Asymmetric regular sampling SPWM method based on tangent approximation algorithm

LI Wei1 LI Weibo1,2 XU Cong1 LU Yue1 CHEN Hui1

(1.School of Automation, Wuhan University of Technology, Wuhan, China 430070)
(2.Institute of Technology, Tibet University, Lasa, China 850012)

【Abstract】 Objectives In order to improve the quality of sinusoidal waveform output by the ship's high-frequency inverter charging device and reduce the CPU occupancy rate, this paper proposes a sinusoidal pulse width modulation (SPWM) method of asymmetric regular sampling based on tangent approximation. Methods According to the basic principle and calculation method of the asymmetric regular sampling SPWM method based on tangent approximation, a Matlab/Simulink simulation model is built, and then the software algorithm flow that can be used in the high-frequency inverter charging device is designed together with the actual output of the tangent approximation method. The effects are then compared and verified by experiments. Results The simulation results show that under pure resistive load and resistive inductive load, the total harmonic distortion (THD) of the load-end waveform based on the tangent approximation method is 2.12% and 2.08%, respectively, and its waveform quality is better than that of symmetric regular sampling. The experimental results show that the THD of a load-end waveform based on the tangent approximation method is significantly lower than that of the symmetric regular sampling method. When the effective value of the input line voltage is 580 V (the modulation ratio is 0.8), the quality of the output waveform is relatively optimal. Conclusions The asymmetric regular sampling SPWM method based on tangent approximation overcomes the shortcomings of the traditional symmetric regular sampling method, such as the low quality of the output waveform and high sampling frequency and high CPU occupancy rate in the traditional asymmetric regular sampling method. The research results can provide a reference for the design of high-frequency inverter charging devices on ships.

【Keywords】 electric inverter; sinusoidal pulse width modulation; regular sampling; tangent approximation;


【Funds】 Excellent Thesis Training Program for Graduate Students of Wuhan University of Technology (2018-YS-064)

Download this article

(Translated by HAN R)


    [1] CHEN M X, SHI B, CHEN Y G. A novel sampling method of SPWM Based on DSP [J]. Electrical Automation, 2011, 33 (5): 45–47 (in Chinese).

    [2] WANG C Y, HU Q, WANG F L. Implementation of improved asymmetric regular sampling algorithm based on TMS320F28335 [J]. Acoustics and Electronics Engineering, 2017 (3): 25–27, 32 (in Chinese).

    [3] ZHOU Y S, GONG H J, ZHANG J, et al. Optimization of sampling methods based on SPWM [J]. Science&Technology Review, 2009, 27 (5): 38–42 (in Chinese).

    [4] GAVASKAR R B, MAHESWARI L, GANESWARI K A. Performance improvement of single phase inverter using SPWM [J]. IOP Conference Series: Materials Science and Engineering, 2017, 225 (1): 012071.

    [5] MUNOZ R M, VALDERRAMA B H, RIVERA M, et al. An approach to natural sampling using a digital sampling technique for SPWM multilevel inverter modulation [J]. Energies, 2019, 12 (15): 2925.

    [6] LI Z Z F, WANG L Z, SHAO X, et al. Simulation implementation of SPWM natural sampling and regular sampling method [J]. Electronic Technology, 2018, 47 (9): 66–68 (in Chinese).

    [7] ZHU C B, LI L, WANG X P. Modeling and simulation of voltage and current double loop control based on SPWM inverters [J]. Chinese Journal of Ship Research, 2009, 4 (5): 54–58 (in Chinese).

    [8] BAHRAMI A, NARIMANI M. A sinusoidal pulse width modulation (SPWM)technique for capacitor voltage balancing of a nested T-type four-level inverter [J]. IEEE Transactions on Power Electronics, 2019, 34 (2): 1008–1012.

    [9] HE L Z, CHENG C. A bridge modular switched-capacitor-based multilevel inverter with optimized SPWM control method and enhanced power-decoupling ability [J]. IEEE Transactions on Industrial Electronics, 2018, 65 (8): 6140–6149.

    [10] LI H L, JIANG J G, QIAO S T. Essential relation between three-level SVPWM and SPWM and analysis on output voltage harmonic [J]. Automation of Electric Power Systems, 2015 (12): 130–137 (in Chinese).

    [11] GUO Y, SHAO D D, GUO J C, et al. Simulation study of harmonic characteristics of modular multilevel converter in medium voltage DC power system on ship [J].Chinese Journal of Ship Research, 2019, 14 (1): 134–143 (in Chinese).

    [12] WANG T J, RAO X, JIANG X Y, et al. Control strategy study on multi-phase induction motor for one DC amplitude-voltage power system [J]. Chinese Journal of Ship Research, 2011, 6 (6): 75–77, 82 (in Chinese).

This Article



Vol 15, No. 06, Pages 46-54

December 2020


Article Outline


  • 0 Introduction
  • 1 Traditional sampling methods
  • 2 Asymmetric regular sampling based on tangent approximation
  • 3 Modeling and simulation analysis
  • 4 Experimental verification
  • 5 Conclusions
  • References