Battery monitoring program essay

The modular testing system consists of two several types of monitoring models, a battery block-voltage monitoring unit and a battery pack current- and temperature monitoring unit. Following the discussion of the measuring components, a LabView realization of your universal BMS software is defined in detail. Because of the flexible design of the LabView BMS, the program is able to perform control and surveillance actions for any sort of battery app and power supply technology (e. g. Pb, VRLA, NiCd, NiMH and so forth ).

The BMS was originally suitable for VRLR battery packs in uninterruptible power supply devices (UPS), but was also analyzed in electric power vehicles (VW CityStromer, BMW).

In a second step, a universal battery pack management system (BMS) was noticed as a LabView application. The use of a personal computer instead of a microcontroller contributes to much higher overall flexibility of the BMS and permits easy version to various types of battery applications and battery technologies. The LabView-based BMS controls data acquisition, works data processing, visualization and storage and supplies a graphic user interface.

Aside from monitoring features, the BMS evaluates the measured data and treats external parts, such as the charger, the temp regulation system and the inverter controller. A modem power supply management system, as opposed to simple power supply monitors, has the ability to of positively affecting electric battery operation. Ahead of the presentation from the new measuring hardware plus the LabView-based power supply management system, the key principles and general composition of a BMS are mentioned. I INTRO I1

Solid requirements with regards to battery life time, reliability and energy-efficiency are imposed in modem battery pack applications, at the. g., upon batteries in unintermptible power systems (UPS) or batteries in electric powered vehicles (EV). These high demands can only be met by employing complex battery monitoring and managing systems. Currently, battery users (e. g. in telecommunication energy source or in power stations) know inadequate about your their batteries to attract economically enhanced decisions relating to maintenance and replacement.

The employment of a battery monitoring and management system helps choosing the best time for battery maintenance and replacement and, in addition , can lengthen the service intervals due to taking active influence on battery pack operation. BASIC STRUCTURE OF THE BMS Fig. 1 displays the general framework of a power supply management system and divides the duties to be performed into rational blocks [2, almost 8, 91. Power supply management systems require battery pack data (battery block-voltages, current and temperature) and environmental data (temperature). Furthermore, application depending program data is needed.

To obtain these types of values, a specialized info acquisition method is used. A good example of a suitable info acquisition program for BMS is pre1. sented in chapter you 1 This logical prevent of a BMS (see Fig. 1) executes the data control. Apart from solving the sent measured values, this block calculates electric battery quantities (e. g. complete battery ac electricity, average power supply temperature, etc . ), combines quantities just like the battery current and functions statistical examination (e. g. distribution of block voltages, deviation of block concentration from the typical block volt quality, etc .. Furthermore, the data retraite unit demands information about the present maximum and minimum limit of prevent voltages, the ideal battery current etc . This information is either deduced from the system’s battery style or may be provided straight by the user (“parameter correction). The parameters of the battery model need to be continuously designed to the assessed and calculated quantities (e. g., temperatures, average weight current) to ensure that the unit accurately signifies the battery’s present state. 630

To regulate battery operation, battery supervision systems need the appropriate measurement of battery prevent voltages, power supply current and battery temperature ranges. Therefore , within a first step, a modular data acquisition program, specifically designed to get battery applications, was developed. The calculating hardware contains two various kinds of monitoring models, a battery pack block-voltage monitoring unit (VMU) and a battery current- and heat monitoring unit (CMU), which has been developed in cooperation with SIEMENS AKTIENGESELLSCHAFT, Erlangen.

VMUs have already been used in the SIEMENS Masterguard UPS in order to provide the system’s microcontrollerbased BMS with the required tested data. 0-7803-5069-3 /98/$10. 00 01998 IEEE Fig. 1 Structure of a battery monitoring and management (BMS). In Fig. you, the logical block “parameter adaptation is in charge of battery variable determination boost. The “monitoring block in Fig. 1 performs mistake detection and user details activities. Wrong doing detection inspections if a power supply quantity offers exceeded or perhaps is likely to exceed its allowed limits.

