Third, the classification and structure of dual power supply

(A) the classification of dual power supply
Dual power supply is mainly divided into contactor class, molded case circuit breaker class / load isolation switch class, integrated automatic transfer switch electrical class.
Contactor type: This kind of power switching system takes contactor as the switching executive part, and the switching function is completed by intermediate relay or logic control module to form a secondary circuit to fulfill the control function. Generally non-standard products, the shortcomings are obvious, the work of the main circuit contactor needs to be energized for a long time in the secondary circuit, which is prone to temperature rise and heat, contact bonding, coil burnout and other faults. More components, product quality by components, manufacturing process constraints, high failure rate, has been gradually replaced by new products.
Moulded case circuit breaker class: switching execution parts with molded case circuit breakers, switching function with ATS automatic control unit to complete, with mechanical and electrical interlocking, perfect function, good operating performance, high service life, fewer components, easy to install. This category is CB level changeover switching appliances, by two circuit breakers as the current breaking unit, and is equipped with current disconnectors, with a certain degree of protection, circuit breaker on / off capacity than the relay is much higher. However, it is not as effective as PC class products in overcurrent conditions.
All-in-one automatic transfer switch class: integrating switch and logic control in one unit, without the need for an external controller, truly realizing mechatronics. The contact system of the product adopts “single-knife double-throw” design, small volume and simple structure. General conversion time is relatively small, switch switching drive adopts motor drive, switching is smooth and reliable, the operator motor drive only in the switch switch switching instantaneous current through, steady state without providing working current, energy saving is significant. There is no temperature rise, contact bonding or coil burnout. The switches are equipped with electromechanical interlocking devices, which can realize self-injection and self-recovery, self-injection and non-self-recovery, loss of voltage, undervoltage, phase break protection, manual-automatic switching, and time-delay control, etc., and are the mainstream products in the power switching category.
(II) Meaning of dual power supply models
(1) B-type common switch control characteristics: always guard the main power supply and backup power supply system.
(2) I-type switch control characteristics: designed for the utility and utility backup power supply system of the self-injection of non-recovery design. The switching time between the main power supply and the standby power supply is 1 – 999 S. It is equipped with a missing item detection function and over-voltage and under-voltage protection functions.
(3) Type II switching control characteristics: applicable to self-initiation and self-recovery of utility and utility backup power supply systems. The switching time between main power supply and standby power supply is also adjustable (1 – 999S), and it has missing item detection function and over-voltage and under-voltage protection function.
(4) Type III switch control characteristics: Realizes self-initiation and self-recovery of utility power and oil engine power supply system. During the conversion from utility power to oil engine power supply, the oil engine signal will be activated in advance, and the warm-up delay start time of the oil engine can be adjusted (0 – 180 seconds). When the oil tanker is put back to the mains, its cooling delay time is the same as the warming delay time. It also has the function of detecting missing items and over-voltage and under-voltage protection.
(iii) Structure of dual power supply
Dual power supply generally consists of switch body and controller.
Switch body: There are PC class (integral type) and CB class (circuit breaker). PC class can connect, carry, but not for breaking short-circuit current ATSE, the main body of which is a load (isolation) switch, electromechanical integrated switching appliances, the switching mechanism is driven by a motor or excitation. CB class is equipped with an overcurrent detector ATSE, whose main contact can be connected to and used to break the short-circuit current. Commonly used in elevator, fire fighting, lighting and other important load occasions.
Controller: It is mainly used to detect the working condition of the monitored power supply (two-channel), and when the monitored power supply fails (such as phase break, under-voltage, loss of voltage or deviation of frequency in any one phase), the controller issues an action command. Intelligent products with microprocessors and integrated chips can meet the requirements of different loads, have good electromagnetic compatibility, can provide a variety of signals and fire interfaces, communication interfaces.
Fourth, the advantages of dual power supply

