Aiming at improving the harmonic spectra spreading effect, two randomized pulse position modulation strategies are proposed for three-phase four-leg inverters. Based on the volt-second balance law and the fixed switching frequency, the first proposed strategy places the center randomly during one carrier cycle with a limited degree of freedom, and the second proposed strategy randomly changes the carrier slope in each carrier cycle. To get better randomization effect of the proposed strategies, Well Equidistributed Long-period Linear algorithm was introduced to generate random numbers. In order to verify the validity of the proposed strategies, the modulation strategies are implemented with dSPACE DS1007-based real-time operating system. The experimental results show that the proposed strategies have dispersed the discrete harmonics to a wider sideband. Compared with the first strategy, a larger degree of freedom can be achieved in the second proposed strategy with lower harmonic spikes.
ZhongQHomikT.Control of power inverters for distributed generation and renewable energy. Chichester: John Wiley & Sons, 2013.
2.
ZhaoWXRuanXBYangDSet al. Neutral point voltage ripple suppression for a three-phase four-wire inverter with an independently controlled neutral module. IEEE T Ind Electron2017; 64(4): 2608–2619.
3.
ZhangMAtkinsonDJJiBet al. A near-state three-dimensional space vector modulation for a three-phase four-leg voltage source inverter. IEEE T Power Electr2014; 29(11): 5715–5726.
4.
ZhangRPrasadVHBoroyevichDet al. Three-dimensional space vector modulation for four-leg voltage-source converters. IEEE T Power Electr2002; 17(3): 314–326.
5.
PeyghambariADastfanAAhmadyfardA.Selective voltage noise cancellation in three-phase inverter using random SVPWM. IEEE T Power Electr2016; 31(6): 4604–4610.
6.
MatheLLungeanuFSeraDet al. Spread spectrum modulation by using asymmetric-carrier random PWM. IEEE T Ind Electron2012; 59(10): 3710–3718.
7.
BhattacharyaSMascarellaDJoosGet al. A discrete random PWM technique for acoustic noise reduction in electric traction drives. In: Proceedings of the IEEE energy conversion congress and exposition (ECCE), Montreal, QC, Canada, 20–24 September 2015, pp.6811–6817. New York: IEEE.
8.
LiawCMLinYM.Random slope PWM inverter using existing system background noise: analysis, design and implementation. IEE P: Elect Pow Appl2000; 147(1): 45–54.
9.
ShrivastavaYSathiakumarSHuiSY.Improved spectral performance of random PWM schemes with weighted switching decision. IEEE T Power Electr1998; 13(6): 1038–1045.
10.
LaiYSChangYTChenBY.Novel random-switching PWM technique with constant sampling frequency and constant inductor average current for digitally controlled converter. IEEE T Ind Electron2013; 6(8): 3126–3135.
11.
JiangDWangF.Variable switching frequency PWM for three-phase converters based on current ripple prediction. IEEE T Power Electr2013; 28(11): 4951–4961.
12.
BhattacharyaSMascarellaDJoosGet al. Reduced switching random PWM technique for two-level inverters. In: Proceedings of the IEEE energy conversion congress and exposition (ECCE), Montreal, QC, Canada, 20–24 September 2015, pp.695–702. New York: IEEE.
13.
CarlosenaAChuWYBakkalogluBet al. Randomized carrier PWM with exponential frequency mapping. IEEE T Power Electr2007; 22(3): 960–966.
14.
LimYCJungYGOhSYet al. A two-phase separately randomized pulse position PWM (SRP-PWM) scheme with low switching noise characteristics over the entire modulation index. IEEE T Power Electr2012; 27(1): 362–369.
15.
QiCChenXYQiuY.Carrier-based randomized pulse position modulation of an indirect matrix converter for attenuating the harmonic peaks. IEEE T Power Electr2013; 28(7): 3539–3548.
16.
OhSYJungYGYangSHet al. Harmonic-spectrum spreading effects of two-phase random centered distribution PWM (DZRCD) scheme with dual zero vectors. IEEE T Ind Electron2009; 56(8): 3013–3020.
17.
KimKSJungYGLimYC.A new hybrid random PWM scheme. IEEE T Power Electr2009; 24(1): 192–200.
18.
BoudjerdaNBoudoudaAMelitMet al. Optimized dual randomized PWM technique for reducing conducted EMI in DC-AC converters. In: Proceedings of the 10th international symposium on electromagnetic compatibility (CD-ROM), York, 26–30 September 2011, pp.701–706. New York: IEEE.
19.
AdrianVChangJSGweeBH.A randomized wrapped-around pulse position modulation scheme for DC–DC converters. IEEE T Circuits: I2010; 57(9): 2320–2333.
20.
SchulzSEKowalewskiDL.Implementation of variable-delay random PWM for automotive applications. IEEE T Veh Technol2007; 56(3): 1427–1433.
21.
ChangYCLiawCM.A flyback rectifier with spread harmonic spectrum. IEEE T Ind Electron2011; 58(8): 3485–3499.
22.
LeeCKHuiSYRChungHSHet al. A randomized voltage vector switching scheme for three-level power inverters. IEEE T Power Electr2002; 17(1): 94–100.
23.
PannetonFL’EcuyerPMatsumotoM.Improved long-period generators based on linear recurrences modulo 2. ACM T Math Software2006; 32(1): 1–16.
24.
LiYChowPJiangJet al. Software/hardware framework for generating parallel long-period random numbers using the WELL method. In: Proceedings of the 21st international conference on field programmable logic and applications (FPL), Chania, 5–7 September 2011, pp.110–115. New York: IEEE.
