CN218449551U

CN218449551U - Take super capacitor's high-efficient equalizer circuit

Info

Publication number: CN218449551U
Application number: CN202222431516.4U
Authority: CN
Inventors: 杨振宇; 尹志强; 黄学明; 赵远强; 徐华森; 张争; 陈伟波; 郑鹏; 梁伟钊; 董晨旭
Original assignee: China Gezhouba Group Power Co ltd
Current assignee: China Gezhouba Group Power Co ltd
Priority date: 2022-09-14
Filing date: 2022-09-14
Publication date: 2023-02-03
Anticipated expiration: 2032-09-14

Abstract

A high-efficiency balancing circuit with a super capacitor comprises a retired power battery pack, wherein the retired power battery pack is sequentially connected with a switch array, a bidirectional energy converter and a super capacitor energy transfer unit, and is also connected with a load unit; the system also comprises an MCU control and sampling unit, wherein the MCU control and sampling unit is respectively and sequentially electrically connected with the retired power battery pack, the switch array, the bidirectional energy converter and the super capacitor energy transfer unit. The utility model provides a take super capacitor's high-efficient equalizer circuit when realizing initiative equalizer circuit function, reducible electronic components's quantity to reduce circuit hardware cost, and use super capacitor to be used for keeping in and the redistribution of balanced in-process energy, because super capacitor's energy density is high, charge speed is fast, long service life and charge-discharge advantage such as efficient, storage that can be fine and the balanced energy of release in-process are favorable to improving balanced efficiency.

Description

Take super capacitor's high-efficient equalizer circuit

Technical Field

The utility model relates to a technical field, especially a take super capacitor's high-efficient equalizer circuit are recycled to power battery.

Background

As the power batteries of the first generation of electric vehicles have reached the end of life, a large number of retired power batteries will begin to enter the market. Generally speaking, the capacity of a retired power battery is 70% to 80% of the initial capacity of the retired power battery, and it is widely accepted by the industry that the retired power battery can be applied to communication base stations and data centers, charging and replacing power stations and low-speed electric vehicles, and applied to power grids as an energy storage system.

However, the consistency of parameters of the battery cannot be guaranteed in the production process of the battery, and the working environments of the single batteries are different in the use process, so that the difference between the single batteries is increased, the available capacity of the battery pack is reduced, and the service life of the battery pack is shortened. Compared with the power battery pack in service, the inconsistency of the retired power battery is more obvious. This problem is well solved using an equalization circuit.

At present, an equalization circuit is divided into an energy dissipation type passive equalization and an energy transfer type active equalization, wherein the passive equalization is the energy dissipation type equalization, and the problems of low equalization efficiency and balanced heat dissipation exist. Compared with passive equalization, the active equalization circuit can achieve maximum utilization of the capacity of the battery pack, and therefore, the active equalization circuit is a main development direction of the battery equalization circuit in the future. However, in the active equalization circuit, because energy needs to be sequentially transmitted between adjacent batteries in the equalization process, a large number of passive devices are needed as energy carriers, and the equalization time and the conversion efficiency are low.

Disclosure of Invention

The utility model aims to solve the technical problem that a take super capacitor's high-efficient equalizer circuit is provided, when realizing initiative equalizer circuit function, reducible electronic components's quantity to reduce circuit hardware cost, and use super capacitor to be used for keeping in and the redistribution of balanced in-process energy.

In order to solve the technical problem, the utility model discloses the technical scheme who adopts is: a high-efficiency balancing circuit with a super capacitor comprises a retired power battery pack, wherein the retired power battery pack is sequentially connected with a switch array, a bidirectional energy converter and a super capacitor energy transfer unit, and the retired power battery pack is also connected with a load unit; the system comprises a power battery pack, and is characterized by further comprising an MCU control and sampling unit, wherein the MCU control and sampling unit is respectively and sequentially electrically connected with the switch array, the bidirectional energy converter and the super-capacitor energy transfer unit with the retired power battery pack, the MCU control and sampling unit is used for acquiring a state of charge (SOC) value and an open-circuit voltage (OCV) of the retired power battery pack and an open-circuit voltage (OCV) of the super-capacitor energy transfer unit, and the MCU control and sampling unit is also used for controlling the switch array and the bidirectional energy converter.

Preferably, the retired power battery pack comprises n batteries connected in series, the switch array comprises n +1 primary switches and 4 secondary switches, and one ends of the n +1 primary switches are respectively connected with the positive ends and the negative ends of the n batteries connected in series; the other ends of the odd first-stage switches are connected with one ends of the first second-stage switches and the third second-stage switches, and the other ends of the even first-stage switches are connected with one ends of the second-stage switches and the fourth second-stage switches; the other end of the first secondary switch is connected with the other end of the third secondary switch, and the other end of the second secondary switch is connected with the other end of the fourth secondary switch and then connected with the bidirectional energy converter.

