Abstract: The present disclosure provides a control method for a current-limiting control circuit and an electrical system. The current-limiting control circuit includes a high voltage side connected with a direct-current (DC) bus, a low voltage side connected with a load, and a regulating unit connected with the high voltage side and the low voltage side, the regulating unit including at least one MOS transistor, and the control method includes: detecting current I0 of the current-limiting control circuit; determining whether the current I0 is greater than a preset current I; and determining that the current-limiting control circuit has a short circuit fault, and entering a current limiting control mode to limit a persistent growth of the current, in a case where the current I0 is greater than the preset current I.

Abstract: A method, an apparatus, and a system for detecting the working state of a photovoltaic panel, and a photovoltaic electrical system are provided. The photovoltaic panel is arranged in a photovoltaic electrical system including a photovoltaic device and a control device. The photovoltaic device includes the photovoltaic panel and a modulator. The control device includes a demodulator. The photovoltaic device is connected to the control device via a direct current bus. The method includes: detecting the operating state of the photovoltaic panel to obtain a state parameter; modulating, through the modulator, the state parameter to obtain a modulated signal, and loading the modulated signal to the direct current bus; transmitting the modulated signal to the demodulator through the direct current bus. The demodulator demodulates the modulated signal to obtain the state parameter.