Talking about the design idea of ​​gas turbine control system

During the early stages of gas turbine controller development, the turbine itself often lags significantly behind the controller’s progress. Waiting for the full completion of the turbine body before conducting on-line commissioning of the controller can greatly extend the overall project timeline. Moreover, this approach leaves the controller's performance unverified, increasing the technical risks associated with testing and commissioning the gas turbine. To mitigate these challenges, semi-physical simulation tests are conducted after the controller’s hardware and software have been developed. These tests provide a practical way to validate the control system’s design and ensure its reliability before real-world deployment.

A typical gas turbine consists of several key components, including generators, compressors, turbines, combustion chambers, and regenerators. Each of these parts plays a critical role in the overall operation and efficiency of the system. The integration of these components requires precise control, especially during start-up and operation under varying load conditions.

During the initial start-up phase, the turbine is driven by a soft starter unit that gradually accelerates the rotor. As the turbine reaches the ignition speed, the controller activates the ignition nozzle, fuel shut-off valve, and regulating valve to initiate the combustion process. This step is crucial for ensuring a smooth and safe start-up.

Once the ignition is successful, the turbine begins to generate power, and the generator is engaged to further accelerate the system. This phase is known as "double-dragging," where both the motor and the turbine contribute to the acceleration. The control system continuously monitors the generator's starting current, and once it drops below a certain threshold, the motor drive circuit is automatically disconnected. After this point, the turbine continues to operate at idle speed under its own power, marking the end of the start-up sequence.

To enhance the thermal efficiency of the gas turbine across different power levels, a variable-speed and variable-power control strategy is commonly employed. The control system adjusts the turbine’s speed in response to load changes, optimizing the overall performance and ensuring efficient operation under various conditions. This dynamic control approach not only improves energy efficiency but also extends the lifespan of the turbine by reducing mechanical stress during operation.