Patent ID: 9496823
Filing Date: 2016-11-15
CPC Classification: G01R,H02S,Y02E

Claim Text:
1. A fault diagnosis system for diagnosing a photovoltaic array having a photovoltaic string having pluralities of photovoltaic modules connected in series by estimating a fault location of the photovoltaic array, comprising: a signal generator for generating a positive terminal input signal which is an input signal into the photovoltaic string when the signal generation device is connected not to a negative terminal but to a positive terminal of the photovoltaic string and for generating a negative terminal input signal which is an input signal into the photovoltaic string when the signal generation device is connected not to a positive terminal but to a negative terminal of the photovoltaic string; a waveform observer for observing a positive terminal output signal which is outputted from the positive terminal as a reflected wave of the positive terminal input signal and for observing a negative terminal output signal which is outputted from the negative terminal as a reflected wave of the negative terminal input signal; and a diagnosis unit for estimating the fault location based on the positive terminal output signal and the negative terminal output signal observed by the waveform observer, wherein the diagnosis unit includes: a memory unit for storing a string length which is distance between the positive terminal and the negative terminal of the photovoltaic string; a reflected wave analyzing unit for analyzing the positive terminal output signal and the negative terminal output signal observed by the waveform observer, for determining positive terminal reflection time which is amount of time from inputting the positive terminal input signal to observing the positive terminal output signal and negative terminal reflection time which is amount of time from inputting the negative terminal input signal to observing the positive terminal output signal, and for making the memory unit store the positive terminal reflection time and the negative terminal reflection time; and a computing unit for estimating distance from the positive terminal or from the negative terminal to the fault location based on the string length and the positive terminal reflection time and the negative terminal reflection time.