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For the fully resonant wireless power transfer (WPT) system, the high coupling of the converter and the resonant network introduced many problems, such as frequency splitting, the power curve peak limit, and the strict switch strategy. To solve these problems, this paper proposed a new six-switch topology based on the full–-bridge converter. With the unique structures containing two capacitor-isolated switches and a source-isolated diode, the system decouples the converter and the resonant network, and its modes have been decoupled, called the independent power injection and free resonance WPT (IPIFR–WPT) system. The capacitor-isolated switches and the source-isolated diode make the converter operate only when the voltage on the primary capacitor is equal to the source voltage, and the source will be isolated by the diode when the capacitor voltage is great than the source, which provides a wide time margin for the switches of the converter to turn on in advance. In this margin, the operation point is self-determined the same whenever the switches turn on so that the system’s performance is consistent. Based on this characteristic, the system can self-adapt a dynamic change in system parameters, with at least 15% tolerance for the coupling coefficient and 14% for the load resistance.

The aim of this study is to describe the incidence of peripherally inserted catheter tip (PICC) migration after power injection of intravenous contrast for computed tomography (CT) examinations. Retrospective review was conducted of all PICC power injections for CT examinations during the study period: October 16, 2017 through October 23, 2018. Review included evaluation of preinjection and postinjection topograms to assess PICC tip position. Chi-squared statistical analysis was applied. A total of 594 topograms were obtained of power-injectable PICCs during the study period in anticipation of power injection with iodinated contrast media. Of those, 550 patients had satisfactory preinjection topograms and available postinjection topograms; 43 (7.8%) demonstrated tip malposition attributable to power injection of contrast media. Anatomic side of PICC placement and subsequent malposition were independent variables by chi-square test (chi-square = .09, P = .76); 32 of 429 (7.5%) right-sided PICCs versus 11 of 121 (9.1%) left-sided PICCs demonstrated new malposition after contrast media power injection. No complications related to power injection of contrast media through these PICCs were observed. PICC tip malposition secondary to power injection of iodinated contrast media is common and readily identifiable. Obtaining both preinjection and postinjection topograms ensures appropriate catheter position during injection and upon patient departure. Rapid saline flush is a noninvasive maneuver that allows a high chance of successful repositioning of catheter tips. Power injection of contrast media through a power injectable PICC is safe.

Large share of solar energy imposes a higher system flexibility to resolve the increased demand/supply imbalance due to the inherent intermittency and variability of the resource. In this work, we demonstrate that the additional solar-induced flexibility requirement can be fully provided by a special kind of solar farms, namely flexible PV. These plants are able to provide ancillary services by proactive generation curtailment and storage power injection and they can be managed exactly as the secondary reserve currently used. At the current and future penetration levels, we sized the flexible PV fleet required to reduce the Italian imbalance by 36 % (with respect to its 2016 value) while keeping the curtailment at 6 % of the national PV generation. We show how this result can be achieved at an equal or lower dispatching cost than current cost (depending on the solar share). In addition, we found that a fleet composed of many flexible PV plants with different capacity randomly distributed throughout the country provides an optimal solar regulation performance. Finally, we showed that the effectiveness of the proposed imbalance mitigation strategy depends only slightly on the year-specific load, wind, PV and energy prices profiles used to size the capacity of the flexible fleet.

As plentiful roof-top photovoltaic (PV) panels and battery energy storage systems (BESSs) have been installed in residential houses, smart homes which provide reliable and cost-efficient energy for customers have been increasingly developing. This study proposes a smart home coordinated operation framework consisting of day-ahead scheduling of a BESS and deferrable appliances as well as real-time BESS affinely adjustable control. The scheduling aims to minimise daily energy usage bills and the affinely adjustable control aims to eliminate fluctuations of intermittent PV output and at-will uncertain appliances. This study proposes an affinely adjustable robust energy management system (AAREMS) which can optimise the day-ahead scheduling with full consideration of the real-time BESS control under uncertainties. Moreover, affinely adjustable robust counterpart formulation is developed to solve the AAREMS under the worst case of real-time uncertainty realisation. The simulation results verify the high efficiency of the proposed AAREMS in minimising the energy usage bills for the customers and providing certain and invariable power injection for the utility grid.

This paper presents a new computational attractive interval power flow (PF) approach with correlated uncertain power injections while maintaining high estimation accuracy. The key idea is to integrate the ellipsoid convex model with the evidence theory. This allows us to effectively account for uncertain power injection correlations and eliminate irrelevant focal elements, yielding significantly improved computational efficiency. Extensive comparisons with other approaches demonstrate its effectiveness under various conditions.

