RU2813345C1 - Method for checking characteristics of rechargeable batteries and device for its implementation - Google Patents

Abstract

FIELD: electric power industry.

SUBSTANCE: used to test the electrical characteristics of batteries or electric batteries, namely stationary accumulator batteries (AB) of auxiliary systems of transformer substations. For 2 ms, the battery is closed to resistance R1, selected to provide a current in the circuit with the battery equal to 4 currents for a ten-hour battery discharge, and the voltage drop across resistance R1 at the end of the period of time is measured. After this, the circuit is opened and immediately closed for the same period of 2 ms to resistance R2, selected to provide a current in the circuit with the battery equal to 40 currents of a ten-hour battery discharge, and the voltage drop across resistance R2 is measured at the end of the time period. Based on the measured voltage drops, the currents I1 and I2 are calculated. Estimate the internal resistance of the battery using the formula Rin = (R2⋅ I2-R1⋅ I1)/(I2-I1). Determine the actual capacity using the formula Сat=а⋅ Rin^2+b⋅ Rin+c, where a, b and c are empirical coefficients. Determine the actual capacity reduced to normal temperature: Сa=Сat/(1+λ (t-tn)), where t is the temperature of the electrolyte measured at the beginning of the discharge, tn is the normal temperature of the electrolyte,λ is the temperature coefficient. The residual life is estimated using the formula RL=Ca/Cnom, where Cnom is the nominal capacity of the battery at normal electrolyte temperature. The device includes a communication unit that receives commands to measure the internal resistance of the battery to direct current, discharge or charge of the battery, and also transmits the internal resistance measurement results received from the control unit to an external device via a wired or wireless connection, a control unit that sets the load levels for discharge battery with two DC pulses, an input voltage measuring unit that measures the voltage of the battery in a circuit with an electrical load R1, R2, a reverse polarity protection device, a measurement error compensation unit, a unit for measuring the internal resistance of the battery with direct current, connected to the positive contact of the batteries through a reverse polarity protection device, an ADC module that measures the change in voltage on the battery and sends the voltage measurement results to the control unit, power supply.

EFFECT: increasing the convenience and quality of diagnosing the condition of rechargeable batteries, as well as reducing the time of testing without removing the battery from service, simplifying the device.

7 cl, 3 dwg

Description

Field of technology

The invention relates to the electric power industry and can be used to test the electrical characteristics of batteries or electric batteries, namely stationary rechargeable batteries (AB) of auxiliary systems of transformer substations.

State of the art

Among the most common currently known methods for monitoring the condition of a battery is measuring the capacity by discharging [p. 6.11 GOST R IEC 60896-2-99], in which the assessment of the technical condition of the battery is carried out by determining the actual capacity of the battery when discharging a fully charged battery with currents of 0.25 hour - 10 hour discharge to a voltage at the end of the discharge from 1.6 V to 1.8 V, respectively, with current and voltage recording during discharge. The actual capacity is determined as the product of the discharge current and the discharge time, adjusted for the initial temperature of the sample. The obvious disadvantages of this testing method include the need to remove the battery from operation for a long period.

At the same time, it is known that the actual capacity of the battery correlates with the internal resistance of the battery. A way to monitor the condition of the battery is to measure the internal resistance at direct current [p. 6.3 GOST R IEC 60896-2-99] for two values of discharge current and voltage. In this case, the discharge current of the first stage is selected depending on the current of the ten-hour discharge mode and is equal to the rated 10-hour discharge current increased by 4 times; the voltage is recorded at the 20th second of the discharge. The second stage current is selected equal to the rated 10-hour discharge current increased by 20 times, the voltage is recorded at 5 seconds of discharge. Next, linear extrapolation is used to determine the calculated EMF and short-circuit current of the battery. Based on the obtained current-voltage characteristic, the internal resistance of the battery is determined. The values of short circuit current and internal resistance can be used to determine the parameters of protective devices, such as fuses, as well as to estimate the actual battery capacity.

This method requires taking the battery out of service for the measurement period. The difficulty also lies in ensuring the duration of the second stage of the discharge current, especially on a large-capacity battery (for example, with a battery capacity of 3000 A/hour, a current of 6000-12000 A is required); the voltage of consumers when the second stage current flows may be below the permissible level. In addition, ensuring the thermal resistance of the load during the flow of discharge current is a technically difficult task that limits the capacity level of the diagnosed batteries.

To make an approximate assessment of the condition of the battery without removing the battery from service, including the relative change in the actual capacity over time, the method of determining the internal resistance of the battery with alternating current is widely used [examples: devices implementing the Midtronics Secure Power 6/12 (SCP-100) method; Celltron Advantage 5500; CTU-6000 Kit LC], but the accuracy of this method is not sufficient to estimate the residual life of the battery. The physical essence of alternating current resistance differs from the essence of direct current resistance [V.I. Kosyuk, I.B. Shirokov. On the issue of measuring the resistance of chemical current sources. Electrochemical energy. 2009, vol. 9 No. 1, p. 44-48], therefore this parameter cannot be used to calculate short-circuit current and select battery protection means.

A device for automatically monitoring the technical condition of battery elements is known [RF patent for invention No. 2131158, IPC N02M 10/48, G01R 31/36, publ. 05.27.1999], containing a control unit, to one of the outputs of which a switching unit is connected, characterized in that an additional unit for determining the residual capacity of the battery in pulse discharge mode, a charger, a comparison unit, a reference curve unit, an indicator and an internal meter resistance, and a charger and an indicator are connected to the other outputs of the control unit; a comparison unit is connected to the input of the control unit, the inputs of which are connected to the outputs of the reference curve block and the internal resistance meter, the inputs of which are connected through the switching unit to the battery cell under test.

