CN205589009U - Electric vehicle battery management device - Google Patents

Abstract

The utility model provides an electric vehicle battery management device, including a DSP controller, and modules such as voltage acquisition, current acquisition, temperature acquisition, battery equalization and GPS/GPRS connected to the DSP controller; wherein, the DSP controller consists of a DSP chip And its peripheral circuit is formed; the voltage acquisition module includes controllable switches S1, S2, S3, S4, and capacitor C, the first A/D converter and the first single-chip MCU; the current acquisition module includes Hall current sensors connected in sequence , the second A/D converter and the second single-chip MCU; the temperature acquisition module includes digital temperature sensors connected in sequence and the third single-chip MCU; the battery equalization module includes a plurality of equalization units connected in parallel with the battery cells, and the equalization units are It includes a resistor R and a balance switch K. The utility model is implemented to overcome the difficulty and inaccurate measurement of the battery parameters of the electric vehicle, which leads to the inability of the electric vehicle to replenish the electric quantity in time, and improve the service life of the battery.

Description

Electric vehicle battery management device

technical field

The utility model relates to the technical field of electric vehicle battery management, in particular to an electric vehicle battery management device.

Background technique

Battery management technology is a very important technology to ensure the safety of electric vehicles and improve the efficiency of energy use. The battery management device accurately estimates the remaining power of the power battery pack by accurately measuring various important parameters of the system, including remaining capacity, charge and discharge current, terminal voltage and temperature, so as to ensure the battery life of the electric vehicle and prevent overcharging and overdischarging of the battery. Ensure the safety of the vehicle and prolong the service life of electric vehicle batteries.

The inventors found that existing battery management devices have deficiencies, which are: 1. Common mode, differential mode and V/F methods are usually used for the terminal voltage of the storage battery, but the common disadvantage of these methods is that they cannot Effectively isolate the battery pack (strong current) from the vehicle electrical system (weak current), and there are a large number of series-parallel batteries on the electric vehicle, and the resistors, operational amplifiers and other devices used for voltage measurement are prone to deviation due to the influence of temperature and resistance accuracy; 2. The current detection of the battery is usually an indirect measurement method represented by the sampling resistance method, but this method needs to connect the sampling resistance in series with the main power circuit, which cannot be isolated from the control circuit, and is not suitable for the battery management device; 3. Because the temperature inside the battery is usually difficult to measure, it is usually replaced by detecting the ambient temperature of the battery operating place. The commonly used temperature detection method is to detect by thermocouples and thermal resistance sensors. Both thermocouples and thermal resistance sensors are easily affected by the place of use It is limited and has the disadvantage of large heat conduction error, which will cause deviations in temperature detection; 4. Traditional automotive battery management devices often only focus on real-time detection of battery parameters, while ignoring the battery’s requirements for balance. In order to meet power requirements, Electric vehicles need to use multiple single cells in series and parallel. Due to the inconsistency of each single cell, using them in groups will bring hidden dangers in terms of performance, life and safety.

Contents of the invention

The technical problem to be solved by the embodiments of the utility model is to provide a battery management device for electric vehicles, which overcomes the difficulty and inaccurate measurement of battery parameters of electric vehicles, which leads to the inability of electric vehicles to replenish power in time, and improves the service life of batteries.

The embodiment of the utility model provides an electric vehicle battery management device, including a DSP controller, and a voltage acquisition module, a current acquisition module, a temperature acquisition module, a battery equalization module and a GPS/GPRS module connected to the DSP controller ;in,

The DSP controller is formed by a DSP chip and its peripheral circuits;

The voltage acquisition module includes a controllable switch S1, a controllable switch S2, a controllable switch S3, a controllable switch S4, and a capacitor C, a first A/D converter and a first single-chip microcomputer MCU; wherein, the controllable switch S1 and One end of the controllable switch S2 is connected in parallel to the battery pack, and the other end is connected in parallel to the capacitor C; one end of the controllable switch S3 and the controllable switch S4 are connected in parallel to the capacitor C, and the other end is connected to the first A/ On the D converter; the controllable switch S1, the controllable switch S2, the controllable switch S3, the controllable switch S4 and the first A/D converter are also respectively connected to the first single-chip MCU through a control line; The current acquisition module includes a Hall current sensor, a second A/D converter, and a second single-chip MCU connected in sequence; wherein, the Hall current sensor is connected in series between the battery pack and the load;

The temperature acquisition module includes a DS18B20 digital temperature sensor and a third single-chip MCU connected in sequence; wherein, the DS18B20 digital temperature sensor is placed close to the battery pack;

The battery balancing module includes a plurality of balancing units, and each balancing unit is connected in parallel with a battery cell, and each balancing unit includes a resistor R and a balancing switch K; wherein, each balancing switch K is It is driven by PWM signal to realize closing or opening.

