Accumulator internal resistance on-line detector and internal resistance detection method
Technical field
The present invention relates to a kind of accumulator internal resistance on-line detector and internal resistance detection method, belong to the battery technology field.
Background technology
Along with global climate constantly warms, the reinforcement day by day of energy-conserving and environment-protective consciousness, electric automobile replacing fuel automobile becomes inexorable trend.Electric automobile with accumulator as energy source, and accumulator to use one of important parameter of consumption state be exactly its internal resistance.No matter be that accumulator is about to inefficacy, off-capacity or discharges and recharges improperly, embody can both changing from its internal resistance.Therefore can come its duty is assessed by measuring accumulator internal resistance.
The common methods of measuring accumulator internal resistance at present has densimetry, open-circuit voltage method, direct-current discharge method and AC method etc.Wherein:
Densimetry is the internal resistance of estimating accumulator by the density of measuring battery liquid, is usually used in the internal resistance measurement of open type lead-acid battery, the narrow application range of this method.
The open-circuit voltage method is to estimate accumulator internal resistance by the terminal voltage of measuring accumulator, and precision is very poor, even might derive a wrong conclusion.
The direct-current discharge method is by battery is carried out transient large current discharge, and the transient voltage of measuring on the battery falls, and calculates the internal resistance of cell by Ohm law again, though this method has also obtained using widely in practice, can't realize on-line measurement.
AC method is by accumulator being injected a constant ac current signal, measure the voltage responsive signal at accumulator two ends and both phase differential, being determined the internal resistance of accumulator by formula of impedance.This method does not need accumulator is discharged, and can realize the online detection internal resistance of cell of safety, so can the performance of accumulator not impacted.But this method need be measured the phase differential between ac current signal, voltage responsive signal and the voltage and current, and this method not only disturbing factor is many, and has increased the complicacy of system, has also influenced measuring accuracy simultaneously.Simultaneously, existing AC method test internal resistance all utilizes phase-locked amplifying element to carry out small-signal and handles, because special phase-locked amplification chip price is comparatively expensive, so the occasion that this method is controlled cost for needs is also also inapplicable.
Summary of the invention
The present invention be for the method that solves existing AC method test internal resistance owing to influence the problems of measuring accuracy disturbing factor more, a kind of accumulator internal resistance on-line detector and internal resistance detection method are provided.
The accumulator internal resistance on-line detector, it is made up of power module, processor module, detection signal generation module, tested battery gating module and detection signal processing module,
Power module provides working power for processor module, detection signal generation module and detection signal processing module,
The sine voltage signal input end of the sine voltage signal output terminal joint detection signal generating module of processor module, two ac current signal output terminals of detection signal generation module connect two ac current signal input ends of tested battery gating module, the detection signal input end of the ac voltage signal output terminal joint detection signal processing module of tested battery gating module, the detection signal input end of the detection signal output terminal connection processing device module of detection signal processing module;
The measurement of processor module selects signal output part to connect the gating signal input end of battery gating module.
Described processor module is made up of microprocessor and reference voltage circuit,
The reference voltage signal output terminal of reference voltage circuit connects the reference voltage signal input end of microprocessor; The sine voltage signal output terminal of microprocessor is the sine voltage signal output terminal of processor module.
Described detection signal generation module is made up of first filtering circuit and coupling drive circuit,
The sine voltage signal input end of detection signal generation module is the sine voltage signal input end of first filtering circuit, the sine voltage signal output terminal BPOA of first filtering circuit connects the sine voltage signal input end of coupling drive circuit, and two ac current signal output terminal TQIx3, TQIx8 of coupling drive circuit are two ac current signal output terminals of detection signal generation module.
Described tested battery gating module comprises controlled gating switch, first reference resistance, second reference resistance and tested battery clamp, two common ports of described controlled gating switch are two ac current signal output terminals of joint detection signal generating module respectively, the measurement of processor module selects signal output part to connect the control end of this controlled gating switch, be used to control this gate-controlled switch action, respectively first reference resistance, second reference resistance and tested battery strings be linked between two ac current signal output terminals of detection signal generation module successively.
Described detection signal processing module is made up of amplifying circuit, second filtering circuit, full-wave rectifying circuit and peak holding circuit,
The detection signal input end of detection signal processing module is the detection signal input end of amplifying circuit, the detection signal output terminal of amplifying circuit connects the detection signal input end of second filtering circuit, the detection signal output terminal of second filtering circuit connects the detection signal input end of full-wave rectifying circuit, the detection signal output terminal of full-wave rectifying circuit connects the detection signal input end of peak holding circuit, and the detection signal output terminal of peak holding circuit is the detection signal output terminal of detection signal processing module.
