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Woodward 2301E-HT 8237-2046 Hydro Turbine Digital Governor | Control System For Small Francis Hydro Generators - Factory Automation Full-part Support
Source: | Author:kongjiang | Published time: 2026-06-18 | 62 Views | 🔊 Click to read aloud ❚❚ ▶ | Share:
Woodward 2301E-HT 8237-2046 Hydro Turbine Digital Governor | Control System For Small Francis Hydro Generators - Factory Automation Full-part Support

Introduction
The 2301E-HT is a digital speed control designed for Francis hydraulic turbines with one analog gate position output. It can be configured to perform several site-specific functions dependent upon the application. This chapter describes the controls’ I/O (input/output) and functions, including: start and stop sequencing, different control modes, alarms, shutdowns, communications, and other functions.
Description of I/O
The 2301E-HT digital speed control has a wide selection of functions from a fixed amount of I/O (inputs and outputs). The control can be configured in the field to use the I/O to best fit the specific application. During the initial setup of the control, the functions that are needed for the specific application are selected, and the necessary I/O points are assigned accordingly.
Control Inputs
Speed Inputs
Two-speed inputs are available. The use of a magnetic pickup is necessary for this application. The control can be configured to work with one or two (redundant) speed inputs. If configured for two sensors, the controller will always use the highest signal to control. If one of the speed inputs is lost, the control will keep running with just one signal and generate an alarm. If the second signal is lost, then the control will generate a trip and stop the turbine.
Analog Inputs
Two analog inputs are available (4–20 mA). Their functions can be chosen from the following.
• Pond/Tail Level: This analog input is mandatory if pond/tail level control is desired.
• Speed Bias: This analog input comes from a synchronizer/load controller. If the synchronizer/load controller doesn’t have an analog speed bias output, digital inputs in the 2301E-HT can alternatively be used to perform this function (called Speed Bias Raise and Speed Bias Lower).
• Gate Position Feedback: This analog input provides information about the gate's actual position. This is mandatory if an Integrating Gate Actuator is used. If a Proportional Gate Actuator is used, this input can be used as well, just for monitoring purposes.
• Remote Speed Reference: This analog input is used to provide a remote speed reference if droop control is used (either actuator droop or kW droop).
• Gate Position Limiter: This analog input is used if it’s necessary for any reason to limit the gate position to a certain value. If this gate limit is desired but an analog input is not available, there are two digital inputs that can be used alternatively (gate limit raise and gate limit lower).
• Remote Baseload Reference: This analog input is used if the control is in Baseload mode and a remote Baseload reference is enabled.
• Remote Level Reference: This analog input is used to provide a remote level reference if level control is used and the remote level reference is enabled.
• kW Input: This analog input is used to provide the actual generator load to the control. If this option is used, the Current Transformer (CT) and Potential Transformer (PT) will be ignored by the control. If there is no analog input programmed to this function, the control will assume the CT and PT inputs as generator load measurement.
Discrete Inputs
Eight discrete inputs (on/off switches) are available. Five of them are dedicated to the following functions: Run/Stop, Raise Speed/Load, Lower Speed/Load, Generator Breaker Status, and Emergency Shutdown. The other three discrete inputs on the 2301E-HT for Francis turbines are configurable.
The following options are available: • Manual Gate Control Enable: When this discrete input is closed, the gates can be controlled “manually” with the Raise and Lower discrete inputs. Manual Gate control can also be enabled through Modbus. • Pond/Tail Level Control Enable: When this discrete input is closed, the control will switch into pond/tail level control. The Raise and Lower discrete inputs will raise and lower the pond level set point. Pond/Tail Level Control can also be enabled through Modbus. • Auto Follow Enable: This input should be used when the 2301E-HT is being used as a back-up governor. When this discrete input is closed, the control will track the current gate position in all control modes, and the Raise and Lower inputs are disabled. When this discrete input opens, the 2301E-HT will assume control of the unit in whatever control mode is selected. Auto Follow control can also be enabled through Modbus. • Gate Limit Raise & Gate Limit Lower: When one of these discrete inputs is closed, the Gate Limit ramps up or down at a configurable rate. The 2301E-HT is designed so that Gate Limit control is not necessary, but it is available if required by the application. Gate Limit Raise and Lower can also be done through Modbus. • Creep Input #1 & Creep Input #2: Creep detection requires two inputs from proximity probes (or from ZVPU interface modules). By monitoring the Creep #1 and Creep #2 discrete inputs, the control can detect when the unit is creeping. • Dirty Oil Switch Input: This input is intended to be used when a dirty oil indicator has a contact switch on it. When this discrete input closes, it triggers the governor alarm “Dirty Oil Filter,” and the alarm is also sent to Modbus. • Governor Reset: All shutdowns and alarms are latched until the fault condition clears and the control is reset. When this input is closed, it resets the control. The control can be reset through Modbus or by using the Woodward Watch Window. • External Start Permissive: After a start input, the control waits for a momentary closure of this discrete input before starting the unit if this function is used, or this input must be closed before the start command. • Speed Bias Raise & Speed Bias Lower: When one of these discrete inputs is closed, the Speed Bias internal ramp ramps up or down at a configurable rate. For using these discrete inputs, the speed bias source must be configured to digital. Speed Bias Raise and Lower can also be done through Modbus. • Baseload Enable: This input is used to enable the Baseload control mode. In Baseload, the generator load will stay in a determined setpoint either by the Raise Speed/Load inputs, or by a remote Baseload input, or by a Baseload Modbus reference. The following conditions must also be present in order for the baseload control to be enabled: the generator breaker must be closed, and the manual, auto-follow, and level control modes must be disabled. Baseload Enable can also be done through Modbus. • Unload: When in parallel and baseload operation, it may be desired to unload the engine and open the generator breaker. When the unload contact is closed (rising edge triggered), the control starts to slowly decrease the load reference and, either when it reaches a minimum value (unload trip level) or a certain maximum delay after the reference reaches the unload trip level (configurable), it gives an open breaker command (if configured). After that, the engine stays in its rated speed waiting for another command. • Local/Remote: When this discrete input is closed, the 2301E-HT controller will only accept Modbus commands (the analog write Modbus commands don’t use this logic; there are specific Modbus addresses to define if a given Modbus analog write is going to be used or not). If this discrete input is opened, the 2301E-HT controller will only accept discrete commands. If there isn’t any discrete input configured for Local/Remote function, then the commands can come either by discrete inputs or by Modbus commands. • Position/kW Droop: This input is used to switch between valve position or kW droop. When in valve position droop, the controller will use the gate position feedback as a droop feedback to calculate the online reference. When in kW droop, this feedback calculation will be done based on the generator load.
