The two UPS architectures are not significantly different: their main function is to provide uninterrupted, stable, and clean power. Therefore, based on the power supply channel, UPS can be divided into four modes: maintenance mode, bypass mode, AC power mode, and battery mode. AC power mode is the normal operating state of the UPS. In this mode, the UPS converts the input AC power into a stable and reliable output power through rectification (AC->DC), boost (DC->DC), and inversion (DC->AC).
The difference is that the DC system of a power UPS does not directly use batteries, but rather a DC power supply panel (DC operating power supply). The DC power supply panel of the power system is specially customized for the control room equipment of power plant generator sets, substations, and transmission and transformation stations. The DC power supply panel has two types of straight bus voltage: 220VDC and 110VDC, which supply power to the circuit breaker opening and closing and the instruments, relay protection, control, emergency lighting and automatic devices of the secondary circuit.
Online UPS
Power UPS
II. Application Scenarios:
The Burke online UPS series features high efficiency, high performance, double-conversion, pure online operation, and input section with power factor correction (PFC) functionality. The unit includes a maintenance bypass switch and boasts advantages such as low noise, high reliability, low failure rate, long lifespan, and low cost. Furthermore, its N+X modular redundancy solution represents the optimal architecture design for effectively addressing all power supply issues. This architecture effectively isolates the load from abnormal power surges while ensuring stable and reliable output power, allowing for safe load operation. Employing digital control technology, it enables parallel expansion and redundancy, providing users with flexibility in power planning and enhanced security.
In particular, the MP modular system used this time is mainly used in small and medium-sized data centers, network server rooms of large and medium-sized enterprises, system control centers, etc., and is the guardian of the server room.
Power-specific UPS: Power UPS systems are used in the control rooms of power plants, substations, and distribution stations. This is because power plant automation instruments such as DCS often require 110V/220V DC input, so using a power UPS can utilize existing DC power supplies, reducing investment. Therefore, the prerequisite for using a UPS is to have a DC system as a backup power source.
III. Comparison of some characteristics:
1. The inverter in a UPS converts DC power into AC power output. Generally, the DC voltage of a UPS is around 460V, while the DC voltage in power plants is 220V. This leads to the following problems: the lower the DC voltage, the greater the switching current of the inverter. Since losses are proportional to the square of the current, losses increase significantly. At the same time, high current requires high-capacity power switching devices and high-capacity primary windings, and lower DC voltage also requires transformers with higher turns ratios. These are undoubtedly potential expenses that directly affect the equipment's investment cost, operating cost, and depreciation.
2. Conventional UPS systems use battery systems, which are simple in structure and can be directly monitored via the UPS's LCD screen, making operation easy. In contrast, power UPS systems use DC operating power, requiring specialized operating skills.
3. Most power UPS systems require input and output isolation transformers. These machines are bulky, occupy a large area, and are costly. They also have low input power factors, high input losses, and consume more electricity.
4. High input harmonic current of UPS: Generally around 30%, which can be reduced to around 5% after adding a harmonic filter. However, the harmonic filter will reduce the efficiency of the whole machine by about 3% to 5%.
IV. Some key features of this plan:
1. Modular N+X redundancy structure provides redundancy protection for the system. Modules are hot-swappable, facilitating expansion.
2. Invest as you grow: As user load increases, users can purchase UPS modules to expand the system, eliminating the need to purchase UPS cabinets. This results in low subsequent investment costs.
3. Maintenance is quick and convenient. During maintenance, you can simply replace the module, and the maintenance work can be completed in 5 minutes.
4. The UPS and three output distribution panels are integrated into a 19-inch cabinet, which has a small footprint and high integration.
5. Dual-input/dual-output architecture provides multiple protection channels.
In summary, UPS systems are suitable for control rooms in power plants, substations, and distribution stations, where existing DC operating systems exist. They are not suitable for environments such as computer rooms and data centers. Conventional online double-conversion UPS systems can provide the necessary protection for computer rooms, especially modular high-end models, which are well-suited to the future trend of intelligent and high-end development.
