9907-1228 CPC-ll 电流到压力转换器

9907-1200

The CPC-ll (current to pressureconverter, generation ll)is anelectrohydraulic pressure-regulatingvalve control designed for use inpositioning single-acting steam turbinevalve servos.This CPC’s superbaccuracy and resolution make it idealfor steam turbine valve control andrelated turbine speed and loadcontrol. The CPC accepts a 4-20 mApressure demand signal andaccurately controls oil pressure toprecisely position single-acting steamturbine governor-valves.Precise andstable steam valve control directlyrelates to improved steam turbinespeed and load control and reducedsystem mechanical wear.
The CPC’s redundancy features make it ideal for critical steam turbine applications,where turbine up-ime and availability are essential. This converter can be configured toaccept redundant pressure demand inputs, from one or two (redundant) controllers, andvote the input to follow. Aternatively the CPC can be configured to accept signals fromboth its internal oil pressure sensor and an exteral (redundant) oil pressure sensor, anduse the voted healthy signal.
The CPC’s robust design (strong actuator, corrosion-resistant material, single movingrotary valve, and self-cleaning port design) makes it ideal for challenging applications
where dirty or contaminated oil may be present.
Optionally two controllers can be connected to a single CPC in a redundant Master/Slavefashion to allow the turbine to continue to operate if either turbine control fails, or on-inechanges are desired. Designed for use in applications requiring full redundancy,optionally two CPCs can be applied in a dua-redundant fashion, simplifying the entiresystem and control wiring.

The CPC is an electrohydraulic pressure-regulating valve control that utilizes a very accurate internal pressure sensor and PID controller to precisely control steam turbine valves. The CPC consists of a valve-actuator assembly, pressure sensor, and electronic driver module. The unit’s driver module accepts one (or two) 4–20 mA pressure setpoints and compares these setpoints to the sensed oil pressure, to accurately control turbine valve oil pressure.

The CPC controls oil pressure by porting supply-oil to its control-oil output port (turbine valve control oil) or back to the system supply tank. This converter’s special PID architecture allows it to perform very stable pressure control during normal conditions, and respond in milliseconds to desired valve step changes during system or plant transients. As a means of protecting the turbine, an internal valve-return-spring forces the CPC to a failsafe position (port oil to drain) and safely close turbine control valves upon

any internal unit failure (electrical input power failure, pressure sensor failure, processor failure, etc.).