An automated system for monitoring and diagnosing batteries is known [RF patent for invention No. 2283504, IPC G01R 31/36, publ. 09.10.2006], containing a computer consisting of a single-board computer, a monitor, a keyboard, a first and second CAN-bus interface adapter and a power supply, to the second input of the single-board computer of which a keyboard is connected, to the third input-output of the single-board computer a third input-output is connected the first CAN-bus interface adapter, the third input-output of the second CAN-bus interface adapter is connected to the fourth input-output of the single-board computer, the first output of the single-board computer is also the computer output, the second output of the single-board computer is connected to the monitor, the first input-output of the first interface adapter CAN-bus forms the CAN-bus interface highway, which is also the first input-output of the computer, the second input-output of the first CAN-bus interface adapter forms the CAN-bus interface highway, which is also the second input-output of the computer, the first input-output of the second interface adapter CAN-bus forms the CAN-bus interface highway, which is also the third input-output of the computer, the second input-output of the second CAN-bus interface adapter forms the CAN-bus interface highway, which is also the fourth input-output of the computer, the first input-output of the single-board computer is simultaneously as the fifth input-output of the computer, the power supply provides power to the single-board computer and monitor, a battery current and voltage monitoring device containing voltage and current sensors and an information processing unit consisting of non-volatile memory, a real-time clock, a microcontroller, and a CAN-bus interface adapter , the first and second interface devices and the power supply, while the non-volatile memory and the real-time clock of the information processing unit are connected respectively to the sixth input-output and the fifth input of the microcontroller, the first input-output of the CAN-bus interface adapter is connected to the fourth input-output of the microcontroller, the outputs of the first and second interface devices are connected respectively to the first and second inputs of the microcontroller, the second input-output of the CAN-bus interface adapter forms the CAN-bus interface highway, which is also the fourth input-output of the information processing unit, the inputs of the first and second interface devices are simultaneously the first and the second inputs of the information processing unit, the third input of the microcontroller is simultaneously the third input of the information processing unit, the power supply provides power to the microcontroller, the CAN-bus interface adapter, the first and second interface devices, the battery, including the first, second and “n” battery , the first, second and “n” device for monitoring battery parameters, installed directly on the top of each battery bank and consisting of non-volatile memory, real-time clock, microcontroller, CAN-bus interface adapter, 8051 UART code signal adapter, interface devices and a power supply, with non-volatile memory and a real-time clock connected respectively to the sixth input-output and fifth input of the microcontroller, the first input-output of the CAN-bus interface adapter is connected to the fourth input-output of the microcontroller, the outputs of the code signal adapter are standard 8051 UART and the interface devices are connected respectively to the first and second inputs of the microcontroller, the second input-output of the CAN-bus interface adapter forms the CAN-bus interface highway, which is also the fourth input-output of the battery parameters monitoring device, the inputs of the code signal adapter of the 8051 UART standard and the interface devices are simultaneously the first and second inputs of the battery parameters monitoring device, the power supply provides power to the microcontroller, CAN-bus interface adapter, 8051 UART code signal adapter and interface device, the first, second and “m” electrolyte level and temperature sensors placed in the interelectrode space banks of batteries, while the fourth inputs and outputs of the information processing unit and the fourth inputs and outputs of the first, second and “n” device for monitoring battery parameters are connected to the first input-output of the computer via the CAN-bus interface highway, to the first input of the information processing unit the output of the voltage sensor is connected, the second output of the current sensor is connected to the second input of the information processing unit, the first, second and “n” batteries are connected into a battery in series (the negative terminal of the first battery is to the positive terminal of the second, etc.), the positive the terminal of the first battery is connected to the input of the current sensor, the first output of the current sensor is connected to the first input of the voltage sensor and the positive pole of the load and at the same time the battery charger, the negative terminal of the “n” battery is connected to the third input of the voltage sensor and the negative pole of the load and at the same time battery charger, the body of the object is connected to the second input of the voltage sensor, the outputs of the first, second and “t” electrolyte level and temperature sensor are connected to the first inputs of the first, second and “n” battery parameters monitoring device, respectively, to the second The inputs of the first, second and “n”-th device for monitoring battery parameters are connected, respectively, to a pair of positive and negative terminals of the first, second and “n”-th batteries, characterized in that a signaling device, an interface device, and a MIL-STD interface adapter are introduced 1553 V, printer, reference voltage source, first, second and “m”-th EMF sensor, first, second and “n”-th reference voltage sources, and the signaling device is connected through an interface device to the output of the information processing unit, fifth input - The computer output through the MIL-STD-1553B interface adapter, forming a MIL-STD-1553 V multiplex channel, is connected to an external object control system (including for battery control), the printer is connected to the computer output, the reference voltage source is connected to the third input of the information processing unit, the first, second and “m”-th EMF sensor are connected, respectively, to the third input of the first, second and “n”-th battery parameters monitoring device, the first, second and “n”-th reference voltage sources are connected, respectively to the fourth input of the first, second and “n” device for monitoring battery parameters.

There is a known method for assessing the technical condition and rejecting batteries in batteries [RF patent for invention No. 2466418, IPC G01R 31/36, publ. 10.11.2012], characterized by the fact that measuring instruments for measuring voltage are connected to the battery and its constituent batteries and, during the operation of the battery, the voltage is measured quasi-continuously with a constant sampling time interval on each battery and the battery as a whole, the measured values are recorded with ensuring the possibility of saving and accumulating measurement results during the service life of each battery, and from the measured voltage values of each battery and battery for a measurement period of more than one sampling interval, the dimensionless coefficient of battery condition is calculated, which is an indicator of the ratio of the energy given by the battery during the measurement period , to the amount of energy corresponding to the average value of energy given by the batteries in the battery during the measurement period, determined empirically by the formula

where Q _t,n is the dimensionless coefficient of the state of the n-th battery in the battery for the measurement period t in the range from the first measurement t ₁ to the final t _k : U _i is the voltage on the battery at the i-th measurement; Ua _n,i - voltage on the nth battery at the i-th measurement; Us _i is the average value of the battery voltage in the battery during the i-th measurement, while the technical condition of the batteries is assessed by the deviation of the value of the dimensionless condition coefficient from 1, and faulty batteries are rejected when the value of the dimensionless coefficient 1 is exceeded by more than a threshold value, selectable from the range of 10-40% over the measurement period depending on the requirements of the operating conditions.