Preferably, the bidirectional energy converter comprises a first capacitor and a second capacitor, the first capacitor is connected with the secondary switch in parallel, a first diode is connected with the second diode in series and then connected with the second capacitor in parallel, one end of the first capacitor is connected with one end of the second capacitor, and the other end of the first capacitor is connected with the inductor in series and then connected between the first diode and the second diode; the switch also comprises a first switch tube connected with the first diode in parallel and a second switch tube connected with the second diode in parallel.

Preferably, the super capacitor energy transfer unit comprises 4 super capacitors, the first super capacitor is connected in series with the second super capacitor and then connected in parallel with the second capacitor, and the third super capacitor is connected in series with the fourth super capacitor and then connected in parallel with the second capacitor.

The utility model provides a take super capacitor's high-efficient equalizer circuit when realizing initiative equalizer circuit function, reducible electronic components's quantity to reduce circuit hardware cost, and use super capacitor to be used for keeping in and the redistribution of balanced in-process energy, because super capacitor's energy density is high, charge speed is fast, long service life and charge-discharge advantage such as efficient, storage that can be fine and the balanced energy of release in-process are favorable to improving balanced efficiency.

Drawings

The invention will be further explained with reference to the following figures and examples:

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a circuit diagram of the present invention;

fig. 3 is a schematic view of the discharge balance of the single battery B1 according to the present invention;

fig. 4 is a schematic diagram of the discharge balance of the single battery B2 according to the present invention.

Detailed Description

As shown in fig. 1-2, an efficient balancing circuit with a super capacitor includes a decommissioned power battery pack 2, the decommissioned power battery pack 2 is sequentially connected with a switch array 3, a bidirectional energy converter 4 and a super capacitor energy transfer unit 5, and the decommissioned power battery pack 2 is further connected with a load unit 1; the system is characterized by further comprising an MCU control and sampling unit 6, wherein the MCU control and sampling unit 6 is respectively and sequentially electrically connected with the retired power battery pack 2, the switch array 3, the bidirectional energy converter 4 and the super-capacitor energy transfer unit 5, the MCU control and sampling unit 6 is used for collecting the SOC value and the open-circuit voltage OCV of the retired power battery pack 2 and the open-circuit voltage OCV of the super-capacitor energy transfer unit 5, and the MCU control and sampling unit 6 is also used for controlling the switch array 3 and the bidirectional energy converter 4. The load unit 1 is powered by the retired power battery pack 2, and can be generally used in communication base stations and data centers, charging and replacing power stations and low-speed electric vehicles and applied to power grids as an energy storage system according to different application scenes of the retired power battery in echelon utilization.

Preferably, the retired power battery pack 2 includes n batteries connected in series, the switch array includes n +1 primary switches K and 4 secondary switches S, in this embodiment, n is an even number, and one end of the n +1 primary switches K is connected to the positive electrode end and the negative electrode end of the n batteries connected in series respectively; the other ends of the odd first-stage switches K are connected with one ends of the first second-stage switch S1 and the third second-stage switch S3, and the other ends of the even first-stage switches K are connected with one ends of the second-stage switch S2 and the fourth second-stage switch S4; the other end of the first secondary switch S1 is connected with the other end of the third secondary switch S3, and the other end of the second secondary switch S2 is connected with the other end of the fourth secondary switch S4 and then connected with the bidirectional energy converter 4. And S1 and S4 are 1 group, S2 and S3 are 2 groups, and are respectively connected with the bidirectional energy converter 4, and the polarities of the two groups are opposite. When S1 and S4 are open, S2 and S3 are closed, and when S1 and S4 are closed, S2 and S3 are open.

Preferably, the bidirectional energy converter 4 includes a first capacitor C1 and a second capacitor C2, the first capacitor C1 is connected in parallel with the secondary switch, the first diode D1 is connected in series with the second diode D2 and then connected in parallel with the second capacitor C2, one end of the first capacitor C1 is connected with one end of the second capacitor C2, and the other end is connected in series with the inductor L1 and then connected between the first diode D1 and the second diode D2; the switch also comprises a first switch tube M1 connected with the first diode D1 in parallel and a second switch tube M2 connected with the second diode D2 in parallel. Through the switch array device 3, the super capacitor energy transfer unit 5 and the MCU control and sampling unit 6, the bidirectional flow of energy among the single batteries in the retired power battery pack 2 can be realized.

Preferably, the super capacitor energy transfer unit 5 includes 4 super capacitors, the first super capacitor SC1 is connected in series with the second super capacitor SC2 and then connected in parallel with the second capacitor C2, and the third super capacitor SC3 is connected in series with the fourth super capacitor SC4 and then connected in parallel with the second capacitor C2. Each group is connected with 2 super capacitors in series and then connected in parallel for temporary storage and redistribution of energy in the balancing process. Due to the advantages of high energy density, high charging speed, long service life, high charging and discharging efficiency and the like of the super capacitor, the balance energy in the balance process can be well stored and released, and the balance efficiency is favorably improved.

MCU control and sampling unit 6 includes MCU controller, voltage sampling circuit, opto-coupler unit for the state data of gathering the battery (including state of charge SOC, battery open circuit voltage OCV etc.), controls each module according to the balanced strategy piece that sets for through the MCU controller, thereby realizes the charge-discharge equilibrium of arbitrary battery cell in the power battery pack 2 of retirement.

