(1) Power grid
The power grid is a part of the power system. It is a unified network composed of various substations (substations) and output and distribution lines of various voltage levels. Its task is to transmit and distribute electrical energy to electricity consumers.
(2) Power system
The power system consists of generators, power distribution equipment, transformers, power lines, and electrical equipment to form a unity of power generation, విద్యుత్ పంపిణి, and power consumption.
(3) Electrical equipment
Electrical equipment generally refers to the social security of power generation, substation, distribution and direct electricity consumption. Such as: transformers, distribution lines, motors, electrical appliances, electrical measuring instruments, electrical protection devices and electrical appliances.
(4) Sinusoidal alternating current
Sinusoidal alternating current means that the magnitude and direction of the current, voltage and potential in the circuit change with time according to the law of the sine function. This current that changes periodically with time is called alternating current, or AC for short.
(5) Three-phase alternating current
Three-phase alternating current is a power system composed of three alternating current circuits with the same frequency, equal potential amplitude and 120° phase difference.
(6) Phase sequence
The phase sequence is the sequence of the phases, which is the sequence in which the instantaneous value of the alternating current changes from a negative value to a positive value and passes through the zero value. The coloring of the three phases A, B and C should be: A-yellow, B-green, C-red.
(7)Electrical busbar
The electrical bus is a channel device that collects and distributes electrical energy. It determines the number of power distribution devices and indicates how to connect generators, transformers and lines, and how to connect with the system to complete the transmission and distribution tasks.
(8) Electric power
The current flows through the circuit to the electrical equipment, and the electrical equipment does work by consuming the energy provided by the power source. The work done per unit time is called electric power, which is divided into three types: active power P, reactive power Q and apparent power S.
> Active Power: The power produced by current flowing through a purely resistive load. Denoted as P, the unit is watt (W), kilowatt (kW), megawatt (MW)
>Reactive power: In an AC circuit, in addition to p, the current flows through the energy storage element to generate the mutual exchange of electrical energy and magnetic energy without actually doing work. This exchange of power is reactive power. Denoted as Q, the unit is var (var), kilovar (Kvar), megavar (Mvar).
> Apparent power: the geometric sum of active and reactive power. Denoted as S, the unit is volt-ampere (VA), kilovolt-ampere (kva), and mega-volt-ampere (MVA).