scholarly journals Three-level Generalized Discontinuous Pulse-width Modulation Strategy Considering Neutral Point Potential Balance

2019 ◽  
Vol 1187 (2) ◽  
pp. 022009
Author(s):  
WANG Jikang ◽  
LIU Jianzheng ◽  
WANG Yi ◽  
GUO Zhichao
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Neutral Point ◽  
Point Potential

scholarly journals Neutral-Point Potential Balancing Control Strategy for Three-Level ANPC Converter Using SHEPWM Scheme

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4328 ◽  
Author(s):  
Yunlei Zhang ◽  
Cungang Hu ◽  
Qunjing Wang ◽  
Yufei Zhou ◽  
Yue Sun
Keyword(s):  
Control Strategy ◽  
Multiple Solutions ◽  
Pulse Width ◽  
Ant Colony Algorithm ◽  
Pulse Width Modulation ◽  
Neutral Point ◽  
Point Potential ◽  
Harmonic Elimination ◽  
Selective Harmonic Elimination ◽  
Balancing Control

A selective harmonic elimination pulse width modulation (SHEPWM) control strategy is proposed to balance the neutral-point potential (NP) of a three-level active neutral-point-clamped (ANPC) converter. In this strategy, the chaotic ant colony algorithm (ACA) is adopted to solve the SHEPWM nonlinear equations, which does not require presetting the initial values of solutions and can get multiple solutions in the same modulation index. The influence of different solutions corresponding to the SHEPWM switching states on the NP is different, namely, some make the NP increase and others make the NP decrease. Therefore, the NP balancing can be effectively controlled by choosing appropriate solutions in different fundamental periods. The simulation and experimental results further verify the feasibility and effectiveness of the control strategy.

scholarly journals A Novel SVPWM Algorithm Considering Neutral - Point Potential Balancing for Three - Level NPC Inverter

2017 ◽  
Vol 20 (2) ◽  
pp. 69
Author(s):  
Chen Yongchao ◽  
Li Yanda ◽  
Zhao Ling
Keyword(s):  
Control Strategy ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Sampling Time ◽  
Neutral Point ◽  
Control Effect ◽  
Balance Principle ◽  
Imbalance Problem ◽  
Point Potential ◽  
Three Phase

For three-level inverter, complexity of control strategy and neutral-point potential imbalance problem of DC side is the bottleneck restricting its application. In order to solve the problem, a simplified implementation of three- level space vector pulse width modulation (SVPWM) considering neutral-point potential balancing is proposed in this paper. The proposed SVPWM algorithm is based on judging of three phase voltages and voltage-second balance principle, which does not need to perform the sine and cosine c alculations, and thus it is more convenient and effective than traditional SVPWM algorithm. Also, the neutral-point potential balancing can be realized conveniently and effectively. The proposed algorithm can not only effectively simplify the calculation and reduce calculation time greatly, but also achieve the same control effect as traditional SVPWM. It has certain reference significance and can be used to shorten sampling time and improve the inverter performance. Finally, the proposed SVPWM algorithm is verified by simulation and experimental results.

scholarly journals A Virtual Negative Resistor Based Common Mode Current Resonance Suppression Method for Three-Level Grid-Tied Inverter with Discontinuous PWM

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1595
Author(s):  
Qiyu Li ◽  
Hongwei Zhou ◽  
Jiansong Zhang ◽  
Shengdun Zhao ◽  
Jingfeng Lu
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Neutral Point ◽  
Resonance Problem ◽  
Common Mode ◽  
Zero Sequence ◽  
In Series ◽  
Suppression Method ◽  
Lc Filter ◽  
Control Quantity

The output LC filter of a photovoltaic (PV) string three-level grid-tied inverter that connects the filter capacitor neutral point to dc-link capacitor neutral point can reduce the common-mode (CM) current injected to the grid by letting the CM current circulate within the inverter. However, the internal CM current may resonate because of the existence of the resonant frequency of the internal CM LC circuit. Compared with the traditional continuous pulse-width modulation (CPWM), the resonance can be worse if discontinuous pulse-width modulation (DPWM) is applied, for the zero sequence quantity of DPWM contains more harmonics than that of CPWM. In this paper, a virtual negative resistor based common mode current resonance suppression method for a three-level grid-tied inverter is proposed to overcome the CM current resonance problem in DPWM application. Different positions of the virtual negative resistor in the equivalent CM circuit with different feedback variables are analyzed theoretically. The virtual negative resistor connected in series with the inductor in the equivalent CM circuit is selected to damp the CM current resonance for simplification and damping performance. Different from the implementation in CPWM where a pair of small voltage vectors exist and are used to adjust the CM voltage directly, the proposed method for DPWM application is implemented indirectly by adding the CM adjustment quantity to differential-mode (DM) control quantity with appropriate coefficients. Depending on the sector of DM control quantity in the α β reference frame, the coefficients are calculated using one of three specific voltage vectors. Experimental results are given to demonstrate the effectiveness of theoretical analyses and the proposed method.

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

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