Power Injection Research Articles

Tungsten impurity reduction by ICRH in a high power injection and high performance H-mode discharge on EAST

Abstract The decrease in tungsten (W) content with the higher ion cyclotron resonance heating (ICRH) power is observed and explained for the first time in a high power injection (Pinj>10MW), high performance (βN~2, βP~2.8, ne/nGW~80%, fBS~60%) H-mode discharge on experimental advanced superconducting tokamak (EAST). Unlike the previous phenomenon of electron cyclotron resonance heating (ECRH) core W control (Shengyu Shi et al 2022 Nucl. Fusion 62 066031), there is a slight change in the background plasma temperature when higher ICRH is applied, but the toroidal rotational velocity decreases by ~10km/s. Under this condition, the intensity of W unresolved transition array (W-UTA) spectral structure in the region of 45-70 Å (which is composed of W27+-W45+ line emissions) and W44+ density through spectroscopy in the Extreme Ultraviolet (EUV) region decreases markedly. In addition, the poloidal asymmetry of radiation distribution from the tomographic inversions of Soft X-Ray (SXR) emission is reduced obviously. Theoretical modeling results indicate that the reduction in toroidal rotation leads to less W poloidal asymmetry and neoclassical pinch, which is more efficient in alleviating the core W accumulation than the improvement of isotropic hydrogen (H) minority temperature. The effects of isotropic and anisotropic H minority from ICRH on W transport are compared in the simulation lastly.

A large synthetic dataset for machine learning applications in power transmission grids

With the ongoing energy transition, power grids are evolving fast. They operate more and more often close to their technical limit, under more and more volatile conditions. Fast, essentially real-time computational approaches to evaluate their operational safety, stability and reliability are therefore highly desirable. Machine Learning methods have been advocated to solve this challenge, however they are heavy consumers of training and testing data, while historical operational data for real-world power grids are hard if not impossible to access. This manuscript presents a large synthetic dataset of power injections in an electric transmission grid model of continental Europe, and describes the algorithm developed for its generation. The method allows one to generate arbitrarily large time series from the knowledge of the grid – the admittance of its lines as well as the location, type and capacity of its power generators – and aggregated power consumption data, such as the national load data given by ENTSO-E. The obtained datasets are statistically validated against real-world data.

Grid-Forming: A Control Approach to Go Further Offshore?

Offshore wind farms are increasingly being commissioned farther from shore, and high voltage alternating current (HVAC) transmission systems are preferred because of their maturity and reliability. However, as cable length increases, ensuring system stability becomes more challenging, making it essential to investigate shunt reactor compensation configurations and converter control strategies. This study examines three different shunt reactor compensation arrangements and two control strategies, grid-forming (GFM) and grid-following (GFL), across three cable lengths (80 km, 120 km, and 150 km). The systems were evaluated based on small-signal stability using disk margins for different active power operating points, and later for different short-circuit ratios (SCR) and X/R. The results demonstrate that the GFM is preferable for longer cables and enhanced stability. The most robust configuration includes a shunt reactor placed in the mid-cable with additional reactors at both ends of the cable, followed by an arrangement with reactors at the beginning and end. The GFM converter control maintained stability across all operating points, cable lengths, and configurations, whereas the stability of the GFL unit was highly dependent on active power injection and struggled under weaker grid conditions. Thus, for longer HVAC cables, it is necessary to employ GFM control units, and it is recommended to use shunt reactors at the cable start and end, as well as at mid-cable, for optimal stability.

ENHANCING VOLTAGE STABILITY AND ENERGY OUTPUT OF PLTM SALIDO IN THE PLN DISTRIBUTION NETWORK

Distributed generation (DG) integration in PLN’s extended distribution network often encounters voltage instability issues due to high voltage drops. These challenges restrict power delivery and can lead to disconnection, particularly during peak load conditions. This study investigates methods to enhance voltage stability and optimize the energy output of PLTM Salido. Using ETAP Power Station software, various operational schemes were simulated to address the problem of low terminal voltage. The study focused on the impact of reactive power injection and governor settings optimization to maintain generator performance under high demand. Results indicate that reactive power injection significantly improves terminal voltage, ensuring continuous power delivery. Adding a third generator unit further increased energy supply capacity, leveraging the full potential of available hydropower. The optimized operation of PLTM Salido with two generators increased daily energy output by 32.2%, while introducing a third generator boosted energy delivery by 107%. This research highlights the critical role of reactive power management and system configuration in enhancing the performance of small-scale hydropower plants in rural distribution networks.

