Woodward PGPL electro-hydraulic actuator/driver(37519 G version)

Woodward PGPL electro-hydraulic actuator/driver

Product core positioning and application scenarios

1. Core positioning

Technology type: Electro hydraulic integrated actuator, including proportional drive interface, capable of receiving electronic controllers (such as Woodward 2301A series, 700 series, etc.) Peak ®  The 0-200mA position signal output by the 150 and 505 controllers is controlled by a torque motor and a follow-up pilot valve to drive the output shaft, and coupled with a contactless position sensor to achieve closed-loop control.

Alternative value: Used to replace traditional hydraulic mechanical governors such as PG-PL, PGD, PGL, etc., retaining the convenience of the original PG type transmission and connecting rod system, while possessing high precision and flexibility of electronic control.

2. Scope of application

Adaptation equipment: gas engines, steam turbines (such as power generation turbines, industrial compressor driven turbines);

Hazardous Area Compliance: Compliant with UL certification, suitable for Class I Zone 2, A/B/C/D hazardous environments (models with magnetic electric sensor (MPU) options do not have UL/cUL certification);

Linkage system: It needs to be used in conjunction with an electronic governor, and its core function is to convert electronic control signals into mechanical actions, adjust fuel supply or steam valve opening, and achieve speed/load control.

Core components and technical specifications of the product

The PGPL system consists of two parts: the "actuator" and the "driver". The former is responsible for mechanical action output, while the latter realizes electrical signal conversion and closed-loop control. The specific parameters are as follows:

1. Actor: the core of mechanical action

(1) Core configuration and performance

Description of Key Parameters for Categories

Linear output of power cylinder: 16J (12ft lb), 23J (17ft lb), 39J (29ft lb), 79J (58ft lb)

Rotation output: 16N · m (12lb ft), 23N · m (17lb ft), 39N · m (29lb ft), 79N · m (58lb ft) linear stroke 25mm (1 inch), rotation stroke 30 °; Available travel/output is 2/3 of the maximum value

Hydraulic system oil pump: PG spur gear pump (low-speed version 0.812 inches thick, ≤ 1000rpm); High speed version 0.562 inches thick,>1000rpm)

Working pressure: Standard 896kPa (130psi), 58ft lb model 1655kPa (240psi) with built-in oil tank (2.5L/2.6 quarts), requires separate oil selection (refer to manual 25071)

Drive required speed: 200-1000rpm (bidirectional rotation, with check valve); Maximum 1500rpm (unidirectional, with plug)

Power: Maximum 375W (0.5hp), oil cooler needs to be selected for high speed or high ambient temperature

Position feedback non-contact Hall effect sensor outputs 3.6-4.4Vdc feedback voltage to the driver, achieving closed-loop control

Environmental adaptability working temperature: -29~+104 ℃ (-20~+220 ℉, limited by oil temperature)

Vibration resistance: Complies with WGC RV2 standard, maximum 7G parallel direction of drive shaft. Shell material: base/column made of cast iron, feedback shell made of aluminum alloy, internal parts made of surface hardened steel

(2) Optional Features

Oil cooler: It needs to be installed when the actuator temperature exceeds 93 ℃ (200 ℉), and is divided into internal and external types;

Booster servo motor: using starting air to provide instant oil pressure, assisting equipment to start quickly;

Magnetic electric sensor (MPU): 1-2 optional, detects the speed of the prime mover through the drive shaft of the governor (cannot be used as a component of the overspeed protection system).

2. Driver: Electrical signal conversion core

(1) Core configuration and performance

Description of Key Parameters for Categories

Electrical signal input/output input: 18-32Vdc power supply, 0-200mA control signal (from electronic speed controller)

Output: 0-200mA drive signal (to actuator torque motor), 4-20mA position feedback signal (to indicator), built-in 210mA current limit to protect torque motor

The closed-loop control receives the 3.6-4.4Vdc signal from the actuator position sensor. After comparing the control signal, the output is adjusted and calibrated before leaving the factory. No field adjustment is required

Installation and environmental enclosure: cast aluminum box (cannot be directly installed on the prime mover)

Working temperature: -40~+70 ℃ (-40~+158 ℉)

Wiring: Use temperature resistant wires with a temperature rating of ≥ 90 ℃, comply with Class I, Zone 2 wiring standards, and require grounding to avoid electromagnetic interference (EMI). Refer to manual 50532

Wire length limit 16AWG (1.5mm ²): battery driver 457m, driver actuator 457m

14AWG (2.5mm ²): Battery driver 610m, driver actuator 610m shielded wire requires twisted pair, one end grounded and the other end suspended

Key requirements for installation and operation and maintenance

1. Installation specifications

(1) Mechanical installation

Attitude: The actuator should be installed vertically or nearly vertically to avoid force on the drive shaft (the actuator should not be placed on the drive shaft);

Transmission connection: The drive shaft should engage freely without any jamming, side load, or excessive axial clearance. The installation bolts should be evenly tightened to avoid shaking;

Connecting rod adjustment: Using 2/3 of the output stroke to achieve "no load full load" adjustment, the remaining stroke is distributed to both ends (ensuring that fuel can be cut off when turned off and maximum fuel can be provided at full load).

