What Is The Difference Between Dual Power Supply And Dual Circuit Power Supply?

1. Dual Power Supply

Dual power supply is derived from two power supplies (with different properties), and of course there are two power lines, one for normal power and another one for  backup power.

In general, dual power supply can be approved if one of the following conditions is met:

(1) Important party, government and military organs, national defense and scientific research key projects will have serious consequences due to power interruption.

(2) Important news, broadcasting centers, transportation and communication hubs, public utilities, medical and health units, due to power interruption, will cause serious consequences.

(3) Military industrial units, factories and enterprises will cause personal and equipment accidents due to power interruption, massive loss of raw materials, massive scrap of products, shutdown of production and shutdown, and cannot be restored for a long time.

(4) Important public places.

(5) According to the characteristics of production, there are special requirements for the continuity of power supply.

2. Dual Circuit Power Supply

Dual circuit power supply refers to two lines with the same voltage from two substations or two warehouses of one substation. When there is a power failure on one line, the other line can be switched and put into use immediately. It is mostly used in schools, enterprises and institutions, which is convenient and fast.

For example: Wuhan Light Railway in China has two independent power stations for power transmission, using a "dual-circuit" power supply system to ensure normal operation even in the event of a power outage.

3. The difference between dual power supply and dual Circuit power supply

(1) Dual power supply: A device controlled by a microprocessor, which is used for switching between grid power and grid power or grid power and generator power in the power grid system, so that the power supply can be continuously supplied. Two power sources come from different substations (or one power source and one generator).

(2) Double circuit: a load has two circuits of power supply. The two power sources come from the same substation and have different busbars (sometimes due to reverse load, the two busbars may be parallel).

First of all, according to IEC60947-1, the current standard of dual power supply is called dual power supply, the power supply of a load is provided by two circuits, which are independent of each other in terms of safe power supply.

Secondly, the power supply of the dual power supply should be the substation of the electric power industry, not the substation inside the project (the project as a whole is considered as a load).

Again, the power transformers must be drawn from different busbar segments. In some areas, the substation has 2 transformers, but both transformers are distributed by a busbar, and the wiring method of single busbar or single busbar segment is adopted, which cannot be handled as dual power sources.

Therefore, the dual power supply should be a power supply composed of a power supply from different busbar segments distributed from the electrical substation.

There is no such requirement for dual circuits. Two circuits or ring network distributed by one transformer, and two power supplies distributed by two transformers in the same bus section can be considered as double circuits. The dual-circuit power supply can only ensure the power supply needs of the secondary and lower loads.

The dual power supply mode is that two power supplies are drawn from two independent substations, or one power supply is drawn from each of the two busbars of two transformers in one substation. Independence, when one power supply fails due to a fault, the other power supply can also ensure the reliable power supply of the building. The power supply mode of dual-circuit power supply can be dual power supply, or single power supply and dual-circuit power supply. In the case of single power supply and dual loop power supply, the power supply to the entire building will be interrupted when the power supply or busbar fails.

To sum up: and combined with the experience of domestic electricity load. Double circuits are mainly used for secondary loads with high requirements for electricity consumption, such as hospitals, banks and other departments. They are often supplied with two circuits during circuit design. When one power supply fails, the other power supply effectively ensures the electrical continuity and reliability.