Power Supply Selection Principle

There are various problems in general city power grids, but the degree and specific circumstances are different. The problems of the power grid generally include: unstable voltage, continuous high or low voltage, unstable frequency, continuous high or low frequency, abnormal waveform distortion, many harmonic components, high-frequency interference, surge current, electrical noise, power outage, lightning strike, etc. In response to various problems of the power grid, inventors have designed corresponding equipment to solve various power supply problems. For example, for the problem of unstable voltage, there are voltage stabilizers and voltage regulators; for the problem of interference in the city power, there are purified power supplies; for the problem of interruption of the city power, there are generators, UPS, EPS, inverter power supplies; for the problem of lightning strikes, there are lightning arresters and lightning arresters, etc. Science and technology are constantly improving, and the equipment to solve power supply problems is also constantly updated. The voltage stabilizer can only solve the problem of unstable mains voltage; the purified power supply can only solve the interference problem of mains (it also has a narrow range of voltage stabilization); while generators, UPS, EPS, etc. can solve the problem of mains interruption, among which the voltage and frequency quality of the generator power supply are relatively low, the waveform is not pure, the harmonic component is also large, and there is a long conversion time in the process of switching from the mains (even if equipped with an ATS automatic switching switch, there is a 1-6 second interruption), which can only be used in low-end basic equipment power supply places, while precision instruments or critical and important loads must use UPS. On the other hand, the operation of the generator also has a large noise. EPS is an emergency power supply system, which generally has soft start or variable frequency start function and meets the safety design of the fire protection industry. It is more suitable for use in inductive loads. It is a backup emergency power supply for fire emergency lighting, fire elevators, fire pumps and other equipment through inverters using large-capacity batteries. EPS switches with the mains for 1-5 seconds, which can only solve the problem of mains interruption, but cannot solve other problems such as mains interference, and cannot be used for important IT industry-type critical load equipment. The working principle of inverter power supply is similar to that of EPS. It can only solve the problem of power outage and is suitable for emergency lighting or backup of household appliances. UPS can solve all adverse factors of the mains, such as unstable voltage and frequency, various interferences of the power grid, power outage, etc. However, Uninterruptible Power Supply(UPS), as a computer external device, is a precision power supply and is only suitable for IT industry loads such as computers and servers, and cannot be abused for pure power equipment. Pure power equipment is only suitable for power EPS power supply or backup generator set.