This paper presents a single-phase AC-AC matrix converter which is able to compensate voltage harmonics and voltage regulation at critical loads terminals. The converter is composed with the minimum number of switching devices and is controlled using a non-linear law based on passivity achieving a high reliability and robustness during transient and steady state operation condition. The proposed scheme has the advantage that energy storage devices are not required. The converter is connected between the AC mains and the load through a series transformer. A DSP and a FPGA are used to program the passivity-based controller and to determine the state of the switches respectively. In this case, the converter is able to compensate up to 25% voltage sags and 50% voltage swells and to eliminate up to the fifteenth harmonic component. The tested system presents a fast time response and the stabilization time of the load voltage is less than 1 ms. Analysis and modeling as well as simulation and experimental results of a 5 kVA, 127 V, 60 Hz experimental setup are analyzed and presented

This paper introduces a real-time digital twin adaptive remedial action scheme for the prevention of voltage collapse and the enhancement of stability and voltage performance. The scheme calculates the optimal load shedding amount in two stages, providing an effective solution to potential stability and voltage issues prior to implementation in the real power system. Unlike traditional approaches, which rely on offline studies and are labor intensive, the proposed scheme integrates a digital twin of the power grid to online tracing the power-voltage characteristic curves for real-time adjustments. The virtual model enables the real-time monitoring of voltage stability margin, facilitating virtual actions in the digital twin to adjust the load shedding amounts if necessary to reach safety conditions. A weighted least squares-based state estimator serves as a backup against measurement loss between the real power system and the digital twin. In addition, to ensure the desired voltage recovery, the remedial action scheme is based on the FIDVR criteria to recalculate load shedding amounts dynamically, based on voltage deviations, thus enabling the swift restoration of safe voltages and addressing transient behavior issues. The effectiveness of this remedial action scheme is demonstrated through its application to the IEEE 39 bus New England power system. Rigorous hardware-in-the-loop tests confirm its viability, showing significant performance enhancement.

The last thirty years have brought an evolution of electrical power systems. The integration of renewable energy and energy storage, dynamic loads, or distributed resources based on power electronics, including communications systems and protocols, is usual. Fortunately, technological advances have also brought tools to face the complex field of electrical component integration to the power system, such as the real-time power-hardware-in-the-loop (PHIL) simulation. This paper argues why PHIL simulation is a mighty tool for addressing intelligent design, modeling, and computing methods to address complex power systems. Nevertheless, any promising technology can be misunderstood, reducing its positive effect. This article uses two inverters connected to a microgrid to develop the steps from conceptualizing an idea to a PHIL simulation, highlighting the merits, drawbacks, and lessons learned. Two perspectives are developed. First, the multiple, even complex, details required for furnishing a PHIL simulation are described. Second, reflections on how PHIL simulations enhance the scientific impact of the research compared to offline simulations or scale prototypes are made, enabling the transition from academic to applied research to attend to the challenges of modern power systems. The successful results of the microgrid PHIL simulation are shown to prove the merits of this approach.

This paper deals with a battery energy storage system (BESS) in only one of its multiple operating modes, that is when the BESS is charging the battery bank and with the focus on the control scheme design for the BESS input stage, which is a three-phase LCL-filter PWM rectifier. The rectifier’s main requirements comprise output voltage regulation, power factor control, and low input current harmonic distortion, even in the presence of input voltage variations. Typically, these objectives are modeled by using a dq model with its corresponding two-loop controller architecture, including an outer voltage loop and a current internal loop. This paper outlines an alternative approach to tackle the problem by using not only an input–output map linearization controller, with the aim of a single-loop current control, but also by avoiding the dq modeling. In this case, the voltage is indirectly controlled by computing the current references based on the converter power balance. The mathematical model of the three-phase LCL-filter PWM rectifier is defined based on the delta connection of the filter, which accomplishes the requirements of a 100 kW BESS module. Extensive simulation results are included to confirm the performance of the proposed closed-loop control in practical applications.

Voltage sags are one of the most important power quality problems, affecting industrial and commercial customers. Industrial processes are particularly sensitive to relatively minor voltage sags. Utilities have been improved their fault-recovery capabilities, however it is still impossible to eliminate faults in the systems. Therefore, customers will have to improve the ride-through capability of the system equipment in their facilities. This paper presents the application of the single-phase DQ theory as a simple method to detect voltage sags in the AC mains obtaining the voltage peak value. This information can be used to achieve, by analytical manipulations, the input current adjusting during the sag, in order to maintain the load power constant. Applying the above considerations to a single-phase five-level PWM rectifier both objectives power factor correction in steady state and voltage sag compensation in transient state are gotten. Simulation and experimental results have been carried out in a 1 kVA, single-phase power converter