There is a known method for diagnosing a battery with liquid electrolyte [RF patent for invention No. 2539851, IPC G01R 31/36, publ. 11/27/2015], including setting the test mode for the battery being tested, determining the uneven temperature distribution over the surface of the battery, identifying zones on the surface of the body of the battery under test that have an increased temperature relative to the adjacent section of the surface of the housing, determining the location of the identified zone with an increased temperature relative to the structural elements battery, diagnosing, based on the location of the specified zone and its temperature, whether the battery is working or not, characterized in that a section with an increased temperature of the surface of the housing is determined, a section with a minimum surface temperature is determined, the difference in the specified measured temperatures is determined, and this determined temperature difference is compared with permissible value, and if this temperature difference is higher than the permissible value, then this section is diagnosed as faulty.

There is a known method for diagnosing a battery with liquid electrolyte [RF patent for invention No. 2569416, IPC G01R 31/36, publ. 11.27.2015], including setting the test mode for the battery being tested, determining the uneven temperature distribution over the surface of the battery, identifying zones on the surface of the body of the battery under test that have an increased temperature relative to the adjacent area of the body surface, diagnosing based on the location of the specified zone and its temperature is working or not a rechargeable battery, characterized in that they determine the uneven temperature of the surface of the battery case along the height of a separate section of the battery, determine the boundary of the zone with an increased temperature of the surface of the battery for this section of the battery, and this zone boundary is fixed as the level of electrolyte filling in this section of the battery .

It is known to determine the health of the battery without turning it off without warning [RF patent for invention No. 2663087, IPC G01R 31/36, publ. 01.08.2018], in which a monitored battery system comprising a plurality of battery units forming a battery system, and a controller connected to said plurality of battery units, wherein the controller is configured to monitor, for each battery unit, a first voltage and a second voltage, wherein the first voltage corresponds to the absolute value of the shutdown voltage, and the second voltage corresponds to the warning voltage, said first voltage is less than said second voltage, wherein the controller is configured, in response to one of the battery units reaching said second voltage, to provide a first warning signal before any of the battery units reaches said first voltage, wherein the controller is also configured to cause a load reduction command in response to said first warning signal, wherein if the load reduction does not cause said warning signal to cease, the controller is configured to monitor the health status of the battery system, wherein, if the system voltage of said battery system is not reached, the controller refrains from issuing a second warning signal, otherwise the controller is configured to provide said second warning signal.

A battery monitoring device is known [RF patent for invention No. 2741741, IPC G01R 31/36, publ. 01/25/2021], containing a battery connection unit, the input of which is the input of a battery monitoring device, a controlled voltage divider, an operating mode indication unit and a load indication unit, characterized in that the first and second protection blocks, a battery voltage indication unit are additionally introduced , load switching unit, load unit, external load connection unit, automatic load shutdown unit, measurement mode start unit, voltmeter switching unit, the output of which is connected to the first input of the battery voltage indication unit, the second input of which is connected to the output of the controlled voltage divider, input which is connected to the first output of the measurement mode start block, the second output of which is connected to the input of the operating mode selection block, the first input of the measurement mode start block is connected to the first output of the first safety block, the second output of which is connected to the input of the voltmeter switching block, and the third output through the second the protection block is connected to the input of the external voltmeter connection block, the input of the first protection block is connected to the output of the battery connection block, and the fourth output is connected to the first input of the load switching unit, the second input of which is connected to the first output of the automatic load switching unit, the input of which is connected to the first the output of the operating mode selection block, the second output of which is connected to the first input of the operating mode indication block, the second output of the automatic load shutdown block is connected to the second input of the measurement mode start block, and the third output is connected to the second input of the operating mode indication block, first, second and third The outputs of the load switching unit are connected, respectively, to the inputs of the load blocks, external load connection and load indication, the outputs of the external load connection block and the external voltmeter connection block are the first and second outputs of the battery monitoring device, respectively.

A device for monitoring and controlling the technical condition of batteries and molecular energy storage devices is known [RF patent for invention No. 2758004, IPC G01R 31/36, 10/48, publ. 10.25.2021], containing a digital generator of infra-low frequency sinusoidal current with an infra-low frequency channel, a charger-discharge device connected to a battery, while the digital generator of infra-low frequency sinusoidal current through the battery is connected to the input of a monitoring and control device, the outputs of which are connected to a digital generator of infra-low frequency sinusoidal current and a charge-discharge device, characterized in that an ultra-low frequency channel is introduced into the digital generator of infra-low frequency sinusoidal current, and the outputs of the monitoring and control device are connected through switches to the inputs of the digital generator of infra-low frequency sinusoidal current and the charge-discharge device , the output of the ultra-low frequency channel of the digital generator of sinusoidal current of infra-low frequency and the output of the charge-discharge device are connected through switches to the inputs of the molecular energy storage device, the output of which is connected through the switch to the input of the monitoring and control device.

