scholarly journals Neutral Point Clamped Transformer-Less Multilevel Converter for Grid-Connected Photovoltaic System

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 977
Author(s):  
P. Madasamy ◽  
Rajesh Verma ◽  
A. Rameshbabu ◽  
A. Murugesan ◽  
R. Umamageswari ◽  
...  

Transformer-less (TL) inverter topologies have elicited further special treatment in photo-voltaic (PV) power system as they provide high efficiency and low cost. Neutral point clamped (NPC) multilevel-inverter (MLI) topologies-based transformer-less are being immensely used in grid-connected medium-voltage high-power claims. Unfortunately, these topologies such as NPC-MLI, full-bridge inverter with DC bypass (FB-DCBP) suffer from the shoot-through problem on the bridge legs, which affect the reliability of the implementation. Based on the previous above credits, a T type neutral point clamped (TNP)—MLI (TNP-MLI) with transformer-less topology called TL-TNP-MLI is presented to be an alternate which can be suitable in the grid-connected PV power generation systems. The suggested TL-TNP-MLI topologies free from inverter bridge legs shoot-through burden, switching frequency common-mode current (CMC), and leakage current. The control system of the grid interface with hysteresis current control (HCC) strategy is proposed. The effectiveness of the proposed PV connected transformer-less TNP-MLI topology with different grid and PV scenario has been verified through the MATLAB/Simulink simulation model and field-programmable gate area (FPGA)-based experimental results for a 1.5 kW system.

Author(s):  
Palanisamy R

The system is a 3-level Neutral point clamped hysteresis current controlled Inverter with Wind energy as power source. The input DC Power for the multi-level inverter is drawn from wind turbine generator connected through a rectifier circuit. An inductor has been introduced for smoothening the DC output from the rectifier. The inverter uses Neutral Point Clamped topology. The switching pulses for the inverter are achieved by hysteresis current control technique. This system is advantageous over the conventional SPWM based system as the hysteresis current control allows to reduce the low frequency harmonics while also allowing to control the fundamental amplitude depending on frequency. The outputs for the system are verified using MATLAB simulations. The hardware for Hysteresis current control for the inverter is implemented by using a dSPIC microcontroller. The proposed system can be implemented in households for supplying backup power in case of power shortage and can also be used as a primary power source if wind flow is abundant. It is easy to implement, economical and provides clean energy


2014 ◽  
Vol 1030-1032 ◽  
pp. 1423-1431
Author(s):  
Jiang Zeng ◽  
Li Peng Huang

This paper presents a new hysteresis current control method for APF(active power filter) that can reduce switching losses effectively by means of adjusting the hysteresis band width according to the current size. On one hand, this method adjust the overall hysteresis band width according to the size of absolute norm of three-phase current that optimize the overall switching frequency, reduce the total switching losses effectively. On the other hand, it adjust hysteresis band width of each phase by comparing the output reference current to reduce the switching times which switching losses is larger, while increasing the switching frequency which switching losses is smaller, so as to maintain overall control precision. Computer simulation is conducted on an electromagnetic transient program. The results show that the new method can effectively reduce the switching losses under the same control accuracy and total switching frequency.


1989 ◽  
Vol 7 (4) ◽  
pp. 251-261
Author(s):  
Takashi Horigome ◽  
Hiroshi Sugimoto

Solar energy development at the New Energy and Industrial Technology Development Organization (NEDO) is concerned with reducing the cost of photovoltaic (PV) systems by promoting low cost, high efficiency solar cell manufacturing technology and photovoltaic system demonstations. The first involves reducing the cost of solar cell modules by producing better silicon materials and improving fabrication techniques. A number of demonstration systems are in operation.


2012 ◽  
Vol 460 ◽  
pp. 308-312
Author(s):  
Qing Shou Song

In accordance with the advantage of conventional hysteresis current control method, this paper advances a novel control method for APF. In conventional hysteresis current control, the hysteresis band (HB) is fixed and actual compensating current is limited in a fixed HB. Firstly, the connection between HB and switching frequency must be found correctly. Then, the variable hysteresis band current controller is designed according to the connection. Finally, the Matlab simulation results show that the switching frequency of VSI is held nearly constant and the proposed controller can track reference current well[1]. The problems of increasing switching losses and audible noise which happened in high-frequency state can be resolved in conventional hysteresis current control.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hani Vahedi ◽  
Abdolreza Sheikholeslami ◽  
Mohammad Tavakoli Bina ◽  
Mahmood Vahedi

Hysteresis Current Control (HCC) is widely used due to its simplicity in implementation, fast and accurate response. However, the main issue is its variable switching frequency which leads to extraswitching losses and injecting high-frequency harmonics into the system current. To solve this problem, adaptive hysteresis current control (AHCC) has been introduced which produces hysteresis bandwidth which instantaneously results in smoother and constant switching frequency. In this paper the instantaneous power theory is used to extract the harmonic components of system current. Then fixed-band hysteresis current control is explained. Because of fixed-band variable frequency disadvantages, the adaptive hysteresis current control is explained that leads to fixing the switching frequency and reducing the high-frequency components in source current waveform. Due to these advantages of AHCC, the switching frequency and switching losses will be diminished appropriately. Some simulations are done in MATLAB/Simulink. The Fourier Transform and THD results of source and load currents and the instantaneous switching frequency diagram are discussed to prove the efficiency of this method. The Fourier Transform and THD results of source and load currents are discussed to prove the validity of this method.


Energies ◽  
2017 ◽  
Vol 10 (10) ◽  
pp. 1610 ◽  
Author(s):  
Triet Nguyen-Van ◽  
Rikiya Abe ◽  
Kenji Tanaka

Sign in / Sign up

Export Citation Format

Share Document