无论是哪一种变频器，都大量使用了晶闸管等非线性电力电子元件，不管采用整流方式，变频器从电网中吸取能量的方式都不是连续的正弦波，而是从脉动的断续方式向电网索取电流，这种脉动电流和电网的沿路阻抗共同形成脉动电压降叠加在电网的电压上，使电压发生畸变，经傅立叶原理分析可知，这种非同期正弦波电流是由于频率相同的基波和频率大于基波频率的谐波组成。
ORK ROTARY SCREW COMPRESSOR W/YORK ISN CODEPAK
DYNATEC 510-6-P12-24 GLUE MACHINE USED*
GIANT LOT OF FUSES,GOULD SHAWMUT ,FUSETRON,BUSS,
GOULDS ITT 1X1 1/4-6 COMMERCIAL WATER PUMP 1/2 HP, NEW
RELIANCE ELECTRIC 3RA2004 SERVO DRIVE USED
RELIANCE ELECTRIC BRUSHLESS AC SERVO CONTROLLER, USED
GRACO 205395, 50:1 FIREBALL BARRELL 425 AIR PUMP, USED
MAGNETEK L717 GP+ 10 HP E PLUS ADJUSTABLE SPEED
RELIANCE ELECTRIC 3RA2002 SERVO DRIVE USED
TEST GUAGE CART - 3 GAUGES, 3 DRAWERS, USED
RELIANCE ELECTRIC 3RA2001 SERVO DRIVE USED
RELIANCE ELECTRIC 3RA2008U SERVO CONTROLLER USED
WESTINGHOUSE LD3600WK 600A CIRCUIT BREAKER USED
