CN101114724A - Nickel-hydrogen battery management system for electric vehicle - Google Patents

Abstract

The invention relates to a Nickel-metal hydride battery management system for electric vehicles, comprising a system mainframe connected with a pressure and temperature detection module, a fan controlling module and a capacity detection instrument. The system mainframe is a single chip microcomputer and is connected with a serial interface 1, a serial interface 2, a data memory, a clock, a RS232 serial interface and a digital quantity interface. The capacity detection instrument is connected with the single chip microcomputer after being connected in series with a battery current divider, a current divider voltage signals adjustment and a voltage frequency conversion. The single chip microcomputer comprises a serial interface communicating with an AGV controlling computer and a display unit. The battery pressure and the temperature detection module are connected with the single chip microcomputer after being connected in series with five-bath battery voltage signals adjustments, an analog signal multiplexer, an A/D module number conversion interface. The single chip microcomputer comprises a five-bath temperature sensor, a photoelectric isolation serial interface and the fan controlling module. The system reduces weight, improves energy utilization rate and ensures favorable working conditions for the battery.

Description

Nickel-hydrogen battery management system for electric vehicle

Technical field

In production logistics, terminal charges accounts for 15.5% of processing cost.Seeking mechanization and intelligentized carrying technology and equipment both at home and abroad always.AGV (Automatic guided vehicle: be a kind of flexibility and intelligent logistics transfer robot automatic navigation vehicle), bring into use at warehousing industry from the fifties abroad, be widely used at present in fields such as manufacturing industry, harbour, harbours.At home, the application of AGV also begins gradually, in enterprise automation production process and computer integrated manufacture system (CIMS), industries such as especially supermatic tobacco, automobile, civil aviaton, iron and steel, postal service, seal paper money, industries such as Qing Jie electronics, medicine, food highly, special trade such as freezing, nuclear material, photosensitive material has broad application prospects.

The distinguishing feature of AGV is unmanned, is equipped with automatic guiding system on the AGV, can safeguards system just can travel automatically along predetermined route under the situation that does not need artificial pilotage, and goods or material are transported to the destination from starting point automatically.Another characteristics of AGV are flexible good, high and the intelligent level height of automaticity, the driving path of AGV can change and change flexibly according to storage goods yard requirements, the technological process of production etc., and the expense of operating path change is compared very cheap with the traditional conveyer belt and the conveyer line of rigidity.AGV generally is equipped with charging crane, can with the automatic interface of other logistics equipments, realize goods and material handling and carrying full process automatization.In addition, AGV also has the characteristics of cleaner production, and AGV relies on the storage battery that carries that power is provided, and noiseless, pollution-free in the running can be applied in many places that require the operational environment cleaning.

The AGV major part of present domestic use is an imported product, the battery that its product uses is an ickel-cadmium cell, please refer to Fig. 1 every nickel-based battery group management system schematic diagram, charger charges to ickel-cadmium cell, in the process of ickel-cadmium cell to the load motor discharge, only its charge/discharge capacity is measured, instrument is by the SOC of switching value reflection battery.Present charger adopts the power source charges of silicon controlled rectifier, and noise was big when its weak point was charging, and has the environmental pollution problem every nickel-based battery.

Summary of the invention

The product that the objective of the invention is to avoid above-mentioned weak point of the prior art and a kind of nickel-hydrogen battery management system for electric vehicle is provided,

Ni-MH battery is the high-tech product that China has strong resources advantage, has stronger competitive advantage in the international market.This battery has high-energy-density, high power, is fit to heavy-current discharge, capable of circulationly discharges and recharges, pollution-free for other battery, is described as " green power supply ".Each developed country of the world is all stepping up to develop this product technology, at present the U.S., all closely industrialization of Japan.

The characteristics of AGV Vehicular dynamic battery are to discharge and recharge frequent and require quick charge, every day to discharge and recharge number of times between 10-20 time, each charging interval within 8 minutes, the big electric current quick charge of needs, this has proposed very large challenge to battery performance.Guarantee the useful life of battery, it is very important correctly using battery, and this comprises correctly and discharges and recharges, correctly uses.Our battery management system is developed just for this purpose, is for adapting to the innovation that the Ni-MH battery demand is done on the primary cell management system.

