This paper presents the topology and control of a photovoltaic inverter with an internal battery storage system in conjunction with droop control designed to perform ancillary services such as frequency and reactive power support (voltage regulation), active power dispatch through a proposal to control the charging and discharging of batteries and harmonic current compensation (active filter) in a microgrid connected to an IEEE 13-bus system. The converter in question consists of two stages, a 3-level NPC DC/AC converter and Boost and Buck-Boost DC/DC converters. The system in question is capable of helping to dampen frequency oscillations, as well as regulating the PCC charging curve by charging or discharging the battery bank. In addition, the proposed system is capable of supplying reactive power to the grid on a permanent basis, thus helping with voltage control. It is also capable of compensating for harmonic currents caused by non-linear loads connected to the PCC. In this context, we can see the multifunctionality of the photovoltaic inverter in helping to mitigate disturbances associated with the power quality, with the differential of charge and discharge control to preserve the useful life of the energy storage system. For this study, Matlab/Simulink software was used to implement and validate the proposed topology and control systems. In the computer simulations carried out, satisfactory results were obtained in relation to the execution of the ancillary services mentioned above, thus demonstrating the viability of the proposed strategy.

The widespread use of static converters for controlling electrical machines and the concern for electrical power quality in industrial environments provide an opportunity for utilizing these devices to enhance the power quality. In this context, this work presents a back-to-back converter model for driving induction machines. The converter is designed to correct the power factor of the point common coupling (PCC), compensate for harmonic currents (acting as an active filter), and withstand voltage sags. The necessary control system models were developed, and an alternative implementation for these functions in the converter was proposed. The results demonstrate the technical feasibility of this solution, as the converter operated within its nominal limits by compensating for harmonics and reactive power. Moreover, the equipment showed resilience to severe voltage sags. The contribution of this paper focuses on the multifunctionality of the frequency converter for driving induction machines. It emphasizes the advantage of the inverter in improving power quality in industrial environments through reactive power compensation and harmonic current compensation, thus functioning as an active power filter. Additionally, it is worth highlighting its ability to handle voltage dips. In this regard, this paper contributes by providing an operational strategy for driving the induction machine during such transients.

This work aims to present a control proposal for dual-stage photovoltaic inverters to supply reactive power aiming at voltage stability in steady state and during short-term momentary sags. For this, a study was carried out on the control and modeling techniques of the DC/DC and DC/AC converters of the photovoltaic generating unit, in addition, a modified MPPT algorithm was implemented that, together with an AVR system, will manage the power in transient regime, decreasing the active power and increasing the reactive power in order to restore the voltage level in the grid. In addition, the dynamic saturation of the current in the switches and the power of the inverter was carried out so that they operate within their nominal limits. The entire system was executed in a computational environment on the Matlab/Simulink platform. Satisfactory results were obtained regarding the supply of reactive power and assistance in voltage restoration carried out by distributed generation during momentary sag.

Maintaining a constant frequency is vital for grid stability and reliability, especially during dynamic changes in load and generation, which are caused by the increasing incorporation of renewable intermittent energy sources such as solar and wind power. These energy sources decrease the system’s inertia, which compromises the primary frequency regulation, a process historically sustained by the speed regulators of conventional synchronous generators. In this study, to mitigate this issue, we investigate a battery energy storage system (BESS) operating with virtual synchronous machine (VSM) control to provide ancillary services of primary frequency control. A multilevel cascade H-bridge static converter with eleven levels is controlled to emulate the dynamic behavior of a conventional synchronous machine, allowing primary frequency control support. The case studies are evaluated using Matlab/Simulink R2024a software and tested under contingency scenarios involving load rejection and step-load insertion within an isolated power grid comprising other synchronous machines, alongside an analysis of the BESS-controlled power dispatch. Our simulation results demonstrate that the energy storage system, operating under a virtual synchronous machine (VSM) strategy, effectively emulates the dynamic behavior of a conventional synchronous generator, enabling controlled active and reactive power dispatch. Furthermore, the proposed control strategy provides virtual inertia support, mitigating the Rate of Change of Frequency (RoCoF) following disturbances, improves the damping of frequency oscillations, and ensures a smoother frequency recovery after load variations. These findings indicate that the proposed BESS can provide effective primary frequency control support in power systems characterized by a high penetration of converter-interfaced renewable energy sources. Nonetheless, further investigations into the influence of VSM parameters on the system’s dynamic response are needed to further optimize the performance of the proposed solution.

This paper aims to present the computational implementation of a photovoltaic generating unit integrated with an energy storage system using Lithium-ion batteries connected on grid. The system under analysis aims to control the power factor at the PCC (Point of Common Coupling), as well as regulate the load demand curve. For this, the control of the inverter and the dc/dc converters of the photovoltaic plant and the battery bank in a decoupled manner was implemented, thus enabling the individual performance of each device. For charging and discharging the battery bank, a hysteresis control system based on the constant current/voltage method and the constant current method, respectively, was used. The entire implementation was carried out in Matlab/Simulink software. The obtained results demonstrate the technical viability of the system in order to control the power factor in the PCC and regulate its load curve.