- All
- Product Name
- Product Keyword
- Product Model
- Product Summary
- Product Description
- Multi Field Search
English
Views: 342 Author: Jeannie Publish Time: 2025-03-31 Origin: Site
There is such an example, let me tell you: as we all know, the cow is a kind of livestock, and after eating grass, it can also pour out the food and chew it repeatedly. Rural people are familiar with it and call it inverted milling. But in this process, after all, the cow has eaten grass, but it can still be poured out, it is not all spit out, it is still converted into energy in the stomach to maintain various functions of the body. So let's take this as an example to talk about inductance coils:
An inductance coil is fed with alternating current, which is not the case at all. For example, if an inductor coil is fed with alternating current i=Imsinωt, then the voltage at both ends of the inductor coil can be expressed as u=Umsin(ω t+π/2) and the instantaneous power can be expressed as p=Umsin(ω t+π/2) ×Imsinω t=UIsin²ωt. This means that the instantaneous power still varies sinusoidally, but at twice the frequency of the mains supply.
Since the instantaneous power changes according to the sinusoidal law, it means that the inductance coil first asks the power supply for electrical energy and converts it into magnetic energy, and then returns the energy to the electrical energy, and all of it is returned, and so on!
The inductor coils are first requested from the power supply, and then all are returned after requesting. In fact, this is a process of repeatedly storing and releasing magnetic energy, which is completely caused by alternating currents, and in the end it does not consume a little electrical energy, and what exists is only an exchange of energy.
Therefore, we say that the inductance coil is an energy storage element, not an energy-dissipating element, and the active power is 0 (its own resistance loss is not counted).
There are also large and small energy exchanges, and there are scales, just like how much to drink, how much to spit out, how much to drink, how much to spit out? This scale is calibrated by the reactive power Q. Reactive power Q is expressed as a RMS value, Q=UI=I² XL=U²/XL.
An inductance coil can store energy, i.e., magnetic energy. However, this energy is an instantaneous value, and we cannot say how much energy we have stored in a certain process, we can only say how much energy we have stored in a certain moment. This energy is denoted by W, W=1/2Li², where i is the instantaneous value
