Three-phase four-wire system general power quality controller and control method thereof

Abstract

The invention discloses a three-phase four-wire system general electric energy quality controller and a control method thereof. A circuit topology structure of the electric energy quality controller comprises a power supply side circuit, and A, B and C three-phase power grid power supply ends Vsa, Vsb and Vsc are connected with the power supply side circuit; the power supply side circuit is connected with a load side circuit through a common bridge arm, the load side circuit is connected with series coupling transformers Ta, Tb and Tc to form a series compensation device, and the output of thecommon bridge arm is connected with a power supply neutral line N and neutral lines of converter sides of the series coupling transformers Ta, Tb and Tc through a filter inductor Lf7 at the same time; a three-phase compensation voltage is output to compensate a three-phase power grid voltage such that a load voltage is a three-phase constant, balanced and symmetrical sine voltage. A single energystorage capacitor structure is adopted, the capacitor capacity is small, the capacitor voltage fluctuation is low, and the loss is small; few power electronic devices are adopted, and the formed universal power quality controller is simple in circuit structure, low in manufacturing cost and high in efficiency; and the control method is simple and easy to implement.

Description

technical field [0001] The invention belongs to the technical field of power quality control, and in particular relates to a three-phase four-wire general power quality controller and a control method thereof. Background technique [0002] With the development of modern science and technology, on the one hand, the factors causing power quality problems continue to grow; on the other hand, various complex, sophisticated, and power-quality-sensitive electrical equipment continue to popularize, and people's requirements for power quality and reliability The higher and higher, the contradictions of the above problems are becoming more and more prominent. Technically, power quality problems are further divided into voltage quality problems on the power supply (network) side (such as voltage rise, drop, transient, harmonics, etc.) and current quality problems on the load side circuit (current harmonics, balance, etc.). Various interferences in the power grid (power supply) and l...

AI Technical Summary

Problems solved by technology

The circuit topology of adding the fourth bridge arm uses a single energy storage capacitor, there is no problem that the neutral line current directly charges and discharges the energy storage capacitor, and the fluctuation of the capacitor voltage is small, but this topology will increase the number of power electronic switching devices , high cost

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