A control device includes a processor configured to detect a voltage at an intermediate point connecting a first DCDC converter and a second DCDC converter, control the first DCDC converter and the second DCDC converter, and when the detected voltage at the intermediate point exceeds a first threshold, limit an output of the first DCDC converter after an output current of the second DCDC converter reaches a predetermined value.

A power supply system includes a set of power supply units, each power supply unit arranged electrically in series and defining a common power supply, each power supply unit having a power module and a selective bypass for selectively bypassing the respective power module. The power supply system can meet a power demand.

A power supply system includes a set of power supply units, each power supply unit arranged electrically in series and defining a common power supply, each power supply unit having a power module and a selective bypass for selectively bypassing the respective power module. The power supply system can meet a power demand.

A fuel cell power system that includes multiple strings that each have multiple sub-stacks of fuel cells. Each sub-stack is electrically isolated from other sub-stacks and each sub-stack can be independently controlled by a DC control module on a printed circuit board. The DC control module of a sub-stack can regulate or shut off the output power of the sub-stack if the sub-stack becomes weak or fails. A sub-stack can be shut off while other sub-stacks in the system continue to operate. The output power of other sub-stacks can be increased to compensate for sub-stacks that are shut down.

A power feeding system includes a direct current (DC) bus for supplying DC power, a renewable energy power generation device connected to the DC bus, a first converter connected to the DC bus and converting a bus voltage supplied to the DC bus into a load voltage supplied to a load device, a storage battery, a second converter provided between the storage battery and the DC bus and capable of bidirectionally converting the bus voltage and a battery voltage of the storage battery, and a power management device controlling the second converter to charge and discharge the storage battery. The power management device controls the second converter to change the bus voltage based on difference power obtained by subtracting load power supplied to the load device from supply power supplied to the DC bus, the supply power including generated power generated by the renewable energy power generation device.

A power converter includes: an input unit configured to be electrically connected to a device; a voltage charge unit configured to change voltage; a voltage adjustment unit configured to adjust the voltage supplied to a transmission line; a target setting unit configured to set a first target value of the voltage change unit; a voltage monitoring unit configured to observe the voltage of the transmission line; and a threshold determination mechanism configured to calculate a second target value of the voltage adjustment unit in accordance with voltage of the transmission line. The target setting unit of the power converter is configured to generate the first target value as an output target of the voltage charge unit in accordance with the voltage observed by the voltage monitoring unit. The first target value has characteristics to change a threshold voltage for controlling output of the voltage adjustment unit depending on time.

A power integration system with motor drive and battery charging and discharging function includes a motor, a power integration circuit, and a battery. The motor includes multi-phase paths, and each path has an inductor. The power integration circuit includes an inverter and a charger. The inverter includes multi-phase bridge arms, each bridge arm has an upper switch and a lower switch, and each bridge is correspondingly coupled to each inductor of the motor. The charger a switch, the upper switch and the lower switch of at least one bridge arm of the shared inverter, and the inductor of the shared motor. The switch is coupled between any two bridge arms. The power integration circuit receives a DC power provided by a DC power apparatus, and the charger converts the DC power to charge the battery, and the battery provides power required to drive the motor through the inverter.

A DC bus control system for controlling power fluctuations in a DC bus connecting an input power source and a load, comprising: a main stabilization device including a first charging/discharging element and a first power converter; a plurality of the sub stabilization devices including a second charging/discharging element, a charging element, or a discharging element and a second power converter, wherein the plurality of the sub stabilization devices includes a first sub stabilization device having a charging/discharging element and a second power converter and at least one second sub stabilization device having a charging element or a discharging element and a second power converter, and a response speed of the first sub stabilization device is set such that a charging amount of the charging element or a discharging amount of the discharging element of the second sub stabilization device changes with a predetermined time constant.

A DC bus control system for controlling power fluctuations in a DC bus connecting an input power source and a load, comprising: a main stabilization device including a first charging/discharging element and a first power converter; a plurality of the sub stabilization devices including a second charging/discharging element, a charging element, or a discharging element and a second power converter, wherein the plurality of the sub stabilization devices includes a first sub stabilization device having a charging/discharging element and a second power converter and at least one second sub stabilization device having a charging element or a discharging element and a second power converter, and a response speed of the first sub stabilization device is set such that a charging amount of the charging element or a discharging amount of the discharging element of the second sub stabilization device changes with a predetermined time constant.

A voltage control system includes: a converter controlling portion; a current value acquisition portion; and a voltage value acquisition portion. The converter controlling portion sets a duty ratio in a present cycle by adding an addition term to a feedforward term, the addition term being determined by use of a current deviation, which is a difference between a target value of an output current in the present cycle and a current measured value in a previous cycle, and the duty ratio in the previous cycle, the addition term being corresponding to an increase of the output current in the present cycle.