The loss of the power grid is divided into management line loss and technical line loss. Management line loss through management and organizational measures to reduce; technical line loss through a variety of technical measures to reduce. Technical measures to reduce network losses include measures that require a certain increase in investment in the technical transformation of the power network and measures that do not require increased investment only to improve the operation of the power grid. This paper only discusses the main technical measures to reduce network loss.

The transformation of the power network is due to various reasons, the power transmission and transformation capacity of the power grid is insufficient, and the "stuck neck" and the power supply radius is too long. These problems not only affect the safety and quality of power supply, but also affect the line loss. (1) Adjust the unreasonable network structure, set up new transmission and distribution lines, transform the original lines, increase the cross-section of the wires, and adopt low-loss transformers. (2) the power grid boost, simplify the voltage level and transformer level, reduce the repeated substation capacity.

Economic operation of power network and equipment

Economic operation of power system and power network The economic operation of power system is mainly to determine the combination of units and economic distribution of load. At this time, the economy of the whole system is considered, and the line loss is not the decisive factor. Therefore, under the premise of the economic distribution of the active load of the system, the economic operation of the power network and its equipment is an effective measure to reduce line loss.

(1) Reasonable distribution of reactive power: while the active power is reasonably distributed, the reactive power should be reasonably distributed. According to the principle of nearby arrangement to reduce reactive power long-distance transmission. Line loss should be calculated in a variety of ways to develop a reasonable mode of operation; should be reasonable adjustment and use of compensation equipment to improve the power factor.

(2) Determine the reasonable operation mode of the ring network: whether it is closed or open-loop operation, and at which point the open loop is related to the safety, reliability and economy of the power grid. In order to enhance the reliability of power supply and improve the economy of power supply, it should be closed loop operation, but closed loop operation will lead to the complexity of relay protection, thus affecting the reliability. Open-loop operation should select the solution point according to the result of network loss calculation.

(3) The reasonable operating voltage of the power network: The operating voltage of the power network has an impact on the no-load loss of the components in the power network. Generally, in 35kV and above power supply networks, increasing the operating voltage by 1% can reduce losses by about 1.2. Improving the voltage level of the power grid is mainly to do a good job in the reactive power balance of the whole network, including increasing the voltage of the generator port, improving the power factor of the user, and adopting reactive power compensation devices. Adjust the tap of the transformer under the premise of reactive power balance. In the 10kV distribution network, the no-load loss accounts for about 50% to 80% of the total loss, especially in the middle of the night, due to the low load, the proportion of no-load loss is larger, so it should be based on the user's requirements for voltage offset, Appropriately reduce the voltage operation. For the low-voltage power grid, its no-load loss is very small, and the operating voltage should be increased. It can be seen that in the operation of the power grid, a large number of on-load voltage regulating equipment can reasonably adjust the operating voltage of the power grid under different load conditions.

(4) Adjust the load curve and balance the three-phase load: the load peak-valley difference is large, and the line loss is large under the same power supply. When the three-phase load of the transformer is unbalanced, especially the low-voltage network, it not only affects the safe operation of the transformer but also increases the line loss.

The economic operation of the transformer The loss of the transformer accounts for 30% ~ 60% of the total line loss of the whole system, and reducing the loss of the transformer is an important part of the loss reduction of the power grid. Generally, in addition to the selection of energy-saving transformers, more than two transformers should be installed in the substation for parallel operation. This not only improves the possibility of power supply, but also can reasonably stop the number of parallel operation transformers according to the load and reduce the transformer loss.

Reactive Power Compensation of Power Grid

Improve the power factor of the load to improve the power factor of the load, can reduce the reactive power sent by the generator and the reactive power transmitted through the line and transformer, so that the line loss is greatly reduced, but also can improve the voltage quality, improve the transmission capacity of the line and transformer.

The installation of reactive power compensation equipment shall be based on the reactive load and reactive power distribution in the power grid to reasonably select the reactive power compensation capacity and determine the distribution of the compensation capacity to further reduce the loss of the power grid.

The economic operation of smart grid is an effective way to reduce the cost of power supply. Reasonable selection of technical measures to reduce network loss is an extremely important work. In addition to understanding various technical measures, power grid management workers also need to choose more appropriate loss reduction measures according to the actual needs of the power grid, so as to get twice the result with half the effort.