Balanced output system based on multi-winding transformer

Abstract

The invention discloses a balanced output system based on a multi-winding transformer. The system comprises a battery unit module, a multi-winding transformer, two groups of switch tubes, a controller and a filter module, and when the output is carried out, the controller generates a PWM signal with a fixed duty ratio to drive a primary side switch tube and control a secondary side switch tube to be in an off state; equalization of the battery pack is achieved through forward excitation, and a secondary side output function is achieved through flyback excitation; and when the battery unit module is charged, the controller generates the PWM signal with the fixed duty ratio to drive the secondary side switch tube, the primary side switch tube is controlled to be in an off state, and the function of charging the primary side battery unit module is achieved through flyback. The multi-winding transformer is used for balancing the battery unit modules, the secondary side of the transformer is used for achieving external output, the available capacity of the battery pack is improved, the service life of the battery pack is prolonged, and meanwhile the integration level of a balance system is improved.

Description

technical field [0001] The invention relates to the technical field of active equalization of battery energy, in particular to an equalized output system based on a multi-winding transformer. Background technique [0002] Batteries are widely used in artificial satellites, hybrid electric vehicles, electric vehicles, uninterruptible power supplies, and photovoltaic systems due to their advantages in cycle life, mass specific energy, and volume specific energy. These applications often require a high voltage power supply. However, the terminal voltage of a battery is relatively low, and in order to achieve the required voltage level, multiple batteries need to be connected in series to form a battery pack to meet the voltage required by these applications. During operation, the battery is repeatedly charged and discharged, and due to the different chemical and electrical characteristics of the battery during the manufacturing process, there may be inconsistencies between bat...

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Problems solved by technology

[0004] Chinese Invention Patent (Application No. CN201410211996.0) discloses a battery pack equalization circuit based on multi-secondary transformers and its implementation method, by using multi-secondary transformers and corresponding The module balances the energy between the batteries and realizes the modularization of the balanced circuit, but the control method has certain complexity and has certain requirements for control accuracy, which will increase the complexity of the system design

[0005] Chinese Invention Patent (Application No. CN201820835035.0) discloses a voltage equalization circuit for battery packs based on transformers. Each battery cell corresponds to a voltage equalization unit. However, since each battery needs a voltage equalization unit, this transformer-based battery pack voltage equalization circuit is very bulky and is not suitable for a large number of battery cells.

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