Woodward 9907-955 |CPU Module, Origin: United States
1.9907-955 Product Overview
The Woodward 9907-955 belongs to the 505/505E series digital turbine controllers. It is a microprocessor-based control module designed for single-valve steam turbines,
including single extraction/admission systems or split-range actuator configurations.
The controller features a front panel Operator Control Panel (OCP) with a two-line, 24-character display and multi-function keypad, allowing easy on-site configuration and monitoring.
2. 9907-955 Technical Specifications and Parameters
| Parameter | Details |
|---|---|
| Power Supply | +24 VDC, approx. 1 A |
| I/O Outputs | Discrete Outputs: 8 Analog Outputs: 6 Actuator Outputs: 2 |
| Display / HMI | Two-line, 24-character LCD, with multi-function keypad |
| Dimensions | Approx. 14 × 11 × 4 in (35.6 × 27.9 × 10.2 cm) |
| Weight | Approx. 9.11 lbs (4.13 kg) |
| Operating Temperature | –4 to +140 °F (–20 to +60 °C) |
| Storage Temperature | –40 to +185 °F (–40 to +85 °C) |
| Humidity Standard | 95% RH at 20-55 °C for 48 hours without damage |
| Protection Class | Typically meets industrial dust and water protection standards |
| Communication Protocol | Supports Modbus, RS-232 / RS-422 serial interfaces |
3. Brand History
Woodward, Inc., founded in 1870 and headquartered in Fort Collins, Colorado, USA, is a global leader in energy control systems. The company has a long history of innovation in turbine control, engine management,
and power generation systems.
Woodward products are widely recognized for their reliability and precision in demanding industrial and power generation applications.
4. Applications in Industrial Automation
The 9907-955 plays a critical role in industrial automation and power generation environments:
- Steam Turbine Control: Manages startup, speed regulation, and extraction/admission control of steam turbines.
- Power Generation Systems: Used in power plants to regulate turbine-driven generators for stable frequency and load management.
- Compressor and Pump Drive Control: Ensures precise speed control for turbine-driven compressors and pumps.
- Process Industry Applications: Applied in chemical plants, refineries, and other industries requiring precise turbine operation.
- Safety and Protection Functions: Includes overspeed protection, critical speed avoidance, actuator travel limits, and event logging for operational safety.
The testing system adopts two testing methods, online or offline. The software implements intelligent processing module functions,
and the expert system provides solutions for testing problems.
3. Hardware circuit implementation of driver testing system
The testing system mainly includes a measurement and control platform with a computer as the core, as well as a testing platform for installing
test drivers, analog loads, specialized measuring instruments, and other equipment. The circuit design adopts pulse diagnosis anti-interference
and redundancy design to ensure accurate and reliable hardware design. The specific connection diagram is as follows:
Figure 2: Connection diagram of drive testing system
3.1 Startup Circuit
The startup circuit provides working voltage for the tested driver, and three current limiting resistors are connected in series to prevent surge
current. At the same time, contactors, thermal relays, and filters ensure stable and reliable voltage quality. During the power on process,
simply control the computer to issue a power on command, activate the contactor, complete the power on process, and achieve a safe and
reliable “soft start”. The schematic diagram of the startup circuit is shown below.
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