Power Control Method Research Articles

A study of automatic output power control methods for stand-alone photovoltaic power generation systems

Abstract The conventional power generation system’s output power automatic control structure is generally unidirectional, and the control coverage is small, leading to the increase in the random error obtained in the final test. Therefore, the design and research of this article are proposed. According to the current control demand, the generation system shall be stabilized first, and the power compensation shall be calculated. The multi-step mode shall be adopted to improve the control coverage and design the multi-step automatic control structure. According to this, it is constructed, and the automatic control processing is realized using jump balance. The test results show that compared with the traditional DFIG-DRWT system power output automatic control method and the traditional three-phase asynchronous generation system power output automatic control method, the random error finally obtained by the designed independent photovoltaic power station output power automatic control method is relatively effective. This indicates that the application effect and coverage of the designed power automatic control method are high, that controllability has been significantly improved, and that control flexibility has also been strengthened.

An Optimization of RSRP on Wi-Fi and LTE-LAA Coexistence Networks

Over the last decade, mobile traffic has grown at an exponential rate, resulting in a scarcity and incompetent use of licensed spectrum by mobile network operators. Therefore, it is important to maintain effective communication to avoid disconnecting signals. The technique of regulating the power of a transmitter in order to improve the communication signal or entire quality of service is known as power control. It is mostly used to improve the performance of a communication device by controlling the transmission power. Power control, in most scenarios, allows the transmission or signal power to be scaled, leading to improved signal quality. On the other hand, power control methods are aimed at avoiding unnecessarily high-power transmission. Hence, particle swarm optimization (PSO) is a computational method for optimizing the reference signal received power (RSRP) by iteratively attempting to improve an unnecessarily high-power transmission solution in terms of a given quality measure. The objective of this research is to evaluate the optimum RSRP value and proposed ideal energy detection threshold for Wi-Fi and LTE-LAA in order to obtain fair coexistence between two networks. Thus, simulations for PSO are carried out using MATLAB software. Based on the results obtained, there are improvement in throughput for both networks after PSO implementation therefore, an ideal energy detection threshold is suitable to use in order to get fair coexistence between Wi-Fi and LTE-LAA networks. Consequently, all the results obtained will be used in following research work in order to evaluate user’s handover in various scenarios.

A Novel Point of Common Coupling Direct Power Control Method for Grid Integration of Renewable Energy Sources: Performance Evaluation among Power Quality Phenomena

Robust control mechanisms are needed in microgrids to ensure voltage source inverters (VSIs) effectively integrate renewable energy sources such as solar photovoltaic (PV) systems into the power network. Current control approaches often have limitations regarding velocity, stability, and robustness. The paper details a newly developed method named Point of Common Coupling Direct Power Control (PCC-DPC) for renewable energy systems connected to the grid. PCC-DPC is used to instantly control voltage at the point of common coupling (PCC) inside the microgrid as opposed to other conventional techniques. This leads to a simplified controller design that does not require complex Park transformations and phase-locked loop (PLL) systems, and has a lower computational burden and less power fluctuation in a stable manner. Moreover, this research critically examines power quality phenomena through comparing PCC-DPC with a Vector Current Controller (VCC). Simulations performed on an Opal Re-al-Time simulator showed improved tracking performance and overall system efficiency due to the PCC-DPC approach over others. These results demonstrate that it can effectively be used as one of the most suitable methods for integrating renewable energy into electricity grids, which is reliable in regards to changes in power grid dynamics.

Highly Nonlinear Light-Nucleus Interaction.

The interaction between light and atomic nuclei is typically weak and confined within the linear and perturbative regime, which limits the achievable nuclear excitation probability and impedes potential applications such as nuclear optical clocks, nuclear lasers, and nuclear energy storage. In this Letter we show that the interaction between hydrogenlike thorium-229 ions (^{229}Th^{89+}) and contemporary intense lasers propels light-nucleus interaction into a highly nonlinear and nonperturbative regime. This interaction unlocks remarkably efficient nuclear excitation: over 10% of the ^{229}Th nuclei can be excited to the isomeric state by a single femtosecond laser pulse. Moreover, the laser-driven ^{229}Th^{89+} ions radiate multiple wavelengths of light that are high-order harmonics of the laser frequency, akin to the high harmonic generation process from laser-driven atoms but with distinct characteristics. These results pioneer a new frontier for exploring light-matter interaction, furnish a powerful method for efficient control over atomic nuclei, and pave a new way of nuclear coherent light emission.

