Om kraftkvalitet

Power quality (PowerQuality), strictly speaking, the main indicators for measuring power quality are voltage, frequency and waveform. In a general sense, it refers to high-quality power supply, including voltage quality, current quality, power supply quality and power quality. Power quality problems can be defined as: deviations in voltage, current or frequency that cause power equipment failure or malfunction, including frequency avvikelse, spänningsavvikelse, spänningsfluktuation och flimmer, trefasobalans, omedelbar eller övergående överspänning, vågformsförvrängning (harmonik), spänningssag, avbrott, tillfällig stigning och kraftförsörjningskontinuitet .
An ideal power system should supply power to users at a constant frequency (50Hz) and a sinusoidal waveform at a specified voltage level (nominal voltage). In a three-phase AC power system, the voltage and current of each phase should be in a symmetrical state with equal amplitude and a phase difference of 120. Since the parameters of the system components (generators, transformers, lines, etc.) are not ideally linear or symmetrical, the load properties are different and change randomly, and due to the imperfect control means, operation, external interference and various faults, this ideal state does not exist in reality, which has led to various problems in the operation of the power grid, electrical equipment and electricity consumption, and the concept of power quality (Power Quality) has also been generated.
In a general sense, power quality refers to high-quality power supply. But so far, there are still different understandings of the technical meaning of power quality. On the one hand, this is due to different perspectives. For example, power companies may simply regard power quality as the qualified rate of voltage (deviation) and frequency (deviation), and use statistics to illustrate that 9% of the power system Kraft uppfyller kvalitetskraven; Kraftanvändare kan i allmänhet betrakta kraftkvaliteten som om strömförsörjningen till lasten är normal; och tillverkare av utrustning tror att kvalificerad kraftkvalitet innebär att kraftförsörjningsegenskaperna fullt ut uppfyller behoven hos de normala konstruktionsförhållandena för elektrisk utrustning, men i själva verket begränsas kraven för kraftförsörjningsegenskaper för olika tillverkare och olika utrustning, särskilt från varandra . å andra sidan är förståelsen för kraftkvaliteten också begränsade av utvecklingsnivån och utvecklingen av kraftsystemet, särskilt prestandan och strukturen av kraftbelastning