Selection of UPS power supply
As a high-tech product developed to meet the needs of the power market, the UPS power system has obvious power protection functions: when the city power is cut off, it will continue to supply power to the load without interruption; in the city When the power is unstable, it can avoid the load from under-voltage, surge impact, etc., and comprehensively improve the power supply quality; when the power supply system (including UPS) fails, it can give the load (especially the computer and network system) a comprehensive It also protects against overload, short circuit and battery over-discharge, providing a stable working environment for the load.
As the IT system gradually moves towards centralized management, the application of UPS power protection systems by enterprises will become more in-depth. The application of UPS will show a trend from a single machine to a redundant structure, from focusing on system reliability to focusing on system availability, and from a pure power supply system to ensuring changes in the entire IT operating environment. With the development of information technology, electronic technology, and control technology, various advanced technologies have been widely used in the design, development and production process of UPS. The following six major development trends will appear in UPS technology.
Through the analysis and synthesis of various types of information, the intelligent intelligent system should not only complete the control function of the normal operation of the corresponding part of the UPS, but also complete the real-time monitoring of the operating UPS, and the important data in the circuit The information is analyzed and processed, and functions such as whether each part of the circuit is working normally can be derived from it; when a UPS fails, it can be analyzed in time based on the detection results, diagnose the fault location, and give the treatment method; take necessary actions in time according to site needs Self-emergency protection and control action to prevent the expansion of the impact of the fault; complete necessary self-maintenance, have the function of exchanging information, and can input information to the computer or obtain information from the networked machine at any time.
The digital UPS adopts the latest digital signal controller (DSP) to digitize Hall sensor devices, which realizes 100% digital operation of the UPS system. A multiple microprocessor redundancy system is also adopted, and multiple microprocessors with independent power supplies are used to control the rectifier, inverter and internal static bypass, thus improving the digitalization and reliability of the system.
The power switch of the first generation of high frequency UPS is a thyristor, the second generation is a high-power transistor or field effect tube, and the third generation is an IGBT (insulated gate bipolar transistor). The switching speed of high-power transistors or FETs is an order of magnitude higher than that of thyristors, and the current capacity and speed of IGBT power devices are much larger and faster than those of high-power transistors or FETs, which makes the operating frequency of the power conversion circuit Up to 50kHz. The increase in the frequency of the conversion circuit greatly reduces the inductance, capacitance, noise and volume used for filtering, and greatly improves the UPS efficiency, dynamic response characteristics and control accuracy.
Redundant Parallel Technology Through the development of new application technologies, it can realize the redundant parallel operation of multiple modules in the UPS without additional central control components. The load is evenly distributed, and a certain module has a problem. When the load is automatically transferred, the maintenance can be hot-swappable, which greatly improves the reliability of the power supply of a single UPS. Coupled with the redundant operation of the system composed of multiple UPSs, if a single UPS fails, it will be shut down immediately, and the other UPS systems will automatically assume the full load without any impact on the load.
Integration With the development of informatization, the application fields of power protection continue to expand and requirements continue to increase. It is difficult for UPS to meet these requirements alone. It must control the links involved in the entire power system. UPS From the initial equipment protection and system protection pure backup power technology development to today's integrated application of information protection, intelligent management and overall computer room integration, its connotation has been extended to power generation, power distribution, transformation, uninterrupted power supply, computer room, power equipment , Power cables, data wiring, environmental monitoring and system management, etc., are no longer UPS in the original sense. UPS equipment is just the core component of the system.
From the perspective of UPS power technology, based on the continuous optimization of power output characteristics, the research on power input characteristics makes electromagnetic compatibility and low harmonic pollution become important indicators. Harmonic processing technology and The electromagnetic compatibility design can improve the load characteristics of the power supply to the power grid, reduce the burden on other equipment, and improve the source effect of the power supply. The concept of green power has begun to be paid attention to. The development of electronic technology and computer technology, in addition to greatly improving the power performance of UPS, its network management can realize remote monitoring, digital power control technology enables products with customized functions, and intelligent design makes it highly intelligent Monitorable, controllable and adaptive equipment.
