EPS solution based on Delta VFD (Variable-frequency Drive)

1 Introduction??

EPS (Emergency Power Supply) is the acronym for emergency power supply. EPS is widely used in industrial and civil buildings and other important power supply loads where sudden power failures will cause major economic losses to normal production and life. It is an important part of modern building safety and security facilities. EPS is generally used as a backup support power supply for fire fighting or production in emergency situations. For example, in places such as high-rise buildings, shopping malls, hospitals, rail transit, and underground shopping malls, there are many people, few exits, and limited natural light sources. Once a fire occurs or the power grid is damaged, the light source disappears into darkness, and at the same time, there are many people and few exits. The consequences will be disastrous. At the same time, the fire brigade will be unable to carry out disaster rescue work due to lack of power supply, which aggravates the degree of disaster. It can be seen that EPS plays an increasingly important role in the safety of modern society, and is the patron saint of the "urban lifeline system".

At present, EPS adopts different control methods and control methods, and the loads carried by EPS can be summarized into three types: one is EPS mainly used for emergency lighting and accident lighting; the other is that besides emergency lighting and accident lighting, there are also Three-phase series EPS with mixed loads such as air conditioners, elevators, rolling shutter doors, exhaust fans, and water pumps; the third is the frequency conversion series EPS that directly supplies power to the motor. This article describes the most comprehensive mixed load three-phase series EPS power supply.

2 EPS system based on Delta VFD (Variable-frequency Drive)

Delta's EPS solution mainly utilizes the VFD (Variable-frequency Drive) to act as the drive function of the inverter AC motor for the fan, pump, and rolling door of the fire protection system. Delta’s EPS customized VFD (Variable-frequency Drive) can truly realize the connection of the common DC bus, so it can be applied not only to the EPS industry, but also to the chemical fiber and glass manufacturing industries. Delta's special VFD (Variable-frequency Drive) is used together with the synchronization card to achieve the same input and output phases, thus meeting the application of special occasions. In view of the particularity of motor drives in the EPS industry, Delta VFD (Variable-frequency Drive) mainly adds parameters such as automatic torque compensation, torque compensation limit, and abnormal restart to meet the needs of special industries. The EPS charging module matched with VFD (Variable-frequency Drive) reduces costs for customers, reduces heavy transformers, and reduces transportation costs.

2.1 Overall overview of EPS special machine

One of the main features of Delta's EPS special machine is that it can realize a common DC bus, thus expanding the application field of EPS special machine. At the same time, the direct current of the internal contactor and soft-start circuit meets the needs of battery direct start of the EPS special machine. Delta EPS dedicated VFD (Variable-frequency Drive) can form a highly reliable mixed-load dedicated inverter by matching appropriate low-pass filters and transformers. And ensure the output voltage stability and waveform smoothness of the inverter. Delta’s special VFD (Variable-frequency Drive) for EPS emergency power supply can meet the application of most occasions in the EPS industry, and is the first choice of a dedicated VFD (Variable-frequency Drive) for EPS manufacturers.

2.2 Features of Delta EPS special machine

(1) The auxiliary power supply of the VFD (Variable-frequency Drive) and the contactor of the soft-start circuit are all DC-based, so direct DC power supply can be fully realized.

(2) Super strong hardware and software protection functions ensure the reliability of VFD (Variable-frequency Drive).

(3) It contains a variety of modulation methods, so it can be applied to a variety of transformers, thus ensuring that the voltage waveform at the output terminal is closer to a sine wave.

(4) Delta EPS VFD (Variable-frequency Drive) has two specifications of AC380V and AC220V, and the power range is from 0-220KW, which can meet the needs of customers in different occasions.

(5) The adoption of the synchronization card ensures the same input and output phases.

2.3 Delta EPS dedicated VFD (Variable-frequency Drive) application design

(1) Electrical principle design. Figure 1 shows the principle of EPS with AC and DC dual power supplies. The principle of DC single power supply EPS is shown in Figure 2.

(2) Definition of control terminals

2.4 Design of special parameters of Delta EPS VFD (Variable-frequency Drive)

3 Conclusion

Delta's EPS dedicated VFD (Variable-frequency Drive) truly realizes customized services, completely based on EP