- 标题
- 摘要
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- 实验方案
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Improved three-vector based dead-beat model predictive direct power control strategy for grid-connected inverters
摘要： Since only one inverter voltage vector is applied during each duty cycle, traditional model predictive direct power control (MPDPC) for grid-connected inverters (GCIs) results in serious harmonics in current and power. Moreover, a high sampling frequency is needed to ensure satisfactory steady-state performance, which is contradictory to its long execution time due to the iterative prediction calculations. To solve these problems, a novel dead-beat MPDPC strategy is proposed, using two active inverter voltage vectors and one zero inverter voltage vector during each duty cycle. Adoption of three inverter vectors ensures a constant switching frequency. Thus, smooth steady-state performance of both current and power can be obtained. Unlike the traditional three-vector based MPDPC strategy, the proposed three vectors are selected based on the power errors rather than the sector where the grid voltage vector is located, which ensures that the duration times of the selected vectors are positive all the time. Iterative calculations of the cost function in traditional predictive control are also removed, which makes the proposed strategy easy to implement on digital signal processors (DSPs) for industrial applications. Results of experiments based on a 1 kW inverter setup validate the feasibility of the proposed three-vector based dead-beat MPDPC strategy.
关键词： Grid-connected inverter,Model predictive control,Constant switching frequency,Power errors,Direct power control,Three vectors
更新于2025-09-23 15:23:52
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Impact of Grid Voltage Feed-Forward Filters on Coupling between DC-Link Voltage and AC Voltage Controllers in Smart PV Solar Systems
摘要： This paper presents a novel study of impact of filters of grid voltage feed-forward signals on the coupling between dc-link voltage and ac voltage controllers in smart photovoltaic (PV) solar systems which are used for voltage control in distribution systems. A comprehensive linearized state space model of a PV system including the dynamics of grid voltage feed-forward filters, dc-link voltage and ac voltage controllers is developed for the first time. This model is validated by electromagnetic transients software PSCAD/EMTDC. This model is used to identify the coupling between dc-link voltage and ac voltage controllers by eigenvalue and participation factor analyses. The impact of time constant of feed-forward filters on this coupling is studied by eigenvalue sensitivity analysis for PV systems with Proportional and Proportional Integral type ac voltage controllers. The range of time constants over which the filters interact with controllers and create instability for systems with different strengths and X/R ratios is identified. Insights are provided on the choice of time constants of grid voltage feed-forward filters for stable system design. The developed state-space model can also be used for impact studies of various other parameters e.g. system strength, X/R ratios, types and gains of controllers, on system stability.
关键词： AC Voltage Control,Smart Inverter,Photovoltaic (PV) System,Reactive Power Control,Control Interaction
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT-Europe) - Sarajevo, Bosnia and Herzegovina (2018.10.21-2018.10.25)] 2018 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT-Europe) - Peak Shaving of a Grid connected-Photovoltaic Battery System at Helmholtz Institute Ulm (HIU)
摘要： High demand of photovoltaic (PV) energy presents a challenge to operation and control of a power system. A Battery Energy Storage System (BESS) is an effective way to shave the peaks and to smooth the load during energy production changes with dynamic power demand. This paper introduces a novel peak shaving method with a PV-battery storage system. The method is tested on a system in Ulm, Germany. The PV-battery system has 31 kWp from a PV array, which is connected to a 76 kWh Li-Ion battery with a peak power of 60 kW. The system has been in operation since May 2015. The threshold on load and State of Charge (SOC) of the battery is applied in the peak shaving method. The average of SOC and actual state of energy of the battery are used for the determination of the change in the threshold value on load.
