RU2265921C2 - System for diagnosing lead storage batteries - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed system designed for direct computer-aided monitoring of lead battery voltage across each cell, electrolyte temperature, specific gravity, and level, as well as voltage between battery poles and battery current is provided with respective sensors. All sensors responding to battery voltage, electrolyte temperature, specific gravity, and level and related to respective battery cells are connected to microcontroller that has switch, analog-to-digital converter, and microprocessor mounted on cell lid together with voltage converter affording power supply to microcontroller and sensors from battery cell. Voltage sensors inserted between battery poles and battery current sensors are also provided with microcontrollers. All microcontrollers are connected through electric isolators to local computer network single channel formed by communication line between first and second serial ports of controller connected to measurement data processing unit.

EFFECT: enhanced precision of evaluating battery parameters, reduced number of connecting lines, and enlarged functional capabilities of system.

1 cl, 1 dwg

Description

The invention relates to electrical engineering, in particular to chemical current sources, and can be used to monitor the technical condition, diagnose and improve service, for example, lead-acid batteries.

A known system for diagnosing lead storage batteries (a.s.1783475 (51), 5 G 05 V 23/02), containing a block for processing measurement results (BORI), voltage sensors, four electrolyte temperature sensors in each battery element, the first of which is set below the minimum electrolyte level, the second is at the point corresponding to the nominal level, the third is at the maximum level, the fourth is above the maximum electrolyte level, as well as a controlled amplifier for the current sensor connected to the first ADC. All temperature and voltage sensors through the switch are connected to the second ADC. Both ADCs are associated with BORI. The aim of the invention is to expand the functionality by determining the density and level of electrolyte. The specified invention has the following disadvantages:

- determination of the density of the electrolyte by the voltage of the open circuit (NRC), i.e. by battery EMF, it requires a long time for the battery to be in the “storage” mode (at least 24 hours after charging);

- the introduction of an amendment to the electrolyte density determined by the NRC by integrating the current during discharge or when the battery is charged and calculating the value of the given or received capacitance (in ampere-hours), respectively, of a decrease or increase in electrolyte density leads to an accumulation of error with each repetition of the “charge - battery discharge ";

- the calculation of the electrolyte level according to the readings of four temperature sensors installed at different heights in the battery requires a significant difference in the temperature of the electrolyte and the air space above the surface of the electrolyte. However, such a temperature difference can practically only occur at intense discharge or charge currents. In most cases, the current flowing along the AB is relatively small and, in addition, there is no jump in temperature at the interface, so the error in calculating the level from the temperature difference will be high;

- with long-term “storage” of the battery, i.e. in the absence of current, the temperature of the electrolyte and the air space above the level of the electrolyte are aligned with each other, so the possibility of calculating the level of electrolyte in this way is excluded;

- when artificially creating a temperature difference, for example, by turning on the cooling system and mechanical mixing of the electrolyte, an unsteady change in temperature occurs over time, which leads to a dependence of the calculated value of the electrolyte level on the point in time at which the temperature was measured, i.e. to the unreliability of the calculation results;

- in the indicated system, all voltage and temperature sensors related to various battery batteries are connected through the switch to one ADC, therefore the potential difference between the input contacts of the switch (when connecting up to 120 batteries in series to the battery) can reach 360 V and the ADC will periodically under the changing potential relative to the ground, which can lead to a breakdown of isolation not only of the switch and the ADC, but also of the associated BORI. In addition, a large number of trunk lines are required to connect sensors to a single switch.

The closest technical solution to the invention (prototype) is a battery monitoring device (RU 940260055 A1, IPC H 01 M 10/48, published 05/20/96). The device consists of a housing, inside of which there are electrodes, a plug and a valve to prevent spillage of electrolyte, and measurement sensors are integrated into the battery plug: level, temperature and density of the electrolyte. These sensors are connected to a measurement system consisting of a power supply, a comparison system, a control system, an indication and alarm system, and a high-frequency amplifier.

In the specified device provides an increase in the accuracy of measuring density, temperature and electrolyte level compared with the above device. However, a large number of connecting lines are also required to connect the sensors to the measurement system. In addition, the device does not perform the functions of measuring current, battery voltage, voltage between the poles of the battery and between each pole of the battery and the housing, the measurement results of which can calculate the insulation resistance of the battery.

The invention is aimed at expanding the functionality and reliability of the system, as well as reducing the number of connecting lines due to the fact that the system containing the processing unit of the measurement results, temperature, density and electrolyte sensors in the battery cells is supplemented with a current sensor AB, voltage sensor AB, alternately connected through the switch between the poles of the battery or between each pole of the battery and the housing, and voltage sensors on each battery. All sensors (battery voltage, temperature, density and electrolyte level) related to one battery cell are connected to a microcontroller containing a switch, an analog-to-digital converter, and a microprocessor installed on the battery cover together with a voltage converter that provides power to the microcontroller and sensors from Served battery AB. The voltage sensors between the poles of the battery and the battery current are also equipped with microcontrollers. All microcontrollers are connected via galvanic isolation devices to the monochannel of the local area network, formed by the communication line between the first and second serial ports of the controller connected to the measurement processing unit.

