Intelligent control box for overhead transformer

Abstract

The invention relates to the technical field of power transformation facilities for voltage drop from 10kV or 20kV to 0.4kV, in particular to an intelligent control box for an overhead transformer. The intelligent control box comprises a box body, a main switch and a capacitor. A cable channel is formed on each of the two sides of the box body. An upright post is arranged in the box body. The main switch is arranged on one side of the upright post. Grounded interlock switches are arranged on the other side of the upright post. A knife fuse switch is arranged below a beam in the box body, and is connected with the capacitor which is arranged on the box body. A controller is arranged below the knife fuse switch. A general packet radio service (GPRS) instrument is arranged above the beam. The application effects of unified design, unified mounting and consistent operation and maintenance of related equipment of a power distribution network are ensured, the running cost of an enterprise is lowered, and economic benefits are improved; energy is saved, loss is reduced, and low-voltage unbalancedness and harmonic pollution are improved; and data can be monitored in real time, the implementation of state overhauling in the future is technically guaranteed, and the safety of operation personnel is greatly improved.

Description

technical field [0001] The invention relates to the technical field of substation facilities for stepping down 10kV or 20kV to 0.4kV, in particular to an intelligent control box for overhead transformers. It is a complete and standardized design of transformer platform and energy-saving control box equipment, especially in the aspects of safe operation of distribution network, low-voltage three-phase unbalance and power factor control, smart grid terminal data collection and energy-saving loss reduction. Background technique [0002] Distribution overhead transformers and control boxes are important parts of urban power grids. As an important link in the transmission of electric energy from medium-voltage distribution networks to users, the operating status and safety performance of substations have an important impact on the stable operation of the entire power grid. There are many types of power distribution overhead transformers in my country, and the structures are also ...

AI Technical Summary

Problems solved by technology

[0004] 1. There are many types of substations, and the structure and operation mode are inconsistent, which leads to great differences in installation, operation and maintenance and low-voltage operation.

[0005] 2. The equipment is quite old, many of them are seriously corroded, their functions are not perfect, their insulation level and practicability are greatly reduced, and there is a risk of operation, which is a risk factor for the power grid and surrounding facilities and pedestrians

[0006] 3. High and low voltage electrified parts are exposed to the outside, and the ability to resist natural disasters and external damage is weak, such as short-circuit tripping caused by foreign objects blown by strong winds, grounding and short-circuit accidents caused by dense fog and sandstorms, etc.

[0007] 4. There is no reactive power phase compensation function, and the neutral point offset problem caused by the unbalanced low-voltage 0.4kV load cannot be reduced; the uncertainty and randomness of the low-voltage load cannot bring great influence to the control of the low-voltage system. Great difficulty, especially in areas that use low-voltage single-phase power supply and remote areas

[0008] 5. There is no grounding device in the low-voltage 0.4kV part, which cannot effectively guarantee the safety of operators; as a professional problem, the problem of low-voltage insulation and grounding has not been effectively solved, and the personal protection of operators is in a blank state

[0009] 6. The online monitoring system is incomplete, and the operation data of distribution network terminals cannot be obtained in real time, which will cause a bottleneck effect on the realization of condition-based maintenance and the development of smart grid; Weak points of the line and the status of heavy load users, load forecasting, and joint operation planning and operation methods are of great help

[0011] 8. Harmonic pollution cannot be suppressed; in the power grid, there are a large number of nonlinear loads, this non-sinusoidal wave can be decomposed into a DC quantity by Fourier series, the fundamental sine quantity and a series of frequencies are integer multiples of the fundamental frequency The sum of the higher harmonic sine components of

Due to the existence of various harmonic sources in the power system, the high-order harmonic interference becomes the "pollution" of the power grid, such as: the internal friction of the cable increases, the cable generates heat, and the service life of the cable is shortened; the impact on the motor is greater , not only the loss increases, but also the rotor of the motor vibrates; and the influence of high-order harmonics on the capacitor is more prominent. When the voltage containing high-order harmonics is applied to both ends of the capacitor, the impedance of the capacitor to the high-order harmonics is very small , so the capacitor is prone to overload and damage

The interference of high-order harmonics often leads to the malfunction of the power supply air switch, causing power outages in the power grid, which seriously affects the normal operation of electrical equipment, and high-order harmonics also generate interference signals to communication equipment

[0012] 9. The overall facilities are closed and non-transparent, and the internal situation cannot be understood in real time. The operator must open the closed facility of the equipment through professional facilities to understand the internal operation situation, which increases the operating time and complexity of the operation

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