Introduction
Accurate and stable control of the speed of the prime mover (engine, turbine) is crucial in key fields such as power generation, ship propulsion, and industrial drive. The Woodward 2301A speed controller, as a proven classic electronic speed control device, is widely used worldwide for speed and load control of diesel engines, gas engines, steam turbines, and gas turbines due to its sturdy structure, flexible configuration, and excellent reliability. This article provides a comprehensive analysis of the functions, installation, debugging, operation, and maintenance of the 2301A speed controller based on Manual 82020D.
Product Overview and Application Fields
1. Core functions
The 2301A speed controller is an electronic speed controller based on a printed circuit board. By monitoring the signal of a magnetic speed sensor (MPU) and comparing it with a reference speed set internally or externally, the controller outputs a control signal to drive a proportional actuator, thereby accurately adjusting the opening of the fuel or steam valve of the prime mover, achieving:
Isochronous mode: maintains constant speed operation, unaffected by load changes.
Droop mode: adjusts the speed proportionally according to the load, suitable for multi machine parallel or infinite power grid operation.
Load distribution: With the help of load sensors, precise load sharing can be achieved among multiple generators.
2. Main models and power supply
2301A offers multiple models to adapt to different applications:
Supply voltage special function forward acting model reverse acting model
88-132 Vac/90-150 Vdc series actuator 9905-136 9905-138
10-40 Vdc series actuator 9905-135 9905-137
88-132 Vac/90-150 Vdc standard speed control 9905-132/9907-015 * 9905-134/9907-017*
10-40 Vdc standard speed control 9905-131/9907-014 * 9905-133/9907-016*
88-132 Vac/90-150 Vdc 0-400 mA output 9905-448-
*Compliant with EU directive models.
The reverse acting system is designed specifically for applications equipped with Woodward EGB governors/actuators. In the event of electronic control failure, the mechanical backup governor can take over control, avoiding shutdown and improving system redundancy and safety.
Core points of installation and wiring
1. Power requirements
Low voltage model: 10-40 Vdc, low impedance power supply (such as battery) must be used, and it is strictly prohibited to draw power from high voltage sources through series resistors and Zener diodes.
High voltage models: 88-132 Vac (50-400 Hz) or 90-150 Vdc.
Important reminder: When disconnecting the battery, it is necessary to ensure that the charging device (such as the AC generator) is also disconnected from the control to prevent damage.
2. Shielding and grounding (key for EMI control)
All signal lines (MPU, actuators, auxiliary inputs, etc.) must use twisted pair shielded wires.
The shielding layer is only grounded at the controller end and connected to the chassis grounding bolt below terminal 9. The length of the grounding wire should be less than 5 centimeters.
The other end of the shielding layer must remain open and insulated, and must not be grounded at the sensor or actuator end.
Avoid laying signal lines in parallel with high current cables, and if necessary, use conduit or double-layer shielding.
3. External adjustment and options
Speed adjustment: Connect terminals 11-12 to a 100 Ω multi turn potentiometer, providing approximately ± 5% speed adjustment.
Sag adjustment: Connect terminals 13-15 to a 2k Ω potentiometer, providing a maximum sag of approximately 8%.
Minimum fuel contact point: used for normal shutdown, strictly prohibited from being used as part of emergency shutdown circuit.
Speed signal failure override: used in situations where there is no speed signal during startup (such as some steam turbines).
Idle/rated ramp contact: controls the switching between idle and rated speed, with adjustable ramp time (1-22 seconds).

Debugging and dynamic adjustment steps
1. Initial preset (before startup)
Rated speed potentiometer: Adjust counterclockwise to minimum.
Reset and gain potentiometer: placed in the middle position.
Slope time, low idle, droop (if used): Adjust counterclockwise to minimum.
Compensation for actuators:
Diesel engine/gas turbine: set to scale "2".
Steam turbine/carburetor gas engine: set to scale "6".
Start fuel limit: Adjust clockwise to maximum.
2. Startup and stability adjustment
Set the rated speed reference: The signal generator can be used to simulate the MPU frequency, or fine tune it after startup.
Check MPU signal: When turning, the voltage between terminals 7-8 should be ≥ 1.0 Vrms.
Stable operation adjustment:
Fast traveling car: Slowly decrease the gain counterclockwise.
Slow traveling car: increase reset clockwise; If it is ineffective, both the gain and actuator compensation can be fine tuned simultaneously.
Dynamic optimization:
Gradually increase the gain until the actuator becomes slightly unstable, and then reverse to stabilize.
Adjust the reset to reduce overshoot or adjustment time through sudden load/unload test response.
Email:wang@kongjiangauto.com