This paper proposes an interoperable energy management system (EMS) for grid-connected HESSs, enabling the provision of ancillary services to the grid. Power systems are evolving towards a more renewable and decentralised structure, where energy storage systems (ESS) have emerged as a key energy asset to ensure the power balance and the system stability. In this context, hybrid ESSs (HESS) are an interesting solution because they take advantage of the dynamic properties of different ESS technologies. The proposed EMS structure ensures an adequate internal power allocation between the different ESS packs even when operating at power or state of charge limits. The proposed structure can be easily adapted and combined with specific control functions to provide a wide variety of grid services. Moreover, a power dispatch algorithm is included to allocate the power between the parallel power converters to maximise the system efficiency. The results from two representative use cases demonstrate the effectiveness of the proposed EMS to determine the operating setpoints of a modular HESS and to provide different grid-oriented services.

The growing penetration of renewable sources, mainly interfacing the grid via power electronics, represents a new challenge for frequency stabilization in power systems. As conventional generation is replaced by non-synchronous sources, the amount of inertia available in the network decreases. Moreover, the associated controls of synchronous machines (PSS, AVR, governor) are also replaced by devices that typically do not modify their behaviour to frequency or voltage changes. As a possible solution to these new conditions in the grid, new functionality has been proposed in the context of the ABS4TSO (Advanced Balancing Services for Transmission System Operators) project. In this paper we present an automatic hardware-in-the-loop (HiL) testing procedure that validates novel functionality aiming at frequency stability issues arising nowadays in low inertia grids. The existing HiL setup is verified against the expected response (modelled in a pure simulation environment) and validated against laboratory tests. Such a setup allows us to properly define the specification of novel ancillary services based on the real behaviour of non-synchronous sources.

Wide deployment of wireless sensor and actuator networks in cyber-physical systems requires systematic design tools to enable dynamic tradeoff of network resources and control performance. In this paper, we consider three recently proposed aperiodic control algorithms which have the potential to address this problem. By showing how these controllers can be implemented over the IEEE 802.15.4 standard, a practical wireless control system architecture with guaranteed closed-loop performance is detailed. Event-based predictive and hybrid sensor and actuator communication schemes are compared with respect to their capabilities and implementation complexity. A two double-tank laboratory experimental setup, mimicking some typical industrial process control loops, is used to demonstrate the applicability of the proposed approach. Experimental results show how the sensor communication adapts to the changing demands of the control loops and the network resources, allowing for lower energy consumption and efficient bandwidth utilization.

Software implementations of controllers for physical subsystems form the core of many modern safety-critical systems such as aircraft flight control and automotive engine control. A fundamental property of such implementations is stability, the guarantee that the physical plant converges to a desired behavior under the actions of the controller. We present a methodology and a tool to perform automated static analysis of embedded controller code for stability of the controlled physical system.

A vast majority of control systems require the use of networks for the communication between the different agents: sensors, controllers, and actuators. The existing paradigm regards the messages, between sensors and controllers and between controllers and actuators, as periodic. Although this strategy facilitates the analysis and implementation, it leads to a conservative usage of the communication bandwidth. Based on previous work by the authors, an aperiodic strategy is proposed in this paper for the dynamic allocation of bandwidth according to the current state of the plants and the available resources. The case of control loops closed over Controller Area Networks (CANs) is discussed in detail and illustrated on a train car.