How to use switching power supplies in parallel?
Switching power supply is a power supply widely used in various electronic devices, including DC switching power supply and AC switching power supply. Switching power supplies can provide stable, reliable, and efficient voltage and current outputs, making them the preferred power source for many electronic devices. However, in some cases, a single switch power supply output cannot meet the requirements, and multiple switch power supply outputs need to be used in parallel. In this article, we will provide a detailed introduction on how to use switch mode power supplies in parallel for output.
1. Principle of parallel connection
Connect multiple switching power supplies in parallel to combine them into a larger output power. The principle of parallel connection of power supplies is simple: connect all the positive poles of the power supplies and all the negative poles of the power supplies. This can coordinate all power sources to output larger currents and voltages together. Multiple power sources connected in parallel, each outputting the same voltage and current. If there are more parallel output power sources, the output power will also be higher.
2. Applicable occasions for parallel power supply
Multiple switch power supplies connected in parallel can be applied to various electronic devices, such as high-power LED lighting, high-speed motor drives, frequency converters, and so on. In these applications, the output voltage or current of a single switching power supply cannot meet the requirements. Parallel connection of multiple switching power supplies can increase output power and meet the application needs of high power, high voltage, and high current.
3. Precautions for parallel power supply
The parallel connection of power supplies must follow certain specifications, otherwise it may cause problems such as unstable power output, shortened power supply life, and equipment damage. Here are a few things to pay attention to:
(1) The power supply model must be consistent
Parallel connection of multiple switching power supplies must use the same model of switching power supply to ensure that their output voltage and current are the same. If different models of power supplies are connected in parallel, the output power and stability of the power supplies may be affected.
(2) The length of cables connected in parallel should be consistent
For multiple switching power supplies connected in parallel, their output voltage and current must be within the same voltage and current range. Connecting wires of different lengths will increase impedance changes and voltage drops, which can lead to unstable output of the power supply. Therefore, the cable length must be the same and the wire diameter should also be the same to ensure the stability of the power output voltage and current.
(3) The output terminals of the switching power supply must be separately connected to the load
Multiple switching power supplies connected in parallel must be separately connected to different loads to fully utilize the output power. If the output terminals of multiple power sources share a load, the failure of one of the power sources will cause the output current of the shared load to be too high, thereby damaging the load.
(4) The output current of parallel power supply should be equal
When multiple switching power supplies are connected in parallel, their output currents must be equal to avoid situations where the output current of a single power supply is too large. If the output currents of multiple power supplies are different, the power supply with the smaller current may experience overload during operation, thereby affecting the normal operation of the power supply.
(5) When the power output is connected in parallel, the cable interface must be connected for protection
When multiple switching power supplies are connected in parallel, the wiring cables connecting the power supplies must be protected. Because under high power, high voltage, and high current, the joint may loosen, resulting in arc light. At the same time, the joint of the power output parallel connection must be regularly inspected and maintained to prevent problems such as poor contact of the joint and aging of the insulation material.