EV and PV penetration impact on grid with conservative voltage regulation and reactive voltage compensation.

As global interest grows in renewable energy sources, the impact of combined Electric Vehicle (EV) and PhotoVoltaic (PV) penetration on the power grid stability requires renewed attention, to incorporate new technologies to maintain the power quality under operational constraints. Energy-saving techniques such as Conservation Voltage Reduction (CVR) allow the power utilities to transmit voltage at a lower operation limit, increasing the generation margin to absorb the peak load demands. Increased reverse PV penetration results in grid overvoltage while EV charging absorbs the reactive power causing grid instability. Both overvoltage and loss of reactive power in the grid can be reduced by using CVR and reactive power injection techniques. A power electronic secondary var controller (SVC) can dynamically inject reactive power into selected grid buses. This work compares the voltage stability of an IEEE 33 bus system operating with and without CVR. The simulation studies analyzed the effects of EV penetration level, and PV hosting capacity with SVC compensation paired with and without conservation voltage reduction technique. The analysis results demonstrate that tandem usage of CVR and SVC maintains the grid voltage under operational limits, meets load and EV demand, and increases power efficiency and PV penetration.

Enhanced Power Injection Strategies for Voltage Sag Minimization: Integrating the Maximum Apparent Power of the Converter and the Thévenin Equivalent

Enhanced Power Injection Strategies for Voltage Sag Minimization: Integrating the Maximum Apparent Power of the Converter and the Thévenin Equivalent

Design and Implementation of solar Grid-connected inverter with the approach of maximum power injection and THD reduction in partial shading conditions using cascaded repetitive controller

Design and Implementation of solar Grid-connected inverter with the approach of maximum power injection and THD reduction in partial shading conditions using cascaded repetitive controller

Optimal active and reactive power dispatch in the presence of wind farms using voltage indicators and metaheuristic methods

Wind power plants penetration into power grids has grown considerably due to the fact of being cheap and clean. As a result, many countries require that the wind turbines must be capable of offering ancillary services such as reactive power control and voltage regulation. Furthermore, some voltage stability indices rely on both reactive and active power; consequently, it is useful to take also into account the active power during the planning stage so as to fulfil the load requirement and to enhance the voltage stability. The present study intends to present an optimization algorithm permitting to diminish the electrical losses and enhance the voltage profile by getting the fittest allocation of active power production of traditional generators and wind power plants. Besides, wind farms reactive power injection is determined. To verify the proposed algorithm, a 40 MW wind farm (WF) made up of doubly fed induction generator (DFIG) and the 14 IEEE bus system are used. In the case study, three different metaheuristic methods are used to resolve the objective function. Finally, the simulation results are reported.

Research and impact on the target injection power smoothing algorithm in aircraft system-level HIRF testing

Research and impact on the target injection power smoothing algorithm in aircraft system-level HIRF testing

The Effectiveness Of Red Power Injection On The Hematological Profile Of Layer Chicken (Gallus domesticus)

Layer chickens are one of the most popular types of mass-produced laying hens in Indonesia. One way to keep laying hens healthy is to fulfill their micronutrient and vitamin needs. Giving vitamins such as Red power injection is very good for broilers, layers and fighters. Red power injection contains extra liver which contains vitamin B12, folic acid, and iron which are useful for maintaining chicken health. In this study, researchers wanted to test the effectiveness of Red power injection supplements in increasing blood in laying hens (Gallus domesticus). The study used an experimental research method using two treatments for one day. Four laying hens (Gallus domesticus) that have been provided are divided into two treatment groups with a dose of group one 0.8 ml / head and a dose of group two 1.2 ml / head. The variable observed was the increase of Hematology Profile (Erythrocytes, Leukocytes, and Hemoglobin). The results showed an increase in the Hematology Profile tested. The increase in the Hematology Profile is due to the effect of nutrition on chickens has been fulfilled, Red power injection is a supplement containing liver extract which helps the formation of Hematology Profile in Laying Hens (Gallus domesticus).

