CN105203968A - Lead-acid battery residual energy on-line measuring system - Google Patents

Abstract

The invention discloses a lead-acid battery residual energy on-line measuring system which comprises a data acquisition module, a data processing module and a display module which are connected in sequence, wherein a current sensor is arranged in the data acquisition module, and is used for conducting real-time monitoring on charge-discharge current of a battery; the data processing module is used for conducting time integral of signals collected by the current sensor to acquire the real-time discharge quantity of the battery. The measuring system adopts the depth of charge (DOC) as the parameter for reflecting the charged state of the battery, and the parameter is calculated by adopting the actual capacity of the battery but not the non-nominal capacity, and can better reflect the actual condition of the battery; besides, the measuring system can periodically conduct deep discharge on the battery, the capacity can be restored, the Ct value can be rectified, and the accuracy of the measuring system can be improved.

Description

A kind of on-line measurement system of lead-acid accumulator dump energy

Technical field

The present invention relates to a kind of on-line measurement system of lead-acid accumulator dump energy, belong to field of measuring technique.

Background technology

Accumulator also claims secondary cell, be can be by obtained electric energy conversion chemical energy store and can be by chemical energy electric energy export a kind of device.Lead-acid accumulator is widely used in automobile, boats and ships, the industry spot such as petrochemical complex, is current tradition and uses one of accumulator widely.

Usually adopt the charged state SOC of battery to carry out the dump energy of characterizing battery at present, traditional SOC measuring method utilizes the nominal capacity of battery to calculate.But along with the impact of the factor such as aging, battery nominal capacity can change, and thus causes these measuring methods promptly and accurately can not reflect the actual conditions of battery.

Current also have method such as employing fuzzy logic or neural network etc. to realize the on-line measurement of battery electric quantity, and these methods achieve prediction effect comparatively accurately in theory.But in engineering reality, said method also exists algorithm complexity, and cost is high, hardware design difficulty is large waits deficiency.

Summary of the invention

Goal of the invention: technical matters to be solved by this invention is to provide a kind of on-line measurement system of lead-acid accumulator dump energy, measuring system of the present invention adopts depth of charge as the parameter of reflection battery charge state, and this parameter adopts the actual capacity amount of battery to calculate.

For solving the problems of the technologies described above, the technical solution adopted in the present invention is:

An on-line measurement system for lead-acid accumulator dump energy, comprises the data acquisition module, data processing module and the display module that connect successively; Containing current sensor in described data acquisition module, described current sensor is monitored in real time to accumulator cell charging and discharging stream; Described data processing module by current sensor Real-time Collection to signal integration is carried out to the time, obtain battery real-time discharge capacity;

Described measuring system adopts following steps to carry out on-line measurement to lead-acid accumulator dump energy:

Step 1, initiation parameter, comprises initial actual capacity C _t, nominal capacity C _t, low power threshold and deep discharge threshold value;

Step 2, arranges discharge condition zone bit d, and charged state zone bit c, arranges variable count, Q _d, Q _crepresent respectively and store charge cycle number, equivalent discharge capacity, charge volume;

Step 3, when current sensor detects battery discharging, is set to 1 by d, and electric discharge terminates then d to be set to 0;

Step 4, when current sensor detects charge in batteries, is set to 0 by c, and charging terminates then c to be set to 1;

Step 5, when current sensor detects that battery discharging is interrupted, and now d is 1, calculates DOC and Q _evalue, DOC value output display system shows; Otherwise perform step 7;

Step 6, if DOC is less than low power threshold, display electricity is not enough, and prompting user stops using or charges as early as possible; D is set to 0, returns step 5;

Step 7, if c is 1, then makes count increase by 1, and calculates C _tif, C _tvalue is less than nominal capacity C _t80%, system prompts user battery life is about to come to an end; Otherwise, if C _tvalue is less than deep discharge threshold value, and suggestion user carries out deep discharge;

Step 8, is set to 0 by c, returns step 3.

Wherein, described initial actual capacity C _tby battery under standard operating temperature and discharge rate carry out deep discharge reality release electricity, in use procedure, data processing module is to C _tvalue refreshes, and method is as shown in formula (I):

$C_t\left(k\right)=C_t(k-1)-\frac{Q_e}{{\mathrm{w\η}}_c}+Q_C---\left(I\right);$

That is: C in a upper charge cycle _tvalue and battery discharge capacity, the algebraic sum of actual charge volume, note is just charged as, and it is negative for discharging; Wherein, in formula (I), k is charge cycle number, Q _efor discharge capacity, Q _cfor charge volume, η _cfor charge efficiency, w is the correction factor of actual discharge rate and battery charge efficiency relation.Specify to carry out deep discharge every half a year or suitable cycle index to battery, correct C to reach _twith the effect of capacity restoration.

