Experienced Client engineers selected the instrumentation/components, designed the hardware platform for the battery module test station, and developed test specifications to define the desired testing procedures. Although the Client had expert test engineering and software programming resources on staff, the Client chose to engage DMC to handle the software programming portion of the test system development. This allowed the Client to expedite the overall implementation schedule of the test system (in turn allowing the Client to begin realizing cost savings sooner from reduced warranty servicing costs), as well as to allow the Client's engineering resources to focus their valuable time on developing and executing their battery pack remanufacturing process.
DMC programmed a LabVIEW-based Test Control Application to test the Battery Control Unit in full accordance with the Client's prescribed testing specifications. DMC implemented this application rapidly by leveraging existing code modules from the DMC Battery Test Platform and molding these preexisting frameworks to the Client's unique hardware architecture and testing requirements.
The Test Control Application provides fully automated functional testing of battery pack samples through a "Test Executive" architecture. This highly configurable architecture allows engineering users to establish a library of defined test procedures by adjusting input settings and grading criteria for pre-defined test processes (based on testing specs). A flexible test sequence management interface then allows these test procedures to be sequenced together to build a comprehensive functional testing regiment.
The Test Control Application also provides users with a Manual Mode interface that provides direct, on demand control of all test stand connections and instrumentation. This increases the overall flexibility of the test system by allowing operators to perform ad-hoc testing operations and detailed diagnostic investigations that are not formally instantiated as part of an automated test procedure.
The automated testing capabilities provided by this test station include the following:
- DUT Connection Test: Performs appropriate continuity measurements to ensure proper Device Under Test connection to test stand
- 2 Point Resistance Measurement Test: Performs resistance measurements between pairs of DUT connection points to verify proper impedances and continuity/connection paths
- CAN Response and Programming Test: Verifies CAN and CCP communications with the DUT are operating properly and obtains DUT model and software version information of current DUT
- Isolation Resistance Test: Performs DC HiPot isolation resistance measurements between configurable DUT Connection points (e.g. from Battery Control Unit's high voltage bus to low voltage / chassis connections)
- Voltage Sense Test: Verifies that the Battery Control unit is properly and accurately measuring and reporting full stack voltages and cell voltages across a range of expected pack voltages
- Thermistor Sense Test: Applies configurable resistances to the DUT's Thermistor sense connections, and verifies that the Battery Control Unit is properly and accurately measuring and reporting thermistor temperature data and associated temperature based fault codes
- Current Sensor Test: Applies a configurable current flow through the DUT's current sensor to verify that the Battery Control Unit is properly and accurately measuring and reporting current flow (in both directions)
- Isolation Detection Test: Induces an isolation fault between high voltage and low voltage / chassis connection points on the DUT and verifies that the DUT properly identifies and responds to this fault condition