1. The utility model provides a battery internal resistance on-line monitoring device based on undercurrent pulse discharge method, includes battery, singlechip U1, lock-in amplifier U56, difference amplification module, filtering module, constant current source module, reverse phase amplification module, conditioning module and AD conversion module, its characterized in that: the constant current source module and the differential amplification module are electrically connected with the storage battery, the single chip microcomputer U1 is electrically connected with the phase-locked amplifier U56, the single chip microcomputer U1 is electrically connected with the constant current source module through the phase-locked amplifier U56, the storage battery is electrically connected with the filtering module through the differential amplification module, the filtering module is electrically connected with the conditioning module through the reverse phase amplification module, the conditioning module is electrically connected with the AD conversion module through the filtering module, and the AD conversion module is electrically connected with the single chip microcomputer U1.

2. The on-line monitoring device for the internal resistance of the storage battery based on the small-current pulse discharge method according to claim 1, characterized in that: the positive pole and the negative pole of the storage battery are respectively connected with two wires, the number of the wires is positive 1, positive 2, negative 1 and negative 2, the positive 1 of the storage battery is electrically connected with the upper end of a resistor R68 of the direct current constant current source, the negative 1 of the storage battery is electrically connected with the lower end of a resistor R76 of the direct current constant current source, the positive 2 of the storage battery is electrically connected with a resistor R75 of the differential amplification module, and the negative 2 of the storage battery is electrically connected with a resistor R76 of the differential amplification module.

3. The on-line monitoring device for the internal resistance of the storage battery based on the small-current pulse discharge method according to claim 1, characterized in that: the pin 24 of the singlechip U1 is electrically connected with the pin 1 of the lock-in amplifier U56, and the pin 13 of the lock-in amplifier U56 is electrically connected with the triode Q2 through the resistor R62 of the constant current source module.

4. The on-line monitoring device for the internal resistance of the storage battery based on the small-current pulse discharge method according to claim 1, characterized in that: the single chip microcomputer U1 reads a conversion result V of the U55 of the AD conversion module through the SPI interface, and finally the single chip microcomputer U1 calculates to obtain the internal resistance R of the storage battery according to a formula R which is V/0.1.

Background

In a power system transformer substation, a storage battery plays a role in lifting, under the condition that the transformer substation stops operating, the opening and closing of a high-voltage switch are all dependent on a direct-current power supply provided by the storage battery, the storage battery operates in a floating charge mode at ordinary times, the failure of the battery is not easy to find, and the failure of the battery can be verified only by discharging the battery out of a system. Practical experience proves that the internal resistance of the battery is increased along with the failure of the battery, and the health state of the battery is judged by monitoring the internal resistance of the battery on line.

The prior art has the following problems:

by looking up the relevant paper data, the measurement of the internal resistance of the battery can be divided into a direct current discharge method and an alternating current injection method "

1. Direct current discharge method

And (4) carrying out two times of different high-current discharge, recording current and voltage values of the two times, and obtaining the battery internal resistance R according to a formula of (U1-U2)/(I1-I2) (the formula is not obtained in a derivation process).

The advantages are that: it is simple.

The disadvantages are as follows: the battery is damaged by heavy current discharge, and the internal resistance of the battery is not suitable to be measured in real time; the required thick wiring of the cable is inconvenient (each battery needs to be wired); the discharging current is large, and the multi-path electronic switch for routing inspection and switching is not easy to select.

2. AC injection method

An AC constant current source is used for coupling a constant AC current to the battery, the phase-locked amplifier U56 and the AD converter are used for sampling the tiny AC voltage at the two ends of the storage battery, and the internal resistance of the battery is calculated according to the ohm law resistance R which is U/I

The advantages are that: the injected current signal is small, has no influence on the battery, and can carry out internal resistance measurement in real time

The disadvantages are as follows: the technology is complex, and the alternating current constant current source is not easy to design; some power consumers are very insensitive to the mode of 'ac injection' and cannot accept the introduction of ac signals in dc systems psychologically.

