A brief discussion on the power supply system of controllers

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For the power supply system of controllers, integrated power supplies are basically used in China. Due to the low prices of DCS systems in our country and the resulting low profits, DCS manufacturers do not have the funds to invest in developing power supply systems. The power redundancy of foreign DCS systems is shown in the figure below. Before installing the two power supplies in the cabinet, they need to be adjusted under load separately. During adjustment, the load on both power supplies must be identical; they need to be set to the same output level before being installed in the cabinet. There is a power supply monitoring board in the power system, which can display the output status of the two power supplies. The two units can supply power to the load simultaneously. It is best to operate at a balanced voltage. 20 years of operation have proven that the power supply system is excellent. 　　　　The two power supplies of the domestic DCS operate in redundancy, with one in use and one as a backup. If the AC input power of one of them drops suddenly, it can switch to the backup power supply. If the slope drops, it is not possible to switch to the backup power supply. This is one of the disadvantages of the power supply system. 　　　　The N+1 power supply scheme has not been adopted in China’s DCS systems. Imported DCS systems use N+1 power supply, which also presents many problems. The N+1 power supply concept means that once the power consumption of each module connected is known, by adding up the power requirements of all modules – and since the power supply for each module is constant – the total required power is divided by that power supply capacity, thereby determining the number of power supplies needed. If there are decimal places, the value is incremented by one to become an integer; this integer is N, and then one is added to it, resulting in N+1.