Purpose of the present invention can reach by following measure:

A kind of nickel-hydrogen battery management system for electric vehicle, its nickel-hydrogen battery management system for electric vehicle is connected with cell voltage, the temperature detecting module that detects cell voltage variation and temperature height by intelligent battery management system main frame, fan opens, stop controlling and the fan control module of state-detection, the capacity check instrument of battery charging and discharging capacity constitutes

Intelligent battery management system main frame is a single-chip microcomputer, be connected to serial ports 2, data storage, the clock ofserial ports 1, the connection capacity detecting instrument of cell voltage, temperature detecting module, the RS232 serial ports of download alarm logging information, transmit the digital quantity interface of information to AGV control computer;

After the capacity check instrument is connected in series successively by battery shunt, the adjustment of shunt voltage signal, voltage-frequency conversion, be connected on the single-chip microcomputer of capacity check instrument, single-chip microcomputer is connected to AGV control computer communication serial ports and display unit and constitutes, by serial ports 2 and intelligent battery management system host communication;

Cell voltage, temperature detecting module by five road battery voltage signals nurse one's health, after analog signal Port Multiplier, A/D analog-to-digital conversion interface be connected in series successively, be connected on the single-chip microcomputer of cell voltage, temperature detecting module, single-chip microcomputer is connected to No. five temperature sensors, the photoelectricity isolated serial port constitutes, byserial ports 1 and intelligent battery management system host communication, voltage, temperature detecting module are installed in the place of close battery in the battery case.

Intelligent battery management system main frame is connected to fan control module, the single-chip microcomputer of fan control module is connected to fan swicth, commutation detects, fan power supply detects and receives on the fan by fan swicth, commutation, be connected to the photoelectricity isolated serial port on the single-chip microcomputer of fan control module and constitute, byserial ports 1 and intelligent battery management system host communication.

The present invention has following advantage compared to existing technology:

In native system, we adopt Ni-MH battery to replace traditional ickel-cadmium cell.Now the Ni-MH battery capacity that adopts is original 1/2nd, and weight is original 1/4th, and volume is original 1/3rd.By this improvement, increased the useful space of vehicle, alleviated weight, improved capacity usage ratio, reduced cost, more energy-saving and environmental protection.

Management system can guarantee that battery does not overcharge, not overdischarge, be no more than the nominal operation temperature, when unbalanced degree acquires a certain degree between battery, in time reminds the user that battery is safeguarded, guarantees that battery works under suitable state.

Description of drawings

Fig. 1 septum primum nickel-based battery group management system schematic diagram;

Fig. 2 AGV power train in vehicle application systematic schematic diagram (battery charge and discharge), wherein dotted line inside is divided into nickel-hydrogen battery management system for electric vehicle figure;

Fig. 3 intelligent battery management system main frame theory diagram;

Fig. 4 intelligent battery management system mainframe program flow chart;

Fig. 5 capacity check instrument schematic diagram;

Fig. 6 voltage, temperature detecting module theory diagram;

Fig. 7 fan control module schematic diagram.

Embodiment

Please refer to Fig. 2 AGV power train in vehicle application systematic schematic diagram (battery charge and discharge), in the dotted line wherein is nickel-hydrogen battery management system for electric vehicle figure, its nickel-hydrogen battery management system for electric vehicle is connected with cell voltage, the temperature detecting module that detects cell voltage variation and temperature height by intelligent battery management system main frame, fan opens, stop controlling and the fan control module of state-detection, and the capacity check instrument of battery charging and discharging capacity constitutes.Battery management system information is sent to dispatching by AGV control computer, the operation of dispatching control charger, AGV car;

Please refer to Fig. 3 intelligent battery management system main frame theory diagram, intelligent battery management system main frame is the mainboard that a single-chip microcomputer constitutes, be connected to serial ports 2, data storage, the clock ofserial ports 1, the connection capacity detecting instrument of cell voltage, temperature detecting module and fan control module, the RS232 serial ports of download alarm logging information, transmit the digital quantity interface of information to AGV control computer;

Single-chip microcomputer is byserial ports 1 and cell voltage, temperature detecting module, fan control module communication, obtains the information such as voltage, temperature, fan of battery; By serial ports 2 and the communication of capacity check instrument, obtain charge/discharge capacity, battery SOC information, please refer to Fig. 4 intelligent battery management system mainframe program flow chart, by comprehensive judgement and analysis to these information, judge whether battery, charging have fault, judge whether battery needs to safeguard, judges the residing state of battery, again by these information being passed to AGV control computer, so that AGV control computer is handled it with switching value (digital quantity output) communication of AGV control computer.When warning message, main frame deposits warning message and time of being taken place in data storage, in order to inquiry.The user can download warning message with computer by 232 interfaces, is convenient to analyze.

The interface signal of single-chip microcomputer and AGV control computer is as follows:

State to the report of vehicle-mounted control computer has 5, corresponding 5 relays.

