Ball Valve,Api Ball Valve,Jis Ball Valve,Soft Seat Ball Valve RST VALVE GROUP CO.,LTD , https://www.stainlesssteel-valves.com
Development of Digital Valve PCC Intelligent Governor
**Abstract:**
This paper presents a novel turbine governor known as the Digital Valve PCC Programmable Intelligent Governor, developed by Tianjin KeYin Automatic Control Equipment Co., Ltd. This advanced control system utilizes a Programmable Computer Controller (PCC) as its central processing unit, integrating electromagnetic ball valves for electro-hydraulic conversion and two-way cartridge valves for mechanical amplification. The design eliminates the need for lever mechanisms and complex pipeline structures, offering a more streamlined and reliable solution. Field applications in hydropower stations have demonstrated that this governor surpasses national standards in performance, with easy commissioning, low maintenance, and high reliability. Key features include intelligent control, digital valve technology, multi-tasking capabilities, and user-friendly interfaces.
**Keywords:** Intelligent Governor, PCC, Digital Valve, Cartridge Valve
**Preface:**
Traditional turbine governors often rely on PLCs as their core control units. However, the Digital Valve PCC Programmable Intelligent Governor introduces a new control concept, using PCC as the main controller. This system replaces conventional electro-hydraulic converters and main pressure valves with solenoid and cartridge valves, enabling a more efficient and accurate control mechanism. The choice of controller is crucial for the development of an advanced governor, and after thorough evaluation, PCC was selected due to its industrial-grade reliability, scalability, and ease of programming.
**1. Main Features of the Digital Valve PCC Intelligent Governor**
(1) **Innovative Control Concept**: Utilizing a new generation of PCC, which supports high-level programming and parallel task execution, enhancing efficiency and flexibility.
(2) **High Reliability**: With a mean time between failures (MTBF) of up to 500,000 hours, ensuring long-term stability.
(3) **Multi-Tasking Capabilities**: PCC allows different tasks to run concurrently, improving response speed and system performance.
(4) **Intelligent Regulation**: Adaptive PID control adjusts automatically to grid conditions, including isolated network operation and sudden load changes.
(5) **Digital Frequency Measurement**: Using PCC’s high-speed counting module (HSC), achieving high accuracy and reliability in frequency detection.
(6) **Field-Adjustable Curves**: Allows real-time curve modifications, improving adaptability to power station conditions.
(7) **Large Memory Capacity**: Provides sufficient resources for complex control algorithms and data storage.
(8) **Solenoid Valve as Digital Valve**: Eliminating oil leakage issues, ensuring stable and safe operation.
(9) **Fault Lock Function**: Ensures hydraulic locking even during power loss or signal failure.
(10) **No Lever Structure**: Reduces dead zones and improves speed control accuracy.
(11) **User-Friendly HMI**: Touchscreen interface with full Chinese display, making operation intuitive and informative.
(12) **Easy Maintenance and Debugging**: High integration and reliability reduce the need for specialized maintenance personnel.
**2. Main Functions of the Digital Valve PCC Intelligent Governor**
The governor supports automatic, electric manual, and manual operation modes, allowing seamless switching without disturbances. It includes features such as no-load frequency tracking, power regulation, self-diagnosis, communication with host computers, and intelligent shutdown control. Additional functions like water level adjustment, wave control, and multi-level password protection enhance system safety and usability.
**3. System Composition**
The Digital Valve PCC Intelligent Governor consists of a PCC CPU module, high-speed DI modules, pulse output modules, A/D conversion modules, and communication interfaces. The frequency measurement process uses high-speed digital input, ensuring precise and timely frequency detection. The digital valve control system employs PWM signals to drive solenoid valves, offering fast and accurate actuation.
**4. Electro-Hydraulic Servo System**
The electro-hydraulic system uses standard components, replacing traditional electro-hydraulic converters and main pressure valves. The use of solenoid valves and cartridge valves ensures high reliability, minimal maintenance, and excellent performance under various operating conditions. The absence of mechanical feedback simplifies the system and enhances stability.
**5. Operation Process**
During automatic operation, the governor follows pre-set boot rules, adjusting based on frequency or opening commands. In case of failure, it seamlessly switches to alternative control modes. The system can also be controlled via a touch screen or host computer, enabling remote monitoring and parameter adjustments.
**6. Application Results**
Field tests at hydropower stations have shown that the Digital Valve PCC Intelligent Governor outperforms existing standards. For example, at the Yangtou Hydropower Station, the governor achieved a speed dead zone of 0.015%, with excellent dynamic response and stability. These results confirm its suitability for modern hydropower systems and support the move toward unattended operations.
**Conclusion**
The Digital Valve PCC Intelligent Governor has proven to be a reliable and efficient solution for turbine control. It not only addresses the limitations of traditional governors but also meets the evolving needs of modern hydropower plants. After passing national technical tests and being successfully deployed in multiple stations, it has received positive feedback from users. Supported by government innovation funds, this technology represents a significant advancement in the field of turbine control.