TY - JOUR

T1 - Harmonic distortion in three‐phase inverters controlled by synchronous sigma‐delta‐modulation

AU - Mertens, A.

PY - 1992/11

Y1 - 1992/11

N2 - Several soft switching three‐phase inverters have been proposed in the literature, using a resonant AC or DC voltage link in order to reduce switching losses. This allows operation with higher switching frequencies. In these inverters, the switching instances have to be synchronized with the periodic zero crossings of the link voltage. Thus synchronous pulse modulation strategies like Sigma‐Delta‐Modulation have to be used for control. The benefit of high switching frequency has to be considered in the light of performance of the modulation scheme, which can be measured by determining the r.m.s. value of the distortion current. In this paper, this magnitude is calculated analytically for three‐phase inverters controlled by synchronous Sigma‐Delta Modulation. The derivation is based on the assumptions of constant link frequency and large ratio of link‐ to output frequency. The solutions allow to calculate the r.m.s. distortion current for any periodic shape of the link voltage including DC. Simulations show that the results hold for link‐ to output frequency ratios down to 100. The spectral performance of synchronous Sigma‐Delta‐Modulation is compared with conventional pulse width modulation.

AB - Several soft switching three‐phase inverters have been proposed in the literature, using a resonant AC or DC voltage link in order to reduce switching losses. This allows operation with higher switching frequencies. In these inverters, the switching instances have to be synchronized with the periodic zero crossings of the link voltage. Thus synchronous pulse modulation strategies like Sigma‐Delta‐Modulation have to be used for control. The benefit of high switching frequency has to be considered in the light of performance of the modulation scheme, which can be measured by determining the r.m.s. value of the distortion current. In this paper, this magnitude is calculated analytically for three‐phase inverters controlled by synchronous Sigma‐Delta Modulation. The derivation is based on the assumptions of constant link frequency and large ratio of link‐ to output frequency. The solutions allow to calculate the r.m.s. distortion current for any periodic shape of the link voltage including DC. Simulations show that the results hold for link‐ to output frequency ratios down to 100. The spectral performance of synchronous Sigma‐Delta‐Modulation is compared with conventional pulse width modulation.

UR - http://www.scopus.com/inward/record.url?scp=0026944235&partnerID=8YFLogxK

U2 - 10.1002/etep.4450020603

DO - 10.1002/etep.4450020603

M3 - Article

AN - SCOPUS:0026944235

VL - 2

SP - 351

EP - 358

JO - European Transactions on Electrical Power

JF - European Transactions on Electrical Power

SN - 1430-144X

IS - 6

ER -