1), the 1-3 relay represents charge/discharge capacity, is set by the user the charge/discharge capacity value (percentage) of each relay correspondence, during discharge, this relay disconnects when battery capacity is lower than the set point of certain relay; During charging, when battery capacity this relay closes during greater than the set point of certain relay;

2), No. 4 relays are represented the maintaining of battery palpus.Because of battery can cause the SOC of each battery unbalanced after use a period of time, the continuation use can cause overcharging of battery or cross puts, and shortens the useful life of battery.Management system when confirming that battery need be safeguarded, provides maintenance signal by after the informixs such as voltage difference between cell voltage, temperature, SOC, the battery are judged, notifies the operations staff that battery is safeguarded.

3), No. 5 relays represent battery failures, this relay closes when battery management system is found the system failure, notice vehicle-mounted control computer battery needs repairing.Send fault-signal when following situation takes place: cell voltage is too high, battery temperature is too high, cell voltage is low excessively, fan failure.After receiving this signal, should stop battery charge immediately or safeguard charging in battery charge or during safeguarding.

Please refer to Fig. 5 capacity check instrument schematic diagram, the capacity check instrument is obtained battery charge, puts dot information, is adjusted to suitable amplitude through the shunt voltage signal and delivers to the voltage-frequency conversion by the battery shunt, deliver to after the voltage-frequency conversion is converted to frequency to voltage signal on the single-chip microcomputer (battery capacity metering), single-chip microcomputer is connected to AGV control computer communication serial ports and display unit and constitutes;

The capacity check instrument is responsible for detecting the charge/discharge capacity of battery, shows this charging capacity and the current SOC of battery during charging; During discharge, show the capacity and the current SOC of battery that emit.By light-emitting diode indicating instrument current state.Instrument is by serial ports and the communication of AGV control computer, information such as transfer capacity, SOC.The capacity check instrument has two buttons, is used for being provided with the instrument parameter.

Following parameters can be set:

Battery capacity; 1-500AH

Charging coefficient; 1000 (fixed values)

Charge value RELAY1,1-100%, when RELAY1 value (charge value＞closure);

Charge value RELAY2,1-100%, when RELAY2 value (charge value＞closure);

Charge value RELAY3,1-100%, when RELAY3 value (charge value＞closure);

Place value RELAY1,1-100%, when RELAY1 value (place value＜disconnect);

Place value RELAY2,1-100%, when RELAY2 value (place value＜disconnect);

Place value RELAY3,1-100%, when RELAY3 value (place value＜disconnect).

Annotate: RELAY1 value＞RELAY2 value＞RELAY3 value

Please refer to Fig. 6 voltage, temperature detecting module theory diagram, cell voltage, temperature detecting module by five road battery voltage signals nurse one's health, behind the analog signal Port Multiplier, A/D analog-to-digital conversion interface serial connection, be connected on the single-chip microcomputer, single-chip microcomputer is connected to No. five temperature sensors, the photoelectricity isolated serial port constitutes.

Voltage, temperature detecting module are installed in the battery case place near battery, and the voltage and the temperature of each monocell of battery pack detected, and pass to the management system main frame by serial ports.Detection module satisfies following technical indicator:

Voltage detecting precision: 1%;

Reference voltage detection: 0-2.5VDC;

Temperature detecting precision: 0.5 degree;

Temperature detection scope :-40-120 degree.

Each module detects the voltage and the temperature of five batteries, and each module of N can detect the voltage and the temperature of 5*N piece battery, and intermodule is by the isolated serial port cascade and link mainboard, can detect 256 batteries at most.

Please refer to Fig. 7 fan control module schematic diagram, the single-chip microcomputer of fan control module is connected to fan swicth, commutation detects, and fan power supply detects and receives on the fan by fan swicth, commutation, is connected to the photoelectricity isolated serial port on the single-chip microcomputer of fan control module and constitutes.

Because of battery pack needs fan for cooling, so fan control module is set.Its function has: fan start and stop control and fan failure are reported to the police.Fan control module is subjected to host computer control by serial ports and management system host communication.Open fan during battery charge, open fan when battery temperature is spent greater than 35, during operation, temperature is lower than 32 degree and then closes fan; When fan hinders when stopping operating for some reason, fan control module sends warning message to main frame.

Mainboard sends instruction by serial ports to fan control module, the start and stop of control fan.Single-chip microcomputer is by the mains switch control fan of control fan.Series connection one testing circuit on the fan power supply line, the current impulse when detecting the DC fan commutation is introduced single-chip microcomputer with pulse, uses the single-chip microcomputer pulse count, can detect rotation speed of the fan, thereby judge whether fan is normal, and send to mainboard by serial ports.

