1. Background introduction
In recent years, with the deepening of urban and rural distribution network transformation, the demand for power consumption is increasing. The normal operation of various power equipment requires the power supply system to have good stability and efficient power supply capacity.
However, in the process of power supply in the power system, since most of the electrical equipment are inductive load equipment, it reduces the power of the grid operation, increases the current reactive power, and causes a lot of power loss. At the same time, it also affects the normal operation of the equipment and accelerates the loss of the equipment. In order to reduce the negative impact of reactive power, using JP compensation cabinet for power compensation is an effective solution. JP compensation cabinet is a kind of common equipment to compensate power, and its core device is low-voltage capacitor. The application of JP compensation cabinet improves the overall operation efficiency of power grid.
2、 Existing problems
The traditional JP compensation cabinet mostly adopts the scheme of "miniature circuit breaker + capacitor switching switch + low voltage capacitor". The capacitor branch is generally set to 1-6 channels, and the branch switching is controlled by the external compensation controller. In practical application, the traditional capacitor switching switch is prone to produce inrush current when switching, which has impact on the capacitor and power grid, resulting in the decline of capacitor life and easy damage. At the same time, due to the use of a large number of discrete devices in the capacitor compensation part, the JP compensation cabinet has large volume, complex wiring and difficult debugging; Moreover, due to the particularity of the installation mode and location, it is difficult to find the cause of the failure and replace the damaged components.
3. Reactive power compensation design
According to the transformer capacity of a supporting community in Shandong power grid, the design capacity configuration of the JP compensation cabinet is as follows:
3.1 Product introduction
SFR-L series low-voltage power capacitor module is a new generation of reactive power compensation products for 0.4kV low-voltage distribution system, which can achieve high efficiency and energy saving, reduce line loss, improve power factor and power quality. This series of products are mainly used in the occasions where harmonic pollution is not serious.
The product is mainly composed of intelligent measurement and control unit, thyristor composite switch circuit, high breaking capacity miniature circuit breaker, two △ type common compensation self-healing power capacitors or one Y-type separate compensation self-healing power capacitor and communication module, which are integrated through reasonable structural design to replace the traditional reactive power compensation mode of power capacitor.
3.2 Design chart
4、 Project summary
SFR-L series low-voltage intelligent capacitors replace the original reactive power compensation device composed of controller, fuse, AC contactor and low-voltage capacitor, and change the bulky structure of traditional reactive power compensation devices, so that the new generation of low-voltage intelligent reactive power compensation device has better compensation effect. It has the characteristics of lower power consumption, smaller volume, more cost saving, more flexible use, more convenient maintenance, longer service life and higher reliability, which adapts to the higher requirements of modern power grid for reactive power compensation.
This series of products have been used in many box-type power distribution systems in Shandong power grid, with reliable operation and good compensation effect, achieving the expected goal, improving the overall operation efficiency of the power grid, and getting unanimous praise from users.
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