关键词： Load,Peak shaving,target power,Control system
更新于2025-09-23 15:22:29
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Cooperative Operation of R-SFCL and Online Current Limitation Strategy of GCPVS under Asymmetrical Faults
摘要： Grid-connected photovoltaic (GCPVS) should remain grid-connected and inject specified reactive current in accordance with fault-ride-through (FRT) requirements. To minimize voltage ripples on the DC link voltage and restrict the maximum phase currents, a modified online current limitation strategy (OCLS) is presented in this paper. Transient performance of GCPVS is enhanced as resistive-type superconducting fault current limiter (R-SFCL) is applied under severe asymmetrical faults. By introducing proper resistance selection process, the cooperative operation of OCLS and SFCL is proved to be effective.
关键词： reactive power control,transient performance,superconducting fault current limiters (FCL),online current limitation strategy (OCLS),photovoltaic systems,Fault ride-through (FRT) capability,symmetrical and asymmetrical faults
更新于2025-09-23 15:22:29
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - The Calculation of Energy Saving in use Light Management Systems
摘要： Light management systems are increasingly used in interior and exterior lighting. These systems offer many benefits for users of lighting. One of the most important advantages of these systems is the possibility of saving energy consumption for lighting purposes. Before deciding to use a lighting management system, it is worth knowing what value of savings energy this system will bring in specific case. The article present results of measurements basic light and electric parameters of LED luminaires with the possibility of controlling via DALI signal and obtained on base these measurements characteristic power control. Presented the method of calculating potential energy savings based on the received measurement results. Sources of differences between simulation calculations and real savings in using energy. The article present the differences between the evaluation of savings energy consumption simulation in the DIALUX program and real values. On the example of an existing lighting control system installed in sample room.
关键词： Light Management Systems,power control characteristics of LED luminaires,LED luminaires
更新于2025-09-23 15:21:21
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Laser Doppler Vibrometry Measurements of Conversion of Surface Guided Waves to Optical Fiber Modes
摘要： This paper investigates a multi-pair two-way massive MIMO amplify-and-forward full-duplex relay (FDR) system over Ricean fading channels, where multiple pairs of full-duplex users exchange information within pair through a full-duplex relay with a very large number of antennas (M for transmission and M for reception). First, the zero-forcing reception/zero-forcing transmission and maximum-ratio combining/maximum-ratio transmission processing matrices with imperfect channel state information at the relay are presented. Then, the corresponding asymptotic expressions (in M ) of the end-to-end signal-to-interference-plus-noise ratio are derived. Finally, the asymptotic spectral ef?ciency (SE) and energy ef?ciency (EE) at the general power scaling schemes when the number of the relay antennas tends to in?nity is analyzed. Theoretical analyses and simulation results show that, when M → ∞, the effects of channel estimation error, the self-loop of each user as well as the relay, inter-user interferences, the noise at users and the relay can be eliminated, respectively, if the power scaling scheme is properly selected. Besides, the considered multi-pair two-way FDR outperforms the multi-pair two-way half-duplex relaying on SE and EE performances when M is large. Moreover, a low complexity power control scheme is proposed to optimize the SE and we analyze the impact of the number of user pairs on the SE.
关键词： imperfect CSI,power control,full-duplex,Massive MIMO,Ricean fading channels
更新于2025-09-23 15:21:01
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Resource and Power Allocation in SWIPT Enabled Device-to-Device Communications Based on a Non-Linear Energy Harvesting Model
摘要： Due to the limited battery capacity in mobile devices, simultaneous wireless information and power transfer (SWIPT) has been proposed as a promising solution to improving the energy efficiency (EE) in Internet of things (IoT) networks, i.e., device-to-device (D2D) networks, by allowing mobile devices to harvest energy from ambient radio frequency (RF) signals. However, the non-linear behavior of RF energy harvesters has largely been ignored in existing works on SWIPT. In this paper, we propose to maximize the sum EE of all D2D links in a D2D underlaid cellular network by optimizing the resource and power allocation based on a non-linear energy harvesting (EH) model. Toward this end, we first propose a pre-matching algorithm to divide the D2D links into a SWIPT enabled group and a non-EH group that cannot meet the EH circuit sensitivity. We then develop a two-layer iterative algorithm to jointly optimize the D2D transmission power and the power splitting ratio to maximize the EE for each SWIPT enabled D2D link. On this basis, we build the preference lists for both SWIPT enabled D2D links and cellular user equipment (CUEs), and propose a one-to-one constraint stable matching algorithm to maximize the sum EE of all SWIPT enabled D2D links by optimizing the spectrum resource sharing between D2D links and CUEs. The sum EE of non-EH D2D links is maximized through an iterative power control algorithm and a one-to-one stable matching algorithm. Simulation results show that our proposed algorithms achieve a much higher sum EE than the existing matching based energy-efficient resource allocation scheme for SWIPT enabled D2D networks.