A distributed double-layer control algorithm for medium voltage regulation and state of charge consensus of autonomous battery energy storage systems in distribution networks

The increasing integration of Distributed Generation (DG) based on Renewable Energy Sources (RES) in traditional distribution systems necessitates the adoption of smart grid strategies. These strategies rely heavily on energy storage actuation to manage the inherent variability of RES and ensure autonomous operation. This article presents a hierarchical digital control strategy for managing distribution power systems, utilizing Battery Energy Storage Systems (BESS) to regulate voltage amplitude and enhance overall behavior for efficient energy management. At the primary control level, operating at a minute-scale actuation rate, an integral voltage regulation loop determines the BESS power injection or consumption, refined by a fuzzy conditioning of signals that accounts for the state of charge and operational modes of each device. Laplacian and random switching secondary consensus control strategies, operating at a slower rate, ensure coordinated action among individual units. The convergence of these strategies is analytically validated using Lyapunov’s theory under idealized conditions. Extensive dynamic simulations over a 24-hour period demonstrate the proposed strategy’s effectiveness in improving power quality and coordinating voltage regulation, particularly in terms of enhancing the power factor and reducing the standard deviation of voltage and power variables over time in a coordinated manner.

GENETIC ALGORITHM-BASED OPTIMIZATION OF DISTRIBUTED GENERATOR PLACEMENT IN DISTRIBUTION NETWORKS TO MINIMIZE POWER LOSSES

An increase in electrical energy can lead to an increase in power losses and a decrease in voltage in the system. One of the efforts made to reduce power losses that occur in the distribution network is by placing the optimal Distributed Generation (DG) in the right location. Installation of DGs with suboptimal capacity and placement location can result in greater active power losses and further reduce voltage stability. This study discusses the optimization of DG placement in the electric power distribution network using genetic algorithm methods that are known to be effective in solving complex optimization problems. The IEEE 33 bus distribution system, which is a standard system frequently employed in power flow research, was the subject of the case study. The Newton-Raphson method is a commonly used iterative method for power flow analysis due to its accuracy in calculating power flow in electrical networks. The research findings indicate that the most suitable location for two DG units with an injection power of 6,626 MW is on buses 3 and 4. The placement of this DG has the potential to substantially mitigate power losses within the distribution network. The placement of two DG units on buses 3 and 4 results in a more significant improvement in system power losses than the placement of DG units on other buses. Power losses of buses 3 and 4 experienced power losses of 67724.69 MW, while system losses were reduced by 1137621.21 MW, or 5.61 percent.

The long-term influence of a magnetar power in stripped-envelope supernovae. Radiative-transfer modeling of He-star explosions from 1 to 10 years

Much interest surrounds the nature of the compact remnant that formed in core collapse supernovae (SNe). One means to constrain its nature is to search for signatures of power injection from the remnant in the SN observables years after explosion. In this work, we conduct a large grid of 1D nonlocal thermodynamic equilibrium radiative transfer calculations of He-star explosions under the influence of magnetar-power injection from post-explosion age of about one to ten years. Our results for SN observables vary with He-star mass, SN age, injected power, or ejecta clumping. At high mass (model he12p00), the ejecta coolants are primarily O and Ne, with and dominating in the optical, and with strong in the infrared -- this line may carry more than half the total SN luminosity. For lower He-star masses (models he6p00 and he3p30), a greater diversity of coolants appear, in particular Fe, S, Ar, or Ni from the Si- and Fe-rich regions. All models tend to rise in ionization in time, with twice-ionized species (i.e., O Ne S or Fe dominating at sim \,10\,yr, although this ionization is significantly reduced if clumping is introduced. Our treatment of magnetar power in the form of high-energy electrons or X-ray irradiation yields similar results -- no X-rays emerge from our ejecta even at ten years because of high-optical depth in the kilo-electronvolt range. An uncertainty of our work concerns the power deposition profile, which is not known from first principles, although this profile could be constrained from observations. Our magnetar-powered model he8p00 with moderate clumping yields a good match to the optical and near-infrared observations of Type Ib SN\,2012au at both 289--335\,d (power of $1-2 and 2269\,d (power of 1040\ Unless overly ionized (i.e., if the optical spectrum shows only strong we find that all massive magnetar-powered ejecta should be infrared luminous at 5--10\,yr through strong line emission.