Tested data, alarm messages and information related to service or maintenance needs are given towards the user interface by monitoring block. In contrast to the monitoring block, the “management block is liable for fault elimination, which aims to keep the battery pack within specific limits of operation. If a quantity is going to exceed a limit, the management system reacts, for instance , by initiating the cooling system. In serious situations, e. g., regarding exhaustive relieve, the problem avoidance may possibly limit or perhaps interrupt the latest to protect the cells against reversion.

Furthermore, the administration block is able to control intelmethod, preligent asking algorithms such as the IU,, sented in [3], which usually limits the ideal of each battery pack block-voltage instead of just limiting the complete battery volts during the time of constant-voltage charge. In Fig. 1, the external components, which are influenced by the management prevent (charger, coolingheating system, inverter controller) will be summed up in the “control block. The hnctional prevent “in-/output presents the user user interface which gives picked data and messages towards the user and which allows user intervention, elizabeth.. the static correction of battery pack or program parameters. Info selection and data storage area are showed through the logical block “data management. 111 DATA OBTAIN SYSTEM Fig. 2 reveals the framework of the calculating and data acquisition system, consisting of electric battery block-voltage monitoring units (VMU) and current- and temp monitoring devices (CMU) [ one particular, 2]. Data transfer between the computing units (any number and sequence is definitely possible) and the data buy unit (DAU), which symbolizes the interface to the info processing prevent of Fig., is performed using a fiber-optic transmitting system (FOTS). Optic data transmission delivers electric efficiency of the do it yourself measuring program and brings about high immunity against electromagnetic noise. Power for the VMU and CMU is drawn straight from the scored batteries which will minimizes the quantity of electrical connections and therefore contributes to an easy and fast assembly. The VMU measures about eight trouble each starting from 0. 3 V to 16 Versus with an accuracy of 0. 15 YO, which enables the measurement of single-cell and block voltages for any sort of battery.

With respect to the shunt resistor, the CMU is able to assess battery current, e. g., over a range fiom OA up to n 300 A. The CMU also measures battery temperatures (-5OC to 6OOC). When the battery management system does not need measured data, the monitoring devices rest in a stand-by method during which the modules’ electricity consumption is definitely negligible compared to the self-discharge of the batteries. When measured values are required, the products are started up by the central data acquisition unit making use of the fiber-optic transmitting ring.

Following some setup-routines are completed, the VMUs and CMUs start the measuring method. As soon as info is available, the modules store the assessed values within their transmission buffers. Receiving a socalled “data-locomotive, the first component 631 214 “.. ” I capital t Data Obtain Unit My spouse and i 1 I actually “-I Fibre Optic Transmission System (FOTS) T T t 8 block trouble Fig. a couple of 8 prevent voltages 8 block trouble 5 temperatures and three or more currents big t 5 temperature ranges and several currents to Structure with the measuring and data acquisition system [ 10.

The electric power data insight and data output indicators of the dramón port (TxD, RxD) happen to be transformed into optic signals and are transmitted with the fiber optic transmission system. The electric handshake alerts RTS and CTS as well as DSR, DTR and DCD are not transmitted so that, on the other hand, only one tranny ring should be used, but , however, hardware handshake signals can not be used. Therefore , during the development of the LabView BMS very much effort had to be taken to ensure the synchronization of data interaction between the testing units (CMU and VMU) and the computer.

Having started out the Labview application the first time, the user comes up to provide essential system details, e. g., the number and sequence in the measuring products, the value of the shunt resistor for current measurement, the time between new measurement requests and the paths for info storage. Right now, the presented system is pre-configured to deal with about eight computing modules. The default time interval between measurement demands is set to four secs, but could be augmented along with shortened (down to one second) by the consumer. After the receipt of a valid data cycle, LabView decodes the transmitted data.

