The steam turbine DEH system is a key part to ensure the safe and stable operation of the steam turbine. As the core component of the DEH system, the CPU card PCA-6740 is responsible for executing control algorithms, data processing and logical operations. Given its importance, when the CPU card encounters a hardware failure, there must be a redundant or backup mechanism to ensure the continuous operation of the control system to prevent system downtime caused by a single point failure.

The PCA-6740 CPU card plays the role of a core processor in the DEH system, responsible for receiving input signals from sensors, executing complex control algorithms, and outputting instructions to actuators such as oil motors to adjust the speed and load of the steam turbine. Its performance directly affects the response speed and control accuracy of the steam turbine.

In order to improve the reliability and availability of the system, the DEH system usually adopts a redundant architecture, especially for key components such as the CPU card. The basic principle of redundant design is to deploy additional, identical components in the system to take over its functions when the main component fails, thereby ensuring the continuous operation of the system as a whole.

In the DEH system, the CPU card PCA-6740 often adopts a dual redundant configuration, that is, there are two identical CPU cards working in parallel. One is the main processor and the other is the backup processor. During normal operation, the main processor assumes all control tasks, while the backup processor synchronizes the status of the main processor and is ready to take over at any time.

When the main processor PCA-6740 detects a hardware failure or software anomaly, the system automatically triggers a redundant switch, and the backup processor immediately becomes the new main processor and continues to perform control tasks, while the faulty processor is isolated and marked as waiting for repair.

In order to ensure the smoothness and seamlessness of the redundant switch, real-time data synchronization must be performed between the two CPU cards. This includes the replication of information such as control parameters, sensor readings, and historical event records. Once the switch occurs, the backup processor can immediately start working from the latest data state, avoiding control interruption and data loss.

The redundant system also includes a fault detection mechanism that can identify the failure mode of the CPU card PCA-6740 and isolate it from the system to prevent the fault from spreading. This usually involves self-checking and mutual checking functions to ensure that only healthy processors participate in control decisions. By adopting this dual redundant configuration, combined with real-time data synchronization and fault detection and isolation mechanisms, hardware failures can be effectively responded to and the continuous operation of the control system can be ensured.
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Pressure reducing valve PQ-235C
LVDT Sensor TD-1-100-10-01-01
PRESSURE GAUGE YN-100/ 0-6MPA
low cost linear position sensor TDZ-1-H 0-100
PROBE SENSOR G14B25SE，330500
Speed Sensor SZCB-02-B117-C01
Power Board SY-V2-POWER (Ver 1.10)
platinum resistance temperature detector WZP2-230
Booster Relay YT-300N1
linear position actuator DET50A
PRESSURE SWITCH BH-013044-013
Vibration monitoring instrument SDJ-3L/G
Oil temperature sensor YT315D
Microprocessor voltage controller MVC-196
Low Resistance Probe XS12J3Y
RTD WZPM2-08-120-M18-S
linear displacement measurement HTD-150-6
CPU card for relay iPACT5961
Speed Transducer SMCB-01-16L
Module ID Fan PSM 692U