The closest analogue to the claimed method is a method for measuring the internal resistance of a battery to direct current according to the two-pulse method: the ratio of the voltage difference at the terminals of the battery to the difference in the currents passing through it. An example of the implementation of the two-pulse method is given in the guidelines for diagnosing an operational direct current system at electrical substations, MOESK 2009. In this case, the multiplicity of current pulses is not strictly specified and may differ in different experiments, but the second pulse, as a rule, is about half of the first. To isolate from the transient process, it is recommended to carry out current and voltage measurements at least 2 ms after switching.

One of the devices that implements the two-pulse method, the prototype of the present invention, is a device for measuring the internal resistance of stationary batteries [RF utility model patent No. 131876, IPC G01R 27/08, publ. 27.08. 2013], containing a microcontroller, an indicator, a keyboard, a control unit connected to the microcontroller, a voltage sensor connected in series, a multiplexer, an ADC, the output of which is connected to the microcontroller, a current sensor connected to the multiplexer, characterized in that an N-number is additionally introduced into it parallel-connected transistor switches, the control terminals of which are connected to the outputs of the control unit, the collectors through current-limiting thermostable resistors - to the voltage sensor and the positive pole of the battery under test, and the emitters - through the current sensor to the negative pole of the battery, as well as the N-number of protection elements from overvoltages that are connected in parallel to transistor switches. First, using the keyboard and indicator, the number of switched keys is set. Then the controller, upon command from the keyboard, initiates the measurement process by sequentially sending switching commands to the control unit, resulting in a serial connection of the battery to a resistance equal to the value of the thermally stable resistor divided by the number of switches turned on. After the next switch-on, there is a time delay commensurate with the time of the transition process from switching on one key. After turning on the last key, the microcontroller performs a time delay necessary to ensure stationary mode. Next, the microcontroller turns on the multiplexer to measure current and the analog signal from the current sensor is sent to the ADC. The microcontroller receives codes from the ADC and averages the obtained values, followed by multiplication by the reduction coefficient obtained during the calibration process. Similarly, after switching the multiplexer to voltage measurement, the signal from the voltage sensor is measured and the value is saved. Next, the microcontroller begins sequential switching off of the keys with a time delay doubled compared to switching on after the next switch off. When the switches are turned off, overvoltages occur in the measuring circuit due to the inductance of the connecting wires. To protect the keys, as well as the power supply circuits of the working equipment, surge protection elements are used. When the number of switches turned off reaches half of the specified value, the microcontroller performs a time delay and measures current and voltage. After measurements, the microcontroller sequentially with the required time delay turns off the remaining keys, calculates the value of the internal resistance and displays it on the indicator.

The main disadvantage of the proposed device is the need to measure the current in the circuit. A high-amplitude current meter is a massive element made of a temperature-stable alloy of relatively high cost, which has a high error at low currents.

Another drawback is the selected multiplicity of current pulses - one to two - which overestimates the measured resistance by 1.5-2 times and underestimates the difference in resistance measurements on batteries with different residual life. The difference in the measured resistance of batteries with an actual capacity of 80% and 95% of the nominal capacity is within the measurement error and is 3-4 times lower than the difference in the measured resistance using two pulses of 4 ten-hour discharge currents and 40 ten-hour discharge currents, therefore , taking into account that when the actual capacity decreases by 20%, the battery requires replacement, the selected frequency of current pulses is not acceptable for assessing the actual capacity of the battery.

A significant drawback of the device and the two-pulse method itself is that the results of measuring resistance to short DC pulses are not numerically equal to the results obtained in accordance with clause 6.3 of GOST R IEC 60896-2-99 and are usually lower for the same factor. In other words, by changing the method of measuring resistance, we obtain a different order of magnitude, which can only be compared with values obtained in the same way: which means that the measurement results cannot be compared with the passport data of the internal resistance of the battery; settings are required. The difference in the results can be explained by the fact that the time adjustment after switching has a great influence on the measurement result. The duration of the transition process after a large pulse is longer than after a small one, which introduces a methodological error. As a result, the two-pulse method with some limitations (pulse current multiplicity) can be used as an express method for estimating the actual capacity based on the internal resistance of the battery, but is not suitable as an independent method for estimating short-circuit current and selecting battery protection means.

In addition, the disadvantages of the prototype are the inability to use retrospective data on AB measurements to speed up the diagnosis of AB and improve the quality of prediction of deterioration in the properties of AB and its elements; limiting the capacity of the diagnosed battery by the value of a large current pulse; lack of ability to automatically calculate the actual capacity and residual life of the battery with detuning from the temperature of the battery; the inability to carry out additional measures to monitor the condition of the battery, including measuring the actual capacity of the battery during discharge and conducting a training charge-discharge cycle of individual battery elements.

The essence of the invention

The technical result is to increase the convenience and quality of diagnosing the condition of rechargeable batteries (AB) with a capacity of up to 4000 Ah with a voltage from 2 to 280 V, used in auxiliary systems of transformer substations, as well as reducing the testing time without removing the battery from operation, simplifying the device that implements tests.

The technical result is achieved due to the fact that they use a method for comprehensive testing of the characteristics of rechargeable batteries and a device for implementing the method, including a comprehensive diagnosis of the condition of rechargeable batteries (AB) of a wide range of capacities and voltages used in auxiliary systems of transformer substations, consisting of:

- accurate assessment of the actual battery capacity with adjustment by battery temperature during discharge and internal resistance,