An optimal control method for transmission power of ISOP-DAB converter based on cooperative game

An optimal control method for transmission power of ISOP-DAB converter based on cooperative game

Voltage quality improvement method based on adaptive power control of photovoltaic inverter

Abstract With the increasing penetration rate of distributed photovoltaics in the distribution network in China, the energy pressure has been effectively alleviated. However, the voltage over-limit problem of its parallel outlets cannot be ignored. Therefore, this paper put forward a power control method with photovoltaic inverters which is adaptive. First, the principle of photovoltaic voltage overstepping the limit is analyzed, and second, an adaptive control tactic is brought up for the disturbance of the volatile load of photovoltaic output. Finally, combined with the analysis and verification of simulation examples, the results show that the proposed strategy can effectively improve the voltage quality of the grid and prove the effectiveness of the proposed strategy.

Multi-Stage Optimal Power Control Method for Distribution Network with Photovoltaic and Energy Storage Considering Grouping Cooperation

In view of the current problem of insufficient consideration being taken of the effect of voltage control and the adjustment cost in the voltage control strategy of distribution networks containing photovoltaic (PV) and energy storage (ES), a multi-stage optimization control method considering grouping collaboration is proposed. Firstly, the mechanism by which the access of the PV and ES to the distribution network impacts the node voltage is explored. Then, the unit regulation cost of a photovoltaic inverter and energy storage power is studied. On this basis, the voltage–cost sensitivity is proposed based on the traditional node power–node voltage sensitivity. According to the differences between each group of regulation resources, a multi-stage voltage over-run control strategy based on grouping cooperation is proposed. Finally, the improved 33-node model is taken as an example to verify the correctness and effectiveness of the proposed method.

Power stabilization control of wireless charging system based on LCL‐P compensation structure

AbstractTo enhance the stabilizing function and boost the output power of the inductive coupling power transfer (ICPT) system, a power stabilization control method based on LCL‐P resonance compensation for a wireless energy transmission system is proposed. “L” represents inductance, “C” represents capacitance, “LCL” refers to the primary‐side compensation structure, and “P” indicates that the secondary side is compensated in parallel . Firstly, this paper synthesizes the modeling principle of the gyrator equivalent model of the resonant circuit and coupled inductor, graphically analyzes the resonant compensation structure, and derives the circuit characteristics of the LCL‐P compensation structure. Then, this paper proposes an improved control strategy for the Maximum Power Point Tracking (MPPT) algorithm to dynamically track the output power and thus obtain the optimal operating point through frequency conversion. Lastly, using MATLAB/Simulink software to build the simulation model of the wireless charging system through parameter design, the impact of the conventional DC/DC power control method is contrasted with the algorithmic control suggested in this paper. The results demonstrate that: the device can realize power transfer of 2.7 KW level, the energy transfer efficiency reaches more than 90%, the inverter realizes soft‐switching operation, and the improved MPPT algorithmic control strategy proposed in this paper is utilized to achieve better closed‐loop control of the system. The excellent characteristics of the LCL‐P compensation structure in high‐power transmission applications, as well as the correctness and feasibility of the control algorithm proposed in this paper, are demonstrated through simulation and practical experiments. This is a significant step towards improving the wide‐range adaptation of the wireless charging system, which is based on the LCL‐P resonance compensation to the changes in the load and coupling.

An adaptive power control method for soft open points based on virtual impedance

The fluctuations in power output from distributed power sources are rapid and dramatic, causing voltage fluctuations in the distribution network that threaten the safety of electricity consumption. Soft open points (SOPs) can replace traditional contact switches and are expected to suppress voltage fluctuations. However, traditional power regulation methods based on the reference values are unable to address rapid and large voltage fluctuations. Therefore, this paper proposes an adaptive power control method for SOPs based on virtual impedance. The SOP is modeled as a series link of adjustable impedance and a voltage source. Then, the voltage difference component is used to calculate the reference for the DQ domain to regulate the power flow in real time automatically. By doing so, the proposed method can smooth the voltage fluctuations in the distribution network. Additionally, the virtual impedance is also optimized to minimize the power loss. Finally, the method is validated through simulation and experiments, demonstrating that this method can automatically regulate power and significantly reduce voltage fluctuations.

High Precision Model Predictive Power Control Method for Battery Energy-Stored Quasi Z-Source Inverter

High Precision Model Predictive Power Control Method for Battery Energy-Stored Quasi Z-Source Inverter

Leveraging Pumped Storage Power Plants for Innovative Stability Enhancement of Weakly Interconnected Power Systems

The hybrid AC/DC grid, based on a significant share of renewable energy sources, is gradually becoming an essential aspect of the modern energy system. The integration of intermittent renewable generators into contemporary energy systems is accompanied by the decommissioning of power plants containing synchronous generators. Consequently, this leads to a reduction in system inertia and an increase in the risk of stability disruption. The abrupt disconnection of the primary generator or power line can result in an unanticipated mismatch between power generation and consumption. This discrepancy can trigger substantial and swiftly evolving alterations in power distribution, angular speed, load flow, and the frequency of generators. The risks of an energy system collapse can be mitigated through automation, enabling rapid adjustments to generation and load capacities, as well as power flows, in the electrical network. This article justifies the utilisation of a power control method for high-voltage power line interconnections. The technology of hydro storage power plants and measurements of voltage phasors are employed. The potential for easing power flow restrictions and realising substantial economic benefits is supported by the results obtained using simplified dynamic model of the Baltic power system and Nord Pool electricity market model.