A kind of internal resistance detection method based on above-mentioned accumulator internal resistance on-line detector,
Produce sine voltage signal by processor module, this sine voltage signal inputs to tested battery gating module by the ac current signal that detection signal generation module produces with the frequency homophase, simultaneously control tested battery gating module successively with first reference resistance by processor module, second reference resistance and the series connection of tested battery clamp insert in the alternating current loop of detection signal generation module output, and connect first reference resistance in the ac circuit of synchro control collection, the voltage signal that second reference resistance and tested battery clamp two ends produce, the collection of described voltage signal adopts the four-wire system mode to extract, described voltage signal inputs to the detection signal processing module, processor module obtains the internal resistance value of the tested battery of clamping in the tested battery clamp as calculated according to detected voltage signal.
Advantage of the present invention is: the present invention has adopted two reference resistance calibrations, filtering circuit filtering to the measurement of accumulator internal resistance, has adopted amplifying circuit and peak holding circuit simultaneously, makes the measuring accuracy height of accumulator internal resistance, and it is convenient, low in energy consumption to measure.The present invention both can be used for the measurement of cell batteries internal resistance, also can be used for the measurement of battery pack internal resistance.Use of the present invention is not subjected to the restriction of tested battery tension, can be applicable to various occasions.The present invention can work under the environment of electromagnetic interference (EMI) such as electric motor car and vibrations, and antijamming capability is strong, the reliability height.Also can be applicable in the commercial production, and easy to maintenance.It can pass through standard communication interface, expands.Easy for installation, can under the situation that does not influence original structure, implement to install.
The present invention possesses the realization of being easy to, and volume is little, and cost is low, and the characteristics of good reliability can be applied to the electric automobile field, also can be applicable to other field.
Description of drawings
Fig. 1 is a principle schematic of the present invention;
Fig. 2 is a signal processing flow synoptic diagram of the present invention;
Fig. 3 is the circuit diagram of processor module;
Fig. 4 is the circuit diagram of detection signal generation module;
Fig. 5 is the circuit diagram of tested battery gating module.
Embodiment
Embodiment one: present embodiment is described below in conjunction with Fig. 1, present embodiment is the accumulator internal resistance on-line detector, it is made up of power module 1, processor module 2, detection signal generation module 3, tested battery gating module 4 and detection signal processing module 5
Power module 1 provides working power for processor module 2, detection signal generation module 3 and detection signal processing module 5,
The sine voltage signal input end of the sine voltage signal output terminal joint detection signal generating module 3 of processor module 2, two ac current signal output terminals of detection signal generation module 3 connect two ac current signal input ends of tested battery gating module 4, the detection signal input end of the ac voltage signal output terminal joint detection signal processing module 5 of tested battery gating module 4, the detection signal input end of the detection signal output terminal connection processing device module 2 of detection signal processing module 5;
The measurement of processor module 2 selects signal output part to connect the gating signal input end of battery gating module 4.
In the present embodiment power module 1 comprise ± 5V and ± two power supplys of 12V, it is responsible for entire circuit power supply.
The realization of present embodiment has the advantage that cost is low, measuring speed is fast, reliability is high and antijamming capability is strong.
Embodiment two: below in conjunction with Fig. 2 and Fig. 3 present embodiment is described, present embodiment is for to the further specifying of embodiment one, and described processor module 2 is made up of microprocessor 2-1 and reference voltage circuit 2-2,
The reference voltage signal output terminal of reference voltage circuit 2-2 connects the reference voltage signal input end of microprocessor 2-1; The sine voltage signal output terminal of microprocessor 2-1 is the sine voltage signal output terminal of processor module 2.Other composition and annexation are identical with embodiment one.
The sine voltage signal output terminal of microprocessor 2-1 is the DA port of microprocessor 2-1 in the present embodiment.
Present embodiment possesses the CAN communication interface, is convenient to expansion.
Embodiment three: below in conjunction with Fig. 2 and Fig. 4 present embodiment is described, present embodiment is for to the further specifying of embodiment one or two, and described detection signal generation module 3 is made up of the first filtering circuit 3-1 and coupling drive circuit 3-2,
The sine voltage signal input end of detection signal generation module 3 is the sine voltage signal input end of the first filtering circuit 3-1, the sine voltage signal output terminal BPOA of the first filtering circuit 3-1 connects the sine voltage signal input end of coupling drive circuit 3-2, and two ac current signal output terminal TQIx3, the TQIx8 of coupling drive circuit 3-2 are two ac current signal output terminals of detection signal generation module 3.Other composition and annexation are identical with embodiment one or two.
Embodiment four: present embodiment is described below in conjunction with Fig. 2 and Fig. 5, present embodiment is to embodiment one, two or three further specify, described tested battery gating module 4 comprises controlled gating switch, the first reference resistance R1, the second reference resistance R2 and tested battery clamp 4-1, two common ports of described controlled gating switch are two ac current signal output terminals of joint detection signal generating module 3 respectively, the measurement of processor module 2 selects signal output part to connect the control end of this controlled gating switch, be used to control this gate-controlled switch action, successively respectively with the first reference resistance R1, the second reference resistance R2 and tested battery strings are linked between two ac current signal output terminals of detection signal generation module 3.Other composition and annexation are identical with embodiment one, two or three.