Measuring system of the present invention adopts depth of charge DOC (DepthOfCharge) as the parameter of reflection battery charge state, the actual capacity of battery is adopted but not nominal capacity when this parameter calculates, more can reflect the actual conditions of battery, the computing formula of described DOC is:

$DOC=\frac{C_t-Q_e}{C_t}---\left(II\right);$

Wherein, in formula (II), $Q_e={\∫}_0^{t}li\left(\mathrm{\τ}\right)d\left(\mathrm{\τ}\right);$

Wherein, C _trepresent the actual capacity of battery, Q _efor real-time discharge capacity, 1 is correction factor, and i is electric current, and t is the time; 1 correction factor is by temperature, and electric current, the graph of a relation table analysis of self discharge and the factor such as aging and battery remaining power integrates gained, and relation chart directly can obtain when battery dispatches from the factory.

Beneficial effect: compared to prior art, measuring system of the present invention adopts depth of charge DOC as the parameter of reflection battery charge state, and this parameter adopts the actual capacity of battery but not nominal capacity when calculating, therefore more can reflect the actual conditions of battery; In addition, this measuring system regularly can carry out deep discharge to battery, can correct C again while recovering capacity _tvalue, improves the accuracy of measuring system.

Accompanying drawing explanation

Fig. 1 is the operational flow diagram of lead-acid accumulator dump energy on-line measurement system of the present invention;

Fig. 2 is the system chart of lead-acid accumulator dump energy on-line measurement system of the present invention.

Embodiment

According to following embodiment, the present invention may be better understood.But those skilled in the art will readily understand, the content described by embodiment only for illustration of the present invention, and should can not limit the present invention described in detail in claims yet.

Below in conjunction with the drawings and specific embodiments, content of the present invention is further described.

Composition graphs 1 ~ 2, the on-line measurement system of lead-acid accumulator dump energy of the present invention, comprises the data acquisition module, data processing module and the display module that connect successively; Containing current sensor in data acquisition module, current sensor is monitored in real time to accumulator cell charging and discharging stream; Data processing module by current sensor Real-time Collection to signal integration is carried out to the time, obtain the real-time discharge capacity of battery and also correcting process carried out to it;

Measuring system of the present invention adopts following steps to carry out on-line measurement to lead-acid accumulator dump energy:

Step 1, initiation parameter, comprises initial actual capacity C _t, nominal capacity C _t, low power threshold is 0.2C _twith deep discharge threshold value 0.9C _t;

Step 2, arranges discharge condition zone bit d, and charged state zone bit c, arranges variable count, Q _d, Q _crepresent respectively and store charge cycle number, equivalent discharge capacity, charge volume;

Step 3, when current sensor detects battery discharging, is set to 1 by d, and electric discharge terminates then d to be set to 0;

Step 4, when current sensor detects charge in batteries, is set to 0 by c, and charging terminates then c to be set to 1;

Step 5, when current sensor detects that battery discharging is interrupted, and now d is 1, calculates DOC and Q _evalue, DOC value output display system shows; Otherwise perform step 7;

Step 6, if DOC is less than 0.2C _t, display electricity is not enough, and prompting user stops using or charges as early as possible; D is set to 0, returns step 5;

Step 7, if c is 1, then makes count increase by 1, and calculates C _tif, C _tvalue is less than nominal capacity C _t80% (i.e. C _tvalue is less than nominal capacity 0.8C _t), system prompts user battery life is about to come to an end; Otherwise, if C _tvalue is less than 0.9C _t, suggestion user carries out deep discharge;

Step 8, is set to 0 by c, returns step 3.

Wherein, C _tinitial value be set to battery under standard operating temperature and discharge rate condition carry out deep discharge actual electricity of releasing, in use procedure, data processing module is to C _tvalue refreshes, and method is as shown in formula (I):

$C_t\left(k\right)=C_t(k-1)-\frac{Q_e}{{\mathrm{w\η}}_c}+Q_C---\left(I\right);$

That is: C in a upper charge cycle _tvalue and battery discharge capacity, the algebraic sum of actual charge volume, note is just charged as, and it is negative for discharging; Wherein, in formula (I), k is charge cycle number, Q _efor discharge capacity, Q _cfor charge volume, η _cfor charge efficiency, w represents the correction factor of actual discharge rate and battery charge efficiency relation, the discharge rate that this coefficient also can be provided by battery manufacturer draws the relation chart that charge efficiency affects, and specifies to carry out deep discharge every half a year or suitable cycle index to battery, corrects C to reach _twith the effect of capacity restoration.

