Method, apparatus, and system for detecting working state of photovoltaic panel, and photovoltaic electrical system

A method, an apparatus, and a system for detecting the working state of a photovoltaic panel (30), and a photovoltaic electrical system. The photovoltaic panel (30) is provided in the photovoltaic electrical system. The photovoltaic electrical system comprises a photovoltaic device (10) and a control device (20), the photovoltaic device (10) comprising a photovoltaic panel (30) and a modulator, the control device (20) comprising a demodulator, and the photovoltaic device (10) and the control device (20) being connected to each other by means of a DC bus. The method for detecting the working state of a photovoltaic panel (30) comprises: detecting the working state of a photovoltaic panel (30), so as to obtain a state parameter of the photovoltaic panel (30) (S301); modulating, by means of a modulator, the state parameter of the photovoltaic panel (30), so as to obtain a modulation signal, and loading the modulation signal onto a DC bus (S302); transmitting, by means of the DC bus, the modulation signal to a demodulator (S303), the demodulator being used for demodulating the modulation signal, so as to obtain the state parameter of the photovoltaic panel (30). Said method achieves the effect of improving the communication quality between the photovoltaic device (10) and the control device (20).