With specific embodiment its management process is described below:

1, in the battery charging process, when voltage, temperature detecting module detect the voltage of battery or temperature and surpass alarming value, by serial ports information is passed to the management system main frame, after main frame is received alarm signal, closed alarm relay sends warning message to car-mounted computer, and car-mounted computer is by wireless signal notice control computer, the control computer is the charge closing machine immediately, notifies the operator on duty that battery pack is overhauled simultaneously.

2, vehicle is in running, when the voltage that detects battery when voltage, temperature detecting module is lower than alarming value, by serial ports information is passed to the management system main frame, after main frame is received alarm signal, closed alarm relay sends warning message to car-mounted computer, and car-mounted computer is by wireless signal notice control computer, the control computer stops vehicle operating, notifies the operator on duty that battery pack is overhauled simultaneously.

3, when the fan detection module detects fan failure, by serial ports information is passed to the management system main frame, after main frame was received alarm signal, closed alarm relay sent warning message to car-mounted computer, car-mounted computer is by wireless signal notice control computer, as charging this moment, the control computer is the charge closing machine immediately, moves as vehicle, then out of service, notify the operator on duty that battery pack is overhauled simultaneously.

4, in running, motherboard is by analyzing, the unbalanced degree of battery has reached the degree that needs maintenance, the main frame closure is safeguarded relay, send maintenance information to car-mounted computer, car-mounted computer is by wireless signal notice control computer, and the control computer notifies the operator on duty as early as possible battery pack to be safeguarded.

5, vehicle normal course of operation: during vehicle operating, battery is emitted energy gradually, capacity measurement instrument real time record discharge capacity and residue SOC, and send to the management system mainboard by serial ports, mainboard compares SOC value of battery and each the capacity relay capacity corresponding set point of receiving, when being lower than certain set point, corresponding capacity relay disconnects, after three capacity relays all disconnect, show that battery needs charging.In the running, " the real state of gathering mainboard capacity relay when holding computer; and the time the real main control computer that sends to; when main control computer is received the state that three capacity relays all disconnect; main control computer sends dispatch command to vehicle; vehicle is transferred to charge position, and detects the state of charger.After charger is ready to charging, send charging instruction to charger, charger starts, to battery charge, this moment, capacity measurement instrument record filled the into capacity of battery and the SOC of battery, and sending to mainboard, same mainboard is the real main control computer of passing to during with the capacity relay status by car-mounted computer.After battery was full of electricity, charger stopped charging, and sent charging completion signal to the control computer, and the control computer sends instruction, disconnects charger, and dispatched buses and enter new round operation.

Native system reaches design object fully through field test.Behind the each run 50 minutes, the charging interval, cell voltage, temperature detecting precision reached requirement within 8 minutes, battery capacity metering accurately, battery failures is reported to the police, the battery maintenance signal can be correctly, in time send.Through the field test of some months, affirmation can guarantee that battery moves under kilter.

Claims (2)

1. nickel-hydrogen battery management system for electric vehicle, it is characterized in that: its nickel-hydrogen battery management system for electric vehicle is connected with cell voltage, the temperature detecting module that detects cell voltage variation and temperature height by intelligent battery management system main frame, fan opens, stop controlling and the fan control module of state-detection, the capacity check instrument of battery charging and discharging capacity constitutes

Intelligent battery management system main frame is a single-chip microcomputer, be connected to serial ports 2, data storage, the clock of serial ports 1, the connection capacity detecting instrument of cell voltage, temperature detecting module, the RS232 serial ports of download alarm logging information, transmit the digital quantity interface of information to AGV control computer;

After the capacity check instrument is connected in series successively by battery shunt, the adjustment of shunt voltage signal, voltage-frequency conversion, be connected on the single-chip microcomputer of capacity check instrument, single-chip microcomputer is connected to AGV control computer communication serial ports and display unit and constitutes, by serial ports 2 and intelligent battery management system host communication;

Cell voltage, temperature detecting module by five road battery voltage signals nurse one's health, after analog signal Port Multiplier, A/D analog-to-digital conversion interface be connected in series successively, be connected on the single-chip microcomputer of cell voltage, temperature detecting module, single-chip microcomputer is connected to No. five temperature sensors, the photoelectricity isolated serial port constitutes, by serial ports 1 and intelligent battery management system host communication, voltage, temperature detecting module are installed in the place of close battery in the battery case.

2. a kind of nickel-hydrogen battery management system for electric vehicle as claimed in claim 1, it is characterized in that: intelligent battery management system main frame is connected to fan control module, the single-chip microcomputer of fan control module is connected to fan swicth, commutation detects, fan power supply detects and receives on the fan by fan swicth, commutation, be connected to the photoelectricity isolated serial port on the single-chip microcomputer of fan control module and constitute, by serial ports 1 and intelligent battery management system host communication.

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