How do you design and implement coordinated control strategies for multiple stability devices?

1 Stability devices and control objectives

Stability devices are special equipment that can modify the power system parameters or inject active or reactive power to improve stability. Some examples of stability devices are power system stabilizers (PSS), static VAR compensators (SVC), thyristor-controlled series compensators (TCSC), and flexible AC transmission systems (FACTS). The control objectives of stability devices depend on the type of stability problem they aim to address, such as voltage stability, frequency stability, or transient stability.

2 Coordinated control strategies and benefits

Coordinated control strategies are methods that optimize the coordination and interaction of multiple stability devices to achieve better performance than individual control. Coordinated control strategies can be classified into centralized, decentralized, or distributed, depending on the level of information exchange and decision making among the stability devices. The benefits of coordinated control strategies include enhancing the damping of oscillations, improving the voltage profile, increasing the power transfer capability, and reducing the control effort and cost.

3 Design steps and challenges

The design of coordinated control strategies involves several steps, such as selecting the stability devices and their locations, defining the control objectives and constraints, choosing the coordination scheme and the control algorithm, and testing and validating the performance. The challenges of designing coordinated control strategies include dealing with the nonlinear and dynamic nature of power systems, handling the uncertainties and disturbances, ensuring the robustness and stability of the control system, and coordinating the communication and computation among the stability devices.

4 Implementation methods and issues

The implementation of coordinated control strategies requires the deployment of sensors, actuators, communication devices, and controllers for the stability devices. The implementation methods can be based on hardware, software, or hybrid platforms, depending on the availability and compatibility of the existing equipment and systems. The issues of implementing coordinated control strategies include ensuring the reliability and security of the communication network, updating and maintaining the software and hardware components, and complying with the standards and regulations.

5 Evaluation criteria and tools

The evaluation of coordinated control strategies is essential to assess their effectiveness and efficiency in enhancing power system stability. The evaluation criteria can be based on technical, economic, or environmental indicators, such as damping ratio, voltage deviation, power loss, control cost, or carbon emission. The evaluation tools can be analytical, numerical, or experimental, depending on the complexity and accuracy of the models and methods. Some examples of evaluation tools are eigenvalue analysis, time-domain simulation, and hardware-in-the-loop testing.

7 Here’s what else to consider

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