Used for testing the characteristics of the fuse of the power battery of new energy vehicles
As people's requirements for automobile safety, environmental protection, energy saving and comfort are increasing, electronic products on automobiles are being used more and more. Various types of new connectors and fuses have been continuously introduced, and the fusing capacity has been continuously enhanced. At present, most of the fuses used in the power battery of new energy vehicles are bolt-type fuses, with a making and breaking capacity of up to 500A, and there are typically two types of SF30 and SF51. Let's introduce how to use ITECH high-power power supply and high-power electronic load to test the fusing time of the fuse.
As a component that permanently disconnects the circuit under abnormal conditions (when overload current passes), the fuse plays a vital role in the safety of the car body. Therefore, the fusing time index of the fuse is one of the items that must be tested. In the ISO8820-5_2007 and ISO8820-1_2005 national standards for road vehicle fuses, the parameter definitions and test indicators of the fuse are described in detail.
Complete fuse-related tests include conduction voltage drop test, fusing time, progressive current and segmentation capability test. This article mainly takes SF30 and SF51 as the object to be tested, focusing on the fusing time test.
Test requirements for fusing time:
The following figure is taken from the fusing test requirements for SF30 and SF51 in the ISO8820-1_2007 national standard. The fusing time must be tested within the range of overload current from 1.1IR to 6.0IR. The greater the overload current, the faster the fusing time. If you look at a 500A fuse, 6IR means that the overload current needs to reach 3000A, and the fusing time is measured under this condition.
Fusing time test program:
For the 3000A fusing time test, the most advanced electronic load and power supply scheme can form a basic test framework, but there are still some difficulties in the scheme, which cannot be satisfied by some current test and measurement instrument vendors. For example: (1) An oscilloscope needs to be added to the fusing time test. The oscilloscope is expensive, but only the current fall time measurement function of the oscilloscope is used in this system, which will increase the equipment cost (2) Hardware, power supply and electronic load At the same time, there are not many professional equipment and instrument manufacturers that meet 3000A. Many use adjustable resistors to achieve it, but the operation will be very troublesome. (3) Lack of professional test software (4) Meet the source and load of 3000A. The plan is feasible. In the early stage, whether the volume is special Huge, detailed This is the concern of every planning laboratory staff.
Regarding the above difficulties, ITECH has made breakthroughs one by one by relying on powerful hardware firmware functions. It has not completed the 3000A fusing time system solution in the laboratory of a well-known domestic fuse manufacturer.
Customer on-site feedback measured pictures
On-site cabinet shipping diagram
Advantages of the fusing time scheme:
(1) Use IT8900A/E series load with Measure function to measure the fusing time
In the fuse fusing time test application, the fusing time corresponds to the time from point C to point E in the figure below (positive pulse width time), and the time measurement accuracy is comparable to that of an oscilloscope.
the amount
The measuring time is determined by sending instructions through the host computer software. For example, to test the rise and fall time of the power supply voltage from 1V to 8V and the current from 1A to 5A, the following instructions can be sent:
SYSTem: REMote
FUNCtion CURRent
CURRent 6
SENSe: TIME: VOLTage1 1
SENSe: TIME: VOLTage2 8
SENSe: TIME: CURRent1 1
SENSe: TIME: CURRent2 5
INPut 1
SENSe: TIME: VOLTage: UP?
SENSe: TIME: VOLTage: DOWN?
SENSe: TIME: CURRent: UP?
SENSe: TIME: CURRent: DOWN?
IT8900A/E series load comes with time measurement function, and the measurement accuracy is comparable to that of an oscilloscope.
Comparison chart of IT8900A and oscilloscope test current fall time
(2) In the fuse test program, it is mainly applied to IT8900A/E series high-power loads and IT6000 series high-power power supplies. The maximum load power can reach 600KW. The IT6000 series power supply 15KW module is only 3U in height, which greatly reduces the volume of the entire system.
(3) Professional host computer software, the software has the function of measuring and recording the melting time under different current magnifications, and the function of drawing the melting waveform curve.
In summary, in the field of new energy, ITECH has a complete, reliable and highly accurate fusing time measurement system. In addition, ITECH also has an on-board charger test system and a battery test system. DC charging pile simulation system, etc.
Shenzhen Linx Technology Co., Ltd. , https://www.linxheadphone.com