In recent years, microgrids have gained attention as a technological alternative to face the energy transition and universal sustainable electrification challenges. Its versatility to operate in grid-connected or isolated mode allows adapting the microgrid concept to several urban and rural applications. This has motivated industry and academia to develop experimental projects, prototypes, and application pilots worldwide. This paper presents a review of some laboratories and test systems of microgrids in Latin America. A brief description of the general information of each microgrid and its main characteristics and components are presented. Also, a discussion of the main advances in distributed generation in Latin America is included

Distributed power generation plays a critical role in the stability and reliability of modern power systems. Due to the rapid growth of renewable energy generation, the requirements of the transmission and distribution system operators are becoming more stringent. Among these requirements, one of the most important is the Low-Voltage Ride-Through (LVRT) capability, which demands that the inverters remain connected to the grid and provide support during voltage sags. For this purpose, flexible current control algorithms stand out because they can manage unbalanced voltages and simultaneously achieve other control objectives. With the aim of presenting a concrete document focused on describing fundamental principles and discussing common design guidelines, this paper presents an overview of flexible current control strategies applied to LVRT capability. The operation features and design aspects of experiences reported in the literature are reviewed. Moreover, the paper proposes a general methodology to design LVRT flexible current control algorithms. Finally, current and future trends are discussed.

This paper presents the design and implementation of a prototype based on a SEPIC (Single-Ended Primary Inductance Converter) used to measure the characteristic curves of photovoltaic (PV) panels. The SEPIC is controlled to emulate a variable resistance at the output of the PV panel in order to obtain a set of values (voltages and currents) for different operating points at the output of the panel. The set of voltages and currents are stored and sent to a computer in order to display the characteristic curves in real-time. The performance of the prototype is firstly evaluated though simulations in PSIM and subsequently by experimental results. The results show the outstanding performance of the SEPIC converter and its suitable use for this kind of applications due to its low input current ripple and its operation as a buck-boost converter. The resulting prototype allows the characterization of PV panels up to 500 W.

Multi-functional photovoltaic (PV) inverters incorporate ancillary services to enhance power quality and mitigate stability issues in distribution networks. These next-generation PV inverters will achieve a higher utilization of the inverter’s rated capacity, improving the cost-effectiveness of PV technology. However, the power required to perform ancillary services, such as load compensation capabilities, could exceed the inverter’s capacity, risking the components’ integrity. Therefore, multi-functional control algorithms must limit the power capacity according to the system’s nominal currents. Despite this, most control proposals do not address this issue when load balancing capabilities are included for PV inverter control. This paper proposes a flexible control strategy for three-phase multi-functional PV inverters, considering load balancing functionalities while keeping the inverter currents within safe operating limits. The proposal introduces two control parameters whose variation results in different load compensation capabilities. These parameters can be adapted dynamically according to the inverter rated capacity not used for active power injection and the load compensation requirements. Additionally, a control algorithm is proposed to limit the inverter current according to the nominal values supported by the device. This algorithm also allows setting compensation objectives following a priority scheme in which the injection of the PV active power is prioritized over the load compensation functionalities. Reactive power compensation and load balancing functionalities are also considered at a lower level of hierarchical priority. The proposal was evaluated through experimental tests on a multi-functional PV inverter prototype under various operational conditions. The experimental results show an excellent control strategy performance, achieving the control objectives under unbalanced load conditions.

This paper presents a comparative analysis between different control techniques for voltage source inverters (VSI), based on shunt active power filter. The main purpose is to study the behaviour of each technique for a given reference current. In addition, some simulations are presented in ATP. The reference signals tracking for different current control techniques and different converter topologies is shown by these simulations. The control techniques are compared based on some criteria such as maximum steady state error and effective error of the current generated by the inverter.