Corey A Kemper,1 Casper Mihl,2,3 Bibi Martens,2,3 Michael C McDermott,2,4 Babs MF Hendriks2,3 1Bayer U.S. LLC, Bayer Pharmaceuticals, Radiology R&D, Indianola, PA, USA; 2Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; 3Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands; 4Bayer AG, Radiology R&D, Berlin, GermanyCorrespondence: Corey A Kemper, Bayer U.S. LLC, Bayer Pharmaceuticals, Radiology R&D, 1 Bayer Dr, Indianola, PA, USA, Tel +1 412 225 3907, Email corey.kemper@bayer.comPurpose: To compare an investigational device (MEDRAD® Centargo CT Injection System, “Centargo”) to the currently available MEDRAD® Stellant CT Injection System (“Stellant”), in terms of efficiency, injector performance, and user satisfaction.Patients and Methods: A total of 425 patients at two sites were enrolled; 198 patients in phase one, a randomized study (98 Stellant and 100 Centargo). The second observational phase included 227 patients who were injected with Centargo. Phase one recorded times for setup, disassembly, and patient changeovers. Demographic data, subjective image quality, and injection parameters were collected. Phase two assessed usability via a questionnaire provided to all end-users of both systems (radiographers).Results: Patient changeover times were statistically significantly faster with Centargo (15.4s ± 8.7s vs 53.7s ± 19.6s, p < 0.001). Centargo day-setup times were similar to Stellant (138.1s ± 92s vs 151.8s ± 30.6s, p = 0.33) and end-of-day-disassembly times were significantly slower (60.6s ± 27s vs 17.1s ± 12.9s, p < 0.001). Based on four different scenarios modelling patient throughput, the projected time savings with Centargo over Stellant was 40– 63%, with the highest efficiency improvements for higher throughputs and the use of larger contrast medium bottles. Both Centargo and Stellant usability averaged between “Very Easy” and “Easy” in all responses to the questionnaire. There were no instances of interrupted injections due to communication loss or detected air and no insufficient images due to injector performance. No safety issues were identified.Conclusion: Centargo was able to demonstrate improved efficiency as compared to Stellant while maintaining injector performance and high usability scores.Keywords: power injection, efficiency, time savings, usability, Centargo

This paper deals with power injection on single phase grid connected inverter. The simple method is introduced to understand the concept of grid connected systems. A phase Lock Loop (PLL) method estimates the phase-angle of grid system. The output of PLL is used to defines Iref , and the current of inverter becomes a feedback (IL). Both current are derived to produce PWM using current mode controller method. As long as the grid system on fault condition like voltage distortion, therefore the single-phase inverter that connected into the grid should change the role and keep stabilization. The voltages sag and swell are the possible conditions that occurred on a power system. Voltage Sag is an event where the line voltage decreases from the nominal line-voltage for a short period of time. Voltage swell is the event when the line voltage increase from the nominal line voltage. By using PSIM software, the injection and absorption of power into a grid system is verified during a voltage sag, swell, and normal. The simulation shows voltage grid vg, current inverter iinv, current grid, active power P, reactive power Q. The waveform of the measured parameter is analized to define the role of inverter toward grid. the The result shows performance of the proposed inverter to absorb reactive power during swell, and inject reactive power when sagging.

In this article, a novel analytical approach (named as zero bus load flow (ZBLF)) is proposed for DG placement to the distribution network under the scenario of known power injection from the utility/substation. The study is carried out for deferent load levels and for two different distribution networks (viz. 33- and 69-bus distribution networks). In this work, biomass (working at the power factor same as that of the load power factor) is considered as the DG source. From this study, it may be noticed that, by placing the DG at the selected bus, the active power loss of the network may be reduced even when the power supply from the utility grid is zero. In this paper, a combined approach of ZBLF and symbiotic organism search (SOS) has been proposed for the placement of multiple numbers of DGs for the scenario when the power supply from the utility/substation is known. Both the technical as well as the economic aspects of the DG placement for both the distribution networks are studied and presented in this research paper. DG placement using the proposed method also founds to be economical to the utility.

