The selection of capacity of single-phase AC voltage regulator should first be considered according to its power load, and the capacity and size of single-phase AC voltage regulator should be selected. Assuming that the capacity of single-phase AC voltage regulator is too large, it will not only increase the investment of equipment, but also cause the transformer to be in no-load state for a long time, which will increase the reactive power loss without using its function and operation; However, if the capacity of single-phase AC voltage regulator is too small, the transformer will be overloaded for a long time, which is easy to burn out the transformer. Therefore, we should have a correct direction in the selection of single-phase AC regulator capacity, which can save resources and energy to a great extent.

The capacity of single-phase AC voltage regulator shall also be selected according to the economic capacity, or if the load is asynchronous motor, its capacity shall be considered according to its power synthesis; Even the capacity of the transformer can be selected according to the total power close to the lighting and the capacity of the single-phase AC regulator can be selected according to the actual peak load total power. Such consideration not only ensures that every family is guaranteed and every user can choose at ease, but also can make a round-trip use of resources for the society.

Selection method of voltage regulator

1. Capacity safety factor

AC regulated power supply takes the output apparent power (kVA) as the nominal rated capacity, but generally, the load is not purely resistive, that is, the power factor cos ￠ 1, and the actual active power output by the regulator kW = capacity (kVA) × COS￠。 Therefore, in the actual selection, the regulated power supply shall be reasonably selected according to the specific conditions such as the rated power, power factor and load type of electrical equipment, and the output power shall be left with appropriate margin, especially the margin shall be larger in the selection of impact load. The specific selection safety factor is shown in the table below

Load nature equipment type safety factor selection regulated power supply capacity

Pure resistive load incandescent lamp, resistance wire, electric furnace and other equipment 1.25 ~ 1.5 times the total load power

Inductive and capacitive load fluorescent lamps, fans, motors, water pumps, air conditioners, computers, refrigerators, etc. 2 ~ 3 ≥ 2 ~ 3 times the total load power

In the environment of large inductive and capacitive loads (such as motors and computers), the starting current of the load should be considered to be particularly large (up to 5 ~ 8 times of the rated current), so the capacity of the voltage regulator should be 2.5 ~ 3 times of the load power.

For example, one three-phase motor is 2.2kW and one motor is 5.5kW. When voltage regulator is selected, the capacity is ≥ (2.2kW + 5.5kW) × 2.5 = 19.25 KVA, that is, at least three-phase sjw-20 KVA voltage regulator shall be selected.

2. Output capacity curve of non compensated regulated power supply

When the input phase voltage of the self coupling voltage regulator (single-phase 0.5kva ~ 3KVA, 10K horizontal and below, three-phase 9KVA and below) is lower than 198v, the output capacity begins to decrease; When the input phase voltage is equal to 160V, it drops to 50% of the rated capacity of the regulator. Therefore, at the low end of the power supply voltage, special attention should be paid to reducing the load derating, so as not to overload and burn the voltage regulator;

The self coupling voltage regulator can output 220V and 110V at the same time. However, even if it is all output by 110V, the load carried by the voltage regulator shall not exceed 50% of the rated capacity, otherwise it is overloaded.

Most computers are 350W now,. It is recommended that you choose a voltage regulator of more than 8000w

In addition, the capacity level of each single-phase AC voltage regulator shall be reasonably selected according to national standards.