ANALISIS PLTS ATAP ON GRID 618,8 KWP PADA GEDUNG UNIVERSITAS HKBP NOMENSEN

Indonesia is currently highly dependent on fossil fuels whose availability is limited and has an emission effect on the environment, for the sustainability of the availability of electrical energy, alternative energy sources are needed in the form of new renewable energy, one of which is the Solar Power Plant (PLTS). This study discusses the analysis of rooftop PLTS on the 618.8 Kwp network at HKBP Nommensen University Medan using data from the Fusion Solar application. To analyze the effect of PLTS injection into the electricity network. The process of collecting UHN PLTS electricity data and measuring progress on changes that focus on the PLTS process and output was carried out from August 1 to August 31, 2023. The data collection in question is solar energy data that emits light and heat (irradiance) which can be utilized as an energy source through Photo Voltaic which produces certain electrical power. Furthermore, the activity to check or investigate the condition of the PLTS through the data above is to find out the actual condition of the PLTS. Data can be observed from and until the date above, and produces a total energy for consumption of 34.81 MWH and for export of 25.75 MWH with a total PLTS production of 60.56 MWH. And import data that occurred during August 2023 with a total of 0.3 KWH. With the injection of PLTS power into the grid, it can increase the large voltage on the bus that is directly connected to the PV.

Modeling and Control of Dual Active Bridge‐Modular Multilevel Converter‐Based Solid State Transformer for Grid Integration of SPV and Battery Energy Storage

ABSTRACTThis article deals with the modeling and control of a solid‐state transformer (SST) based on a dual active bridge (DAB) and modular multilevel converter (MMC) for integrating solar photovoltaic (SPV) and battery energy storage (BES) systems into the grid. SST uses DABs for bidirectional DC‐DC conversion and an MMC for DC‐AC conversion. A hybrid control method is developed in this study, which combines proportional‐integral (PI) controllers and model predictive control (MPC) to achieve the multiple objectives of the SST. The DABs' control system uses PI controllers for power extraction from the SPV system and to regulate the charging and discharging of the BES according to power generation and demand fluctuations. MPC is applied to control the active power injection, regulate the DC‐link and sub‐module capacitor voltages of the MMC. Moreover, the developed hybrid control method ensures reliable SST performance even under adverse conditions like grid voltage distortion, unbalance, and frequency variations. An energy management strategy is developed based on total power generation, reference active power injection, and the state of charge of the BES. This strategy ensures accurate reference power injection to the grid despite dynamic changes in operating conditions. The article also presents a detailed mathematical model of the DAB and MMC components, and the stability of the control algorithm is analyzed theoretically. The effectiveness of the SST and the proposed hybrid control scheme is demonstrated through MATLAB/Simulink simulations and hardware‐in‐the‐loop experimental results under various operating conditions.

Frequency-Voltage-var Function for Active Front-end VFD on Oil and Gas Platforms with Offshore Wind Generation

Renewable energy resources emerge as a sustainable alternative to augmenting the energy supply of floating production storage and offloading (FPSO) platforms. However, the increased generation at FPSO based on converter-interfaced energy decreases the system-equivalent inertia constant, which becomes more susceptible to frequency deviations. This paper proposes and evaluates the combined frequency-voltage-var control performance to mitigate frequency variation in a typical FPSO unit with penetration of floating wind energy generation. The control functions are communication-free and embedded in the active front-end variable frequency drives (AFE-VFDs), which are installed on the FPSO and have the primary function of controlling the speed of water injection pumps. The FPSO electrical power system model is developed in MATLAB/Simulink®. Comparative results obtained from the AFE-VFD equipped with volt-var, freq-var, and combined freq-volt-var functions are shown to highlight the proposed solution merits. The results have shown a conflicting behavior with the frequency and voltage deviation improvement associated with absorption and injection of reactive power, respectively. Accordingly, the frequency-volt-var prioritizes frequency deviations during heavy transient events and voltage deviations during regular operation.

