Application of Smart Capacitor in Gas Station——SFR-L Series Low Voltage Power Capacitor Module 2020 Nov.20

Case introduction

Two 185kW air compressors are installed in a gas station in Zhejiang Province. The load current of each air compressor fluctuates from 0 to 350A with the gas filling condition, the power factor is 0.84, and the distance between the power distribution room and the field control cabinet is about 300 meters. Before the transformation, there are the following problems: after the load increased, the air compressor issued an over-current alarm from time to time, the terminal voltage dropped from 227.5vac to 215vac, and the line loss increased. The field measurement data are as follows (measuring instrument: FLUKE43B)

Reactive power compensation solution

According to the load and actual site conditions, reactive power compensation is performed at the control cabinet, and the configuration is as follows:

Product introduction

SFR-L series low-voltage power capacitor module is based on two (△ type) or one (Y type) compensation capacitor as the main body, highly integrated with composite switch module, microprocessor and various functional modules. The product adopts modular structure, small size and convenient maintenance. It is mainly used for reactive power compensation when the harmonic is not very serious. It is not only suitable for local compensation, decentralized compensation, but also suitable for centralized compensation.

This series of products adopts double zero-crossing switching technology to ensure that over-voltage and high inrush current will not generated when switching capacitors, thus prolonging the service life of capacitors and switching life of millions of times. The product has complete protection functions, with special protections such as capacitor internal temperature, grid harmonic content, over-current, over-voltage, under voltage, three-phase unbalance, etc., making the product more safe and reliable.

The product can be used by multiple building blocks. When multiple units are used, the main engine will be automatically generated, and the rest will be slave machines, forming a reactive power automatic control system. Individual fault slave machines will automatically exit without affecting the work of other machines. If the host engine fails, it will automatically exit and generate a new host to form a new system. The intelligent degree is very high. At the same time, this series of products also integrates the function of power meter, which can measure the conventional electrical parameters of the system.

(Technical Data Sheet)

Application effect

After the completion of reactive power compensation of this scheme, the expected goal is achieved. The power factor of the air compressor branch is increased to 0.98, the line voltage loss is reduced to 6vac, the air compressor operates stably (the previous over-current alarm is released), the power environment is purified, and the safe and stable operation of the equipment is greatly improved. Which also greatly improves the effective utilization of electric energy; reduces the loss of power distribution lines, increases the terminal voltage of the air compressor and extends the service life of cables and equipment.