What is line loss? What is the formula for calculating line loss?

The following technical measures can be adopted to reduce the power loss of power supply lines, improve the quality of power supply voltage, and make electrical equipment and power supply lines in the best economic operation state.

1) Reduce contact resistance. Contact resistance exists on the contact surfaces of electrical connections. Eliminating or reducing contact resistance is especially important for wires that often have large currents flowing through them. Its power-saving effect is better.

2) Reduce eddy current loss. The secondary end of some electrical equipment, such as electric welding machines, belongs to low-voltage and high-current circuits. In order to reduce the electrical loss, that is, the ohmic loss of the cable, and keep the arc stable, the welding machine must be placed in the closest place to welding, and the cable must not be wound into a coil and placed on the steel plate, otherwise it will cause eddy current loss.

3) Put in a backup circuit. Some users have spare cables and lines, and if these backup circuits are also put into operation, the cross-section of the distribution line can be multiplied without additional investment. It also reduces the current density on the circuit, so that the accident rate is greatly reduced, and the role of the backup loop is not affected.

This principle also applies to feeders of individual electrical devices.

4) Adjust the power supply line. Reasonable adjustment of the load of the power supply line and reduction of the current on the power supply line will receive obvious power saving effect.

5) Reduce no-load loss. Disconnecting the power supply line at off-duty can reduce the no-load operation loss on the line, generally up to 3%-5%. If conditions permit, the use of timed power automatic control, the power saving effect will be better.

When the current passes through the wire, it heats up, and the resulting loss is called wire loss.

Line loss cannot be measured directly, it is calculated by subtracting the amount of electricity supplied from the amount sold.

The energy loss caused by the transmission of electrical energy through the transmission line is referred to as line loss. In addition to the lines that transmit electric energy, there are also transformers and other transmission and transformation equipment in the power network, which will also produce power loss, and the sum of these power losses (including line loss) is called network loss.

There are several ways to reduce line loss:Increasing the voltage level of the power system, including using a higher voltage to transmit electricity as much as possible when other conditions are reasonable, and ensuring the voltage level during operation.

The power flow in the line should be reasonable, especially the flow of reactive power on the line should be reduced as much as possible.

Choose a reasonable wire material and cross-section.

Line loss is calculated by the following formula: p=v a. Line loss rate = (line loss power supply) * 100% = (power supply - electricity sold) power supply * 100%.

Line loss is the voltage or electrical energy consumed by the resistance, the cross-sectional area and length of the wire determine the amount of resistance, the current determines the amount of voltage or electric energy loss, the larger the current passed, the more voltage loss, the greater the power loss, the longer the passing time, the more power loss.

Calculation of line loss

The theoretical calculation of line loss is an important technical management means to reduce loss and save energy and strengthen line loss management. Through theoretical calculations, the distribution of power loss in the power grid can be discovered, and management and technical problems can be exposed through calculation and analysis.

To provide a theoretical and technical basis for loss reduction work, it can make the loss reduction work focus on the key points, improve the efficiency of energy saving and loss reduction, and make the line loss management more scientific. Therefore, in the process of construction and transformation of the power grid and the normal management, the theoretical calculation of line loss should be carried out frequently.

The theoretical calculation of line loss is a cumbersome and complex work, especially for distribution lines and low-voltage lines, which is more difficult due to the large number of branch lines, large loads, large amounts of data and complex situations. There are many methods for calculating line loss theory, each with its own characteristics and different accuracy. This section describes a method that is relatively simple and highly accurate.

It is the power loss and loss generated in the process of transmitting electric energy from power plants to power users in the process of transmission, substation, distribution box and marketing. Specifically, it refers to the current flowing through the power grid in a certain period of time (billed from the userEnergy metersOpen to all power equipment of the user, excluding the user's billing energy meter) when the active and reactive power and voltage loss of Liang Luyuan.

What are the main components of line loss:

1. The core loss and winding resistance of step-up and step-down transformers, the loss of resistance of overhead lines and cable lines, the corona loss on high-voltage lines, and the reactors on series and parallel ** roads (or in substations).