Overall Concept Design of 2.45 GHz ECR Ion Source with Tunable Magnetic Field

The design of the ECR ion source was made for an operating frequency of 2.45 GHz. The ion source is considered to be used for producing protons and double charged helium ions. The source construction as well as the separate components design are presented in the study. The operating modes include both ECR and microwave operating regimes. The extraction system with the beamforming was developed. The beam adjustment is implemented by the longitudinal shifting of the electrodes against the plasma electrode position. The performance of the 2.45 GHz waveguide line to provide the stable power injection into the plasma chamber is considered. The numerical simulation of the waveguide line components was made and optimised.

A coordinated control strategy for energy storage stations to suppress overvoltage in sending-end AC grid caused by DC blocking

Abstract A DC blocking event will cause a substantial quantity of reactive power injection into the sending-end AC grid, leading to overvoltage, which severely affects the secure and reliable functioning of the system. Synchronous condensers (SCs) offer the dual advantages of substantial capacity and rapid response speed, but their output target reactive power requires about 200-500 ms, much slower than energy storage stations. Therefore, this article introduces a coordinated control strategy for energy storage stations, grounded in the Karush-Kuhn-Tucker (KKT) conditions. The strategy in question is designed to optimize the reactive power margin, ensuring that the energy storage station’s total active power output remains steady while maximizing the reactive power it can absorb, as defined by the objective function. By solving the Lagrange equation in MATLAB, the objective value for the optimized energy storage unit’s output power is ascertained and subsequently allocated to individual energy storage units. In addition, the energy storage station, in conjunction with the SCs, jointly absorbs reactive power to mitigate overvoltage in the sending-end AC grid during DC blockages. Finally, simulations confirm the efficacy of the proposed coordinated control strategy.

Power flow distribution identification via machine learning algorithm and distributed resource clearing method

Abstract Under the background of dual carbon, a large number of distributed new energy sources are connected to the demand side, which leads to great risks in the operation of the power system. As an effective solution, distributed power transaction still has problems, such as high clearing time, unknown low-voltage distribution network structure, and resource scheduling ignoring user needs. Therefore, this paper proposes an optimal regulation method of demand-side resources based on distributed transactions. Based on the historical operation data of the distribution network, the eXtreme Gradient Boosting (XGBoost) algorithm is used to study the relationship between node injection power, node voltage, and node-side line power flow. It is also used to check the results of distributed transactions and design a market mechanism for rapid clearing and settlement of distributed transactions. The results of an example show that the identification of power flow distribution in a distribution network based on reinforcement learning can meet the security check requirements of distributed transaction results.

Operational reliability and non-deterministic resilience estimation of active distribution network incorporating effect of real-time dynamic hosting capacity

Active distribution networks are increasingly recognized essential for achieving sustainable development goals. Traditionally, hosting capacity was considered as a static measure for planning distributed energy resources integration. This work introduces the concept of dynamic hosting capacity, which recurrently re-evaluates hosting capacity in response to erratic modern grid conditions. The introduction of dynamic hosting capacity facilitated testing variations of power injection from minimum to 100 %, sustaining power system governing parameter limits. This embarked the need of operational reliability assessment and enhancing situational awareness for optimum power injection and balance. To achieve operational reliability analysis based on dynamic hosting capacity, hybrid probability distribution function-based Monte Carlo simulation is proposed. This resulted in 85–90 %. improvisation of solar photovoltaic generation and load alignment, as this methodology provides comprehensive and accurate assessment of system performance under diverse uncertainties. The framework's validation includes projection of time-varying operational reliability indices, over time independent reliability indices i.e., dynamic loss of load probability, dynamic loss of load expectation, dynamic loss of load duration, dynamic loss of load frequency, dynamic grid margin, and dynamic grid dependency. This resulted in 30 % improvement in assessment of grid margin, facilitating reliable uncertainty handling competence. Additionally, expectation maximization algorithm is proposed to evaluate non-deterministic resilience due to ambiguities associated with solar photovoltaic distributed energy resources. The non-deterministic resilience assessment testified 80 % bounce-back rate, demonstrating better adaptability and robustness. The entire analysis is conducted in MATLAB, validated using Typhoon Hardware-in-Loop real-time platform, and compared with existing literatures to demonstrate its effectiveness.