The drawing shows a structural diagram of the proposed system for the diagnosis of lead batteries.

It consists of a unit for processing measurement results 1, a local area network controller (LAN) 2, a voltage sensor AB 3, a current sensor AB 4. The voltage on each battery is measured using a voltage sensor 5, and temperature sensors (DT) are placed in the battery electrolyte 6 , level (ДУ) 7 and density (ДП) 8 of electrolyte. The voltage sensor AB using the switch 9 is alternately connected between the poles of the battery or between each pole of the battery and the housing (not shown). The output of the switch 9 is connected to the microcontroller 10. The power of the switch 9 and the microcontroller 10 is supplied from the voltage converter 11. The current sensor is also connected to the microcontroller 10, powered by the voltage converter 11. All sensors (5, 6, 7, 8) related to one battery, connected to the microcontroller 10 mounted on the cover of the corresponding battery together with a voltage converter 11, providing power to the microcontroller and sensors from the same battery AB. The number of sets consisting of sensors (5, 6, 7, 8), microcontrollers 10 and voltage converters 11 corresponds to the number of batteries in the battery. Each microcontroller 10 of the system is equipped with a galvanic isolation device 12, through which they are connected to the monochannel of the local area network 13, formed by the communication line between the first and second serial ports of the controller of the local area network 2, which has two-way communication with the processing unit 1.

The described system provides direct control of the parameters: density, level and temperature of the electrolyte in the batteries, voltages on all batteries, battery current, voltage between the battery poles, or between each battery pole and the housing, from the measurement results of which it is possible to calculate the insulation resistance of the battery. Microcontrollers 10 receive signals from sensors, analog-to-digital conversion, preliminary smoothing of high-frequency pulsations caused by noise in the electronic circuit and external electromagnetic interference, scaling and storing the input measurement signals before receiving a command from controller 2. At the request of the controller 2, microcontrollers 10 convert the measurement data into the serial code and transmit them through the galvanic isolation device 12 to the mono channel of the local area network 13.

The voltage measurement on all batteries using sensors 5 allows you to identify "lagging" batteries, timely stop the discharge, preventing the voltage drop on any of the batteries below the limit value. This prevents battery failure. The controller of the local area network 2 periodically polls the microcontrollers 10 mounted on the batteries, or the microcontrollers of the voltage control devices AB, or the current AB. Due to the fact that the monochannel of the local area network 13 is formed by a communication line between the first and second serial ports of the controller, the reliability of information transfer is increased, since in the event of a break in the communication line, the microcontrollers can be interrogated via the second serial port. Controller 2 performs preliminary processing of the measurement results (reliability control, smoothing of high-frequency pulsations, scaling, recalculating the density to the nominal level and temperature, determining whether the parameters exceed the permissible limits or deviate from the planned values) and transfers information to the processing unit for measurement results 1. In the block processing of measurement results 1 calculations are made according to the measurement results: insulation resistance of the battery; the amount of electricity (capacity) reported for the charge and received from the battery at the time of monitoring during discharge; residual capacity of the battery at the time of discharge control; time until the moment of full discharge of the battery with the current value of current. In addition, using the unit for processing measurement results 1, it is possible to carry out: planning measures for maintenance of batteries; warning about the need for planned activities; issuing operational recommendations on changing the operating mode of batteries in case of deviations from the charge or discharge plans, on turning ventilation on or off, mechanical mixing of electrolyte in batteries, water cooling system. Various forms of displaying information are possible; tracking of emergency information with a light and sound signal. Thus expanding the functionality of the system.

Thanks to the direct measurement of the parameters (density and electrolyte level in the batteries), the error in their determination is reduced. The galvanic isolation of the microcontrollers from the local computer network prevents the high potentials associated with the series connection of the batteries in the battery from entering the controller 2 and the processing unit 1 of the measurement results, which increases the reliability of the AB diagnostic system. The installation of microcontrollers 10 on the battery covers together with a voltage converter that provides power to the microcontroller and sensors from a serviced battery AB reduces the number of connecting lines.

Claims (1)

Diagnostic system for lead storage batteries (AB), comprising a unit for processing measurement results, temperature, density and electrolyte sensors in the AB elements, characterized in that the system is equipped with a controller, an AB voltage sensor, which is connected alternately through a switch between the AB poles or between each AB pole and a housing, a current sensor AB, voltage sensors on each element of the battery, and voltage sensors and sensors of temperature, density and electrolyte level, related to one battery element, are single to the microcontroller mounted on the battery cover together with a voltage converter that provides power to the microcontroller and sensors from the serviced battery of the battery, and the voltage sensors between the poles of the battery and current of the battery are also equipped with microcontrollers, and all microcontrollers are connected via galvanic isolation devices to the monochannel of the local area network, formed by the communication line between the first and second serial ports of the controller connected to the processing unit of the measurement results.