Three-phase power saver and control method thereof

Abstract

The invention relates to a power saver and specifically relates to a three-phase power saver with static reactive generation and source filtering functions and a control method thereof. The three-phase power saver includes a main control part, a power-saving convertor circuit and a detection circuit, and the different components can be combined or split in function or structure. The different components are mutually connected electrically. The AC side of the power-saving convertor circuit is directly connected electrically in parallel with a three-phase AC load or connected in parallel indirectly and electrically via an isolation transformer. The control method of the system is: the power-saving convertor circuit provides a matched reactive power through real-time detection of load-side parameters and filters harmonic waves generated by the load at the same time. The three-phase power saver is capable of improving a power factor on an electrical-power transmission line and also capable of filtering the harmonic waves generated by the load and optimizing the quality of electrical energy so that energy wastage can be reduced and a power-saving objective is achieved.

Description

technical field [0001] The invention relates to a power saver, in particular to a three-phase power saver and a control method thereof. Background technique [0002] With the development of modern industry, the global demand for electric energy is increasing year by year, and the non-renewable resources that generate electric energy are frequently running out, and the price is also rising. Energy saving is an important issue for future generations. topic. [0003] Nowadays, there are a large number of inductive loads represented by electric motors among electric loads. When such loads are working, the grid must not only provide active power, but also must provide a certain amount of reactive power at the same time, which leads to grid-side power This situation greatly reduces the transmission efficiency of energy in the power grid, and because the load runs for a long time under the condition of high voltage and high current, it increases the loss of electric energy during ...

AI Technical Summary

Problems solved by technology

[0009] The above-mentioned first and second schemes of "cure the head for the headache and treat the foot for the foot pain" have not completely solved the problem of energy waste. It is often found that the harmonic content increases significantly when reactive power is compensated; the power factor is found to increase significantly when filtering. reduce

[0010] In the third scheme, the reactive power compensation device and the filtering device are independent of each other. At the beginning of the design, the historical operation data is often used for reference, and the maximum value of the reactive power consumption is taken as the minimum capacity of the reactive power compensation device; the maximum value of the harmonic power is used as the filtering device. The minimum capacity of the device, which makes the two independent energy-saving devices waste capacity for a long time, and the high combined cost makes users discouraged

The more serious situation is that the reactive power compensation device often injects harmonics into the filter device during operation, and the filter device produces reactive power consumption, etc., and the functions cancel each other out, which greatly reduces the overall power saving effect.

Images