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Modern power systems, referred to as cyber-physical energy systems (CPESs), are complex systems with strong interdependencies between power and information and communication technology (ICT) systems. CPESs also have dependencies between the essential grid services. For instance, coordinated voltage control depends on state estimation, which depends on measurement acquisition. Since the operation of CPESs is largely influenced by these grid services, assessing their performance is crucial for assessing the performance of a CPES. Most of these grid services are enabled by the ICT system, i.e., they rely to a high degree on ICT. Hence, properties such as availability, correctness and timeliness, which depend on the involved software, hardware and data of the ICT system, must be considered for assessing the performance of an ICT-enabled grid service. Disturbances and repairs in CPESs impact these properties, which can then propagate and affect the performance of a grid service as well as other dependent grid services. There is, therefore, a need to model the influence of the properties of software, hardware and data on ICT-enabled grid services for single services as well as across several services, resulting in a propagation of these parameters. Current literature lacks such a model, which can used not only to investigate but also to visualise the impact of these properties on the overall perfromance of a grid service as well as other dependent grid services. This paper proposes a meta model for assessing the performance of ICT-enabled grid services, which can be instantiated for different grid services considering their dependencies. A multi-dimensional operational state space, which serves as a visualisation of the performance of grid services in terms of their state trajectory, is also proposed in this paper. The contributions are then demonstrated by a case study with a state estimation service and the widely-used CIGRE medium voltage benchmark power grid augmented with an ICT system. Three scenarios with disturbances are presented to show the benefits of the contributions. Specifically, the performance of the state estimation service considering the disturbances is investigated using the meta model, and the change in performance is visualised as trajectories using the operational state space. These contributions enable new possibilities for planning and vulnerability analyses: property changes in parts of the ICT system can be simulated to investigate their consequences throughout the ICT-enabled grid services. A trajectory representing their performance can then be visualized in the state space based on which measures could be implemented to potentially improve the resilience of the service against the considered disturbances. [ABSTRACT FROM AUTHOR]

This paper proposes a new approach for evaluating distribution voltage regulators using quasi-static hardware-in-the-loop (HIL) simulation. Distribution voltage regulators are used to control the voltage using tap change transformers and are equipped with static control algorithms in order to accomplish different configurations of the distribution electric grid with typical load profiles. The growing penetration of renewable energy in electrical distribution systems is a great challenge for this equipment, and it becomes paramount that its measurement and control algorithms adapt to this new reality. Hardware-in-the-loop testing (HIL) techniques could be used for assessing the performance of the voltage regulator equipment. Most applications of HIL are concerned with accessing the dynamics of electrical system including not only grid modeling, but also the real equipment involved and should be used to test the efficiency of voltage regulation. However, a more simplified approach concerning the HIL tool could be applied to testing distribution voltage regulators in the laboratory prior to installation, evaluating the performance of algorithms and equipment by conducting quasi-static simulations. This paper presents this approach, joining NI LABVIEW laboratory controller software (National Instruments, LabVIEW. Available at https://www.ni.com/pt-br/support/downloads/software-products/download.labview.html#460283, 2023) and an open-source program OpenDSS (The Electric Power Institute, OpenDSS. Available at em https://opendds.org/, 2023). The effectiveness of quasi-static HIL platforms for assessing several aspects of static voltage tap regulators before installing them in the electric grid is demonstrated. The major advantage is the smaller computation complexity of a static simulations compared to dynamic simulators, allowing simpler hardware requirements. In this sense, a large number of medium to long term simulations could be easily performed providing a broader view of the behavior of the electric system including voltage regulators. [ABSTRACT FROM AUTHOR]

IoT and wearable medical devices frequently require ultra-low power solutions that can support long spells of inactivity. This study presents a buck converter to control power stages using a novel pulse frequency modulation (PFM) system that reduces switching losses for low-power systems. The modulation of high and low-frequencies was demonstrated, where the high-frequencies exhibited better energy transformation between the inductor and capacitor, and the low-frequencies could be adjusted for different current loads, to reduce switching losses. This circuit is optimized for light load applications. Using voltage control oscillation (VCO), the frequency range of 0.5 MHz – 2.0 MHz can be adjusted to influence conversion efficiency for different loads. The design was simulated and then fabricated using TSMC 0.18um process. The core size was about 1500 × 1000um that includes power MOS. Measurements result an average conversion efficiency of 91% under a load of 0.1 mA – 10 mA. This chip is suitable for battery-based IoT systems, or wearable medical devices. [ABSTRACT FROM AUTHOR]

The stability and dynamic performance of the system are impacted by the uncertainties present in the converter model and controller parameters. This paper introduces a robust non-fragile control approach that addresses the influence of these uncertainties. The approach involves developing a control law that achieves quadratic stabilization of the closed-loop system while also satisfying the H∞ norm constraint for disturbance attenuation. Based on this concept, a robust non-fragile PI controller is designed explicitly for voltage mode control of a dc–dc buck converter. The effectiveness of the proposed control technique is evaluated from two perspectives: (i) its ability to withstand significant perturbations in plant parameters and load disturbances and (ii) its resilience in the presence of variations in controller parameters. The effectiveness of the proposed control scheme is validated using simulation and experimental results. [ABSTRACT FROM AUTHOR]