If the decoded data is recognized as measured values (and not as error message) these kinds of values happen to be compared with the corresponding maximum and minimum limits. If a assessed value surpasses the suffered interval an alarm communication is produced and shown on the graphic user interface. The minimum and maximum limits may be set by the end user, or always be deduced from an appropriate battery model. User interface: A display shot of the user interface named “front panel, can be seen in Fig. 3. Within the front -panel, the user can offer input information. Besides, the typical battery stops the measuring process and starts mailing the data-locomotive ollowed by its own assessed data to another module in the ring. This kind of module identifies the locomotive and the transmitted data and attaches towards the data string its own assessed values. The central acquisition unit can decode the received data chain as it knows the order from the monitoring models [l]. IV LABVIEW-BASED UNIVERSAL AND BATTERY MONITORING MANAGEMENT SYSTEM (BMS) LabView (Laboratory Virtual Instrument Engineering Workbench) from Countrywide Instruments Organization is a application development application which works on the graphical development language, G, to create programs in stop diagram type.

Since LabView includes your local library of features for data acquisition, serial instrument control, data analysis, data demonstration and info storage this commends alone for the BMS application. LabView courses are called “virtual instruments (VI). These AM?IAIS consist of an interactive interface (“front panel, see Fig. 3), a dataflow diagram that serves as the source code, and icon connections that allow the VI to be known as from higher-level VIS [ five ]#@@#@!. As the BMS is definitely executed on the personal computer, it gives higher versatility and much more graphical tools to get data visualization than microcontroller-based systems.

Therefore , the central unit from the diagram in Fig. you as well as the in-/output interfaces have been completely realized like a LabView software. Data purchase: For interaction between the testing system and LabView (request for and receipt of measured values) one of the dramón ports from the personal computer is used. 632 27-4 Fig. a few Front panel of the LabView-based BMS ten measuring channels and can localize the battery pack block, which can be exceeding their operation restrictions. Fig. some shows the display to get module 1 ) The scored voltage of block one particular has exceeded ts optimum limit and, therefore , has caused the alarm concept on the entrance panel. If the is in hesitation, whether the battery, s workable ca- heat, up to six currents of parallel battery strings as well as the entire battery pack voltage are constantly monitored. Fault detection: In case of an alarm communication, the corresponding monitoring unit is marked. Hitting the “module #, ‘button, the user gets detailed advice about the module’s prevent 1 you block2 1 block3 you block4 block5 block6 block7 block8 i Fig. 4 Detailed information about measuring module 1 633 acity might have decreased, it is also possible to run a battery-check discharge, which allows recognizing and localizing defective cells. This kind of battery-check, which could be defined as a part of the fault detection functions (monitoring) of the BMS, but also as a part of energetic intervention (management) is described below (see “fault prevention and intervention). Data processing: ment, the battery charger, which performs a blockvoltage restricting and therefore battery pack protecting charging algorithm (1Uma), is coupled to the BMS using a second RS 232 serial port. It really is anticipated that future BMS applications, elizabeth.., BMS in electric automobiles, will use modem fieldbus configuration settings, such as MAY bus, that can lead to more flexible, open devices. Data administration: Apart from establishing the entire power supply voltage as well as the average temperature, LabView calculates the battery’s condition of impose using a modified Peukert formula [2, 6, 7]. Switching the button “SOC the state of charge of the battery strings is definitely shown around the display. Furthermore, the syndication of block voltages can be displayed. The histogram in the measured trouble can be seen simply by clicking on the “voltage distribution button.

Mistake avoidance and intervention: With respect to the width of the voltage syndication, e. g. during floating operation, or depending on a decreasing functional battery ability, the BMS is able to understand if a so-called “battery conditioning (in case of lead acid batteries) should be performed and gives a corresponding meaning to the end user. A “battery conditioning formula performs a particular sequence of discharging and recharging periods which reverses to a certain extent the aging process of the battery packs. A typical sort of reversible injuries of business lead acid electric batteries is the so-called “premature potential loss [4].

To let analysis from the data at a afterwards moment, the measured ideals as well as the text messages given to the person are continually stored. This default storage area mode is useful for battery pack examination in research and development. Using the BMS to get common battery pack applications a great event-controlled storage mode could be chosen, which will stores a measured worth, if it is drastically different make up the value just before. For upcoming commercial power supply applications, for example , battery leasing, another simple storage mode, which just records the alarm messages on the consumer display, can easily be used.