Disclosure of Invention

The invention aims to provide a storage battery internal resistance online monitoring device based on a low-current pulse discharge method, which has the advantages of combining the two methods and is easy to accept by users using the discharge method; the discharge current is only 100mA, the influence on the battery can be ignored, and the internal resistance can be measured in real time; the direct current constant current source is used, the advantage of low difficulty is realized, certain damage to the battery caused by large current discharge in a direct current discharge method is solved, and the internal resistance measurement of the battery is not suitable for real time; the required thick wiring of the cable is inconvenient (each battery needs to be wired); the discharge current is large, a multi-path electronic switch for routing inspection and switching is not easy to select, the alternating current injection method is complex in technology, and the alternating current constant current source is not easy to design; some power consumers are very sensitive to the "ac injection" approach, which is psychologically unacceptable for introducing ac signals in dc systems.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a battery internal resistance on-line monitoring device based on undercurrent pulse discharge method, including the battery, singlechip U1, lock-in amplifier U56, difference amplification module, filtering module, constant current source module, the inverting amplification module, modulate module and AD conversion module, constant current source module and difference amplification module and battery electric connection, singlechip U1 and lock-in amplifier U56 electric connection, singlechip U1 and constant current source module electric connection through lock-in amplifier U56, the battery passes through difference amplification module and filtering module electric connection, filtering module passes through inverting amplification module and modulates module electric connection, modulate module and AD conversion module electric connection through filtering module, AD conversion module and singlechip U1 electric connection.

Preferably, two wires are respectively connected to the positive pole and the negative pole of the storage battery, and the two wires are counted as positive 1, positive 2, negative 1 and negative 2, the positive 1 of the storage battery is electrically connected with the upper end of a resistor R68 of the direct current constant current source, the negative 1 of the storage battery is electrically connected with the lower end of a resistor R76 of the direct current constant current source, the positive 2 of the storage battery is electrically connected with a resistor R75 of the differential amplification module, and the negative 2 of the storage battery is electrically connected with a resistor R76 of the differential amplification module.

Preferably, the pin 24 of the single chip microcomputer U1 is electrically connected to the pin 1 of the lock-in amplifier U56, and the pin 13 of the lock-in amplifier U56 is electrically connected to the transistor Q2 through the resistor R62 of the constant current source module.

Preferably, the single chip microcomputer U1 reads the conversion result V of the U55 of the AD conversion module through the SPI interface, and finally, the single chip microcomputer U1 calculates the battery internal resistance R according to the formula R being V/0.1.

Compared with the prior art, the invention has the beneficial effects that:

a pin 24 of the singlechip U1 is electrically connected with a pin 1 of the phase-locked amplifier U56, a pin 13 of the phase-locked amplifier U56 is electrically connected with a triode Q2 through a resistor R62 of the constant current source module, so that the triode Q62 is periodically turned on and off, the voltage at the upper end of a resistor R65 of the constant current source module is alternatively changed in two states of 1V or 0V, and therefore a constant current source consisting of the U63 and the Q1 of the constant current source module is driven to periodically work, the discharging current of the battery is increased by 100mA and recovered to the original value, the tiny voltage change at two ends of the battery caused by pulse discharging enters a DC blocking loop consisting of C53, C54, R80, R81 and U51 of the filter module after passing through a differential amplifier consisting of U50, R465, R77 and R78 of the differential amplifier module, and enters a DC blocking loop consisting of C53, C54, R80, R81 and U51 of the filter module, filters the battery voltage change, only keeps the voltage change at two ends of the battery, and then is amplified by an inverting amplifier module U8272, R85, C55, R86, R87, R1 and R87, the signal that enters R92 of the conditioning module, U52, C56, R91, R90, R89, R93 is raised the circuit, raise the signal to the scope that U56 requires, the signal is filtered through the filter that C46 of the filter module, C47, R72, R73, C48 make up after U56 of the conditioning module processes, the signal enters U55 of AD conversion module finally, the conversion result V of U55 is read through SPI interface to singlechip U1, singlechip U1 calculates according to the formula R ═ V/0.1 and obtains the battery R, 0.1 in the formula is the 100mA electric current that the above-mentioned constant current source sets for.

Drawings

FIG. 1 is a schematic diagram of a DC discharge process;

FIG. 2 is a schematic diagram of an AC implant process;

FIG. 3 is a functional block diagram of the present invention;

FIG. 4 is a partial schematic view of a constant current source of the present invention;

FIG. 5 is a schematic diagram of a differential amplification section of the present invention;

FIG. 6 is a schematic diagram of a filtering portion of the present invention;

FIG. 7 is an inverted enlarged partial schematic of the present invention;

FIG. 8 is a schematic view of the conditioning portion of the present invention;

FIG. 9 is a partial schematic diagram of a lock-in amplifier U56 according to the present invention;