This paper proposes a coordinated decentralized reactive power optimization (RPO) approach for multi-area power systems with discrete variables. A decentralized RPO model is established, in which the sub-RPO model for each area is built respectively, while other areas taken as external networks are represented by Ward equivalent circuits, and also the load tap changing transformer branch is modeled as an equivalent power injection circuit in order to avoid repetitive updates of the equivalent admittance matrix. We add coupling constraints between areas, given as consensus constraints on the bus voltages at boundaries, which are favor to remain the equivalence between the decentralized RPO model and the original centralized RPO model. The model is then solved using the alternating direction method of multipliers (ADMM). The proposed approach requires very little exchange of boundary information among neighboring areas. Numerical results for IEEE test systems ranging in size from 9 to 118 buses with 2–4 areas and a real-world 739-bus system with 2–4 areas demonstrate that the proposed approach provides markedly improved convergence performance compared to the application of ADMM alone.

This paper aims to propose the vector form implementation into three-phase power flow analysis. The developed algorithm is based on Newton-Raphson method with voltage is represented in rectangular coordinate. The Python programming language and its mathematical libraries are used in this works. Three-phase power flow analysis in vector form utilizes sparse matrix ordering algorithm, so the elements of the coefficient correction matrix can be rearranged easily. This method was used to solve three-phase power flow for balance or unbalance network in two actual distribution system feeders in Lampung, i.e. 119 nodes and 191 nodes. Comparison with traditional Newton-Raphson method (non-vector) shows the vector form is able to solve computation up to eight times faster than non-vector. Keywords : Three-phase power flow, Vector form, Newton-Raphson, Rectangular, Python

In the AC/DC hybrid microgrids equipped with power electronic transformer (PET), different AC grids and DC grids are connected through multiport PET to operate the entire network in a secure and economic manner. This paper proposes a decentralized optimal power flow model, considering the multiport coordinated control strategy of PET, for running autonomous AC/DC hybrid microgrids. To optimize the power flow in the network, the steady state model of PET is established, including voltage source converter power injection model and Kriging model. By introducing a secondary droop control layer can realize the autonomous operation of AC/DC hybrid microgrids and increase the utilization efficiency of distributed generations. Then using the analytical target cascading approach, each AC/DC sub-microgrid is regarded as different autonomous subjects. The distributed PET is as power coupling node and information interaction node to decompose the optimal problem of AC/DC hybrid microgrids equipped with PET which is solved in parallel. The obtained subproblems for these grid levels are solved with a nested solution process. The simulation results verify the correctness and effectiveness of the proposed model in this paper.

This paper characterizes the immunity of I/Os under different supply voltages for fault-tolerant circuit designs against electromagnetic interference. The direct power injection approach is used as a means to characterize the immunity of circuits. In this work, the immunity characterization has been performed under two scenarios: (1) an input buffer of a Field Programmable Gate Array (FPGA) followed by a single flip-flop, and (2) the FPGA input buffer followed by a redundancy-based fault-tolerant circuit. The experimental results show that when downscaling the supply voltage through a set of nominal values (i.e., 3.3, 2.5, 1.8, 1.5, 1.2 V), the immunity of I/Os is decreased from the highest level at 3.3 V to the lowest at 1.2 V. Particularly, the maximum difference in the immunity is about 16.8 dB at the frequency of 600 MHz. Moreover, experiments demonstrate that I/O buffers followed by the redundancy-based fault-tolerant circuit can improve the immunity of the circuit up to 4 dB below the frequency band of 400 MHz. Thus, the redundancy-based fault-tolerant circuit can support I/Os to operate reliably in the harsh environment.

Growing penetrations of distributed energy resources (DERs) increase the power injection variability in distribution systems, which can result in power quality issues such as voltage unbalance. To measure unbalance, organizations such as IEC, NEMA and IEEE define phase unbalance in their power quality standards. However, the definitions in these different standards are not consistent, and voltages that are considered acceptable by one standard may violate good practices defined by another standard. To address this issue, this paper provides analytical comparisons of the most common voltage unbalance definitions, which are supplemented with numerical simulations. The analytical relationships suggest that it is possible to approximately bound the symmetrical-component-based voltage unbalance factor (which depends on the magnitude and relative phase angle) by limiting the line-to-line voltage unbalance, whereas applying line-to-ground voltage unbalance definitions neglects all information about phase angle offsets.

