Abstract: A synchronous rectification control method for a resonant converter includes: obtaining an output current of the resonant converter; obtaining a first parameter if the output current is greater than a first current threshold; obtaining a second parameter if the output current is less than a second current threshold, the first current threshold being greater than the second current threshold, and the first parameter being greater than the second parameter; establishing a first current hysteresis loop according to the first parameter and establishing a second current hysteresis loop according to the second parameter, a parameter of the first current hysteresis loop being the first parameter, and a parameter of the second current hysteresis loop being the second parameter; and using the first current hysteresis loop and the second current hysteresis loop to control synchronous rectification of the resonant converter in a load switching working condition.

Abstract: A resonant converter and a variable cutoff frequency control method of the resonant converter are provided. The variable cutoff frequency control method includes obtaining a first relationship between a lower limit frequency of the resonant converter and a preset voltage outputted by the resonant converter; updating the preset voltage in the first relationship to a correlative voltage between the preset voltage and an actual voltage outputted by the resonant converter, to obtain a second relationship between the lower limit frequency and the correlative voltage; and limiting the lower limit frequency of the resonant converter according to the second relationship.

Abstract: A resonant converter and a variable cutoff frequency control method of the resonant converter are provided. The variable cutoff frequency control method includes obtaining a first relationship between a lower limit frequency of the resonant converter and a preset voltage outputted by the resonant converter; updating the preset voltage in the first relationship to a correlative voltage between the preset voltage and an actual voltage outputted by the resonant converter, to obtain a second relationship between the lower limit frequency and the correlative voltage; and limiting the lower limit frequency of the resonant converter according to the second relationship.

Abstract: Disclosed herein is a distributed battery pack power supply system, a charging control method, and a discharging control method, where a plurality of battery packs or battery groups is directly coupled in parallel or indirectly coupled in parallel as required using a charging/discharging circuit of the distributed battery pack power supply system and a corresponding control policy. A distributed battery includes a plurality of battery packs, and further includes a controller, a bidirectional voltage transformation circuit, a bypass circuit, a charging circuit, and a charging input end. Each battery pack corresponds to one bypass circuit and one bidirectional voltage transformation circuit.

Abstract: An insulation resistance detection circuit, detection method, and detection apparatus are provided. The circuit includes an alternating-current signal source, a resonant cavity, a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch, and a second switch. The alternating-current signal source is sequentially connected to the first resistor, the resonant cavity, the first switch, the second resistor, and the third resistor in series to form a loop. The first resistor is connected to a positive electrode of the alternating-current signal source, and the third resistor is connected to a negative electrode of the alternating-current signal source. One end of the second switch is connected to a negative electrode of a to-be-detected battery, the other end of the second switch is connected to the fourth resistor, and the other end of the fourth resistor is connected to ground.

Abstract: A distributed battery pack power supply system, a charging control method, and a discharging control method, where a plurality of battery packs or battery groups is directly coupled in parallel or indirectly coupled in parallel as required using a charging/discharging circuit of the distributed battery pack power supply system and a corresponding control policy. A distributed battery includes a plurality of battery packs, and further includes a controller, a bidirectional voltage transformation circuit, a bypass circuit, a charging circuit, and a charging input end. Each battery pack corresponds to one bypass circuit and one bidirectional voltage transformation circuit.

Abstract: An insulation resistance detection circuit, detection method, and detection apparatus are provided. The circuit includes an alternating-current signal source, a resonant cavity, a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch, and a second switch. The alternating-current signal source is sequentially connected to the first resistor, the resonant cavity, the first switch, the second resistor, and the third resistor in series to form a loop. The first resistor is connected to a positive electrode of the alternating-current signal source, and the third resistor is connected to a negative electrode of the alternating-current signal source. One end of the second switch is connected to a negative electrode of a to-be-detected battery, the other end of the second switch is connected to the fourth resistor, and the other end of the fourth resistor is connected to ground.