(2) Oil selection and maintenance

Oil requirements: viscosity 100-300SUS (at operating temperature), compatible with nitrile, polyacrylic acid, fluorocarbon sealing materials; Recommend using automotive/gas engine oil (such as SAE 10W30, 15W40) to avoid pollution;

Oil change cycle: Under normal working conditions, it should be replaced every year. In harsh environments (high temperature, high pollution), the cycle needs to be shortened; When changing the oil, it is necessary to drain it while it is hot, rinse it with a clean solvent (such as kerosene), and then add new oil.

(3) Electrical installation

Caution in hazardous areas: Do not plug or unplug connectors when live, and replacement parts must meet the requirements of Class I, Zone 2;

Grounding: Drivers and actuators need to be separately grounded to avoid parallel wiring with high voltage/high current wires and reduce EMI interference.

2. Initial operation and troubleshooting

(1) Initial operation steps

Confirm that the oil level is normal, there is no leakage, and the connecting rod is connected correctly;

Set the "low-speed start" mode on the electronic governor and prepare emergency shutdown measures;

Start the prime mover and gradually adjust the governor to the rated speed to ensure that the actuator operates linearly and without any jamming;

Verify closed-loop control: Change the control signal and check if the actuator output matches the feedback signal (10 ± 5mA corresponds to the minimum position, 175 ± 10mA corresponds to the maximum position).

(2) Common faults and solutions

Possible causes of symptoms and solutions

Unable to start/fuel rack does not open, actuator has no electrical signal, oil pump steering error, low oil level, connecting rod stuck. Check power and control signals; Confirm the direction of oil pump rotation; Oil replenishment; Repair the connecting rod

Slow action/delayed response, low speed (<200rpm), improper oil viscosity (too thin/too thick), worn oil pump, increasing speed or installing a boost servo; Replace the compatible oil; Repair/replace oil pump

Calibrate the connecting rod again due to the fluctuation of the prime mover (traveling/surging), nonlinearity of the connecting rod, oil contamination/foaming, and inaccurate parameters of the electronic governor; Change the oil; Adjust the parameters of the speed controller

Overheating of the actuator, high ambient temperature, driving speed exceeding 1500rpm, and installation of an oil cooler for oil oxidation; Reduce the rotational speed; Replace antioxidant oil

Principles of System Control and Safety Design

1. Control logic (closed-loop feedback)

Signal input: The electronic governor outputs a 0-200mA control signal to the driver based on the speed/load requirements;

Signal conversion: The driver converts the control signal into a 0-200mA driving current and sends it to the torque motor of the actuator;

Mechanical action: The torque motor drives the pilot valve, controls the flow of high-pressure oil to the power cylinder, and drives the output shaft action (adjusts the fuel/steam valve);

Feedback loop: The position sensor of the actuator converts the actual position into a 3.6-4.4Vdc voltage signal and feeds it back to the driver; The driver compares the control signal with the feedback signal, adjusts the output current until they match, and achieves precise positioning.

2. Security protection design

Power loss protection: When the control voltage is lost, the torque motor has no magnetic force, the spring pushes the pilot valve to release oil, and the power cylinder resets to the "minimum fuel" position to prevent the prime mover from overspeeding;

Overspeed independent protection: It is explicitly required that the prime mover be equipped with an overspeed shutdown device independent of the PGPL system (not dependent on the MPU of the actuator) to avoid loss of control caused by actuator failure;

Dangerous area protection: The shell is sealed and the wiring meets explosion-proof standards to prevent sparks from igniting dangerous gases.

Product Support and Services

1. Service Options

Quick replacement/exchange: Provide replacement parts of the same model within 24 hours to reduce downtime;

Fixed cost maintenance/renovation: Clearly define the maintenance cost in advance and restore it to a "near new product" state after maintenance;

Spare parts ordering: The model and serial number (indicated on the nameplate) of the actuator/driver must be provided to ensure that the spare parts match.

2. Compliance and Document Reference

Certification: UL (Class I, Zone 2), compliant with EU Machinery Directive 98/37/EC (without CE marking);

Related manuals: 25071 (hydraulic oil selection), 36692 (power cylinder specifications), 36693 (base specifications), 50532 (EMI control).