Peripherally inserted central catheters (PICCs) may be used to administer contrast injection during CT (computed tomography) scans to improve diagnostic accuracy. This is usually done with the use of a power injector. Research has shown that misplacement of catheters following contrast injection can occur. The aim of this review was to analyse appropriately positioned pre-scan PICCs that malposition following injection of contrast media during a CT scan, evaluate whether tip location or right or left insertion plays a part in the displacement of PICCs after CT, and to ensure those involved are aware of the risks and the safety checks required following such procedures. A quantitative method was used, gathering information from the team's insertion database to review 2045 records of contrast-injectable PICCs between 1 January 2015 and 30 April 2020. Analysis of the data indicated that 1% of appropriately sited PICCs malposition following contrast CT injection and that the catheter is able to self-correct back to its original position at an average interval of 24–72 hours without any other intervention. Further research is needed to explore other factors that could influence the rate of self-correction and complications of prolonged catheter malposition.

Venous air embolism as a complication of contrast media administration from power injection systems in CT is found to occur in 7%-55% of patients, impacting patient safety, diagnostic image quality, workflow efficiency, and patient and radiographer satisfaction. This study reviews the challenges associated with reactive air management approaches employed on contemporary systems, proposes a novel air management approach using proactive methods, and compares the impact of reactive and proactive approaches on injected air volumes under simulated clinical use.Injected air volumes from three power injection systems were measured under simulated clinical use via custom air trap fixture. Two of the systems employed reactive air management approaches, while a new system implemented the proposed proactive air management approach.The proactive system injected significantly less air (average of 0.005 mL ± 0.006 mL with a maximum of 0.017 mL) when compared to two systems with reactive approaches (averages of 0.130 mL ± 0.082 mL and 0.106 mL ± 0.094 mL with maximums of 0.259 mL and 0.311 mL, respectively) (p0.05). CT images were taken of static and dynamic 0.1 mL air bubbles inside of a vascular phantom, both of which were clearly visible. Additionally, the dynamic bubble was shown to introduce image artifacts similar to those observed clinically.Comparison of the injected air volumes show that a system with a proactive air management approach injected significantly less air compared to tested systems employing reactive approaches.The results indicate that the use of a proactive approach could significantly reduce the prevalence of observable, and potentially artifact-inducing, venous air embolism in contrast-enhanced CT procedures.

DC power flow controller (PFC)s are suitable equipment to provide secure/reliable operation of the multiterminal HVDC (MT-HVDC) networks. Also, they enhance the controllability of these grids. This paper proposes a new representation of the Newton-Raphson (NR) based DC power flow (PF) solver to provide suitable DC PF studies of PFC compensated/flexible MT-HVDC grids. To achieve this aim, the power injection model (PIM) (under static condition) for an interline DC PFC (IDC-PFC) is proposed and embedded within the presented DC PF solver (DC-PFS) while the symmetry and original framework of the conductance matrix of the system is yet preserved and the proposed concept imposes a few changes on the related Jacobin matrix. In the proposed model, resistive shunt admittance of HVDC lines is also taken into account. Modifying the physical and control state variables of the whole system (IDC-PFC and MT-HVDC grid) in a common collaboration, the predetermined control objective(s) are obtained. The accurate concept and effectiveness of the presented IDC-PFC models and new representation of the NR-based DC-PFS are verified by performing dynamic and static simulations on an 8-bus MT-HVDC test network.

The IC stripline, an IEC radiated electromagnetic susceptibility (EMS) method, is utilized for evaluating the injection pulling and locking effects of the voltage-controlled oscillator (VCO). An IC stripline with the bandwidth of 2.5 GHz is realized and the test setup is built. A commercial VCO is tested for demonstration. Another IEC conducted EMS test, direct power injection, is also performed for comparison. The results show the effectiveness of characterizing injection pulling and locking of VCO by using the proposed solution.

Occasionally, a patient requiring computed tomography (CT) with poor venous access or in an unstable condition may have a sheath as their only form of IV access. Many institutions prohibit contrast power injection through the side ports, for concern for rupture. We hypothesize that under conditions encountered in CT scanning, the side arm of the sheath introducer is safe for power injection of contrast material. In this in vitro study, we injected contrast at different flow rates varying from 2 to 8 ml/s, through the side port of the sheath. Time-pressure graphs were obtained for each injection from the injector display. The assembly was observed for any signs of leakage or material failure. There was not a single event of leak, rupture, or displacement. Maximum pressures were within the range of conventional contrast administrations. This study suggests that iodinated contrast can safely be injected through the side port of a venous sheath.