Wherein, the voltage acquisition module, the current acquisition module, the temperature acquisition module, the battery balance module and the GPS/GPRS module are all connected to the DSP controller through the internal communication CAN bus.

Wherein, when the first single-chip microcomputer MCU controls both the controllable switch S1 and the controllable switch S2 to be closed, the storage battery pack is implemented to charge the capacitor C; when the first single-chip microcomputer MCU controls the controllable switch When both the controllable switch S3 and the controllable switch S4 are closed, both the controllable switch S1 and the controllable switch S2 are further controlled to be turned off, so as to realize the voltage collection of the battery pack.

Wherein, the Hall current sensor includes a magnetic core, a Hall element, and a conductor; wherein, the conductor is connected in series between the load and the battery; the magnetic core is sleeved on the outer surface of the conductor, and connected to the The Hall element performs magnetic induction; the Hall element is connected to the second A/D converter.

Implementation of the utility model embodiment has the following beneficial effects:

The voltage, current and temperature detection devices are used to detect the parameters of the electric vehicle battery in real time, to realize the accurate measurement of the remaining capacity of the battery, the internal temperature of the battery, the terminal voltage of the battery and the charging and discharging current, and to accurately estimate the remaining power of the electric vehicle battery to ensure the safety of the electric vehicle Endurance, while preventing overcharge and overdischarge of the battery, ensuring the safety of the vehicle and prolonging the service life of the battery of the electric vehicle.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the present utility model. For those skilled in the art, obtaining other drawings based on these drawings still belongs to the scope of the present utility model without any creative effort.

Fig. 1 is a system structure connection block diagram of an electric vehicle battery management device in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the circuit connection structure of the voltage acquisition module in Fig. 1;

Fig. 3 is the graph of the voltage change curve of charging the capacitor C by the voltage acquisition module in Fig. 2;

Fig. 4 is a schematic diagram of the circuit connection structure of the current acquisition module in Fig. 1;

FIG. 5 is a schematic diagram of the working principle of the Hall current sensor in the current acquisition module in FIG. 4;

Fig. 6 is a schematic diagram of the circuit connection structure of the temperature acquisition module in Fig. 1;

FIG. 7 is a schematic diagram of the circuit connection structure of the battery balancing module in FIG. 1;

Fig. 8 is a schematic diagram of a topological structure of an electric vehicle battery management device and an electric vehicle intelligent charging network in an embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figures 1 to 8, in the embodiment of the utility model, a battery management device for an electric vehicle is provided, including a DSP controller 1, and a voltage acquisition module 2 and a current acquisition module connected to the DSP controller 1 3. Temperature acquisition module 4, battery equalization module 5 and GPS/GPRS module 6; wherein,

DSP controller 1 is formed by a DSP chip and its peripheral circuits;

The voltage acquisition module 2 includes a controllable switch S1, a controllable switch S2, a controllable switch S3, a controllable switch S4, and a capacitor C, a first A/D converter and a first single-chip MCU; wherein, the controllable switch S1 and the controllable switch One end of the control switch S2 is connected in parallel to the battery pack, and the other end is connected in parallel to the capacitor C; one end of the controllable switch S3 and the controllable switch S4 are connected in parallel to the capacitor C, and the other end is connected to the first A/D converter; The switch S1, the controllable switch S2, the controllable switch S3, the controllable switch S4 and the first A/D converter are also respectively connected to the first single-chip microcomputer MCU through the control line;

The current acquisition module 3 includes a Hall current sensor, a second A/D converter and a second single-chip MCU connected in sequence; wherein the Hall current sensor is connected in series between the storage battery pack and the load;

The temperature acquisition module 4 includes a DS18B20 digital temperature sensor and a third single-chip MCU connected in sequence; wherein, the DS18B20 digital temperature sensor is placed close to the battery pack;

The battery balancing module 5 includes a plurality of balancing units, and each balancing unit is connected in parallel with a battery cell, and each balancing unit includes a resistor R and a balancing switch K; wherein, each balancing switch K is controlled by a PWM signal Drive to achieve closing or opening.

It should be noted that the voltage acquisition module 2, the current acquisition module 3, the temperature acquisition module 4, the battery equalization module 5 and the GPS/GPRS module 6 are all connected to the DSP controller 1 through the internal communication CAN bus

In the embodiment of the present utility model, the voltage detection module 2, the current detection module 3, and the temperature detection module 4 are responsible for detecting the parameters of the storage battery to estimate the remaining capacity of the battery, and the battery equalization module 5 is used to balance inconsistent batteries to improve battery life. service life. In the GPS/GPRS module 6, GPS is used to locate the location of the car, and GPRS is used to contact the monitoring center, which also enables the system to automatically search for the charging station with the closest distance and the shortest online queuing time when the remaining power is insufficient, and charge it. In order to ensure battery life; in the event of an electric vehicle failure, it is also possible to get in touch with the monitoring center through the GPS/GPRS module 6, and send the current location information to the monitoring center

