Instantaneous power calculation based on intrinsic frequency of single-phase virtual synchronous generator

In order to enhance the stability of single-phase microgrid,virtual synchronous generator(VSG)control method is investigated in this paper.Its electromagnetic model and electromechanical model are established to illustrate the performance of VSG.Considering the 2 nd fluctuation of fundamental-frequency in the output power,an instantaneous power calculation strategy is proposed based on the intrinsic frequency of single-phase VSG.Besides,a virtual power calculation method is presented to achieve islanded/grid-connected seamless transition.Stability analysis and comparison simulation results demonstrate the correctness of the presented power calculation method.At last,the effectiveness of the proposed approach is verified by comparison experiments of islanded/gridconnected operations in a 500 VA single-phase inverter.

An ultra low-voltage, low-power baseband-processor for UHF RFID tag

A novel ultra low-voltage,low-power baseband-processor for UHF radio frequency identification(RFID)tag is presented here.The baseband-processor is compatible with the EPC^(TM) class-1 generation-2(C1G2)UHF RFID protocol,and fits the requirements of ultra low-power of passive tags.Based on the analysis of the special power consumption of the tag,a new architecture is proposed.A novel scheme for generating pseudo-random numbers as well as a new method of partial-decoding is developed.Besides,other low-power techniques are also adopted for the special baseband-processor which implements complex functions,such as encoding/coding,anti-collision and authorization scheme,and reading/writing operation to EEPROM.The chip was fabricated in 0.35 μm 1P3M standard CMOS process.Experimental results show that it achieves low power operation of 3.15 μW@1.5 V with the core area of 1.1 mm×0.8 mm.

Response Time of Reactive Power Based on Different Definitions and Algorithms

Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive power.The term"dynamic response time of reactive power"is often used but has never been clearly defined.This paper summarizes the reactive power calculations under different definitions and algorithms and considers these calculations in terms of signal processing to simulate and analyze the step response.This paper subsequently focuses on the widely used instantaneous reactive power algorithm and finally concludes that the dynamic reactive power response time closely depends on the reactive power calculation method itself.The single-phase instantaneous reactive power algorithm has the fastest response time.The reactive power response time of dynamic reactive devices in power systems is a minimum of a quarter of one cycle time for the well-known and widely used single-phase reactive power algorithms.

A Combined Reinforcement Learning and Sliding Mode Control Scheme for Grid Integration of a PV System

The paper presents development of a reinforcement learning(RL)and sliding mode control(SMC)algorithm for a 3-phase PV system integrated to a grid.The PV system is integrated to grid through a voltage source inverter(VSI),in which PVVSI combination supplies active power and compensates reactive power of the local non-linear load connected to the point of common coupling(PCC).For extraction of maximum power from the PV panel,we develop a RL based maximum power point tracking(MPPT)algorithm.The instantaneous power theory(IPT)is adopted for generation reference inverter current(RIC).An SMC algorithm has been developed for injecting current to the local non-linear load at a reference value.The RL-SMC scheme is implemented in both simulation using MATLAB/SIMULINK software and on a prototype PV experimental.The performance of the proposed RL-SMC scheme is compared with that of fuzzy logic-sliding mode control(FL-SMC)and incremental conductance-sliding mode control(IC-SMC)algorithms.From the obtained results,it is observed that the proposed RL-SMC scheme provides better maximum power extraction and active power control than the FL-SMC and IC-SMC schemes.

Rapid transaction to load variations of active filter supplied by PV system

This paper deals with the analysis and control of a photovoltaic （PV） system connected to the main supply through a Boost converter and shunt active filter supplied by a PV system providing continuous supply of nonlinear load in variation. A robust control of a PV system connected to the grid while feeding a variable nonlinear load is developed and highlighted. This development is based on the control of the Boost converter to extract the maximum power from the PV system using the Perturb and Observe （P and O） algorithm in the presence of temperature and illumination. The proposed modeling and control strategy provide power to the variable nonlinear load and facilitates the transfer of power from solar panel to the grid while improving the quality of energy （harmonic currents compensation, power factor compensation and dc bus voltage regulation）. Validation of the developed model and control strategy is conducted using power system simulator Sim-Power System Blockset Matlab/Simulink. To demonstrate the effectiveness of the shunt active filter to load changes, the method of instantaneous power （pq theory） is used to identify harmonic currents. The obtained results show an accurate extraction of harmonic currents and perfect compensation of both reactive power and harmonic currents with a lower THD and in accordance with the IEEE-519 standard.

Performance analyses of OFDM AF relaying system in the presence of phase noise with APS and IPS

This article investigates the significant performances of orthogonal frequency division multiplexing （OFDM）-based dual-hop system in the presence of phase noise （PN）. A scenario with Rayleigh fading statistics on both hops is assumed. Amplification factor for this amplify-and-forward （AF） relay networks system is divided into two conditions, average power scaling （APS） and instantaneous power scaling （IPS）. Before deriving signal-to-noise ratios （SNR） under APS and IPS, the Gaussianity of intercarrier interference （ICI） is proved firstly. The accurate closed-form expressions of end-to-end SNR cumulative distribution functions （CDF） and probability density functions （PDF） for both cases are obtained later. With the help of moment generating functions （MGF）, we have closed-form asymptotic expressions of bit error rate （BER）, which show that the BER of system in the presence of PN cannot exceed a fixed level even when SNR in high regime. Finally, simulations verify accuracy of the results. Conclusion analysis will provide a useful help in future application of the system.