Measuring system of the present invention adopts depth of charge DOC (DepthOfCharge) as the parameter of reflection battery charge state, the actual capacity of battery is adopted but not nominal capacity when this parameter calculates, not only relevant with battery current state, also discharge scenario is relevant in the future with battery, more can reflect the actual conditions of battery, the computing formula of DOC is:

$DOC=\frac{C_t-Q_e}{C_t}---\left(II\right);$

Wherein, in formula (II), $Q_e={\∫}_0^{t}li\left(\mathrm{\τ}\right)d\left(\mathrm{\τ}\right);$

Wherein, C _trepresent the actual capacity of battery, Q _efor real-time discharge capacity, 1 is correction factor, and i is electric current, and t is the time; 1 correction factor is by temperature, and electric current, the graph of a relation table analysis of self discharge and the factor such as aging and battery remaining power integrates gained, and relation chart directly can obtain when battery dispatches from the factory.

Measuring system of the present invention, from engineering reality, adopts the battery DOC measuring technique based on ampere-hour method, can reflect the actual conditions of battery more realistically; Improving algorithm can degree of execution, reduces Hardware Design cost, has the advantage of high precision, high-level efficiency and stable performance, conveniently promotes the use of.

Claims (3)

1. an on-line measurement system for lead-acid accumulator dump energy, is characterized in that: comprise the data acquisition module, data processing module and the display module that connect successively; Containing current sensor in described data acquisition module, described current sensor is monitored in real time to accumulator cell charging and discharging stream; Described data processing module by current sensor Real-time Collection to signal integration is carried out to the time, obtain battery real-time discharge capacity;

Described measuring system adopts following steps to carry out on-line measurement to lead-acid accumulator dump energy:

Step 1, initiation parameter, comprises initial actual capacity C _t, nominal capacity C _t, low power threshold and deep discharge threshold value;

Step 2, arranges discharge condition zone bit d, and charged state zone bit c, arranges variable count, Q _d, Q _crepresent respectively and store charge cycle number, equivalent discharge capacity, charge volume;

Step 3, when current sensor detects battery discharging, is set to 1 by d, and electric discharge terminates then d to be set to 0;

Step 4, when current sensor detects charge in batteries, is set to 0 by c, and charging terminates then c to be set to 1;

Step 5, when current sensor detects that battery discharging is interrupted, and now d is 1, calculates DOC and Q _evalue, DOC value output display system shows; Otherwise perform step 7;

Step 6, if DOC is less than low power threshold, display electricity is not enough, and prompting user stops using or charges as early as possible; D is set to 0, returns step 5;

Step 7, if c is 1, then makes count increase by 1, and calculates C _tif, C _tvalue is less than nominal capacity C _t80%, system prompts user battery life is about to come to an end; Otherwise, if C _tvalue is less than deep discharge threshold value, and suggestion user carries out deep discharge;

Step 8, is set to 0 by c, returns step 3.

2. the on-line measurement system of lead-acid accumulator dump energy according to claim 1, is characterized in that: in step 1, described initial actual capacity C _tby battery under standard operating temperature and discharge rate carry out deep discharge reality release electricity, in use procedure, data processing module is to C _tthe formula that value carries out calculating is:

$C_t\left(k\right)=C_t(k-1)-\frac{Q_e}{w{\mathrm{\η}}_c}+Q_C---\left(I\right);$

Wherein, in formula (I), k is charge cycle number, Q _efor discharge capacity, Q _cfor charge volume, η _cfor charge efficiency, w is the correction factor of actual discharge rate and battery charge efficiency relation.

3. the on-line measurement system of lead-acid accumulator dump energy according to claim 1, is characterized in that: in step 5, and the computing formula of described DOC is:

$DOC=\frac{C_t-Q_e}{C_t}---\left(II\right);$

Wherein, in formula (II), $Q_e={\∫}_0^{t}li\left(\mathrm{\τ}\right)d\left(\mathrm{\τ}\right);$

Wherein, C _trepresent the actual capacity of battery, Q _efor real-time discharge capacity, l is correction factor, and i is electric current, and t is the time.