This paper presents a comparative study among different models of unified power quality conditioner (UPQC) designed to improve the energy efficiency of the radial distribution networks. An UPQC consists of two voltage-sourced inverters, i.e., series and shunt inverters. In connected UPQC topology, these two are connected with a DC link. In open UPQC (UPQC-O), these two are not physically connected. But, they share a common communication link. Four models are formulated. They are: (1) UPQC without real power injection, (2) UPQC with real power injection, (3) UPQC-O without real power injection, and (4) UPQC-O with real power injection. A planning optimization model is formulated to determine the optimal locations for the series and shunt inverters for these four models. The objective function consists of the investment and maintenance cost of the inverters and battery, and the cost of energy loss. The energy loss comprises of line losses, inverter losses, and transformer loss. The planning optimization is constrained to ensure a desired power quality level of the network. Particle swarm optimization is chosen as the solution tool. The results show that the placement of UPQC-O provides higher energy efficiency as compared to the connected UPQC topology.

Due to the complexity of IC, electromagnetic immunity plays a critical role towards evaluating the EMC performance to avoid the high cost of redesign. This paper focuses on the Direct Power Injection (DPI) immunity of processor chips with different external double data rate3 (DDR3) synchronous dynamic random access memory (SDRAM) in consumer electronics. To complete the DPI test, a test board complying with the standard IEC62132-4 and a dedicated test code have been designed. The effect of DC power injection interference on same DDR model but different DDR pins and the same DDR pin but different DDR models were analysed, the results can be used to locate the system-level EMC issues and optimize the design.

This paper presents a theoretical study of damping, synchronizing and inertial control laws, implemented using controllable power injection devices like HVDC, FACTS or renewable-energy/storage systems which have power-electronic grid interfaces. The approach is to use a simplified dynamical model of a power system to arrive at generalized results regarding the effect of the strategies on the electro-mechanical dynamics of the system. These results are not dependent on the size, network topology and operating condition of the power system. This paper presents a differential-algebraic formulation and generalized eigenvalue analysis to facilitate a unified study of the effects of the control laws on the electro-mechanical modes. The damping, synchronizing and inertial control laws can themselves be extended to include the possibility of mutual-damping, synchronizing and inertial effects when multiple devices are present. The control laws are not only simple and intuitive, but also are found to have a predictable and generally beneficial impact on the electro-mechanical dynamics of the grid, even when detailed models are considered.

The objective of this paper is to improve the voltage profile of the grid in pertinence to grid due to power injection from distributed solar photovoltaic (PV) arrays. Weak grids are modeled as worldwide adaptation of net metering, transactive energy systems, and the possibility of further deterioration of power quality with higher grid penetration. In this paper, a solar PV integrated weak distribution grid modelled as the PV arrays being frequently connected in rural areas, due to various reasons like cheap real estate and lack of accessibility. In this paper, three case studies of PV generation are simulated, i.e., scheduled solar PV generation less than load requirement, PV generation equal to load requirement, and PV generation more than load requirement, by considering the daily solar irradiation and load demand profiles of a residential area under study.

The increasing penetration of Renewable Energy Sources (RES), the liberalization of the electricity markets across the world and devices such as smart meters to realize bidirectional communication with centralized computer systems present the end-users of the power system withnew opportunities to decrease their electricity costs or become active electricity market participants. However, the intermittent nature of RES and dynamic electricity prices require tools against uncertainty to protect the end-users from under utilizing their assets. In this work, we examine theeffectiveness of Robust Optimization (RO)in maximizing the economic benefit of the owner of a home battery storage system in the presence of uncertainty in dynamic electricity prices. The advantage of the robust model is that it keeps its linear class, thus it is not too computationally intensiveto be included in the control algorithm of a residential energy storage controller. We examine the effectiveness of the RO model in doing dynamic electricity price arbitrage and in providing fast response to requests from an aggregating entity for power injection or absorption. In the use-case,the aggregating entity makes requests for flexibility and coordinates 100 such devices using a price signal. The results indicated that the RO approach can be beneficial for a non-conservative agent in the case of low daily price fluctuations. However, if the daily price fluctuations are higher, as in summer, the agent is better off by ignoring uncertainty in the dynamic electricity prices.

The rise in electrical power demand and corresponding transmission or distribution loss is affecting the efficiency of power delivery. A new method for loss allocation in radial distribution system based on proportional sharing is proposed. Based on allocated loss, optimal location of distribution generation (DG) is selected. After selecting the location, optimal size of DG is obtained for that location. Loss allocation to DGs is based on formation of two matrices, power contribution matrix and power sharing matrix. Loss share of DGs and loads are decided based on both power injection by DGs and loss minimisation due to presence of DGs. Results of the proposed method are shown on 69 bus radial distribution system.