Optimized PI controller for 7-level inverter to aid grid interactive RES controller

With the huge rise of energy demand,the power system in the current era is moving to a new standard with increased access to renewable energy sources(RESs)integrated with distribution generation(DG)network.The RESs necessitate interfaces for controlling the power generation.The multilevel inverter(MLI)can be exploited for RESs in two diverse modes,namely,the power generation mode(stand-alone mode),and compensator mode(statcom).Few works have been carried out in optimization of controller gains with the load variations of the single type such as reactive load variation in different cases.Nevertheless,this load type may be unbalanced hence,to overcome such issues.So,a sophisticated optimization algorithm is important.This paper aims to introduce a control design via an optimization assisted PI controller for a 7-level inverter.In the present technique,the gains of the PI controller are adjusted dynamically by the adopted hybrid scheme,grey optimizer with dragon levy update(GD-LU),based on the operating conditions of the system.Here,the gains are adjusted such that the error between the reference signal and fault signal should be minimal.Thus,better dynamic performance could be attained by the present optimized PI controller.The proposed algorithm is the combined version of grey wolf optimization(GWO)and dragonfly algorithm(DA).Finally,the performance of the proposed work is compared and validated over other state-of-the-art models concerning error measures.

P2P Energy Trading Considering Prosumer Preference and System Risk

As an important means of mobilizing demand-side resources,peer-to-peer(P2P)energy trading has drawn more and more attention from scholars.This paper constructs a P2P energy trading framework considering prosumers’trading partner preferences(TPPs)and system risk.At first,we build the P2P trading models of prosumers equipped with different distributed energy resources(DERs),and TPP models.Secondly,to solve the established energy trading problem,a fully distributed double-consensus alternating direction method of multipliers(DC-ADMM)is proposed,which can achieve transaction consensus when considering market players’TPPs.Then,a risk-based security constrained economic dispatch(RBSCED)model based on AC power flow is established for the first time,by which a distribution system operator(DSO)checks system security and obtains risk-based locational marginal prices(RLMPs).Moreover,double-regulated price signals related to RLMPs which contain grid utilization prices(GUPs)and DSO’s retail prices realize management of players’transactions.In the end,the proposed method is applied to an IEEE33 bus distribution system.Results show the proposed method effectively reduces system risk and ensures secure operation of system without direct management.

Tie-line Power Flow Control Method for Gridconnected Microgrids with SMES Based on Optimization and Fuzzy Logic

In an active distribution grid,renewable energy sources(RESs)such as photovoltaic(PV)and energy storage systems(e.g.,superconducting magnetic energy storage(SMES))can be combined with consumers to compose a microgrid(MG).The high penetration of PV causes high fluctuations of tie-line power flow and highly affects power system operations.This can lead to several technical problems such as voltage fluctuations and excessive power losses.In this paper,a fuzzy logic control based SMES method(FSM)and an optimized fuzzy logic control based SMES method(OFSM)are proposed for minimizing the tie-line power flow.Consequently,the fluctuations and transmission power losses are decreased.In FSM,SMES is used with a robust fuzzy logic controller(FLC)for controlling the tie-line power flow.An optimization model is employed in OFSM to simultaneously optimize the input parameters of the FLC and the reactive power of the voltage source converter(VSC)of SMES.The objective function of minimizing the tieline power flow is incorporated into the optimization model.Particle swarm optimization(PSO)algorithm is utilized to solve the optimization problem while the constraints of the utility power grid,VSC,and SMES are considered.The simulation results demonstrate the effectiveness and robustness of the proposed methods.

Single-phase Thirteen-level Dual-boost Inverter Based Shunt Active Power Filter Control Using Resonant and Fuzzy Logic Controllers

This paper addresses the power quality improvement of a single-phase utility grid using a thirteen-level dualboost inverter(TLDBI)-shunt active filter(SAF).The TLDBI uses a single DC source of low voltage magnitude and five switched capacitor arrangement to achieve self-balanced thirteen level output voltages.Moreover,the charging and voltage balancing of the capacitor is achieved by proper switching sequence control in a series,through which boosted inverter output voltage levels are obtained.Compared with the tradional H-bridge multilevel inverters(MLIs),all the elements in the proposed TLDBI are able to withstand a voltage stress which is equal to the input DC source.This feature ensures the performance of the proposed TLDBI in high-frequency applications.The power at the electrical grid is highly affected by a wide range of non-linear loads.The proposed SAF is used for measuring and controlling the current flow from source to load.The difference between the targeted and actual currents from the utility grid is measured by using the modified synchronous reference frame(SRF)theory.The estimated error current is used by the controllers to predict the optimum suitable switching angle and modulation index(MI)to the TLDBI-SAF.In this paper,the traditional proportional-integral(PI)controller,fuzzy logic controller(FLC)and proportional resonant controller(PRC)are compared and the results are presented to validate the performance of SAF.The stability and robustness of the proposed controller is evaluated using Bode,Root locus,and Nyquist plots.The modeling and analysis of the proposed system are done using MATLAB/Simulink environments.The simulation results are presented in the various MI of TLDBI and also subjected to non-linear load conditions.The results are also compared to the claim novelty of the proposed study.