(A) stable and reliable
Dual power supply mainly breaks the traditional output DC voltage mode and directly adopts the two-way channel. Through internal integration, it can make the AC power supply directly into DC power supply, thus improving the utilization rate of the transformer. According to relevant data, the utilization rate of the transformer can be increased by about [X]% after adopting dual power supply. This method makes the power system more stable and reliable, and can play an important role in various occasions. For example, in some places with very high requirements for power supply, such as operating rooms in hospitals, computer data centers, etc., dual power supply can ensure that when the main power supply fails, the backup power supply can quickly take over to ensure the normal operation of the equipment, which provides a strong guarantee for the safety of patient’s life and data security.
(ii) Protection circuit
Compared with the ordinary output power supply, the dual power supply has a higher degree of accuracy. It can directly and independently complete the energization, providing effective protection for the circuit to a certain extent and making the circuit more stable. With the continuous development of technology, the overall performance of dual power supply is continuously enhanced. At present, the accuracy of dual power supply can already reach [specific data], which can better meet the needs of various complex circuits. For example, in the power supply system of some precision instruments, dual power supply can ensure the stable output of the current, to avoid damage to the instrument due to current fluctuations. At the same time, dual power supply can also play a protective role for the electronic devices in the circuit, when the circuit over-voltage, under-voltage and other abnormalities, dual power supply can cut off the power supply in a timely manner, to prevent the electronic devices due to over-voltage and burned or under-voltage can not work properly. This protection function not only extends the service life of electronic devices, but also improves the reliability and stability of the entire circuit system.
V. Application Scenarios of Dual Power Supply

(A) important places
Hospitals as an important place for people’s lives and health, the stability and reliability of the power supply requirements are extremely high. Once the power failure, may endanger the lives of patients. For example, in the process of surgery, if there is a sudden power outage, the backup power supply can be quickly started to ensure the normal operation of surgical equipment for the safety of the patient’s life. According to statistics, a large portion of the medical errors caused by power outages each year can be avoided by dual power supply. Shopping malls are also places with a large flow of people, especially during holidays and other peak periods, the normal operation of lighting, elevators, air conditioning and other equipment is crucial. Dual power supply can ensure that when the main power supply fails in shopping malls, the backup power supply can be put into use in time to avoid the chaos and economic losses caused by power outages. As a transportation hub, the airport’s demand for electricity cannot be interrupted even for a moment. From the flight information display system to the navigation equipment, all need a stable power supply. Dual power supply can ensure that the airport can operate normally under any circumstances, and guarantee the safety and smoothness of travelers.
(ii) Industrial equipment
In industrial assembly lines, the role of dual power supply is particularly obvious. Once the power is interrupted, it may cause the production line to come to a standstill, resulting in huge economic losses. For example, in an automobile manufacturing plant, welding robots, spraying equipment, etc. require a stable power supply. Dual power supply can ensure that when these equipments have a failure of the main power supply, the backup power supply can start quickly to ensure the continuous operation of the production line. In the metallurgical industry, high-temperature furnaces and other equipment require high power stability. Dual power supply can switch to the backup power supply in time when the main power supply has a problem, avoiding the cooling of the furnace due to power failure, which will affect the production progress and product quality. In the chemical industry, many chemical reactions need to be carried out at specific temperatures and pressures, which may cause dangerous accidents in case of power failure. Dual power supply can provide chemical enterprises with reliable power protection to ensure the safety and stability of the production process.
(C) Communication Center Room
As the core hub of information transmission, the communication center room has extremely strict requirements for power supply. As one of the three power sources, dual power supply plays a vital role in the communication center room. It can guarantee the continuous and reliable operation of important loads and ensure the normal work of communication equipment. In the communication center room, a large amount of data transmission and processing requires a stable power supply. If there is a power outage, it may lead to communication interruption, affecting people’s daily life and the normal operation of social economy. Dual power supply can quickly switch to the backup power supply when the main power supply fails to ensure the uninterrupted operation of communication equipment. At the same time, dual power supply can also be used in conjunction with other backup power (such as diesel generators, UPS, etc.) to further improve the reliability of the power supply of the communication center room.