A two-stage power converter has a Power-Factor Converter (PFC) and a Dual Active Bridge (DAB) converter connected together by a DC link voltage. The DAB converter outputs a battery voltage with a battery current. A PFC controller divides a reference power constant by the battery voltage to get a battery current reference that is multiplied by a constant and compared to the DC link voltage to adjust Pulse-Width-Modulation (PWM) control signals to the PFC. The reference power constant is compared to the battery current during Constant-Power mode to cause a DAB controller to modulate duty ratio and phase difference between primary and secondary-side PWM control signals to the DAB converter. The DAB converter duty ratio and phase difference are modulated by comparing the battery current to a battery current limit during Constant-Current mode and by comparing the battery voltage to a battery voltage limit during Constant-Voltage mode.

A two-stage power converter has a Power-Factor Converter (PFC) and a Dual Active Bridge (DAB) converter connected together by a DC link voltage. The DAB converter outputs a battery voltage with a battery current. A PFC controller divides a reference power constant by the battery voltage to get a battery current reference that is multiplied by a constant and compared to the DC link voltage to adjust Pulse-Width-Modulation (PWM) control signals to the PFC. The reference power constant is compared to the battery current during Constant-Power mode to cause a DAB controller to modulate duty ratio and phase difference between primary and secondary-side PWM control signals to the DAB converter. The DAB converter duty ratio and phase difference are modulated by comparing the battery current to a battery current limit during Constant-Current mode and by comparing the battery voltage to a battery voltage limit during Constant-Voltage mode.

A wirelessly charged electronic device, a wireless charging method, and a wireless charging system are disclosed. A charger of a receive end of the system includes an open-loop DC-DC (direct current-to-direct current) converter. When power of a transmit end is greater than a first preset threshold of the transmit end and required charging power is greater than a first preset threshold of a receive end, the open-loop DC-DC converter is controlled to work in a fast charging phase, specifically including: controlling the open-loop DC-DC converter to work in a constant current step-down phase to charge a battery at a constant current, or controlling the open-loop DC-DC converter to work in a constant voltage step-down phase to charge the battery at a constant voltage.

An electric vehicle (EV) charging station for fast charging (e.g. 5 to 15 minutes) an electric vehicle (EV). The EV charging station can be configured to charge multiple EVs and multiple conventional fuel type vehicles at the same time.

A battery pack is provided in which the battery pack itself can recognize a determination of a full charge, which is made by a charger, without using a communication line. A battery pack is provided with a secondary battery, current measurement means for measuring a charging current for charging the secondary battery, and a control circuit which receives an output signal from the current measurement means. The control circuit determines that the secondary battery is fully charged when a reduction rate of the charging current in a unit time exceeds a predetermined value.

A single-phase and three-phase compatible conversion circuit includes an EMC module, a PFC module, a switch K1 and a control module. The EMC module is connected between lines A, B, C and N of a power grid and the PFC module. Three lines A1, B1 and C1 are led out from the EMC module and are connected with the PFC module, and are respectively connected to a set virtual midpoint through capacitors CX1, CX2, and CX3. The virtual midpoint is connected to a bus midpoint of the PFC module through the switch K1. The control module is used for detecting a power grid input signal and controlling the state of the switch K1 according to the type of the power grid input signal. The common-mode noise of the three-phase conversion mode can be reduced, and the three-phase conversion mode can be controlled within a larger bus voltage regulation range.

A single-phase and three-phase compatible conversion circuit includes an EMC module, a PFC module, a switch K1 and a control module. The EMC module is connected between lines A, B, C and N of a power grid and the PFC module. Three lines A1, B1 and C1 are led out from the EMC module and are connected with the PFC module, and are respectively connected to a set virtual midpoint through capacitors CX1, CX2, and CX3. The virtual midpoint is connected to a bus midpoint of the PFC module through the switch K1. The control module is used for detecting a power grid input signal and controlling the state of the switch K1 according to the type of the power grid input signal. The common-mode noise of the three-phase conversion mode can be reduced, and the three-phase conversion mode can be controlled within a larger bus voltage regulation range.

A charging circuit of an on-board charger, where a second end of a first power conversion circuit of the charging circuit is coupled to a first end of a second power conversion circuit, a high-voltage output end of the second power conversion circuit charges a power battery pack of an electric vehicle, and a first low-voltage output end of the second power conversion circuit supplies power to a low-voltage system of the electric vehicle. The first power conversion circuit is configured to, when the electric vehicle is in a charging mode, convert an alternating current input from a first end of the first power conversion circuit into a direct current and transmit the direct current to the first end of the second power conversion circuit.

A charging circuit of an on-board charger, where a second end of a first power conversion circuit of the charging circuit is coupled to a first end of a second power conversion circuit, a high-voltage output end of the second power conversion circuit charges a power battery pack of an electric vehicle, and a first low-voltage output end of the second power conversion circuit supplies power to a low-voltage system of the electric vehicle. The first power conversion circuit is configured to, when the electric vehicle is in a charging mode, convert an alternating current input from a first end of the first power conversion circuit into a direct current and transmit the direct current to the first end of the second power conversion circuit.

A charging method for a non-aqueous electrolyte secondary battery. The battery includes a positive electrode, a negative electrode including a negative electrode current collector, and a non-aqueous electrolyte, in which a lithium metal deposits on the negative electrode during charge, and the lithium metal dissolves in the non-aqueous electrolyte during discharge. The method includes first to third steps. In the first step, a constant-current charging is performed at a first current I.sub.1 having a current density of 1.0 mA/cm.sup.2 or less. In the second step, a constant-current charging is performed at a second current I.sub.2 being larger than the first current I.sub.1 and having a current density of 4.0 mA/cm.sup.2 or less. In the third step, a constant-current charging is performed at a third current I.sub.3 being larger than the second current I.sub.2 and having a current density of 4.0 mA/cm.sup.2 or more.