The present invention relates to a technique for expanding an input voltage range of a power conversion circuit for photovoltaic power generation, and improving the efficiency of the power conversion circuit. The power conversion circuit for photovoltaic power generation with high efficiency over a wide input voltage range may include: a full-bridge converter unit including a full-bridge converter constituted by first to fourth switches, and configured to operate in a resonant boost mode or phase-shift full-bridge series-resonant converter mode, and convert an input DC voltage into a DC voltage having a level equal to or lower than the input DC voltage; an active voltage-doubler rectifier circuit including a half-bridge converter constituted by fifth and sixth switches, a resonance inductor and a resonance capacitor, and configured to boost an input voltage to a target-level DC voltage, and output the DC voltage to a load; and a transformer configured to connect the full-bridge converter and the active voltage-doubler rectifier to each other in their insulation.

The present invention relates to a technique for expanding an input voltage range of a power conversion circuit for photovoltaic power generation, and improving the efficiency of the power conversion circuit.

The power conversion circuit for photovoltaic power generation with high efficiency over a wide input voltage range may include: a full-bridge converter unit including a full-bridge converter constituted by first to fourth switches, and configured to operate in a resonant boost mode or phase-shift full-bridge series-resonant converter mode, and convert an input DC voltage into a DC voltage having a level equal to or lower than the input DC voltage; an active voltage-doubler rectifier circuit including a half-bridge converter constituted by fifth and sixth switches, a resonance inductor and a resonance capacitor, and configured to boost an input voltage to a target-level DC voltage, and output the DC voltage to a load; and a transformer configured to connect the full-bridge converter and the active voltage-doubler rectifier to each other in their insulation.

An active clamp control circuit for a flyback converter can be configured to: control turn-on states of a main switch and an auxiliary switch to make the auxiliary switch turn on for a first time period in at least one switching period, and to make the main switch turn on for a second time period in each switching period, where the first and second time periods are non-overlapping periods of the switching period; and compare a peak value of an inductor current flowing through the main switch against a first threshold to adjust the first time period of the auxiliary switch when the peak value of the inductor current is greater than or equal to the first threshold, such that the first time period is directly proportional to the peak value of the inductor current.

A switching regulator includes a power stage circuit and a control circuit. The power stage circuit operates a high-side switch and a low-side switch therein according to a high-side signal and a low-side signal respectively to generate an inductor current flowing through an inductor therein. The adjustment signal generation circuit in the control circuit generates an adjustment level according to the high-side signal, the low-side signal, and/or the inductor current, wherein the adjustment level is switched between a reverse recovery level and an anti-latch-up level, and is electrically connected to a low-side isolation region of the low-side switch. The reverse recovery level is lower than the input voltage. The anti-latch-up level is higher than the reverse recovery level to avoid a latch-up effect.

A sense terminal is configured to sense a drain-to-source voltage of a field effect transistor and a drive terminal is configured to drive the gate terminal of the field effect transistor to alternatively turn the field effect transistor on and off to provide a rectified current flow in the field effect transistor channel. A comparator is configured to perform a comparison of the drain-to-source voltage of the field effect transistor with a reference threshold and to detect alternate downward and upward crossings of the reference threshold and the drain-to-source voltage. A PWM signal generator is configured to drive the gate terminal of the field effect transistor to turn the field effect transistor on and off as a result of the alternate downward and upward crossings of the reference threshold by the drain-to-source voltage.

A synchronous rectifier alternator and a power allocation method thereof are provided. The synchronous rectifier alternator includes an alternator, a synchronous rectifier circuit and a controller. The alternator converts mechanical energy to alternating current (AC) electrical energy. The synchronous rectifier circuit converts the AC electrical energy to direct current (DC) electrical energy and provides the DC electrical energy to a load. The controller detects a voltage level of the DC electrical energy. When the controller detects that the voltage level is higher than or equal to a first threshold voltage value, the controller controls ONs and OFFs of first transistors and second transistors of the synchronous rectifier circuit, such that at least one of regulator diodes of the synchronous rectifier circuit, a stator of the alternator and the load consume power of the alternator.

In a switching converter having an inductive load, a current may flow through the body diode of a transistor even though the gate of the transistor is being controlled to keep the transistor off. Then when the other transistor of the switch leg is turned on, a reverse recovery current flows in the reverse direction through the body diode. To reduce switching losses associated with such current flows, a gate driver integrated circuit detects when current flow through the body diode rises above a threshold current. The gate driver integrated circuit then controls the transistor to turn on. Then when the other transistor of the switch leg is made to turn on, the gate driver first turns the transistor off. When the gate-to-source voltage of the turning off transistor drops below a threshold voltage, then the gate driver integrated circuit allows and controls the other transistor to turn on.

A switching regulator includes a power stage circuit and a control circuit. The power stage circuit operates a high-side switch and a low-side switch therein according to a high-side signal and a low-side signal respectively to generate an inductor current flowing through an inductor therein. The adjustment signal generation circuit in the control circuit generates an adjustment level according to the high-side signal, the low-side signal, and/or the inductor current, wherein the adjustment level is switched between a reverse recovery level and an anti-latch-up level, and is electrically connected to a low-side isolation region of the low-side switch. The reverse recovery level is lower than the input voltage. The anti-latch-up level is higher than the reverse recovery level to avoid a latch-up effect.

In an electric power conversion circuit, a gate controller executes a first operation. In the first operation, the gate controller performs control such that a first lower FET, a first upper FET, a second lower FET, and a second upper FET satisfy the following conditions: a condition that a first state in which the first lower FET is turned on, a second state in which both of the lower FETs are turned off, a third state in which the second lower FET is turned on, and a fourth state in which both of the lower FETs are turned off appear repeatedly in the order; and a condition that the first upper FET is turned on at a middle of a period of the second state and is maintained in an on state until a middle of a period of the third state.

A backflow preventing device includes a backflow preventing element that is connected between a power supply and a load and that prevents electric current from flowing backward from the load side toward the power supply side, and a commutating device that performs a commutation operation for causing the electric current to flow to a commutation path connected in parallel with the backflow preventing element. A plurality of elements including at least one or more of elements constituting the commutating device are configured as a module, so that, for example, the device can be reduced in size. Moreover, a simplified heat-dissipation design and a simplified air-duct design can be achieved.