Woodward 8200-1302

The 8200-1302 is a Woodward 505D series LV-ATX digital controller for amphibious steam turbines, suitable for pure condensing single-valve steam turbines. It can be used in both onshore industrial skid-mounted and Marine scenarios. According to the change notice of PCN07004, new orders will be discontinued as of September 23, 2024. The equivalent alternative model is 8200-2302 (excluding maritime certification). 8200-1302 is equipped with complete closed-loop PID control for speed and load, supporting fully automatic speed increase, critical speed avoidance, grid-connected frequency regulation and independent hardware overspeed interruption protection. It integrates graphic HMI, multi-channel analog/digital I/O and Modbus communication, and can be connected to DCS and ship engine room monitoring systems. 8200-1302 has unique LR and DNV-GL ship class certifications, with a vibration level of RV1. It can withstand wide-frequency vibration ranging from 10 to 2000Hz and is suitable for high-vibration working conditions in engine rooms and skids. The whole machine adopts an embedded panel installation and can also be wall-mounted with a shock-absorbing bracket.

Product Function

The 8200-1302 is a dedicated digital speed controller for single-inlet condensing steam turbines. It is compatible with conventional steam turbines without extraction or make-up steam and is used in two main applications: onshore industrial and marine.

Onshore Industrial Applications:

1. Self-contained power plant steam turbine generators: start-up, warm-up, speed increase, grid connection, load regulation, and primary frequency control;

2. Industrial driven steam turbines: stable speed control for feedwater pumps, fans, and compressor turbines;

3. Complete steam turbine safety protection: overspeed, low oil pressure, trip signal, and valve position fault tripping.

For Vessel-Specific Purposes (Only applicable to 8200-1302 models; alternative models cannot achieve this):

1. Speed regulation of marine steam turbine generators, marine auxiliary steam turbines, and marine boiler feedwater pump turbines;

2. Meets marine engine room vibration, salt spray, and maritime safety regulations; compatible with marine engine room monitoring systems;

3. LR/DNV-GL ship inspection certification; essential hardware for ship project drawing review and classification.

Working Principle

The 8200-1302 is a digital electro-hydraulic closed-loop speed control system, consisting of five parts: signal acquisition, main control and computation, relay output, hydraulic actuator, and feedback loop.

Signal Acquisition:

Rotor Speed: Rotor pulse speed is acquired by a magnetoresistive probe at the turbine front end.

Analog Signals: 4–20mA acquisition of generator power, steam pressure, and hydraulic actuator valve position feedback via LVDT.

Digital Signals: Remote start/stop, tripping, grid connection, and various protection trip hard contact signals.

Main Control and Computation:

The 8200-1302 has a built-in 32-bit microprocessor that automatically switches control loops based on unit status:

Off-grid: Speed PID priority, automatically increasing speed according to the set rate.

Grid-connected: Load PID priority, with fine-tuning of speed to stabilize grid frequency.

Fault Trigger: Real-time detection of overspeed, low oil pressure, and other protection conditions, immediately outputting trip commands.

Relay Output Drive

Internal relays output two types of signals:

Regulating Output: 4–20mA analog signal drives the electro-hydraulic servo valve to control the main steam valve opening;

Logic Switch Output: Relay contacts control the shut-off of solenoid valves, alarm indicator lights, and remote status feedback;

The original 8200-1302 relay meets the high vibration and marine salt spray conditions of RV1; the new relay is only suitable for low vibration control rooms.

Feedback Closed-Loop Correction

LVDT valve position and speed are fed back to the controller in real time, continuously correcting output commands, eliminating regulation steady-state error, and stabilizing speed and load.

Safety Shutdown Logic

When the speed exceeds 110% of the rated speed, an independent hardware circuit drives the trip relay to quickly depressurize and close the turbine main steam valve, while simultaneously locking the fault code.