DC/DC converter output control method

Abstract

The invention discloses a DC / DC converter output control method. A total control unit obtains output total power of a DC / DC converter, according to the output total power, power needed by each power module is calculated, and a control unit of each module, according to the received module power, adjusts output voltages and adjusts output currents through adjusting the output voltages at the same time; and the module control units calculates output power of each module in real time in an adjustment process. According to the invention, random combination of multiple modules can be realized, a flow equalization state can be reached after random parallel connection, and the reliability of flow equalization is guaranteed.

Description

technical field [0001] The invention relates to a DC / DC converter output control method. Background technique [0002] In 2014, the first hydrogen fueled tram rolled off the assembly line. Fuel cells have the advantages of high energy conversion rate, diversified fuels, less environmental pollution, low noise, high reliability, and good maintainability. Due to the soft electrical output characteristics of fuel cell engines and considering the needs of vehicle system control, high-power DC / DC converters are one of the essential key components; how to design hydrogen fuel DC-DC is not only related to The normal operation of the fuel cell stack and the whole vehicle system is also related to the power performance, energy utilization efficiency and stable and reliable operation of other control systems of the entire fuel cell tram. [0003] The currently used high-power DC / DC mainly adopts a single high-power power supply and multiple low-power modules for parallel output powe...

AI Technical Summary

Problems solved by technology

[0004] 1. When the power supply fails, the whole system cannot work normally;

[0005] 2. Low efficiency when working with low power;

[0006] 3. Modular design cannot be carried out. When aiming at different output power, it needs to be redesigned

[0007] There are many schemes for parallel output of multiple modules, but the external characteristics of each module in parallel are difficult to be completely consistent

Due to factors such as the inevitability of errors and the limitation of technological levels, the parameters of each module participating in parallel connection in the actual system will have some differences. This difference can only be minimized as much as possible, but it cannot be completely avoided. In addition, the parameters of each module Parameters (such as: output voltage, current) will also change with changes in external factors such as time and temperature. The differences in parameters between modules caused by such external factors may be much larger than the inherent differences in the modules themselves

Therefore, if the modules are directly connected in parallel, because the external characteristics of each module are inconsistent, the modules with small voltage regulation and good external characteristics will bear more current, or even overload; while some modules with poor external characteristics operate under light load, or even basically is empty

As a result, modules that share too much current will inevitably have greater thermal stress, higher probability of damage, and lower reliability

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