ABB PPA322B｜CNC system PCL｜

PPA322B

Key analog signal acquisition and signal conditioning for generators
Collect AC/DC analog signals such as three-phase voltage, excitation current, and stator current at the generator terminal; Complete isolation, filtering, surge clamping, impedance matching, and level conversion, convert on-site strong electrical signals into standardized measurement signals that can be received by the main control board, and supply AVR voltage regulators and various limiters to participate in closed-loop operation and protection logic.
Switching DI/DO interface processing
DI: Collect external contact signals (excitation permission, excitation switch position, external tripping, local/remote mode, power cabinet status, fan/fuse monitoring, etc.);
DO: Output relay control signals to achieve excitation, tripping, alarm, power unit linkage, and external status indication.
Analog to digital conversion signal front-end unit
As a front-end module for excitation system signal acquisition, it preprocesses the on-site primary side signal and transmits it to the UNITOL5000 main control processor board, which is the data source for AVR regulation, excitation limitation, and fault protection.
Hardware circuit self-test and signal monitoring
Built in measurement circuit disconnection monitoring. Once the PT/CT secondary circuit is disconnected, a measurement circuit fault will be reported, triggering the corresponding protection or channel switching of the excitation system.
External Expansion Interface Hub
Provide hard wired signal interfaces between the excitation system and the central control DCS, synchronization device, and protection device to achieve the issuance of operation instructions, operation status, and alarm signal upload.