关键词： Device-to-device,underlay,energy harvesting,power control,resource allocation,SWIPT,energy efficiency,matching theory
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - Santos, Brazil (2019.12.1-2019.12.4)] 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - Optimal Voltage Coordinated Control for Grid-connected Photovoltaic Systems
摘要： The intermittent penetration of Grid-connected photovoltaic systems and load changing in distribution feeders can cause voltage ?uctuation. This paper aims to analyze the performance of different power control strategies to avoid overvoltage in MV feeders. The strategies use Volt/Var control and Volt/Watt control techniques to ?nd the optimal active or reactive power to be injected/absorbed by the PV inverters with the aim to minimize the voltage deviation and power losses and also coordinate the grid-connected photovoltaic system with the voltage regulation devices of distribution feeders. The strategies are tested in the IEEE 13 node test feeder.
关键词： active and reactive power control,grid-connected photovoltaic systems,Voltage regulation
更新于2025-09-23 15:21:01
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Scheduling of PV inverter reactive power set-point and battery charge/discharge profile for voltage regulation in low voltage networks
摘要： In recent years, renewable energies and storage systems are bringing a significant contribution to power system. Due to the high penetration of non-predictable power sources, especially in the distribution networks, new challenges related to the integration and management of these new resources also combined with storage systems arose in power system research. Accordingly, the aim of this paper is to propose an innovative scheduling method for voltage regulation in low voltage networks. A simple type of contract for ancillary services that foresees the participation of active users endowed with a storage system coupled with a PV system is considered. The method allows to regulate the voltage in a distribution system by using a combined PV and storage system. The voltage regulation is achieved by setting the value of the inverter reactive power on the basis of sensitivity coefficients of the considered node, taking into account the capability curve constrains, as required by new grid codes. A possible tariff policy is also proposed for the ancillary service and for the operation of the realization of the scheduling algorithm. Simulation results demonstrate the effectiveness of the proposed method for the scheduling of the power system.
关键词： Voltage quality,Storage,Ancillary service,Reactive power control,Battery scheduling,Photovoltaic inverter
更新于2025-09-23 15:21:01
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[IEEE 2018 4th IEEE International Conference on Emerging Electronics (ICEE) - Bengaluru, India (2018.12.17-2018.12.19)] 2018 4th IEEE International Conference on Emerging Electronics (ICEE) - Simulation Based Analysis of Grain Boundary in IBC Perovskite Solar Cells
摘要： The active power filter (APF) that consists of a half-bridge leg and an ac capacitor is integrated in the single-phase quasi-Z-source inverter (qZSI) in this paper to avoid the second harmonic power flowing into the dc side. The capacitor of APF buffers the second harmonic power of the load, and the ac capacitor allows highly pulsating ac voltage, so that the capacitances of both dc and ac sides can be small. A model predictive direct power control (DPC) is further proposed to achieve the purpose of this new topology through predicting the capacitor voltage of APF at each sampling period and ensuring the APF power to track the second harmonic power of single-phase qZSI. Simulation and experimental results verify the model predictive DPC for the APF-integrated single-phase qZSI.
关键词： Active power decoupling,second harmonic power,single-phase system,quasi-Z-source inverter,direct power control
更新于2025-09-23 15:19:57