A BBU, or Backup Battery Unit, is installed in a server system to supply temporary power in the event of a power outage. When a power failure occurs, the system immediately switches to the BBU, allowing volatile data to be written to a backup SSD and thus prevent data loss. To ensure stable server performance and real-time data backup during BBU discharge, the OCP ORV3 specifications include test guidelines for BBUs. A BBU mainly consists of a battery pack, a battery management system (BMS), and a bidirectional DC-DC converter. During a power failure, the battery takes over the energy supply, which is then regulated by the DC-DC converter to deliver a stable output voltage, keeping the server running without interruption.
Key Features
This Server BBU Bidirectional Power Automated Test System is a customized solution built upon the Chroma 8000 ATS platform. It is specifically designed for automated testing and validation of BBU bidirectional DC-to-DC converters. Paired with instruments such as the Chroma 62000D, 62000H, and 63200A series, the system covers a comprehensive range of test scenarios for BBU DC-to-DC converters, including charge/discharge functions, discharge characteristics and performance, protection features, and PMBus communication. Unlike traditional automated test software, the software included in this system requires only minimal setup: simply define the test conditions and specifications, and automated testing can begin. Test reports are generated instantly upon completion for maximum efficiency.
BBU DC-to-DC Converter Test Items and Specifications
The diagram below illustrates the power architecture of a data center server system. When the power shelf is operating normally, the BBU's bidirectional DC-to-DC converter converts the external Busbar power to an appropriate voltage to charge the BBU battery. In the event of a power failure, the battery provides backup power, which the DC-to-DC converter then turns into the stable voltage required by the server to ensure continuous operation.
Chroma’s server power testing solution supports development of automated test items and plans aligned with the OCP ORV3 test guidelines. This allows for in-depth evaluation of either the complete BBU module or just the bidirectional DC-DC converter, verifying product performance and reliability under real-world conditions to ensure compliance with today’s stringent server power standards. The test items cover BBU discharge performance, charging characteristics, regulation, timing and transient characteristics, protection, and communication of BBU module status parameters via PMBus.
Discharge Performance
- Discharge voltage and current testing
- Discharge efficiency testing
- Battery-side voltage ramp up/down testing
- Discharge voltage ripple measurement
Charging Characteristics
- Charging voltage and current testing
- Charging efficiency testing
- Busbar voltage ramp up/down testing
Regulation Testing
- Discharge load regulation
- Battery-side voltage regulation
- Comprehensive regulation testing
Timing and Transient Testing
- Discharge output voltage timing measurement
- (Multi-stage) dynamic load testing
Protection Testing
- Over Voltage Protection (OVP) Testing
- Under Voltage Protection (UVP) Testing
- Over Current Protection (OCP) / Over Power Protection (OPP)
- Short Circuit Protection (SCP) Testing
Other
- PMBus Communication Testing
The ORV3 specifications cover a wide range of server power devices and parameters. Chroma’s comprehensive portfolio of test & measurement equipment ensures an automated test system can be tailored to meet specific product specs and testing needs. The recommended test system architecture and supporting equipment for power conversion devices are shown below:
▲ BBU Bidirectional DC-DC Converter Test Architecture
The Chroma 8000 test system includes PowerPro, Chroma's widely adopted power supply testing software platform. PowerPro provides an open software framework that allows users to freely select test hardware, develop their own test programs, automate pass/fail judgments, and conveniently generate reports.
The Chroma 8000 is fully compatible with all relevant device drivers and control commands. When users need to replace test hardware due to upgraded product specifications, the programmed test items and procedures can be reused without modifying the code, allowing seamless interchangeability of ATE equipment. Chroma’s deep expertise in power testing also means reliable technical support and consulting, which helps customers manage changes in test personnel without affecting the maintainability of the test platform.
▲ Chroma 8000 ATS Main Panel
▲ Test Execution (GO/NO GO) Screen
▲ Test Report
