Non-isolated resonant converter and control method thereof

The embodiment of the invention discloses a non-isolated resonant converter and an equivalent excitation impedance adjusting method, the non-isolated resonant converter comprises a controller, a sampling circuit, a switching circuit, a resonant circuit and a rectification output circuit, and the switching circuit is configured to output a square wave signal to the resonant circuit; the resonance circuit is used for adjusting and outputting a square wave signal to the rectification output circuit; the rectification output circuit is used for rectifying the square wave signal to output a direct current signal to a load; the sampling circuit is used for acquiring a voltage value and a current value of the DC signal; the controller controls the resonant circuit to be set as an LLC topology or an LCC topology or a four-device topology in response to the voltage value or the current value. According to the embodiment of the invention, the resonant circuit is set as an LLC topology, an LCC topology or a four-device