The first reference resistance R1 and the second reference resistance R2 in the present embodiment select milliohm level resistance for use.The two ends that the AC signal of detection signal generation module 3 outputs is received the first reference resistance R1, the second reference resistance R2 and tested battery respectively, can realize that the break-make of three branch roads is controlled realization by microprocessor 2-1 respectively by using relay and MUX.
Present embodiment can be good at the calibration measurement result.
Embodiment five: present embodiment is described below in conjunction with Fig. 2, present embodiment is further specifying embodiment one, two, three or four, described detection signal processing module 5 is made up of amplifying circuit 5-1, the second filtering circuit 5-2, full-wave rectifying circuit 5-3 and peak holding circuit 5-4
The detection signal input end of detection signal processing module 5 is the detection signal input end of amplifying circuit 5-1, the detection signal output terminal of amplifying circuit 5-1 connects the detection signal input end of the second filtering circuit 5-2, the detection signal output terminal of the second filtering circuit 5-2 connects the detection signal input end of full-wave rectifying circuit 5-3, the detection signal output terminal of full-wave rectifying circuit 5-3 connects the detection signal input end of peak holding circuit 5-4, and the detection signal output terminal of peak holding circuit 5-4 is the detection signal output terminal of detection signal processing module 5.Other composition and annexation are identical with embodiment one, two, three or four.
The described first filtering circuit 3-1 and the second filtering circuit 5-2 adopt professional filtering chip, only need to regulate its peripheral resistance and can realize precision wave filtering, and its narrow band bandwidth can reach below the 100Hz, makes the frequency content simplification, and effectively filtering noise disturbs.Full-wave rectifying circuit 5-3 adopts high speed amplifier and fast recovery diode to constitute, and it adopts the difference channel structure to realize quick full-wave rectification simultaneously.Peak holding circuit 5-4 adopts active feedback-type structure, and it can guarantee that peak value is stable, reaches quick response.
Detection signal processing module 5 receives the alternating voltage at two reference resistances and tested battery two ends in the present embodiment, behind full-wave rectifying circuit 5-3 and peak holding circuit 5-4, deliver to the AD sample port of microprocessor 2-1, microprocessor 2-1 is through calculating, obtain the resistance of tested battery, this resistance can be sent to host computer by transmission circuit.
Peak holding circuit 5-4 helps guaranteeing the integrality of signal, improves the antijamming capability of system.
Embodiment six: below in conjunction with Fig. 1 to Fig. 5 present embodiment is described, present embodiment is the internal resistance detection method based on embodiment five described accumulator internal resistance on-line detectors,
Produce sine voltage signal by processor module 2, this sine voltage signal inputs to tested battery gating module 4 by the ac current signal that detection signal generation module 3 produces with the frequency homophase, control tested battery gating module 4 successively with the first reference resistance R1 by processor module 2 simultaneously, the second reference resistance R2 and tested battery clamp 4-1 series connection insert in the alternating current loop of detection signal generation module 3 outputs, and connect the first reference resistance R1 in the ac circuit of synchro control collection, the voltage signal that the second reference resistance R2 and tested battery clamp 4-1 two ends produce, the collection of described voltage signal adopts the four-wire system mode to extract, described voltage signal inputs to detection signal processing module 5, processor module 2 obtains the internal resistance value of the tested battery of clamping among the tested battery clamp 4-1 as calculated according to detected voltage signal.
Processor module 2 receives the detection signal of detection signal processing module 5 outputs in the present embodiment by the AD sample port; The ac current signal of the same frequency homophase that detection signal generation module 3 is produced is added in the two ends of two reference resistances and tested battery, and the voltage peak that produce this moment is linear with corresponding resistance.Adopt the four-wire system mode to extract voltage and can control its break-make by MUX.
Embodiment seven: present embodiment is for to the further specifying of embodiment six, and described processor module 2 calculates the internal resistance of tested battery according to detected voltage signal method is:
According to formula:
In the formula, R
zRepresent the internal resistance of tested battery, R
2The resistance value of representing the second reference resistance R2, R
1The resistance value of representing the first reference resistance R1, V
2The voltage of representing the second reference resistance R2 two ends, V
zThe voltage of representing tested battery two ends, V
1The voltage of representing the first reference resistance R1 two ends calculates the internal resistance that promptly obtains described tested battery.Other is identical with embodiment six.
Computation process in the present embodiment is finished in microprocessor 2-1 inside by the mode of software.
The described computing method of present embodiment are simple and reliable, precision height, fast operation.