As shown in fig. 3, when the SOC value voltage of the battery cell B1 in the retired power battery pack 2 is higher than the equalization threshold set in the MCU controller, the MCU controller controls the switch array device 3 to close the switches K1, K2, S1, and S4, and to open the other switches, so that the bidirectional energy converter 4 operates in the Boost circuit mode, and part of the charge of the battery cell B1 is transferred to the supercapacitor energy transfer unit 5 until the SOC value of the battery cell B1 is reduced to the set value;

as shown in fig. 4, when the SOC value of the battery cell B2 in the retired power battery pack 2 is lower than the equalization threshold value set in the MCU controller, the MCU controller controls the switch array device 3 to close the switches K2, K3, S2, and S3, and to open the other switches, the MCU controller makes the bidirectional energy converter 4 operate in the Buck circuit mode, and the charge stored in the super capacitor energy transfer unit 5 is transferred to the battery cell B2 until the SOC value of the battery cell B2 reaches the set value;

the technical effect brought by the method is as follows: the equalization circuit only uses N +5 switches and a bidirectional DC-DC circuit on hardware, the charging and discharging equalization of any single battery in the retired power battery pack 2 is realized through the MCU control and sampling unit 6, the switch array device 3 and the super capacitor energy transfer unit 5, the function of the active equalization circuit is realized, and meanwhile, the number of electronic components can be reduced, so that the hardware cost of the circuit is reduced. The super capacitor is used for temporarily storing and redistributing energy in the balancing process, and the super capacitor has the advantages of high energy density, high charging speed, long service life, high charging and discharging efficiency and the like, so that the balancing energy in the balancing process can be well stored and released, and the balancing efficiency is improved.

The above-mentioned embodiments are merely preferred technical solutions of the present invention, and should not be considered as limitations of the present invention, and the protection scope of the present invention should be defined by the technical solutions described in the claims, and equivalents including technical features in the technical solutions described in the claims. I.e., equivalent alterations and modifications within the scope of the invention, are also intended to be covered by the scope of this invention.

Claims

1. The utility model provides a take super capacitor's high-efficient equalizer circuit, includes retired power battery group (2), its characterized in that: the retired power battery pack (2) is sequentially connected with the switch array (3), the bidirectional energy converter (4) and the super capacitor energy transfer unit (5), and the retired power battery pack (2) is further connected with the load unit (1); the system is characterized by further comprising an MCU control and sampling unit (6), wherein the MCU control and sampling unit (6) is respectively and sequentially connected with the retired power battery pack (2) and the switch array (3), the bidirectional energy converter (4) and the super-capacitor energy transfer unit (5) electrically, the MCU control and sampling unit (6) is used for acquiring a state of charge (SOC) value and an open-circuit voltage (OCV) of the retired power battery pack (2), the open-circuit voltage (OCV) of the super-capacitor energy transfer unit (5), and the MCU control and sampling unit (6) is also used for controlling the switch array (3) and the bidirectional energy converter (4).

2. The efficient equalization circuit with super capacitor as claimed in claim 1, wherein: the retired power battery pack (2) comprises n batteries connected in series, the switch array comprises n +1 primary switches (K) and 4 secondary switches (S), and one ends of the n +1 primary switches (K) are respectively connected with the positive ends and the negative ends of the n batteries connected in series; the other ends of the odd-numbered first-stage switches (K) are connected with one ends of the first second-stage switch (S1) and the third second-stage switch (S3), and the other ends of the even-numbered first-stage switches (K) are connected with one ends of the second-stage switch (S2) and the fourth second-stage switch (S4); the other end of the first secondary switch (S1) is connected with the other end of the third secondary switch (S3), and the other end of the second secondary switch (S2) is connected with the other end of the fourth secondary switch (S4) and then connected with the bidirectional energy converter (4).

3. The efficient equalization circuit with super capacitor as claimed in claim 2, wherein: the bidirectional energy converter (4) comprises a first capacitor (C1) and a second capacitor (C2), the first capacitor (C1) is connected with the secondary switch in parallel, a first diode (D1) is connected with the second diode (D2) in series and then connected with the second capacitor (C2) in parallel, one end of the first capacitor (C1) is connected with one end of the second capacitor (C2), and the other end of the first capacitor (C1) is connected between the first diode (D1) and the second diode (D2) after being connected with an inductor (L1) in series; the circuit also comprises a first switch tube (M1) connected with the first diode (D1) in parallel and a second switch tube (M2) connected with the second diode (D2) in parallel.

4. The efficient equalization circuit with super-capacitor as claimed in claim 3, wherein: the super-capacitor energy transfer unit (5) comprises 4 super-capacitors, a first super-capacitor (SC 1) is connected with a second super-capacitor (SC 2) in series and then connected with a second capacitor (C2) in parallel, and a third super-capacitor (SC 3) is connected with a fourth super-capacitor (SC 4) in series and then connected with the second capacitor (C2) in parallel.