- assessment of the residual life of the battery,

- conducting training cycles of charge-discharge of individual battery elements,

- automatic recording of measured parameters and their comparison with retrospective data during measurements,

in this case, the assessment of the internal resistance, actual capacity and residual life of the battery is performed with a current pulse ratio of 4/40 of the ten-hour discharge current, as well as detuning from the electrolyte temperature,

wherein

first measure and record the temperature of the electrolyte t and the voltage at the terminals of the battery, then, if the voltage is higher than the minimum permissible for the battery, for a time of 2 ms the battery is closed to the first resistance R4, selected to provide a current of 4 currents of a ten-hour battery discharge, and the voltage drop across the battery is measured the first resistance R4 at the end of this period of time; after which they open the circuit and immediately close it to the second resistance R40, selected to provide a current of 40 currents of a ten-hour battery discharge, for the same period of time 2 ms and measure the voltage drop across the second resistance R40 at the end of this period of time,

then, based on the measured voltage drops, using Ohm’s known law for a section of the circuit, the currents in the circuit are calculated after switching the first resistance R4 - I4 and the second resistance R40 - I40,

give an estimate of the internal resistance of the battery Rin, calculated by the formula:

Rin - internal resistance of battery;

R40 - second resistance;

I40 - current strength after switching the second resistance;

R4 - first resistance;

I4 - current strength after switching the first resistance,

Next, the actual capacity of the battery is determined at the measurement temperature using the formula:

Сфt - actual battery capacity,

a, b and c are empirically predetermined coefficients characteristic of the diagnosed battery size and current multiplicity; and the actual capacity normalized to normal temperature:

t is the temperature of the electrolyte or the surface of the battery, measured at the beginning of the discharge,

tn - normal battery temperature,

λ - temperature coefficient from clause 6.11.10 GOST R IEC 60896-2-99, then based on the obtained value Сф the residual resource is estimated using the formula:

Sleep - the nominal capacity of the battery at normal temperature,

if the voltage at the terminals is below the minimum permissible for the battery, then an attempt is made to charge the battery or a training cycle of charge-discharge of individual battery elements and then an assessment of the internal resistance of the battery is carried out.

In further development of the invention, the internal resistance of the battery is assessed without measuring the current pulse using meters.

In development of the invention, the internal resistance, actual capacity and residual life of the battery are assessed using a current pulse ratio of 4/40 of the ten-hour discharge current, as well as detuning from the electrolyte temperature.

In further development of the invention, the surface temperature of the battery is recorded instead of the electrolyte temperature.

In further development of the invention, the next resistance is connected to the circuit in parallel with the previous one, and after measuring the resulting resistance, the circuit is opened.

In further development of the invention, the multiplicity of the second current is 8-20 currents of a ten-hour discharge.

In development of the invention, resistance measurement is carried out on alternating current by shorting the battery for the time necessary to record the measurements in a circuit with an alternating current source, a high-capacity capacitor and an external measuring resistor with a resistance much greater than the internal resistance of the battery, then the actual capacitance is determined at the measurement temperature according to the formula:

a~, b~ and c~ are empirically predetermined coefficients characteristic of the diagnosed battery size and the frequency of the test voltage, while measuring the resistance on I8-20 or on alternating current reduces the accuracy of the Rin estimate, but allows you to diagnose a battery of larger capacity.

In further development of the invention, the battery is closed to resistance for a time in the range of 2-10 ms, and the time is selected so that it is longer than the transient process time of a larger current pulse, but does not lead to overheating of the external resistance and other circuit elements.

In development of the invention, before measuring and recording the temperature of the electrolyte and the voltage at the terminals of the battery, a search is carried out for retrospective results of assessing the actual capacity of the battery being diagnosed, and the result of assessing the actual capacity is compared with retrospective data

In further development of the invention, the battery is closed to resistance for a time in the range of 2-10 ms, and the time is selected so that it is longer than the transient process time of a larger current pulse, but does not lead to overheating of the external resistance and other circuit elements.

A device for implementing the claimed invention, including a power supply; cooling unit; Control block; communication unit; a unit for measuring the internal resistance of the battery with direct current, which includes a signal conditioner, a powerful capacitor, and a power amplifier; reverse polarity protection device; input voltage measurement unit; a measurement error compensation unit and an analog-to-digital converter (ADC) module, characterized in that alternating voltage from the external network is supplied to a power supply unit, which combines the functions of protection against network overvoltage and rectification and supplies rectified voltage to other units of the device, while after supplying power to the cooling unit, the cooling unit begins measuring the temperature inside the device and, if the temperature exceeds a pre-selected set point, turns on forced cooling of the device; after power is supplied to the control unit, the communication unit communicates with an external device via a wired or wireless connection in anticipation of the operator’s command and, upon receiving a command to measure the internal resistance of the battery using the two-pulse method with specified pulse current ratios, the unit for measuring the internal resistance of the battery with direct current is connected to the positive contact of the battery through a reverse polarity protection device, while the input voltage measurement unit measures the battery voltage, and the measurement error compensation unit makes adjustments to the measured voltage by taking into account the voltage drop across the reverse polarity protection device, which requires galvanic isolation of the power circuits a block with voltage measurement circuits on both sides of a reverse polarity protection block; After measuring and adjusting the battery voltage, the unit for measuring the internal resistance of the battery with direct current requests from the control unit the load levels for discharging the battery in two pulses and the pulse time, after which it selects a combination of transistors and load resistors and closes the battery to the load specified by the control unit time, and also sends information to the control unit about the selected load resistance; the ADC module measures the change in voltage on the battery during switching to the load and sends the voltage change values to the control unit at the end of the time of each of the two pulses; Then, based on the load resistance and measured voltage changes on the battery, the control unit calculates the internal resistance of the battery and sends the calculation result via a communication unit to an external device via a wired or wireless connection, where the actual capacity normalized to normal temperature and the remaining battery life are calculated.

A device characterized in that the unit for measuring the internal resistance of the battery with direct current includes a pulse load module, an ADC module and a relay, while the pulse load module includes at least 5 identical boards, each of which is an eight-channel pulse load board containing 8 transistor switches. The device is characterized in that it additionally includes a unit for measuring the internal resistance of the battery with alternating current.