FIG. 10 is a schematic diagram of an AD conversion part according to the present invention;

fig. 11 is a partial schematic view of the single chip microcomputer U1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 3 to fig. 11, an embodiment of the present invention:

the utility model provides a storage battery internal resistance on-line monitoring device based on undercurrent pulse discharge method, including the battery, singlechip U1, lock-in amplifier U56, difference amplification module, filtering module, constant current source module, inverting amplification module, modulate module and AD conversion module, constant current source module and difference amplification module and battery electric connection, connect two lines respectively on the positive and negative utmost point post of battery, count as positive 1, positive 2, burden 1, burden 2, positive 1 and the resistance R68 upper end electric connection of direct current constant current source of battery, the resistance R76 lower extreme electric connection of negative 1 and direct current constant current source of battery, the resistance R75 electric connection of positive 2 and difference amplification module of battery, the resistance R76 electric connection of negative 2 and difference amplification module of battery.

The single chip microcomputer U1 is electrically connected with a phase-locked amplifier U56, a pin 24 of the single chip microcomputer U1 is electrically connected with a pin 1 of the phase-locked amplifier U56, a pin 13 of the phase-locked amplifier U56 is electrically connected with a triode Q2 through a resistor R62 of a constant current source module to enable the triode Q2 to be periodically switched on and off, the voltage at the upper end of a resistor R65 of the constant current source module is alternately changed in two states of 1V or 0V at the moment, so that a constant current source consisting of the U63 and the Q1 of the constant current source module is driven to periodically work, the discharging current of the battery is increased by 100mA at times and recovered to an original value at times, the tiny voltage change at two ends of the battery caused by pulse discharging enters a DC blocking loop consisting of a filtering module C53, C54, R80, R81 and U51 after passing through a differential amplifier consisting of the U50 of the differential amplification module and the resistors R75, R76, R77 and R78, and enters a DC blocking loop consisting of the filtering module to filter the voltage change at two ends of the battery, and only the voltage change at two ends of the battery is filtered by a phase-inverted amplification module U51, after being amplified by an inverting amplifier composed of R85, C55, R86, R87, R88 and K1, the amplified signals enter a signal raising circuit composed of R92, U52, C56, R91, R90, R89 and R93 of the conditioning module to raise the signals to a range required by U56, the signals are processed by U56 of the conditioning module and then filtered by a filter composed of C46, C47, R72, R73 and C48 of the filtering module, finally the signals enter U55 of the AD conversion module, a conversion result V of the U55 is read by an SPI interface through a singlechip U1, finally a storage battery internal resistance R is calculated by a singlechip U1 according to a formula R ═ V/0.1, the storage battery internal resistance R is set by a constant current source, the U1 is electrically connected with the constant current source module through a phase-locked amplifier U56, the storage battery is electrically connected with the differential amplification module, the filtering module is electrically connected with the conditioning module through the inverting filter, and the conditioning module is electrically connected with the AD conversion module, the AD conversion module is electrically connected with the singlechip U1.

The working principle is as follows: a pin 24 of the singlechip U1 is electrically connected with a pin 1 of the phase-locked amplifier U56, a pin 13 of the phase-locked amplifier U56 is electrically connected with a triode Q2 through a resistor R62 of the constant current source module, so that the triode Q62 is periodically turned on and off, the voltage at the upper end of a resistor R65 of the constant current source module is alternatively changed in two states of 1V or 0V, and therefore a constant current source consisting of the U63 and the Q1 of the constant current source module is driven to periodically work, the discharging current of the battery is increased by 100mA and recovered to the original value, the tiny voltage change at two ends of the battery caused by pulse discharging enters a DC blocking loop consisting of C53, C54, R80, R81 and U51 of the filter module after passing through a differential amplifier consisting of U50, R465, R77 and R78 of the differential amplifier module, and enters a DC blocking loop consisting of C53, C54, R80, R81 and U51 of the filter module, filters the battery voltage change, only keeps the voltage change at two ends of the battery, and then is amplified by an inverting amplifier module U8272, R85, C55, R86, R87, R1 and R87, the signal that enters R92 of the conditioning module, U52, C56, R91, R90, R89, R93 is raised the circuit, raise the signal to the scope that U56 requires, the signal is filtered through the filter that C46 of the filter module, C47, R72, R73, C48 make up after U56 of the conditioning module processes, the signal enters U55 of AD conversion module finally, the conversion result V of U55 is read through SPI interface to singlechip U1, singlechip U1 calculates according to the formula R ═ V/0.1 and obtains the battery R, 0.1 in the formula is the 100mA electric current that the above-mentioned constant current source sets for.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.