Hybrid single‐carrier‐based pulse width modulation scheme for single‐phase three‐level neutral‐point‐clamped grid‐side converters in electric railway traction

2016 ◽  
Vol 9 (13) ◽  
pp. 2500-2509 ◽  
Author(s):  
Shunliang Wang ◽  
Wensheng Song ◽  
Junhui Zhao ◽  
Xiaoyun Feng
Keyword(s):  
Pulse Width ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Neutral Point ◽  
Modulation Scheme ◽  
Single Carrier ◽  
Railway Traction ◽  
Electric Railway ◽  
Grid Side

scholarly journals Design and Simulation of a Single Phase Four Level Neutral Point Clamped Inverter

2019 ◽  
Vol 8 (2) ◽  
pp. 5285-5287
Keyword(s):  
Normal Mode ◽  
Pulse Width ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Reference Signal ◽  
Neutral Point ◽  
Half Cycle ◽  
Adjustment Strategy ◽  
Four Levels ◽  
Sinusoidal Pulse Width Modulation

In this paper, sinusoidal pulse width adjustment strategy for single stage four levels neutral point clamped inverter is proposed disposed of normal mode voltage. Sinusoidal pulse width modulation is much of the time utilized in modern applications. The gating sign are created by contrasting a sinusoidal reference signal and a triangular bearer sign of recurrence. The quantity of heartbeats per half-cycle relies upon the transporter recurrence

Appropriate Switching State Selection to Avoid Sapacitor Imbalance in Five-Level NPC

2018 ◽  
Vol 9 (1) ◽  
pp. 276
Author(s):  
Kuthuri Narasimha Raju ◽  
Chandra Sekhar Obbu ◽  
Ramamoorthy M
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Reference Signal ◽  
Neutral Point ◽  
Modulation Scheme ◽  
Zero Crossings ◽  
Load Demand ◽  
Capacitor Voltage ◽  
State Selection ◽  
Switching State

<p>An intrinsic problem with neutral point clamped (NPC) multilevel inverters (MLI) is unbalance of capacitor voltage. There are many mitigation techniques well established in the literature to balance the neutral point voltage for 3-level inverter. These techniques employ either Carrier based pulse width modulation (CBPWM), Space vector pulse width modulation (SVPWM) or hybrid of both the PWM techniques. Balancing becomes complicated as the level of the inverter increases due to addition of capacitor junctions. The imbalance in capacitor voltages may cause uneven voltage distribution among switching devices and sometimes may cause failure. It also increases harmonic content in its output waveform. This paper develops new modulation scheme for balancing capacitor voltages for Five-level inverter .The scheme is a hybrid PWM which is a combination of both CBPWM and SVPWM techniques. As per this scheme CBPWM is applied to meet the load demand and at the zero crossings of the reference signal, CBPWM is blocked and for one carrier cycle. During this SVPWM is applied with   appropriate switching state selection to neutralize the imbalance in capacitor voltage.</p>

scholarly journals A Topology Synthetization Method for Single-Phase, Full-Bridge, Transformerless Inverter with Leakage Current Suppression—Part II

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 446 ◽  
Author(s):  
Xiumei Yue ◽  
Hongliang Wang ◽  
Xiaonan Zhu ◽  
Xinwei Wei ◽  
Yan-Fei Liu
Keyword(s):  
Leakage Current ◽  
Pulse Width ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Neutral Point ◽  
Double Frequency ◽  
The Core ◽  
Photovoltaic Application ◽  
Topology Model ◽  
Sinusoidal Pulse Width Modulation

This paper proposes a topology derivation methodology to achieve small leakage current or zero leakage current for photovoltaic application. The core of the proposed method is a unified topology model and MN principle to show how to derive all possible topologies based on unipolar sinusoidal pulse width modulation (USPWM) and double-frequency USPWM (DFUSPWM). Part II of this paper discusses the topology synthetization method to achieve zero leakage current. Two types of neutral point clamped (NPC) topologies based on USPWM and DFUSPWM are elaborated. Two possible connections for the NPC cell are introduced, and detailed NPC topology derivation procedures are also provided. All existing NPC topologies are derived, and twenty-two new NPC topologies are found based on the new topology derivation methodology for a single-phase, full-bridge, transformerless inverter.

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