随着运行时间的增长,光伏连接器会出现氧化、老化、松动等现象,易导致接触不良、发热等问题,最终可能引起断路、电弧等故障,对光伏系统的高效、安全运行造成不良影响.由于光伏连接器故障会引起其等效阻抗的变化,该文采用扩频时域反射法(spread spectrum time domain reflectometry,SSTDR)来进行检测:通过向光伏连接器所在的光伏组件串注入正弦高频信号调制的伪随机序列序列测试信号,分析入射信号与反射信号的相关特性,再与健康状态下的特性进行比较,来实现光伏连接器故障在线诊断.对此进行仿真计算并在4块光伏板组成的光伏组串中进行实验,发现开路故障时包络面积最大可达到5×105,而脱离故障时包络面积最小为0.8×105,二者皆远大于健康时的包络面积0.07×105,可有效诊断光伏连接器是否发生故障.
SSTDR-based Fault Detection in Photovoltaic Connector
The oxidation, aging, loosening and other phenomena will appear in the photovoltaic connector with the growth of its operation time, and it is easy to lead to bad contact, heating and other problems, which may eventually cause circuit break, arc and other faults, and cause adverse effects on the efficient and safe operation of the photovoltaic system. The failure of the photovoltaic connector can cause the change of the equivalent impedance, therefore, the spread spectrum domain reflection method is adopted to perform tests. The photovoltaic module is strung into sinusoidal high-frequency signal to modulate the pseudo random sequence sequence and to test signals, and the incident signal and the reflection signal are analyzed to realize the online diagnosis of photovoltaic connector fault. The simulation calculation and experi-ment in the photovoltaic group are composed of four photovoltaic panels. It is found that the maximum envelope area can reach 5×105 in the open fault, and the minimum envelope area at the fault is 0.8×105, which are far greater than the healthy envelope area 0.07×105. Thus, whether the photovoltaic connector is faulty can be effectively diagnosed.
万方数据
维普
