The power industry's requirements for the selection of dcdc power supply modules

Due to the complexity of the power grid, the power industry isdcdc power moduleThe needs of the company are also diverse. Here are a few key points for selection:

1. Quick start

Certain power applications have strict requirements on the startup sequence of the power module. We have dealt with a case in the past. Customers need to use ±15V, 10W (signal acquisition) and 12V, 10W (controller power supply) in their power control cabinet project. They purchased a certain brand of power supply. The system has been communicating poorly and the problem has not been found. After that, the customer sought support from the FAE of Jinshengyang. After analysis, the start-up delay times of the two power supplies were 370ms and 350mS, respectively. Because the communication system was powered on before the control system, the communication system was in disorder. Slowly lead. Switching to Jinshengyang URA2415YMD-10WR3 and URB2412YMD-10WR3, the startup time is about 20ms, which solves customer problems.

2. Low no-load power consumption

Some monitoring equipment in the electric power industry only operates when abnormal and requires high power, and is in a standby state for a long time during normal operation, such as FTU and anti-shake modules. Most of these systems use batteries as a backup power source. If the no-load power consumption of the DC_DC module is too high, it will cause problems such as short battery life and premature damage. For example, in a certain anti-shake module project, when the power grid loses voltage, the power module needs to provide about 20W of power to power the relay within 1.5 seconds, but most of the time, the relay does not operate and the system is close to no load. At this time, the energy of the battery is consumed by DC/DC, and the greater the no-load power consumption of the power supply, the shorter the battery life. In order to extend the battery life, the no-load power consumption of the power supply must not be higher than 0.3W, and the no-load power consumption of the 20W power supply on the market is generally about 0.5W-1.5W. Jinshengyang URB2424LD-20WR3 adopts frequency conversion technology, and its no-load power consumption is about 0.12W, which meets the application requirements.

3. High isolation voltage, low isolation capacitance

Generally, the isolation voltage of the dcdc power module in the industrial control industry only needs 1500VDC, but the control system in the power industry generally chooses a power module with a withstand voltage of 3000VDC and above to ensure that the control system is not affected by the outside world.

In the case of power electronic products, it is also necessary to pay attention to minimize the parasitic capacitance between the primary side and the secondary side, that is, it is required to select a power module with as low isolation capacitance as possible to reduce the impact of common mode interference on the system. Generally speaking, the 1-2W unregulated open-loop DC_DC powered by the driver is recommended to select an isolation capacitor lower than 10pF, while for the closed-loop design of dcdc, try to select an isolation capacitor lower than 150pF.

4. High efficiency in full load range

Many equipment in the power industry are under light load or even no-load conditions for a long time, so achieving high efficiency in the full load range is of great significance to the reliability of the power supply system, but this is often ignored by most power supply manufacturers. The technical parameters are more attractive, and the full load efficiency is often high, but the efficiency is lower under light load conditions of 5%-50%, which will cause the actual working temperature of the power module to rise higher, leading to a series of thermal design problems . In fact, for the power supply system, the full range of high efficiency means lower power loss and temperature rise, which can effectively improve the system reliability. Therefore, when selecting the power supply, special attention should be paid to its corresponding efficiency under no-load and light-load conditions. curve.

5. EMC characteristics

EMC performance is the guarantee for the normal and safe operation of electronic systems. At present, the electronic industry has put forward high requirements on the EMC performance of products. We often encounter customers complaining that the system resets and restarts or even fails early due to poor EMC handling. Excellent EMC characteristics are the core competitiveness of power modules.

6. Limit temperature characteristics

The geographical area where the power module is applied is very wide, and there may be scorching tropical heat and severe cold similar to Russian winter. Therefore, the operating temperature range of the dcdc module is required to be -40 degrees to 85 degrees. If it is used in automotive BMS and high-voltage bus monitoring applications, the operating temperature needs to be -40 degrees to 125 degrees.

The extreme temperature test is a method to test the reliability of the power module, such as high temperature aging, high temperature& low temperature live performance test, high and low temperature cycle impact test and long time high temperature and high humidity test. Formal power supply development will go through the above tests. Therefore, whether there are such test equipment has also become the basis for judging whether the power supply manufacturer is a copycat manufacturer.