Instructions on how to use the output of switching power supply in parallel
Switching power supply is a kind of power supply widely used in various electronic devices, including DC switching power supply and AC switching power supply. Switching power supply can provide stable, reliable and efficient voltage and current output, making it the first choice for many electronic devices. However, in some cases, a single switching power supply output can't meet the demand, so it is necessary to use multiple switching power supply outputs in parallel. In this paper, we will introduce in detail how to use the output of switching power supply in parallel.
1. The principle of parallel connection
The output of a plurality of switching pow supplies are connected in parallel, so that they can be combined into lar output power. The principle of parallel connection of power supplies is simple: connect all the positive poles of power supplies and connect all the negative poles of power supplies. Doing so can coordinate all the power sources and jointly output greater current and voltage. Multiple power supplies connected in parallel, each of which outputs the same voltage and current. If the number of power supplies output in parallel is larger, the output power will be larger.
2. Suitable occasions for parallel power supply.
The output of multiple switching power supplies connected in parallel can be applied to a variety of electronic devices, such as high-power LED lighting, high-speed motor driving, frequency converters and so on. In these applications, the output voltage or current of a single switching power supply cannot meet the demand. Connecting multiple switching power supplies in parallel can increase the output power and meet the application needs of high power, high voltage and high current.
3. Matters needing attention in parallel power supply
The parallel connection of power supplies must follow certain specifications, otherwise it will lead to unstable power output, shortened power supply life, equipment damage and other problems. Here are a few things to pay attention to:
(1) the power supply model must be consistent.
Multiple switching power supplies connected in parallel must use the same type of switching power supply, so as to ensure that their output voltages and currents are the same. If different types of power supplies are connected in parallel, the output power and stability of power supplies may be affected.
(2) The lengths 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. However, connecting wires with different lengths will increase impedance change and voltage drop, which will lead to unstable output of power supply. Therefore, the cable length must be the same and the wire diameter should be the same, so as to ensure the stability of the output voltage and current of the power supply.
(3) The output end of the switching power supply must be connected to the load respectively.
Multiple switching power supplies connected in parallel must be connected with different loads to make full use of output power. If the output terminals of multiple power supplies share a load, the failure of one power supply will lead to excessive output current of the shared load, thus damaging the load.
(4) The output currents of parallel power supplies should be equal.
When multiple switching power supplies are connected in parallel, their output currents must be equal, which can avoid the situation that 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 smaller current may be overloaded during operation, thus affecting the normal operation of the power supply.
(5) When the power output is connected in parallel, the cable interface must be protected.
When multiple switching power supplies are connected in parallel, the cables connecting the power supplies must be protected. Because under high power, high voltage and high current, the joint may loosen, thus generating arc light. At the same time, the joint of parallel connection of power supply and output must be inspected and maintained regularly to prevent poor contact of the joint and aging of insulation materials.
