Energy balance control method of cascaded H-bridge type energy storage system

Abstract

The invention discloses an energy balance control method of a cascaded H-bridge type energy storage system. The method comprises a cascaded H-bridge type energy storage system inter-phase energy balance control method and a cascaded H-bridge type energy storage system in-phase energy balance control method. The interphase energy balance control method comprises the following steps: calculating interphase energy balance coefficients among an A phase, a B phase and a C phase in a cascaded H bridge; and realizing energy balance by adjusting carrier waves of the corresponding phases through the inter-phase energy balance coefficients. In the in-phase energy balance control method, in-phase energy balance coefficients in the A phase, the B phase and the C phase in a cascaded H bridge are calculated; and the energy balance is realized by adjusting the carrier waves in the corresponding phases through the in-phase energy balance coefficients. In the invention, working time of a cascaded H-bridge PCS power tube is changed by multiplying the carrier waves of the energy storage system by the corresponding balance coefficient, a purpose of differentially charging and discharging different power units among the phases A, B and C and in the same phase is realized, and finally, the balance of energy stored in the energy storage units among the phases and in the phases is realized.

Description

technical field [0001] The invention belongs to the technical field of power electronics, in particular to an energy balance control method for a cascaded H-bridge energy storage system. Background technique [0002] In the context of the energy crisis, new energy power generation technologies represented by photovoltaic power generation and wind power have developed rapidly. However, the energy generated by new energy is seriously affected by environmental factors, and the output energy of new energy is fluctuating, intermittent and unpredictable. It has brought great challenges to the operation of the existing power system. [0003] The introduction of energy storage system on the new energy grid-connected side is considered to be an effective means to solve the problem of new energy grid-connected. When the output energy of new energy is greater than the active power dispatching, the energy storage system can absorb part of the energy. The energy system releases energy t...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims at the deficiencies of the prior art, in order to solve the problem of energy imbalance between phases and within phases in the cascaded H-bridge energy storage system in the process of storing and releasing energy, the present invention proposes the cascaded H-bridge energy storage system energy Equilibrium control method, this method changes the working time of the cascaded H-bridge PCS power tubes by multiplying the carrier of the energy storage system by the corresponding equalization coefficient, and realizes the control of different power units of the three phases A, B, and C between phases and within the same phase. The purpose of differentiated charging and discharging, and finally achieve the balance of energy storage between phases and phases of energy storage units

Images