A device characterized in that it additionally includes a discharge and training cycle unit, consisting of an electrical load and an ADC for measuring the voltage on the battery.

A device characterized in that it additionally includes an indication unit, which receives from the control unit current information about the position of the device contacts, current and voltage levels, current processes and displays it on the display.

A device characterized in that the cooling unit sets the intensity of forced cooling of the device, taking into account the results of measuring the temperature inside the device.

The declared technical result, namely: increasing the convenience and quality of diagnosing the condition of rechargeable batteries (AB) with a capacity of up to 4000 Ah with a voltage from 2 to 280 V, used in auxiliary systems of transformer substations, as well as reducing the time of testing without removing the battery from operation, simplification of the device that implements the tests is achieved by using the claimed method and device for its implementation:

- increasing the accuracy of estimating internal resistance, actual capacity and residual life of the battery is achieved by using a current pulse ratio of 4/40 of the ten-hour discharge current, increasing the time range between switching and measuring the voltage on the resistance, as well as detuning from the electrolyte temperature;

- simplification of the device for implementing the claimed method is achieved by assessing the internal resistance of the battery without measuring the current pulse using meters, and the use of an indication unit increases ease of use.

Brief description of drawings:

In fig. Figure 1 shows a schematic diagram of a device for comprehensive testing of battery characteristics.

In fig. 1 the following designations are adopted:

1. Power supply;

2. Cooling unit;

3. Control unit;

4. Communication unit;

5. Unit for measuring the internal resistance of the battery with direct current;

6. Reverse polarity protection device;

7. Input voltage measurement unit;

8. Measurement error compensation unit;

9. ADC module;

10. Unit for measuring the internal resistance of the battery with alternating current;

11. Block of discharge and training cycle;

12. Display block. In fig. Figure 2 shows the appearance of a prototype device for comprehensive testing of battery characteristics.

In fig. Figure 3 shows an internal view of a prototype device for comprehensive testing of battery characteristics.

Carrying out the invention

The claimed method is implemented as follows: Upon receiving an operator command to measure the internal resistance of the battery on alternating current, the unit for measuring the internal resistance of the battery with alternating current 10 (Fig. 1), powered by power supply 1 (Fig. 1), is connected to the positive contact of the battery and starts generate a high-power sinusoidal signal, while the input voltage measuring unit 7 (Fig. 1) measures the battery voltage, and the measurement error compensation unit 8 (Fig. 1) makes adjustments to the measured voltage by taking into account the voltage drop on the reverse polarity protection device 6 ( Fig. 1), which requires providing galvanic isolation of the voltage measurement circuits on both sides of the reverse polarity protection unit. ADC module 9 (Fig. 1) selects the alternating component of the voltage on the battery, measures it and sends it to control unit 3 (Fig. 1), where the internal resistance of the battery to alternating current is calculated, taking into account a predetermined amplitude level of the alternating current. Next, control unit 3 (Fig. 3) sends the calculation result via a communication unit to an external device via a wired or wireless connection, where the actual capacity normalized to normal temperature and the remaining battery life are calculated.

Upon receiving the operator's command to discharge the battery, control unit 3 (Fig. 1) sends a command to connect the discharge unit and training cycle 11 (Fig. 1) to the positive contact of the battery with a pre-selected load according to the capacity connected to the battery and the estimated discharge time. After the start of the discharge, control unit 3 (Fig. 1) sends commands to measure the voltage on the battery with a voltage meter built into the discharge and training cycle block 11 (Fig. 1), and sends data on the voltage level on the battery and torque to an external device via a communication unit measurement time, where the actual capacity normalized to normal temperature and the remaining life of the battery are calculated.

When receiving a command to carry out a training cycle of battery charge-discharge from the operator, control unit 3 (Fig. 1) sends a command to connect the discharge unit and training cycle 11 (Fig. 1) to the positive contact of the battery with a pre-selected load according to the capacity of the connected battery and the calculated discharge time, as well as connecting the power supply to the positive contact of the battery. After which the power supply 1 (Fig. 1) supplies energy at the required voltage to the battery, and the discharge and training cycle unit 11 (Fig. 1) controls the voltage level on the battery and, after reaching the voltage level of a predetermined maximum value of the power supply 1 (Fig. 1) turns off the voltage supply to the battery, and the discharge and training cycle block 11 (Fig. 1) closes the battery to a pre-selected load and continues to control the voltage level on the battery. After reaching the battery voltage level of a predetermined minimum value, the battery charge is repeated using power supply 1 (Fig. 1) until the voltage level of a predetermined maximum value is reached. Then the battery is disconnected from the device.

A possible design of a prototype device for comprehensive testing of the characteristics of rechargeable batteries in the working/transport position is presented in Figures 2-3.

Device design features:

A double frame design is used. This design was chosen in order to maximally protect the internal conductive non-insulated parts and radiators from possible short circuits to the housing, to protect against mechanical damage to electronic modules, to ensure ease of maintenance and assembly during manufacture or in case of repair, to reduce the level of vibration during operation.

In order to prevent accidental damage to the display, breakage of buttons or false alarms, and to prevent mechanical damage to the front parts of the installation during operation, equipment and cables are placed on the front side in pockets and hanging loops for devices and cables, as well as storage of operating instructions.

For more convenient monitoring of the temperature of the connectors, preventing damage to the pins during setup and changing modes by the operator, as well as a more convenient process for checking the tightness of the connectors, the connectors are made on the rear surface of the installation. The side covers provide the possibility of installing non-woven filters. To make it more convenient to move the unit when testing individual battery cells, the unit is equipped with wheels with stops and handles. Latching buttons are used to provide protection against false activation when connected to the network.

