise hydraulic pressure control is required to position turbine inlet valves. The converter provides accurate pressure modulation corresponding to electronic speed or load commands from turbine controllers.
Marine propulsion systems using steam turbines also employ the CPC-II converter to control governor valves responsible for propulsion speed regulation. Its robust design allows reliable operation in vibration-intensive and temperature-variable marine environments.
Chemical processing plants, offshore energy installations, and other hazardous industrial environments benefit from the unit’s explosion-protection certifications and wide environmental operating range.
Compatibility and Upgrade Path
The CPC-II platform was designed as a mechanical and functional upgrade for older electrohydraulic converters. In many installations, the 9907-1199 can replace CPC-I or Voith E360 converters without requiring structural modifications to the mounting or hydraulic interfaces.
This backward compatibility significantly simplifies modernization projects where older turbine control hardware must be upgraded while minimizing downtime and mechanical redesign.
FAQ
What signal does the converter accept from the turbine controller? The 9907-1199 accepts a standard 4–20 mA analog command signal that represents a pressure demand from the turbine control system.
Can the unit tolerate contaminated hydraulic oil? Yes. The CPC-II design incorporates contamination-resistant valve geometry and control algorithms that allow operation with oil cleanliness around ISO 20/16, though proper filtration is still recommended.
Is this model suitable for hazardous environments? Depending on the configuration and certification package, the converter can meet ATEX and IECEx requirements for installation in classified industrial zones.