Radial ribs are important supporting parts of umbrella antenna, and its shape is a crucial factor affecting the overall reflector accuracy. Considering the difficulty of in-orbit shape sensing, a fiber-optic shape sensing (FOSS) method for the radial rib is presented in this paper, then on the basis of FOSS a shape active control method for the radial rib driven by Macro-Fiber Composite actuators is proposed. Firstly, combining the deformation characteristics of the radial rib structure, an improved Ko displacement algorithm is proposed for its shape sensing using distributed fiber-optic. Then, establish the shape active control model with the Influence-Coefficient-Matrix method, and propose a closed-loop shape active control method with FOSS as feedback for the radial rib. In this paper, the optimization problem of solving control voltage is established by using the Least-Square method, and Root-Mean-Square error is taken as the convergence condition. Finally, numerical simulation and experiment show that the relative error of the shape sensing with fiber-optic is less than 5%, and the shape accuracy of radial rib after control is improved by more than 90% to reach submillimeter level, which verifies the effectiveness of the radial rib shape active control method based on FOSS. [ABSTRACT FROM AUTHOR]

Voltage-sensing phosphatases (VSPs) dephosphorylate phosphoinositide (PIP) signaling lipids in response to membrane depolarization. VSPs possess an S4-containing voltage sensor domain (VSD), resembling that of voltage-gated cation channels, and a lipid phosphatase domain (PD). The mechanism by which voltage turns on enzyme activity is unclear. Structural analysis and modeling suggest several sites of VSD-PD interaction that could couple voltage sensing to catalysis. Voltage clamp fluorometry reveals voltage-driven rearrangements in three sites implicated earlier in enzyme activation—the VSD-PD linker, gating loop and R loop—as well as the N-terminal domain, which has not yet been explored. N-terminus mutations perturb both rearrangements in the other segments and enzyme activity. Our results provide a model for a dynamic assembly by which S4 controls the catalytic site. Voltage-sensing phosphatases dephosphorylate PIPs upon membrane depolarization. Here, authors provide a model for a dynamic assembly by which the voltage sensor controls the catalytic site with the aid of the N-terminus. [ABSTRACT FROM AUTHOR]

Aiming at the problem of zero sequence voltage generated by unbalance parameters of line to ground, which affects arc suppression effect of grounding fault of controllable voltage source. By analyzing the influence of ground unbalance parameters on the arc suppression effect of controllable voltage source under different grounding modes, the mechanism of full compensation arc suppression based on zero sequence voltage of neutral point is revealed, and on this basis, a fully compensated arc suppression model of controllable voltage source controlled by double closed loop PI is established, and the deviation control is carried out by using the neutral voltage of distribution network and the voltage of fault phase supply. The residual voltage ring adopts the ground fault phase residual voltage for closed loop control. The simulation results show that the dual-closed-loop PI control algorithm can continuously stabilize the output waveform of the controllable voltage source. When the transition resistance is 0.1 ~ 10 kΩ, the residual voltage stabilization time of the independent controllable voltage source grounding method is 43 ms ~ 2.4 s, and the parallel arc suppression coil grounding method is 43 ms ~ 4.7 s. The proposed dual closed-loop PI control method for neutral point voltage deviation and fault residual voltage can stabilize the residual voltage of the grounded fault phase to below 10 V, forcing reliable arc extinction at the grounded fault point, exhibiting good stability. Low-voltage simulation tests have also proved the feasibility of the algorithm. [ABSTRACT FROM AUTHOR]

HVE-400 ion implanter is special ion implantation equipment for semiconductor materials boron and phosphorus doping. The ion source and extraction deflection system are at high voltage platform, while the corresponding control system is at ground voltage position. The control signals and measurement signals of various parameters at the high-voltage end need to be transmitted between ground voltage and high voltage through optical fibers to isolate high voltage. Upgrading is carried out due to the aging of the optical fiber transmission control and monitoring system, which cannot work stably. The transformation replaces the original distributed single-point control method with an advanced distributed centralized control method, and integrates all control and monitoring functions into an industrial control computer for digital operation and display. In the computer software, two kinds of automatic calculation of ion mass number are designed. After upgrading, the implanter high-voltage platform control and monitoring system features digitalization, centralized control, high reliability, strong anti-interference, fast communication speed, and easy operation. [ABSTRACT FROM AUTHOR]

To improve the total efficiency of a dual-bridge series resonance converter, a pulse width modulation plus phase-shifted modulation with voltage balance condition is proposed for a hybrid dual-bridge series resonance converter. The control scheme is unified for the whole operating condition and with simple calculation. By employing the proposed voltage balance control, the equivalent unity voltage gain operation can always be achieved, while a simplified two degrees of freedom control can be easily formed. Wide soft-switching range and reduced tank current can be ensured by the pulse width modulation in active hybrid bridge, and power level is adjusted by the phase-shifted modulation. In addition, a magnetizing current compensation method is also employed to improve the soft-switching performance of low voltage side four MOSFETs. The effectiveness of the proposed control is verified by the experimental results. [ABSTRACT FROM AUTHOR]