Control unit 1 (Fig. 1) is designed to control peripheral controllers, for floating point calculations and decision-making in critical situations. The unit board has three LEDs for signaling states. The unit has: two CAN channels (4 wires, with power), two RS485 interfaces main and auxiliary, one RS422 interface for configuration and debugging, expansion connectors with a pitch of 2.54 mm for daughter boards. The expansion connectors provide 16 additional logic level pins.

The unit for measuring the internal resistance of the battery with direct current 5 (Fig. 1) may include a pulse load module, an ADC module and a relay.

The pulse load module is designed to control the battery load in a given voltage range and consists of 40 or 80 transistor switches. There are 4 operating voltage ranges in total: 300-100, 110-34, 36-9, 9-2. Each range has its own number of transistors. The number of switches in the first and fourth ranges will be 80 transistors, and in the second and third - 40 each. The load resistor ratings in each pulse load module differ and are designed for its own voltage range. The pulse load module consists of 5 or 10 identical boards. This is an eight-channel pulse load board containing 8 transistor switches. The power supply is 24 V (2 wires). There are 16 control lines. In addition, 5 or, respectively, 10 boards are connected to two low-impedance operating buses, each. This connection must be low-impedance (copper bus or corresponding stranded wire), since it introduces an error in the measurements. The ADC is designed to measure the input voltage level within 2 V. Its input is isolated by a high-voltage capacitance, which allows the measurement of weak pulse and sinusoidal signals. The ADC includes a processor board insert. The attraction relay 11030113 was selected as the relay.

The unit for measuring the internal resistance of the battery with alternating current 5 (Fig. 1) is designed to generate a high-power sinusoidal signal. It consists of three parts: a signal conditioner, a powerful capacitor, and a power amplifier. The signal conditioner is based on the use of a digital-to-analog converter (DAC), which is part of the microcontroller.

CD60-J with a capacity of 1000 μF was chosen as a powerful capacitor. The power amplifier is a purchased class D audio frequency amplifier MP3123 based on the TPA3123D2 microcircuit with high efficiency, which allows you to obtain a voltage amplitude of more than 10 V and a current of more than 1 A.

The discharge and training cycle unit 11 (Fig. 1) is designed to discharge batteries with a capacity of up to 4000 Ah in the voltage range of 3-300 V and currents of 0-100 A with a power dissipation of up to 7.5 kW; as well as for training batteries with a capacity of up to 4000Ah with a nominal voltage of 2 V.

The block is based on a powerful MOSFET transistor STW88N65 in a TO-247 package, designed for voltages of more than 300 V.

At a temperature of +25°C, such a transistor is capable of dissipating 400 W. At higher temperatures this parameter will decrease. Assuming 150 W per transistor, then 50 transistor loads will be required to dissipate 7.5 kW of power. To limit the temperature inside the structure to 50°C, 150W would require a massive heatsink and forced air cooling. Heatsink calculations show that the approximate heatsink dimensions for a single board dissipating about 650 W are 300 mm × 125 mm × 60 mm with a single heatsink weighing about 1.61 kg.

To obtain a power of 7.5 kW at a voltage of 300 V, it is necessary to provide a current of 25 A (0.5 A per transistor). For 75 V this will already be 100 A (2 A per transistor). For compactness, 4 transistors are placed on one radiator.

Cooling unit 2 (Fig. 1) is an air cooling system in which 1-20 fans are turned on and off, as well as their speed is regulated based on temperature measurements at 1-4 points. Block 2 (Fig. 1) consists of one board, which contains: a CAN connector with power (4 lines), 4 connectors for connecting external temperature sensors, and an auxiliary programming connector. Working with block 2 (Fig. 1) comes down to transmitting commands via the CAN bus and receiving responses. DS18B20 can be used as a temperature sensor. Fans - SG121238BS.

To power the device (Fig. 1-3), an AC/DC converter LRS-100-24 with an output voltage of 24 V is used. This voltage, in comparison with 12 V, allows you to obtain a sinusoidal signal with an amplitude of 10 V. This signal level will improve the accuracy of voltage measurements at low internal resistance of the battery.

The display unit 12 (Fig. 1) consists of one board on which are located: graphic display backlight, TIC154A graphic display (on top of the backlight), control circuit and communication with the main controller (via CAN bus), CAN connector with power (4 lines) , auxiliary programming connector or separate board and color display, for example, WKS50WV009-WCT.

Control of block 12 (Fig. 1) is reduced to transmitting commands via the CAN bus. The commands include: Request for device parameters (Fig. 1-3); turning on/off the screen backlight; reset screen state; switching mode (character-graphic); transmission of output information.

Communication unit 4 (Fig. 1) is built on the use of ready-made purchased Bluetooth solutions (BLE112, BLE113), representing a UARTa (serial port) extender. It is located on the daughter board of control unit 3 (Fig. 1).

The input voltage measuring unit 7 (Fig. 1) is designed to measure the input voltage level in the range of 3-300 V and signal the polarity reversal condition. To maintain sufficient accuracy over the entire input voltage range, three ADC channels with different input resistive dividers are used. Additionally, block 7 (Fig. 1) provides reverse polarity signaling.

The measurement error compensation unit 8 (Fig. 1) is designed to measure the voltage on a powerful input diode, which introduces an error into the load voltage. Block 8 (Fig. 1) contains galvanic isolation of the input, since it measures a relatively high input voltage.

