CN204089239U - A kind of cell batteries dynamic equalization charging circuit - Google Patents

Abstract

The utility model relates to battery technology field, be specifically related to a kind of cell batteries dynamic equalization charging circuit, it adopts following technical scheme: monomer whose storage battery dynamic equalization charging circuit comprises a cell batteries, this cell batteries one end and charging inductance L electrically connect, and this cell batteries other end and gate-controlled switch power device VT one end electrically connect; The described gate-controlled switch power device VT other end and diode VD one end electrically connect, and one end of this diode VD other end and storage capacitor C electrically connects; It is managed independently the charging process of cell batteries, charging current or charging voltage are controlled, all cell batteries are made all to be operated in optimum state, to improve the useful life of cell batteries, and can when not affecting the charging of other cell batteries, excise the cell batteries broken down, improve the reliability of whole batteries.

Description

A dynamic equalization charging circuit for single storage battery

【Technical field】

The utility model relates to the technical field of storage batteries, in particular to a dynamic equalization charging circuit for single storage batteries. the

【Background technique】

At present, there are two main types of battery equalization circuits, energy consumption type and energy non-consumption type. In the energy consumption equalization circuit, a shunt resistor is connected in parallel to each single battery in the battery pack to consume the excess energy in the multi-capacity single battery to achieve the purpose of equalization. In the energy non-consuming equalization circuit, inductors and capacitors are used as energy storage components, and common power conversion circuits are used to redistribute excess energy between batteries to achieve energy transfer between batteries. the

The problem with the energy-consuming battery balancing circuit is that it needs to turn on the shunt resistor in the monomer balancing module to convert the excess energy into heat and consume it, which leads to the low efficiency of this balancing circuit and the inability to control the shunt current, so there is energy waste and thermal management issues. the

The problem with the transformer non-consumption equalization circuit is that the secondary windings cannot be completely matched, it is difficult to compensate the leakage inductance voltage difference, it is not easy to be modularized, and the voltage of the single battery cannot be measured. the

The basic idea of the converter non-consumption equalization circuit is to transfer the energy in the high-voltage single battery to other single batteries through the converter, which has low efficiency to varying degrees and cannot accurately control the size of the shunt current. and thermal management issues. the

It can be seen that although the above various equalization schemes can realize the equalization of battery charging, they cannot accurately manage the charging of each single battery in the battery pack, and if one or several single batteries in the battery pack If it is damaged, the entire battery pack cannot continue to work, which is not conducive to improving the life and reliability of the entire battery pack. the

【Content of utility model】

The purpose of this utility model is to aim at the defects and deficiencies of the prior art, to provide a single battery dynamic equalization charging circuit with simple structure, reasonable design and convenient use, which independently manages the charging process of the single battery and controls the charging current or the charging voltage is controlled to make all the single batteries work in the optimal state, so as to improve the service life of the single batteries, and can cut off the faulty single batteries without affecting the charging of other single batteries, so as to improve The reliability of the entire battery pack. the

The utility model relates to a single battery dynamic balanced charging circuit, which includes a single battery, one end of the single battery is electrically connected to the charging inductance L, and the other end of the single battery is electrically connected to one end of the controllable switching power device VT. Connection; the other end of the controllable switching power device VT is electrically connected to one end of the diode VD, the other end of the diode VD is electrically connected to one end of the energy storage capacitor C, and the other end of the energy storage capacitor C is electrically connected to one end of the battery cell. the

After adopting the above-mentioned structure, the beneficial effect of the utility model is: a dynamic equalization charging circuit for a battery cell described in the utility model, which independently manages the charging process of the battery cell, controls the charging current or the charging voltage, and makes All single batteries work in the optimal state to increase the service life of the single batteries, and can cut off the failed single batteries without affecting the charging of other single batteries to improve the reliability of the entire battery pack. the

【Description of drawings】

The accompanying drawings described here are used to provide a further understanding of the utility model and constitute a part of the application, but do not constitute an improper limitation of the utility model. In the accompanying drawings:

Fig. 1 is the structure schematic diagram of the single storage battery dynamic equalization charging circuit of the present utility model;

Fig. 2 is the accumulator battery pack that n has the single accumulator accumulator that novel dynamic balanced charging circuit of the present utility model is formed. the

【Detailed ways】

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the schematic embodiments and descriptions are only used to explain the utility model, but not as a limitation to the utility model. the

As shown in Fig. 1, a battery cell dynamic balance charging circuit described in this specific embodiment includes a battery cell, one end of the battery cell is electrically connected to the charging inductance L, and the other end of the battery cell is connected to the One end of the controllable switching power device VT is electrically connected; the other end of the controllable switching power device VT is electrically connected to one end of a diode VD, the other end of the diode VD is electrically connected to one end of an energy storage capacitor C, and the other end of the energy storage capacitor C is electrically connected to One end of the single storage battery is electrically connected. the

In the utility model, the charging current control method of the dynamic equalization charging circuit of the monomer storage battery adopts the following steps:

a. According to the principle of energy conservation, the relationship between the PWM wave driving VT and the charging current and capacitor voltage in steady state can be calculated;

b. In one switching cycle, when neglecting the tube voltage drop of the diode and power device and ignoring the internal resistance of the battery, and assuming that the power device is turned on when the driving voltage is high, in one PWM cycle, the constant current source outputs to the charging The energy in the circuit is

W _s =u _C ×i ₀ ×T _off (1)

＝u _C ×i ₀ ×T _off

In the formula, W _s - the energy output from the constant current source to the charging circuit;

i ₀ ——Constant current output by constant current source;

T _off - the time when the driving pulse PWM is low level;

u _C - the voltage across the capacitor C.