Control Outputs
Actuator Output Analog Outputs Two analog outputs are available: Actuator output and Analog #1 output. The Actuator output can be configured either for 4–20 mA, 0–20 mA, or for 0–200 mA. Analog Output #1 is 4–20 mA only, and it is a configurable analog output. This output has the following options:
• Tachometer (Analog Output default)
• Gate Position • Gate Limit
• Speed Adjustment
• Pond/Tail Level
• Pond/Tail Level Setpoint
• Speed Bias • Generator Power
• Actuator output • Baseload Reference
Relay Outputs
Four relay outputs are available. All relay outputs can be used as normally open or normally closed (configurable). The first discrete output is Shutdown indication. The others discrete outputs are configurable and the available configuration is shown below:
• Gate Position Switch #1: This switch can be set to trigger at a specific gate position as the gates go open or as they close.
• Gate Position Switch #2: This switch can be set to trigger at a specific gate position as the gates go open or as they close.
• Speed Switch #1: This switch can be set to trigger at a specific % of rated speed as the speed increases or decreases.
• Speed Switch #2: This switch can be set to trigger at a specific % of rated speed as the speed increases or decreases. • Speed Switch #3: This switch can be set to trigger at a specific % of rated speed as the speed increases or decreases. • General Governor Alarm: This relay option closes the relay when an alarm condition is present. All shutdown conditions are also considered alarms. • Brake Permissive: This relay option closes the relay when the control is in the “STOP” mode, the gates are closed, speed and gate position signals are valid, and the speed is below a configurable value. • Creep Indication: This relay option closes the relay when creep is detected on the unit. The relay will stay closed until a configurable time after the unit stops creeping. At that point, the relay will open, and the control will continue monitoring the unit for another creep condition. • Speed Bias Enabled: This relay option closes to inform if the Speed Bias signal (either analog or digital) is enabled and in use at the moment. • Gate Position Signal Failure: This relay option closes when the Gate position signal is enabled, and its input fails. Input failed means that the current in this input is below 2 mA or above 22 mA. • Level Signal Failure: This relay option closes when the Level signal is enabled, and its input fails. Input failed means that the current in this input is below 2 mA or above 22 mA. • Remote Signal Failure: This relay option closes when the Remote signal is enabled, and its input fails. Input failed means that the current in this input is below 2 mA or above 22 mA. • Speed Bias Signal Failure: This relay option closes when the Speed Bias signal is enabled, and its input fails. Input failed means that the current in this input is below 2 mA or above 22 mA. • Incomplete Start: This relay is closed when an incomplete start is detected. An incomplete start is detected when a start command is issued, and the turbine speed does not reach a configured value in a configured time. • Minor gate Position Mismatch: The control continuously compares the actual gate position to the gate position demand in the control. If they do not match within the “Minor Mismatch Window” for more than the “Minor Mismatch Delay” time, the control will issue a “Minor Mismatch” alarm. • Overspeed Shutdown: This relay option closes the relay when there is an Overspeed Shutdown. • Dirty oil indication: This output will be closed when the discrete input for dirty oil is closed. • Modbus Link Error: This output will be closed when there is a Modbus link error. • Speed Input #1 Fault: This output will be closed when there is a Speed Input #1 error. • Speed Input #2 Fault: This output will be closed when there is a Speed Input #1 error. • Generator CB_Aux Open Command: This relay option sends a generator opening command if an unload command is given and the unload conditions are fulfilled in order to open the breaker. • kW Switch #1: This switch can be set to trigger at a specific kW as the kW increases or decreases. • kW Switch #2: This switch can be set to trigger at a specific kW as the kW increases or decreases. • Remote Level Reference Signal Failure: This relay option closes when the Remote Level Reference signal is enabled, and its input fails. Input failed means that the current in this input is below 2 mA or above 22 mA.

2301E-HT – Hydro Turbine Control (Francis), 24 VDC, Ordinary Location *Documentation: Product Spec: 03459, Manual: 35092 8237-2046