Two-stage three-level three-phase four-wire system energy storage converter neutral-point potential balancing method and system

A three-phase four-wire system, potential balance technology, applied in the field of energy storage, can solve the problems of limited ability to suppress midpoint potential oscillation, increase switching loss, increase device voltage stress, etc., to achieve long-term stable operation, improve The effect of running stability and improving balance ability
CN112909919AActive Publication Date: 2021-06-04CSR ZHUZHOU ELECTRIC LOCOMOTIVE RES INST
6 Cites 1 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
CSR ZHUZHOU ELECTRIC LOCOMOTIVE RES INST
Publication Date
2021-06-04

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a neutral-point potential balancing method and system for a two-stage three-level three-phase four-wire system energy storage converter, and the method comprises the steps: controlling a three-level Buck / Boost circuit to work in a Boost mode or a Buck mode according to a low-voltage side inductive current reference value iLref in the three-level Buck / Boost circuit in the energy storage converter; according to the difference between the midpoint potential reference delta(uref) and the midpoint potential offset delta(u), adjusting the duty ratio of each switch tube in the Buck / Boost circuit in the Boost mode or the Buck mode is adjusted, so that the total voltage of the direct-current bus is constant and balanced with the midpoint potential. The method has the advantages of constant direct-current bus total voltage, neutral-point potential balance, improvement of the operation stability of the converter and the like.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention mainly relates to the technical field of energy storage, in particular to a two-stage three-level three-phase four-wire energy storage converter midpoint potential balancing method and system. Background technique

[0002] Energy storage technology has broad application prospects in the fields of improving grid reliability, demand side management, and access to new energy sources. Energy storage connected to the power system can improve the security and stability of the power grid, alleviate the load peak-valley difference, improve power quality, and promote the application of renewable energy; it forms an independent micro-grid with distributed power, which can improve the stability of the micro-grid system. The electrochemical energy storage system mainly includes a battery management system (BMS) and a bidirectional energy conversion system (Power Conversion System, PCS). It mainly has the following functions: 1) Under grid-connected ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More