, surface leakage loss of overhead line insulator and dielectric loss of cable route.

2. All kinds of transformers.

Losses in protective devices and meters as well as secondary circuits, losses in connection line resistance, power systems.

The active loss in the reactive power compensation equipment includes the loss in the condenser and its auxiliary equipment, the loss in the generator when it is in phase modulation operation, and the loss in the shunt capacitor. Other unknown losses.

Measures to reduce line loss in the power grid:

1. Reactive power compensation is adopted.

The device improves the power factor.

Under the condition that the active power p of the load remains unchanged, increasing the power factor of the load can reduce the reactive power q required by the load, thereby reducing the reactive power sent by the generator and the reactive power through the line and the rubber transformer, and reducing the active power and electric energy loss of the line and the transformer.

2. The power grid is transformed, and the load loss part of the power grid element varies with the voltage level under the condition that the load power remains unchanged.

The increase in the grid voltage, the current through the grid elements will be reduced accordingly, and the load loss will also be reduced. Boosting is an effective measure to reduce line loss.

3. Improve the accuracy of metering, replace the eliminated electric energy meter, reduce the measurement loss, and actively adopt the all-electronic electric energy meter with good error, high accuracy, small starting current, strong overload capacity, anti-tilting and anti-theft, which can realize automatic management of meter reading and low meter loss, improve the measurement accuracy and reasonably set the metering point.

Summary. Hello, I can only find it for you.

The formula for calculating the line loss ratio.

Line loss rate. = (Line loss power supply) * 100%.

Power Supply - Electricity Sold) Power Supply * 100%.

1 Transmission line losses.

1) The formula for calculating the active power loss of a single line is as follows:

p i2r where p -- loss of power, w;

i--load current, a;

r--wire resistance,

2) Three-phase power lines.

The active loss of the line is.

P pa ten pb ten pc 3i2r

3) Effect of temperature on wire resistance:

The wire resistance r is not constant, and its resistance value is given at a certain frequency of the power supply.

Varies with the temperature of the wire.

The temperature coefficient of resistance of copper-aluminum wire is A.

Hello, we can only query the line loss rate calculation formula for youLine loss rate = (line loss power supply) * 100% = (power supply - electricity sold) power supply * 100%1 Transmission line loss When the load current passes through the line, power loss will occur on the road resistance. (1) The formula for calculating the active power loss of a single line is p -- loss power, w; i--load current, a; r--wire resistance, (2) the active loss of the three-phase power line line is p pa ten pb ten pc 3i2r (3) the influence of temperature on the wire resistance: the wire resistance r is not constant, and its resistance value changes with the change of wire temperature in the case of a certain power supply frequency.

The temperature coefficient of resistance of copper-aluminum wire is A. Related Q&A.

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Line loss is the voltage or electrical energy consumed by the resistance, the cross-sectional area and length of the wire determine the amount of resistance, the current determines the amount of voltage or electrical energy loss, the greater the current passed, the more voltage loss, the greater the power loss, the longer the passage time, the more power loss, than into your electricity: resistance formula: r l s = when the euro passes through the 5kw three-phase load, the current is about 9a voltage loss u loss = ir = power loss p = i2r = is squared) the power loss of a day w = degree through 10kw three-phase load, The current is about 18A voltage loss u loss = IR = power loss P = I2r = power loss in one day w = 130Wx24 = degree When passing through a 20kw three-phase load, the current is about 36A voltage loss u loss = IR = power loss P = I2R = power loss in one day w = degree The above description:

As the number of degrees increases, the line loss also increases, and the greater the load, the greater the loss. A 1x increase in current and a 1x increase in voltage loss, and a 4x increase in power loss or energy loss. The line loss of 5000 degrees you talked about is 400 degrees, and the line loss of 10000 degrees is 800 degrees, which is correct when the load is constant, but not when the load changes.

Because the current increases or decreases by a factor of 1, the loss of electrical energy is approximately an increase or decrease of a factor of 4.

Questions. What does 100 35 mean.

It means to divide the two.