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The increased deployment of renewable energy in power networks makes it necessary to maintain equilibrium between generation and demand due to their intermittent behavior. However, numerous strategies, including load shedding, load shifting, and energy storage technologies, can also be utilized to meet the increasing demand for load. This article proposes a course of action based on demand response (DR), which prioritizes demand-side monitoring, within the automatic generation control paradigm. A rule-based fractional control scheme with a two-degree-of-freedom topology is developed for the frequency regulation of a deregulated identical hybrid two-area power system in a DR framework. A quasi-oppositional Harris Hawks optimization is investigated along with the proposed controller to tune the controller coefficients adaptively. A thorough examination of the preferred system, including the DR approach, significantly enhances the frequency regulation services and offers a significant improvement over conventional frequency regulation in terms of system dynamics. Research is further enhanced by considering natural random time delay in the DR framework to analyze the dynamic behavior of the system. An experimental evaluation using the OPAL-RT 5700 is presented to verify the practicality of the suggested technique for intermittent sources and loads.

Harbor cranes particularly use induction motors (IM) as the main prime mover, which are powered by the grid through the machine side converter (MSC) followed by a grid side converter (GSC). To supply power to multiple cranes in parallel, double-circuit lines are utilized. Failure of a single feeder causes voltage instability in the load bus. To analyze the voltage stability on the load bus, this article proposes a comprehensive model of the GSC while simplifying the MSC as constant power loads (CPL). When used to describe the CPL behavior of the connected IM load, the proposed modeling shows how input admittance behaves as a negative incremental, growing voltage instability on the load bus. This study uses Nyquist-based stability analyzes to address the voltage stability issue caused by a double-circuit line failure and a negative incremental input admittance. The feasibility of creating a phase-locked loop (PLL) for such grid disturbances is investigated. The possibility of installing a static VAR compensator (SVC) with a battery energy storage system (BESS) on the load bus is explored if there is no equilibrium point in the $P_{e}$ - $\delta$ curves during line failure.

In this article, we propose an improved high-boost-gain split-source inverter (SSI) for renewable energy generation. The proposed inverter retains the features of the existing SSIs, such as single-stage boost inversion with a reduced number of passive components and elimination of the inverse modulation–duty relationship constraint of the impedance-source inverters. It also provides additional features that include higher boost inversion ability than existing SSIs to connect low-voltage renewable energy sources to the grid, no voltage-source short-circuit issue, which increases the robustness of the proposed inverter and pulsewidth modulation dead times can be relieved, and the negative input dc-terminal and ac-neutral are electrically connected in the proposed inverter, resulting in a constant common-mode voltage and elimination of leakage ground currents for grid-interfaced PV power systems. A detailed circuit operation and analysis is provided, and experiments are performed on a 400-VA prototype inverter to confirm the working of the proposed topology.

Inverter topologies for integrating a rooftop photovoltaic (PV) unit into a microgrid are becoming increasingly complex. This paper proposes a high-voltage boosting transformerless inverter (HVBTI) topology for enhancing such applications. The coupled inductor-based high voltage gain feature of the HVBTI configuration allows power to be delivered into the grid from a lower voltage PV source without using higher duties. In addition, HVBTI suppresses leakage current as the common connection shared between the $-ve$ terminal of the PV source and the grid neutral point. In comparison to existing topologies, the HVBTI topology uses a compact pulse width modulation strategy to control only six controllable switching devices. Again, using lower-rated switching devices is more cost-effective while increasing reliability and efficiency. In a laboratory prototype of a 1 kVA grid integrated system, the proposed HVBTI configuration is validated, and the maximum efficiency of the HVBTI is estimated at approximately 95$\%$.

The power transfer capacity of transmission lines is limited by the stability of the power system. In addition, the dynamics of photovoltaic (PV) integration through the grid-following inverter (GFI) affects the stability limits, which are not well studied in the literature. This article, therefore, focuses on the stability-constrained power transfer capabilities of transmission lines with single-phase PV-GFI integration. An adaptive tuning method is proposed based on the Lyapunov function (LF) analysis that increases the power transfer capability limit. Outer and inner control loop parameters are considered as candidates for the proposed method. The proposed tuning law is not affected by the active and reactive power requirements, low-voltage or overvoltage ride-through, network impedance, and load changes. In addition, an active damping method using a capacitor voltage feedback loop is proposed to eliminate the effect of resonance with improved power quality. The proposed method is validated through simulation and experimental verification for various test scenarios, such as sudden changes in solar irradiance, dynamic load changes, network parameter variation, and grid voltage sag–swell conditions. The proposed tuning method achieves an enhanced power transfer capacity limit compared with the existing method.