Two‐stage power control method of rotary power flow controller for flexible interconnection of distribution network

Two‐stage power control method of rotary power flow controller for flexible interconnection of distribution network

Information control model of distributed energy resources

Currently, there is a constant growth of distributed energy resources, it became necessary to integrate them into the power grid. However, the integration process must consider not only the control parameters of the distributed energy resource but also the parallel operation of several such resources, the parameters of the power system as a whole. At the highest level of control, it is also necessary to consider the economic indicators formed by the energy market. Special devices – controlled inverters – can be effectively used for integration. The most difficult task is choosing a control system for controlled inverters. There are many different control systems such as Proportional-Integral, Deadbeat controllers, etc. The purpose of this paper is to build an information model for controlling distributed power resources. The current control method was used to control active and reactive power. The advantage of current control is resistance to variations in the parameters of the inverter and the external grid, excellent dynamic performance, and higher control accuracy. The proposed approach for building an automatic control system using the Internal model control strategy and taking into account restrictions on the control variable. The advantages of a system with an Internal model control controller compared to a conventional Proportional-Integral controller are the use of a powerful control method based on the object model, the ability to influence the roughness of the system with a separate setting parameter, increased speed with almost complete absence of over-regulation, simplified setup procedure. Such a system is proposed for use in facilities with strict requirements to minimize over-regulation and the speed of working out disturbances and tasks. The PSCAD software app was used to model the work results.

Research on load-resistant enhancement control optimization of composite energy power supply system based on deep reinforcement learning

Abstract To solve the problem of insufficient inertia in the power electronics components under the development trend of power electronics in the transmission system of heavy-duty electric vehicles, combined with the composite energy power supply mode and control method, voltage-based feedback channels and virtual capacitor branches are designed for both engine-generator sets and DCDC control loops. These innovations compensate for system inertia and introduce a TD3 deep reinforcement learning-based adaptive regulation component to manage electrical systems in response to DC voltage fluctuations. This approach enhances the stability of the entire system in the face of load disturbances. Strategy validations demonstrate that this method ensures stable system operation, significantly mitigates DC voltage fluctuations during sudden load changes and is highly adaptable without relying on system models.

Novel resistance control scheme for mitigating current sharing mismatches in parallel dual active bridge converters for DC fast charging stations

Abstract Dual Active Bridge (DAB) converters have gained popularity in electric vehicle charging stations due to their high efficiency and electrical isolation. As the demand for high-powered devices and large-capacity energy storage systems grows, charging systems that integrate multiple interconnected DAB modules are emerging as a promising solution. However, prolonged operation of these modules at high power levels can cause parameter deviations from the initial DAB circuit, resulting in power variations between modules. To overcome parameter deviations, this study presents an enhanced power control approach based on output resistance adjustment, intending to achieve consistent output capacity for multiple DAB modules. In the proposed enhanced power control method, the output resistance of the DAB module is considered to be controllable, and the current-sharing mismatches among DAB modules are fed back to tune the converter output resistance for mitigating current mismatches between modules. Thanks to the proposed control method, each DAB module can operate autonomously and balance the charging current between modules. When one DAB module is suddenly cut out of the system, the other DAB modules still maintain their stability with fully guaranteed load capacity. To demonstrate the feasibility of the enhanced control approach, the small signal model of the DAB system with three modules is derived together with its frequency-amplitude diagram. Then, the effect of virtual resistance on current balancing is comprehensively tested, and the proper control signal with virtual resistance is added to the DAB voltage control loop. The simulation results have demonstrated the reliability of the proposed control method with the ability to balance the charging current between modules and stabilize the system when a single DAB module fails.

Parameter‐free predictive control with flexibility in power adjustment for grid‐connected converters under unbalanced grid conditions

AbstractThis paper introduces a novel finite control set predictive direct power control method for grid‐connected converters without cost function evaluations. Unlike conventional predictive direct power control, since the proposed method does not use the model parameters, their uncertainties do not cause prediction error and inappropriate voltage vector selection. The method employs a new form of voltage vector selection based on the slopes of active and reactive powers. The slopes are predicted in a manner with a low sensitivity to sampling noise, without updating a look‐up table, and recursive methods. Hence, there are no stagnation and convergence issues. Also, the proposed method avoids startup problems caused by data‐lacking due to directly regulating the active and reactive power by a switching logic. Flexible power oscillations control with balanced sinusoidal grid currents without any signal sequence extraction can also be achieved under this method in unbalanced grid conditions. The proposed method is assessed by both simulation and experimental studies, and its performance is compared with existing robust combined and model predictive control methods. The outcomes highlight the influence of the proposed approach and establish its superiority over the other considered methods.

