GB/T 45120-2024Road vehicles - Supply voltage of 48 V - Electrical requirements and tests (English PDF)

4.1 General

A component may include multiple functions. These functions may have different functional states for the same influencing parameter. The influencing parameter specified in this document is the supply voltage, which specifies the minimum functional state requirements for the component.

The functional behavior (including performance degradation) of components related to each selected functional state level and customer perception (e.g., visual, auditory, tactile, and thermal sensation) shall be negotiated between the supplier and the purchaser and described in the required component specifications. See Annex A for application examples.

4.2 Functional state 1 (FS1)

Components shall meet the specified functional requirements, have no performance deviation, and are not allowed to experience performance degradation or shutdown.

4.3 Functional state 2 (FS2)

Components must meet the specified functional requirements. It is permissible to exceed the specified tolerances for one or more performance parameters, but shutdown is not permitted.

4.4 Functional state 3 (FS3)

The component fails to meet the specified functional requirements. Performance degradation or shutdown is permissible. If the necessary operating conditions are met, functionality shall be automatically restored, and performance shall return to the specified level.

4.5 Functional state 4 (FS4)

The component fails to meet the specified functional requirements. Performance degradation or shutdown is permissible. Functionality shall automatically recover and performance shall return to the specified level after a change in vehicle operating conditions (e.g., change in ignition state, vehicle restart) and the necessary operating conditions are met.

4.6 Functional state 5 (FS5)

One or more functions of the component may fail, but spontaneous combustion shall not occur. After testing, the component must be repaired or replaced before continued use.

8.1 Tolerance

Unless otherwise specified, the tolerances for test parameters shall conform to the provisions of Table 3.

8.2 General conditions

Unless otherwise specified, all tests shall be conducted under the following conditions.

- Nominal 12 V/24 V supply voltage (UN). shall comply with ISO 16750-1;

- Nominal 48 V supply voltage (U48N). 48 V;

- Ambient temperature (TRT). 23°C±5°C;

- Relative humidity (RHtest). 25%~75%;

- Test temperature (Ttest). room temperature.

8.3 Sampling rate and numerical resolution

Before each test, the sampling rate/bandwidth, the measurement range of the measurement system, and the resolution of the measured values shall be set to values suitable for the test. Make necessary adjustments as needed. All measurements, including maximum, minimum, or peak values, shall be recorded.

8.4 Interface description

All interfaces that enable DUT performance and meet specific test parameters shall be defined, such as electrical connections and harnesses, mechanical accessories, cooling devices, etc.

8.5 Number of test samples

The number of test samples shall not be less than 2 during the final verification phase.

No requirement is placed on the number of test samples during the initial design verification phase.

8.6 Test voltage

The test voltage shall be measured and recorded (unless otherwise specified, the test voltage refers to the terminal voltage of the DUT). The DUT terminal voltage shall be measured with reference to the ground corresponding to the DUT connector or terminal.

All 48V components with 12V/24V power supply or communication interfaces shall also meet the corresponding requirements for 12V/24V power supplies.

- Unless otherwise specified, during testing of a 12 V/24 V power supply system, the voltage in a 48 V power supply system shall be U48N;

- Unless otherwise specified, the voltage in the 12 V/24 V power supply system shall be UN during the 48 V power supply system test.

48 V components with interfaces for connecting to other power supply voltages shall meet the relevant standard requirements.

8.7 Test procedure

The test procedure shall be negotiated with the customer and recorded in the test plan.

For each test (if applicable), the permissible error storage entries and functional states for each function of the component shall be agreed upon with the customer and recorded in the test plan.

Detailed requirements for test setup, workload (e.g., triggers, vehicle sensors, vehicle actuators, and alternative circuits), and boundary conditions shall be agreed upon by both the supplier and the purchaser and recorded in the test plan and test report.

Components that both supply and consume electrical energy shall be tested in both operating modes.

The test equipment shall have all the interfaces required for the DUT's specified

......