In one PWM cycle, the energy absorbed by the single battery is

W _b ＝E _b ×i ₁ ×T _s (2)

In the formula, W _b - the energy absorbed by the single battery;

E _b ——the electromotive force of the single battery;

i ₁ ——the charging current of the single battery;

T _s - the switching period of the drive pulse PWM.

According to the energy conservation relationship, the energy output by the constant current source to the charging circuit is equal to the energy absorbed by the single battery, so there is

u _C ×i ₀ ×T _off ＝E _b ×i ₁ ×T _s (3)

In the steady state, if the equivalent resistance is R, there

u _C ＝E _b +R×i ₁ (4)

available through derivation

${\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; off</span>}}}{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; off</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; off</span>}}}{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; off</span>}}}\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

According to formula (5), it can be seen that by controlling the driving pulse of the power device VT, that is, the ratio of T _off to T _s , the control of the charging current can be realized;

c. Precisely control the charging current of the single battery, detect the magnitude of the charging current i1, use the detected value as the current feedback signal, and then adjust the driving pulse of VT according to the feedback signal, and then realize the precise closed-loop control of the charging current. the

In the utility model, the charging voltage control method of the dynamic equalization charging circuit of the battery cell adopts the following steps:

1. According to formula (6), it can be known that by controlling the drive pulse of power device VT, i.e. the ratio of _Toff and _Ts , the control of charging voltage can be realized;

II. Precisely control the charging voltage of the single battery, detect the magnitude of the charging voltage, use the detected value as a feedback signal, and then adjust the driving pulse of VT according to the feedback signal, and then realize the precise closed-loop control of the charging voltage. the

In the present utility model, as shown in Fig. 1 and Fig. 2, the dynamic balanced charging circuit of a single storage battery is powered by a constant current source, and the constant current source keeps the current i ₀ constant, and the size of i ₀ can be determined according to the specific conditions of use. Make settings. The whole circuit includes: controllable switching power device VT, energy storage capacitor C, charging inductor L and diode VD; the function of the controllable switching power device VT is to short-circuit point AB when VT is turned on, and the constant current i ₀ does not Flow through the single battery; when VT is cut off, the constant current _i0 charges the capacitor C, therefore, the control of the battery charging current _i1 can be realized by changing the duty cycle of the VT drive pulse. The function of the energy storage capacitor C is to keep the charging voltage basically stable. When VT is cut off, the constant current source charges the capacitor C. When VT is turned on, the energy storage capacitor C charges the inductor L to keep the charging current i ₁ stable. .

The function of the charging inductance L is to filter out the ripple in the charging current _i1 .

The function of the diode VD is to make the current _i1 only flow in one direction. When the VT is turned on, the voltage at both ends of the VT is the conduction voltage. If there is no unidirectional diode, the capacitor C is short-circuited, and the charging circuit cannot work normally. And when VT is cut off, the constant current source delivers energy through the one-way diode.

In the present utility model, when a number of battery cells are combined into a battery pack, the removal method of the faulty battery cells is as follows:

First of all, a single battery with a dynamic balanced charging circuit is called a unit; in Figure 2, n units are connected in series to form a battery pack, and the two ends of the battery pack are respectively connected to the two ends of the constant current source electrical connection. the

Secondly, the number n of units connected in series in the battery pack is determined by the working voltage of the battery pack. the

Again, when a certain unit or several units fail in the entire battery pack, the driving pulse of the faulty unit can be completely set to high level, which is equivalent to bypassing the faulty unit, and bypassing the faulty unit can ensure that other units Normal charging. the

The beneficial effects of the utility model are as follows:

(1) Compared with the energy-consuming equalizing circuit, the novel monomer storage battery dynamic equalizing charging circuit provided by the utility model does not need to consume electric energy, which improves the efficiency of the equalizing circuit. the

(2) The new single storage battery dynamic equalization circuit does not need a transformer, and uses fewer power devices at the same time, and has a simple structure. the

(3) It can accurately control the charging current of the single battery in the battery pack;

(4) It can accurately control the charging voltage of the single battery in the battery pack;

(5) It can realize the independent charging of each single storage battery in the battery pack, and can set different charging voltages or charging currents for different single storage batteries. the

(6) The faulty single battery can be removed without affecting the charging of other single batteries. the

(7) It can improve the service life of single battery and battery pack;

(8) The reliability of the battery pack can be improved. the

The utility model describes a single battery dynamic balance charging circuit, which independently manages the charging process of the single battery, controls the charging current or charging voltage, and makes all the single battery work in the optimal state, so as to The service life of the single battery is improved, and the faulty single battery can be removed without affecting the charging of other single batteries, so as to improve the reliability of the entire battery pack. the

The above is only a preferred embodiment of the utility model, so all equivalent changes or modifications made according to the structure, features and principles described in the utility model patent application scope are all included in the utility model patent application scope . the

Claims (1)

1. a cell batteries dynamic equalization charging circuit, is characterized in that: it comprises a cell batteries, and this cell batteries one end and charging inductance L electrically connect, and this cell batteries other end and gate-controlled switch power device VT one end electrically connect; The described gate-controlled switch power device VT other end and diode VD one end electrically connect, and one end of this diode VD other end and storage capacitor C electrically connects, and the other end and cell batteries one end of this storage capacitor C electrically connect.