Baidu USA LLC

Yuan Cao

Tianyi Gao

Huawei Yang

A topology of bi-directional multi-output multi-function converter is designed in a BBU. The concept of bi-directional multi-function multi-output converter may be designed for the application of BBUs in a data center to provide multiple control functionalizes, such as battery discharging, battery charging, fan speed control, pump control, as well as providing power for multiple components/devices simultaneously. The proposed converter has two characteristics: bi-direction and multi-output. With the function of bi-direction, the battery discharging and charging can be accomplished with the same converter. With the function of multi-output, different rails of output voltages or power can be applied to different components or devices in BBU, such as fan, pump, control IC chip, sensors and etc. With the proposed concept of bi-directional multi-function multi-output converter, only one converter is required to achieve multiple control functions and provide power to different components, which reduces the volume and cost of a battery backup unit.

Bi-directional multi-function converter for backup battery unit

According to one embodiment, a battery backup system includes an output terminal, one or more BBUs coupled in parallel to provide backup power to an external electronic device coupled to the output terminal, and a control circuit to control the power distribution from the BBUs. Each of the BBUs includes a battery pack having one or more battery cells and a converter to regulate and output power to the output terminal. The control circuit is configured to control a duty cycle for each of the BBUs, which when used to drive the BBU, adjusts power output in order to balance charges amongst the BBUs. The duty cycle of each BBU is determined based on an output voltage across the output terminal, an output current flowing through the output terminal, and characteristics of the battery pack of the BBU.

Charge balancing control for parallel-connected battery energy storage system

According to one embodiment, a BBU includes an array of battery cells, a DC/DC converter coupled to the battery cells, and a first switch logic coupled to the battery cells and the DC/DC converter. The first switch logic is configured to switch the BBU to operate between a first mode and a second mode. When operating in the first mode, the first switch logic causes the output voltage of the DC/DC converter to be provided to an external load. When operating in the second mode, the first switch logic causes the output voltage of the DC/DC converter to be coupled to an internal load for the purpose of determining the health of the battery cells.

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Sunnyvale, CA, United States of America

Yuan Cao