Non-master/slave self-current-sharing grid-connected parallel uninterrupted power supply system and power supply method thereof

Abstract

The invention discloses a non-master / slave self-current-sharing grid-connected parallel uninterrupted power supply system and a power supply method thereof, and belongs to the technical field of power electronics. The system mainly comprises two or more parallel same uninterrupted power supply system units, wherein each uninterrupted power supply system unit comprises four single-phase full-bridge converters (H1-H4), three industrial frequency inductors (LS, L1, L2), a high frequency inductor (L), a direct current filter capacitor (C1), an alternating current filter capacitor (C2), an isolation transformer (T), two bidirectional thyristors (K1 and K2), an air switch (B) and a storage battery (VB); the input side of each uninterrupted power supply system unit is connected with the power grid through the air switch (B); and various uninterrupted power supply system units pass through the second and third industrial frequency inductors (L1 and L2) and the alternating current filter capacitor (C2), are connected in parallel and are connected with the power grid through the two bidirectional thyristors (K1 and K2). The bidirectional energy flow between the uninterrupted power supply and the power grid can be achieved, the power supply system is a green load relative to the power grid, and the efficiency and dynamic response speed of a parallel system are improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics and relates to an uninterruptible power supply system, in particular to a non-master-slave self-equalizing current grid-connected parallel uninterruptible power supply system. Background technique [0002] With the development of information technology, users put forward higher requirements on the power supply quality, power supply efficiency, power supply reliability and other aspects of the power supply system. The uninterruptible power supply system has become an important way to solve the above problems with its superior performance. [0003] According to different structures and working methods, uninterruptible power supply systems can be divided into three types: backup type, online interactive type and double conversion type. At present, the most mainstream and most advanced is the double conversion type uninterruptible power supply system. Its basic structure diagram is as follows...

AI Technical Summary

Problems solved by technology

However, since the traditional active power and reactive power are defined based on the average value, at least one power frequency cycle is required to calculate the power, which seriously restricts the response speed of the system.

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