How to calculate the current power
It is calculated in amperes, which indicates the equality 1A = 1 C / s. Calculate the current strength is possible according to the school physical formula: I = Q / t, where I is the current strength, Q is the charge value, and t is the time for which the charge overcomes the surface. If you take, for example, a cable, then the surface is the cross section of the cable. Based on this formula, we recall from the school program, Ohm's law: the current strength for a certain plot of the network grows parallel to the stress spent on the plot in an inverted proportion of the confrontation of the wire of a particular territory. By Ohm's law, I = U / R, where U is the voltage, R is the resistance of the conductor.
Basically, to determine the current strength, a special instrument is used - an ammeter.
The ammeter is connected to the separation of the chain at the point at which the current force was measured.
There are main methods for determining current: magnetoelectric, indirect and electromagnetic. There is an alternating current, in these cases its strength is divided into:
- instantaneous;
- effective;
- peak.
Power of three-phase network
Three-phase network is a variant of the system for several phases, which consists of the sum of some loads and battery packs that have the same repetition and are shifted in phase by a certain angle between themselves. The phase system is a pair of batteries. Phase systems can be perceived as chains that do not unite with each other. To measure the power of a system of three phases, it is often simply the total number of operating powers of all its phases. And this is calculated by the formula: P = Pa + Pb + Pc, where in the letters Pа, Рb, Рс the voltages of all phases with the angles of shifts between loads and currents in the circuit are multiplied. Accordingly, the fast power equals the sum of the powers of all phases over this chain:
Q = Qa + Qb + Qc.
From the above it follows that in a three-phase circuit with the symmetry of voltage and load, suffice to determine the load of one phase and its value triple.
Three-phase systems have a list of dominance over other systems. Such as:
- economy of production and energy transfer;
- easy earning of the magnetic field in a circle;
- obtaining two loads suitable for operation,( phase-voltage in phase and linear-voltage in the conductor), both in office rooms and home appliances and systems.
Any of the networks used is symmetric( harmonious) and asymmetrical( non-harmonic).
What is a balanced load
Each system consisting of several phases is either symmetrical or asymmetric. Symmetry is determined by the symmetry of the electromotive force, voltage and current. The main property of symmetry is that the sum of the instantaneous numbers of the quantities that form this system at all times is zero. Thus, the equality of the zero value of the sum of the phase gradient.
There are two main ways to bundle the foundations in a multi-phase system by combining a star or a polygon. When the star is connected, the beginning of all the constituent phases are combined into a common node, which is usually considered a neutral point, connecting to the ends respectively. When a polygon is connected, all parts are combined into a closed circular path, and all adjacent elements are connected by the beginning and end. When analyzing systems with many phases, many representations are introduced, which are necessary for characterizing what is happening. The conductors that connect the reproducers and the load are defined as linear, and the conducting beams that connect the neutrality points of the precursors and the load are taken as neutral conductors.
A symmetrical three-phase system is often depicted by graphs, vectors, trigonometric and complex variable functions rather complex in the construction.
Receivers that connect to a three-phase circuit can vary in phase. You can take single-phase or three-phase. As an example of single-phase, you can use incandescent lamps, lighting( fluorescent lamps, nightlights, LED lights, teapots with lighting), household appliances( iron, refrigerator, TV, microwave, washing machine), motors( electric motors).As three-phase - asynchronous motors, induction furnaces.
