Abstract: A power conversion device includes a conversion device having includes a first, a second, a third and a fourth converter, and a control unit. The first converter has a first input terminal and a first output terminal; the second converter has a second input terminal and a second output terminal; the first and the second input terminal are electrically connected to a power supply. The third converter has a third input terminal and a third output terminal, the third input terminal is coupled to the first output terminal; the fourth converter has a fourth input terminal and a fourth output terminal; the fourth input terminal is coupled to the second output terminal, and the third output terminal is electrically connected to the fourth output terminal. The control unit is coupled to the conversion device, receives a power request from a load, and controls an output power of the conversion device.

Abstract: A power conversion device used in electric vehicles includes a transmission assembly and a power converter. The transmission assembly is detachably connected to the electric vehicle and receives a first power from the battery pack of the electric vehicle. The power converter is electrically connected to the transmission assembly and converts the first power into a second power or a third power. The power converter is configured outside the electric vehicle.

Abstract: Provided are a provisioning method for cloud service and a system thereof. The provision method according to some embodiments may include collecting a resource utilization rate of each of a plurality of cloud nodes, receiving a regular instance request from a client, determining whether there is a cloud node among the plurality of cloud nodes that satisfies a first condition, in which the collected resource utilization rate is less than a first threshold value, designating a specific cloud node from among the plurality of cloud nodes based on a determination that there is no cloud node that satisfies the first condition, and terminating at least some of spot instances pre-provisioned on the specific cloud node and provisioning a requested regular instance.

Abstract: The present invention provides a soft-transition controller for use with a synchronous converter having primary and secondary rectifiers. In one embodiment, the soft-transition controller includes a primary driver configured to provide a primary drive signal to the primary rectifier operating in a synchronous mode, while the secondary rectifier is operating in a diode mode, to provide an output voltage of the synchronous rectifier. Additionally, the soft-transition controller also includes a complementary driver coupled to the primary driver and configured to provide a soft-transition drive signal during a transition period, which transfers the secondary rectifier from the diode mode to a synchronous mode while maintaining the output voltage within a predetermined voltage range.

Abstract: A system for, and method of, increasing effective pulse-width modulated (PWM) drive signal resolution and a power converter incorporating the system or the method. In one embodiment, the system includes: (1) a duty cycle calculator configured to calculate a theoretical duty cycle for a PWM drive signal to be provided to an associated power converter based on at least one operating condition thereof, the theoretical duty cycle not a member of a pre-established set of allowable duty cycles and (2) a duty cycle approximator coupled to the duty cycle calculator and configured to generate a sequence of members of the set of allowable duty cycles, wherein the sequence at least approximately averages to the theoretical duty cycle.

Abstract: A UPS system for communications systems. The UPS system comprises an input stage that generates primary and standby AC power signals. The primary and standby AC power signals are passed through an isolation transformer and through an output rectifier to obtain an output DC power signal. A plurality of output inverters are used to generate a plurality of output AC power signals from the output DC power signal. A switch circuit is provided to connect one or more of the output DC power signals to one or more loads of the communications system.