V OVERVIEW To determine the lessening battery capability in case of power packs during flying operation (UPS-batteries), it is possible to operate a battery-check discharge (e. g. 10% of nominal battery capacity). During the electric battery check the battery block-voltages will be recorded and compared with the corresponding values coming from previous assessments. In case of significant deviations, the battery’s workable capacity Qo has most likely decreased too. Therefore , a “battery conditioning has to be recommended.

If a measured temperature is greater than its limitations or the differences between the measured temperatures exceed a predetermined limit, a water blood circulation system is started up. This system may possibly either cool or high temperature the power packs or may establish a uniform temperature syndication. Parameter edition: In this paper, a new produced, flexible LabView-based battery management is shown. Through the LabView realization in the BMS (in contrast to older processor based ideas [3]) it absolutely was possible to develop an easily adaptable monitoring and management system for any sort of battery application.

Additional monitoring or management features to get BMS can easily be added to the LabView software program. Even unanticipated demands about BMS, that may turn up with the usage of fresh battery solutions, can be met without problems. NI ACKNOWLEDGEMENTS The authors would like to thank SIEMENS AG, Erlangen for supporting the development of the presented battery pack measuring system and, furthermore, acknowledge D. Linzen to get his input to this project. VI1 RECOMMENDATIONS A. Lohner, S. Buller, E. Karden, R. W.

De Doncker, “Development of a Highly Accurate, Universal and cheap Measuring System for Power supply Management Systems, 15 Electric power Vehicle Conference, seminar (EVS), 1998, Brussels (Belgium) E. Karden, P. Mauracher, A. Lohner, “Battery Supervision Systems to get Energy-Efficient Power supply Operation: Technique and Functional Experience, 1 3 ~ Electric Automobile Symposium, mil novecentos e noventa e seis, Osaka (Japan), Vol. 2 pp. 91-98 The amount of impose Qo which can be stored in and discharged by a power supply at nominal values of current and temperature, is in general not really equal to the nominal ability QN, which is an effect of aging.

Consequently , which is a version parameter in the modified Peukert equation, should be updated frequently, e. g., during the health cycles. As a result of modular framework of the LabView application, hotter battery models may be integrated according to individual user’s requirements. Control interfaces: eo, Apart from interaction between LabView and the calculating system for data buy, the BMS has to have additional interfaces to control external parts such as the cooling or the battery charger. At the mo634 A. Lohner, E.

Karden, R. T. De Doncker, “Charge Equalizing and Lifetime Elevating with a New Charging Method for VRLA Batteries, 19 International Telecommunication Energy Meeting, 1997, Melbourne (Australia), pp. 407-41 1 27-4 [4] A. Lohner, “Batteriemanagement fQr verschlossene Bleibatterien am Beispiel von USV-Anlagen, Dissertation are Institut fiir Stromrichtertechnik ebenso Elektrische Antriebe, RWTH-Aachen, 98 [5] Countrywide Instruments Firm, “LabView Customer Manual, Part Number 320999A-01, mil novecentos e noventa e seis Edition [6] R. Giglioli, A. Buonarota, P. Menga, M.

Ceraol “Charge and Discharge 4th Order Energetic Model of the Lead-Acid Battery, 10* Electrical Vehicle Seminar, Hongkong, 1990, pp. 371-382 [7] Watts. Peukert, “Uber die Abhangigkeit der Kapazitat von der Entladestromstiirke bei Bleiakkumulatoren, ETZ, Band 18, 1897 [SI E. Dowgiallo jr. “Innovative On-Board Instrumentation intended for EV Power supply Characterization, DOEEPRI Beta Electric battery Workshop almost eight, 1991, pp. 215-218 [9] H. Kahlen, B. Hauck “Batteriemanagementsysteme fiir Traktionsbatterien, Fachtagung der Deutschen Gesellschaft fiir elektrische StraBenfahrzeuge (dges), 1995, Berlin 635

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