The operation of the device (Fig. 1-3) begins with the fact that alternating voltage from the external network is supplied to the power supply 1 (Fig. 1), which combines the functions of protection against network overvoltage and voltage rectification and supplies rectified voltage to other units of the device (Fig. 1). .1-3). After power is supplied to the cooling unit 2 (Fig. 1), the cooling unit 2 (Fig. 1) begins measuring the temperature inside the device (Fig. 1-3) and if the temperature exceeds a pre-selected setpoint, it turns on forced cooling of the device (Fig. 1-3 ). After power is supplied to the control unit 3 (Fig. 1), the communication unit 4 (Fig. 1) communicates with an external device via a wired or wireless connection, awaiting an operator command and, upon receiving a command to measure the internal resistance of the battery using a two-pulse method with specified current ratios pulses, the unit for measuring the internal resistance of the battery with direct current 5 (Fig. 1) is connected to the positive contact of the battery through a reverse polarity protection device 6 (Fig. 1), while the input voltage measuring unit 7 measures the voltage of the battery, and the measurement error compensation unit 8 (Fig. 1) makes adjustments to the measured voltage by taking into account the voltage drop across the reverse polarity protection device 6 (Fig. 1), which requires galvanic isolation of the voltage measurement circuits on both sides of the reverse polarity protection unit 6 (Fig. 1) with power circuits of block 8 (Fig. 1). After measuring and adjusting the voltage of the battery, the unit for measuring the internal resistance of the battery with direct current 5 (Fig. 1) requests from the control unit 3 (Fig. 1) the load levels for discharging the battery with two pulses and the pulse flow time, after which it selects a combination of transistors and load resistors and closes the battery to the load for a time specified by the control unit, and also sends information about the selected load resistance to control unit 3 (Fig. 1). ADC module 9 (Fig. 1) measures the change in voltage on the battery during switching to the load and sends to control unit 3 (Fig. 1) the values of the voltage change at the end of the time of each of the two pulses. Based on the load resistance and measured changes in voltage on the battery, control unit 3 (Fig. 1) calculates the internal resistance of the battery and sends the calculation result via a communication unit to an external device via a wired or wireless connection, where the actual capacity normalized to normal temperature and the remaining life are calculated AB.

Claims (17)

1. A method for checking the characteristics of rechargeable batteries, which consists in assessing the internal resistance, actual capacity and residual life of the rechargeable battery, characterized in that they measure the temperature of the electrolyte and for 2 ms close the battery to resistance R1, selected to provide current in the circuit with a battery with a value of 4 currents of a ten-hour battery discharge; measure the voltage drop across resistance R1 at the end of the time period when the battery is shorted to resistance R1; after which they open the circuit and immediately close it for the same period of time 2 ms to resistance R2, selected to provide a current in the circuit with the battery equal to 40 currents of a ten-hour discharge of the battery, and measure the voltage drop across resistance R2 at the end of the period of time the battery is closed to resistance R2; from the measured voltage drops, using the known Ohm's law for a section of the circuit, the currents in the circuit are calculated after switching the first resistance I1 and the second resistance I2; further, using the formula: Rin = (R2⋅I2-R1⋅I1)/(I2-I1), give an estimate of the internal resistance of the battery Rin, determine the actual capacity using the formula: Cфt = a⋅Rin^2+b⋅Rin+s , where a, b and c are empirically predetermined coefficients characteristic of the diagnosed battery size; Next, the actual capacity is determined, reduced to normal temperature: Сф=Сфt/(1+λ(t-tн)), where t is the temperature of the electrolyte measured at the beginning of the discharge, tн is the normal temperature of the electrolyte, λ is the temperature coefficient; Based on the obtained Sf value, the residual resource is estimated using the formula: RL=Cf/Cnom, where Cnom is the nominal capacity of the battery at normal electrolyte temperature. 2. The method according to claim 1, in which retrospective results of estimating the actual capacity of the battery being diagnosed are searched, and the result of estimating the actual capacity is compared with retrospective data. 3. A device for testing the characteristics of rechargeable batteries, measuring the internal resistance of the rechargeable battery to direct current, characterized in that it includes: - a communication unit that receives commands to measure the internal resistance of the battery to direct current, discharge or charge the battery, and also transmits the results of measuring the internal resistance received from the control unit to an external device via a wired or wireless connection; - a control unit that sets load levels for discharging the battery with two DC pulses; - an input voltage measurement unit that measures the battery voltage in a circuit with an electrical load R1, R2; - reverse polarity protection device; - a measurement error compensation unit that corrects the voltage measured by the input voltage measurement unit by taking into account the voltage drop across the reverse polarity protection device; - a unit for measuring the internal resistance of the battery with direct current, connected to the positive contact of the battery through a reverse polarity protection device and, after measuring and adjusting the battery voltage, shorting the battery to the load for 2 ms; - an ADC module that measures the change in voltage on the battery during switching to the load at the end of the time of each of the two pulses, and also sends the voltage measurement results to the control unit; - a discharge and training cycle unit, including an electrical load and an ADC for measuring the voltage on the battery, connected to the positive terminal of the battery for discharging the battery, measuring the voltage on the battery and transmitting information about the voltage level on the battery and the moment of measurement to the unit control, as well as monitoring the voltage on the battery during the charge cycle during the training cycle of charging and discharging the battery; - a power supply unit connected to all other units of the device and combining the functions of rectifying the external network voltage and overvoltage protection, and also connected to the battery during charging in the training cycle. 4. The device according to claim 3, characterized in that it is equipped with a cooling unit with an air temperature sensor inside the device that regulates forced cooling of the device. 5. The device according to claim 3 or 4, characterized in that it is equipped with an indication unit that displays on the display current information about the position of the device contacts, current and voltage levels. 6. Device according to any one of paragraphs. 3-5, characterized in that it includes a control unit that, based on the load resistance and measured voltage changes on the battery, calculates the internal resistance of the battery to direct current when receiving a command from the communication unit to measure the internal resistance of the battery to direct current. 7. Device according to any one of paragraphs. 3-5, characterized in that it includes a control unit that sets the load resistance during the discharge of the battery when receiving a command from the communication unit to discharge or conduct a training cycle of charging and discharging the battery.