A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

The invention relates to a device (200) for measuring a current through a choke (130) of a voltage converter (100) comprising an integrator circuit (140), an amplifier circuit and an NTC resistor (160). The amplifier circuit comprises an inverting and a non-inverting amplifier input connection (152, 154) and an amplifier output connection (156). The non-inverting amplifier input connection (154) is supplied with an amplifier input signal according to an integrator output signal. A voltage signal characterising the current through the choke (130) is applied at the amplifier output connection (156) of the amplifier circuit. The NTC resistor (160) is arranged in the feedback path of the amplifier circuit between the inverting amplifier input connection (152) and the amplifier output connection (156).

A control circuit for a resonant circuit includes a resonant current detecting circuit, a current adjustment circuit and an on-time control circuit. The resonant current detecting circuit is configured to receive a resonant current, a first reference and a second reference, and to provide a detected current signal based on the resonant current, the first reference and the second reference. The current adjustment circuit is configured to receive the detected current signal and a charging reference, and to provide an on-time control signal based on the detected current signal and the charging reference. The on-time control circuit is configured to receive the on-time control signal and an on-time initial value, and to provide an on-time signal to control a switch of the resonant circuit based on the on-time control signal and the on-time initial value.

Example embodiments of systems, devices, and methods are provided herein for energy systems having multiple modules arranged in cascaded fashion for storing power from one or more photovoltaic sources. Each module includes an energy source and converter circuitry that selectively couples the energy source to other modules in the system over an AC interface for generating AC power or for receiving and storing power from a charge source. Each module also includes a DC interface for receiving power from one or more photovoltaic sources. Each module can be controlled by control system to route power from the photovoltaic source to that modules energy source or to the AC interface. The energy systems can be arranged in single phase or multiphase topologies with multiple serial or interconnected arrays. The energy systems can be arranged such that each module receives power from the same single photovoltaic source, or multiple photovoltaic sources.

A bidirectional power supply system receives power from a low voltage (LV) primary power supply, providing power to a control unit of a LV board net in a first mode of operation. A high voltage (HV) board net is coupled to a HV traction battery. A DC-DC converter, in the first mode, transfers energy from the LV board net to the HV board net to power components of the HV board net via the primary power supply, and, in a second mode of operation, transfers energy from the HV board net to the LV board net to power the control unit via the traction battery. The bidirectional power supply system includes a measurement element to detect whether the primary power supply is lost, and a switching element to switch operation of the DC-DC converter from the first mode to the second mode, when the primary power supply is lost.

A control unit is provided. The control unit is configured to provide a control signal for controlling a power unit. The power unit includes a first positive voltage terminal, a second positive voltage terminal, a first negative voltage terminal, a second negative voltage terminal, and a switching element. The first negative voltage terminal and the second positive voltage terminal are coupled to each other in a short circuit manner. One terminal of the switching element is electrically connected to the first negative voltage terminal. The control unit is configured to: receive a pulse width modulation signal; receive a first power supply signal; receive a second positive voltage terminal signal; output a second power supply signal; and output the control signal for controlling the switching element to be turned on or turned off.

A power supply system 1 includes: a variable voltage power supply 7 that outputs power of a variable voltage from a pair of secondary-side input/output terminals 72p and 72n; and power lines 21 and 22 that connect the pair of secondary-side input/output terminals 72p and 72n and a load 4. The first power line 21 is provided with a first switch unit 31 and a third power line 23 that connects both ends of the first switch unit 31, and the third power line 23 is provided with a third switch unit 33, a DC power supply 30, and a second switch unit 32 in series. The fourth power line 24 connects the third power line 23 and the second power line 22. The fourth power line 24 is provided with a fourth diode 34a that allows an output current of the DC power supply 30.

A power supply system 1 includes: a DC power supply 30; a variable voltage power supply 7 serving as an isolated bidirectional DC/DC converter that outputs power of a variable voltage E2 from a pair of secondary-side input/output terminals 72p and 72n; a positive electrode power line 21 and a negative electrode power line 22 that are connected to both electrodes of the DC power supply 30; a switching circuit 5 including a plurality of arm switching elements 51, 52, 53, and 54 that connect the power lines 21 and 22 and a load 4; a backflow prevention switching element 34 that is provided on the positive electrode power line 21 between the pair of secondary-side input/output terminals 72p and 72n; a power supply driver 6 that operates the variable voltage power supply 7 and the backflow prevention switching element 34; and a switching circuit driver 8.

A power supply system 1 includes: a variable voltage power supply 7 that outputs power of a variable voltage E1 from a pair of secondary-side input/output terminals 72p and 72n; a first power line 21 and a second power line 22 that connect the pair of secondary-side input/output terminals 72p and 72n and a load 4; a first switch unit 31 that is provided on the first power line 21; a third power line 23 that connects both ends of the first switch unit 31; and a bypass line 25 that connects the pair of secondary-side input/output terminals 72p and 72n, a first DC power supply 33 is provided on the third power line 23 to output DC power, and a bypass diode 33a is provided on the bypass line 25 to allow an output current of the first DC power supply 38.