The invention discloses an on-line monitoring and state
evaluation system for photovoltaic grid-connected power generation. The
system comprises an electric quantity collection unit, an input unit, an output unit, an ARM9
data management unit, a CPLD / FPGA interface conversion unit, a temperature and illumination measuring unit and a
power supply unit. According to the invention, a multi-CPU whole
embedded system that is composed of an ARM 9, an ARM7, a DSP is employed, so that reliability of a measurement
control unit is substantially improved and expandability is high; an FFT is used as a basic electrical
energy quality measuring
algorithm, high precision sampling and synchronous transmission are utilized and real-time measurement on an environmental parameter is combined; and moreover, an inter-
harmonics measuring
algorithm and a
harmonics source positioning and responsibility
distribution method are put forward; consequently, on-line and real-time monitor on an electrical
energy quality and an operation state of a photovoltaic grid-connected
power station comprehensively and various
stable state and transient events are recorded. Therefore, it is convenient for operation staff to visually monitor the operation state of the photovoltaic grid-connected
power station as well as reliable data and sufficient basis are provided for analyzing causes of a disturbance and a fault, wherein the disturbance and the fault occur in the operation; and thus the invention of on-line monitoring and state
evaluation system is an important basis for realization of
new energy access of a
power grid.