DEVICE FOR MEASURING THE ELECTRIC POWER QUALITY OF CABINET PANEL USING THE 5TH HARMONIC FREQUENCY ANALYSIS

摘要

PURPOSE: A device for measuring the power quality of a panel board by using the fifth harmonic wave analysis is provided to efficiently measure the power quality. CONSTITUTION: A device (100) for measuring the power quality of a panel board comprises a current transformer (110), a digital signal processor (120) for measuring the power quality, and a microprocessor (210). The current transformer reduces the current amount relative to a current signal inputted from each branch line of the panel board in a three-phase four-wire system or a single phase system. The digital signal processor performs the harmonic wave analysis relative to the current signal inputted from each branch line and stores a current level or a voltage level of fifth harmonic wave in a register. The microprocessor receives the current level or the voltage level of fifth harmonic wave from the digital signal processor, compares it with a predetermined reference value, and determines that there is the failure in the power quality when the current level or the voltage level of fifth harmonic wave is greater than the reference value. [Reference numerals] (120) Electricity quality constant volume DSP (ADE7880); (210) Microprocessor; (AA) A phase input; (BB,DD,FF,HH) CT sensor; (CC) B phase input; (EE) C phase input; (GG) N phase input