A Framework for Optimum Determination of LCL-Filter Parameters for N-Level Voltage Source Inverters Using Heuristic Approach

Abstract

The use of voltage source multilevel inverters (VS-MLIs) has grown enormously over the last decade, and it is expected that these inverters will be deployed in future power grids (smart grids), especially for medium voltage-high power applications. This paper investigates the application of passive power filters (PPFs) for harmonic mitigation at the output of VS-MLIs for more efficient grid integration of renewable energy sources. It proposes a generic model, using a heuristic approach, for the optimum design of an LCL power filter at the output of VS-MLIs. The proposed model transforms the LCL filter design problem into an optimization problem and applies a genetic algorithm (GA) to solve it. The objective function to be optimized is a multi-objective function based on inverters' total harmonic distortion and energy losses. The optimization problem is subject to applied design constraints. As a main optimization objective, a precise evaluation methodology for the inverter power losses is presented, which was built according to a practical switching device datasheet. The method is applicable to any VS-MLI topology and any number of levels (N). As a case study, the proposed design optimization approach was implemented to optimally design the LCL filter at the output of a grid connected 11 KV, 5 MVA 7-level cascaded H-bridge multilevel invert (CHB-MLI). The IGBT module Device IGBT of type FZ400R65KE3 by Infineon was used for simulation. MATLAB-SIMULINK is used for the modelling and simulation. We found that the proposed design approach is more generic, efficient, and simple to apply than conventional design approaches which requires more system detail, relies more on the designer's experience, and normally does not results in optimum design. The proposed approach is generic and can be applied for different VS-MLIs topologies and for any number of levels (N).

Examining the impacts of DM filters to PFC isolated Ćuk converter for DCM operation by comparing Si and SiC MOSFET

“…After writing state equations in ( 6), ( 7), ( 8), ( 9), (10) with the form of (11), mathematical model for switch on interval is obtained in (12).…”

“…State equations is written with the form of (11) to have mathematical model of first switch off interval in (18).…”

“…6, LCL filter structure is given. LCL filter is very common in inverter and three phase rectifiers as in [8][9][10][11] . Nevertheless, LCL filter integration for PFC single phase converter is not examined in detail in literature.…”

An Active and Reactive Power Controller for Battery Energy Storage System in Microgrids

“…GA is a heuristic algorithm with simple concept and easy implementation and offers a parallel searching of the solution space rather than point-to-point searching. It also does not need an initial solution and differentiation from the nonlinear objective functions that does not need a very accuracy solution [20]- [22]. It can find an approximation of optimal solution for LPF design quickly.…”

Integrated Renewable Smart Grid System Using Fuzzy Based Intelligent Controller

“…This relives power quality and instability issues in case of distributed systems [6,7]. In [8] genetic algorithm was used to optimize fuzzy controller in Un-interrupted power supply applications. 5-H Bridge Multi-Level Inverter with LCL filter was used [9] to regulate the grid current.…”