Shunt Active Power Filters in Three-Phase, Three-Wire Systems: A Topical Review

The increasingly extensive use of non-linear loads, mostly including static power converters, in large industry, commercial, and domestic applications, as well as the spread of renewable energy sources in distribution-generated units, make the use of the most efficient power quality improvement systems a current concern. The use of active power filters proved to be the most advanced solution with the best compensation performance for harmonics, reactive power, and load unbalance. Thus, issues related to improving the power quality through active power filters are very topical and addressed by many researchers. This paper presents a topical review on the shunt active power filters in three-phase, three-wire systems. The power circuit and configurations of shunt active filtering systems are considered, including the multilevel topologies and use of advanced power semiconductor devices with lower switching losses and higher switching frequencies. Several compensation strategies, reference current generation methods, current control techniques, and DC-voltage control are pointed out and discussed. The direct power control method is also discussed. New advanced control methods that have better performance than conventional ones and gained attention in the recent literature are highlighted. The current state of renewable energy sources integration with shunt active power filters is analyzed. Concerns regarding the optimum placement and sizing of the active power filters in a given power network to reduce the investment costs are also presented. Trends and future developments are discussed at the end of this paper. For a rigorous substantiation, more than 250 publications on this topic, most of them very recent, constitute the basis of bibliographic references and can assist readers who are interested to explore the subject in greater detail.

Improving Power Quality in a Grid-Connected Hybrid Power System through the Implementation of a Fuzzy Logic Controller

The examination of modeling and designing grid-connected hybrid power systems with efficient control strategies is the focus of this study. Integration of wind and photovoltaic systems into the ac-bus bar system is a common practice in enhancing operational performance. Utilization of Matlab Simulink software is employed for the design of this hybrid system, incorporating efficient MPPT control algorithms to optimize power generation from solar and wind sources under varying climatic conditions. Analysis of the maximum power point tracking mechanism and control methods of the hybrid power system is conducted, particularly in response to changes in weather conditions such as wind speed and solar radiation. Maintaining grid voltages and Unity Power Factor (UPF) while feeding currents into the grid is essential for the hybrid system. The employment of Proportional Integral (PI) control instead of Fuzzy Logic Controller (FLC) in the voltage-oriented control approach is explored to enhance power quality.

Analysis of interval type-2 fuzzy controller based interleaved sepic PFC converter for PQ enhancement in power solutions

The Power solutions have become indispensable for all the devices in recent years with an appropriate power conversion circuitries and control methods to ensure good dynamic response, improved stability, reliability and efficiency. The main intent of this article is to impart the designing of interval type-2 fuzzy logic controller (IT2FLC) based interleaved Sepic power factor correction (PFC) converter. This work also involves the careful design of the robust controller with enhanced precision and good power quality (PQ) performance at the AC mains. In addition, the development of IT2FLC based power solution improves the overall power conversion with stabilized output in the perspective of its quick rise time, less overshoot and fast settling time in comparison to other traditional controllers. Further, the uncertainties and issues associated with the conventional proportional integral (PI) and fuzzy logic controllers (FLCs) are handled effectively by the proposed IT2FLC controller. Moreover, this preferred converter is modeled with an internal parasitics and its performances are evaluated and compared with other conventional Zeigler Nicholas (ZN) tuned PI controller and FLC by dint of MATLAB/Simulink platform. Finally, the experimental test bench set up of 250 W, 48 V power circuitry is devised and the test outcomes confirm the excellent transient behavior and PQ performances of the modeled power solution.

Research on Maximum Power Control of Direct-Drive Wave Power Generation Device Based on BP Neural Network PID Method

Ocean wave energy is a new type of clean energy. To improve the power generation and wave energy conversion efficiency of the direct-drive wave power generation system, by addressing the issue of large output errors and poor system stability commonly associated with the currently used PID (proportional, integral, and derivative) control methods, this paper proposes a maximum power control method based on BP (back propagation) neural network PID control. Combined with Kalman filtering, this method not only achieves maximum power tracking but also reduces output ripple and tracking error, thereby enhancing the system’s control quality. This study uses a permanent magnet linear generator as the power generation device, establishes a system dynamics model, and predicts the main frequency of irregular waves through the Fast Fourier Transform method. It designs a desired current tracking curve that meets the maximum power strategy. On this basis, a comparative analysis of the control accuracy and stability of three control methods is conducted. The simulation results show that the BP neural network PID control method improves power generation and exhibits better accuracy and stability.