As shown in Figure 2, one I/O port of the first single-chip microcomputer MCU is connected to the controllable switch S1 and the controllable switch S2, and the other I/O port is connected to the controllable switch S3 and the controllable switch S4. The single-chip MCU can control the closing or opening of the controllable switches S1 to S4. When the first single-chip microcomputer MCU controls both the controllable switch S1 and the controllable switch S2 to close, the storage battery pack charges the capacitor C, as shown in Figure 3, which is a typical charging curve of the capacitor C; when the first single-chip microcomputer MCU controls the controllable switch S3 When both the controllable switch S4 and the controllable switch S4 are closed, the controllable switch S1 and the controllable switch S2 are further controlled to be disconnected, so as to realize the voltage collection of the battery pack, that is, complete a voltage collection task.

As shown in Figure 4, the Hall current sensor of the current detection module 3 is connected in series between the battery and the load, and the second single-chip MCU processes the data sent by the second A/D converter to complete the conversion from analog to digital.

As shown in Figure 5, the Hall current sensor includes a magnetic core, a Hall element and a conductor; wherein, the conductor is connected in series between the load and the battery; the magnetic core is sleeved on the outer surface of the conductor, and is connected with the Hall element. Magnetic induction; the Hall element is connected to the second A/D converter.

When in use, the conductor is connected in series between the load and the battery, and the Hall element is connected to the second A/D converter. When a current flows through the conductor, a magnetic field will be generated due to electromagnetic induction, and the magnetic field will gather on the magnetic core. Through the Hall effect of the Hall element, the flowing current will be converted into a voltage signal and sent to the A/D converter. The processing of the second single-chip MCU completes the collection of current. The Hall current sensor is a sensor that uses the Hall effect to convert the primary current into a secondary voltage signal.

As shown in Figure 6, the temperature detection module 4 includes a digital temperature sensor DS18B20 and a third single-chip MCU; the DS18B20 temperature sensor has the characteristics of small size, low hardware overhead, strong anti-interference ability and high precision. And it does not need any peripheral components in use, only one port line is needed to realize the two-way communication between the microprocessor and DS18B20.

As shown in FIG. 7 , the battery balancing module 5 includes a plurality of balancing units, wherein each balancing unit includes a balancing switch K and a resistor, such as balancing switches K1 to Kn and resistors R1 to Rn. The balance switch is driven by the PWM signal, and ic is the charge and discharge current. Each single battery has a balance control unit composed of a balance switch K and a balance resistor R corresponding to it. The charge and discharge current and the balance current of the single battery are respectively for ib and ie.

If there is no balancing circuit, then the current flowing through the battery is ic. After adding the balancing circuit, the current flowing through the battery is ib, and the current flowing through the balancing resistor is ie. The relationship between them is:

ib=ic-ie

By controlling the closing of the equalization switch K, the magnitude of the equalization current ie can be controlled, so that the magnitude of the current ib actually flowing through the battery can be controlled. By this method, it is possible to perform differentiated charging and discharging for inconsistent single cells, thereby ensuring The equalization of each single battery eliminates the impact of the inconsistency of the single battery on the performance of the battery pack during battery use.

As shown in Figure 8, the electric vehicle smart charging network mainly includes GPS satellites, GPRS wireless signal towers, monitoring centers and charging stations. Through networking, the battery management device can automatically find the charging station with the closest distance and the shortest online queuing time when the remaining power is insufficient, and charge it to ensure battery life; it can also use GPS/GPRS when the electric vehicle fails. Module 6 gets in touch with the monitoring center, and sends the current location information to the monitoring center.

Implementation of the utility model embodiment has the following beneficial effects:

The voltage, current and temperature detection devices are used to detect the parameters of the electric vehicle battery in real time, to realize the accurate measurement of the remaining capacity of the battery, the internal temperature of the battery, the terminal voltage of the battery and the charging and discharging current, and to accurately estimate the remaining power of the electric vehicle battery to ensure the safety of the electric vehicle Endurance, while preventing overcharge and overdischarge of the battery, ensuring the safety of the vehicle and prolonging the service life of the battery of the electric vehicle.

What is disclosed above is only a preferred embodiment of the utility model, and of course it cannot limit the scope of rights of the utility model. Therefore, equivalent changes made according to the claims of the utility model still fall within the scope of the utility model.

Claims (4)

1. an electric vehicle battery management device, is characterized in that, comprises DSP controller (1), and the voltage acquisition module (2) that all links to each other with described DSP controller (1), current acquisition module (3), temperature Acquisition module (4), battery equalization module (5) and GPS/GPRS module (6); Wherein, The DSP controller (1) is formed by a DSP chip and its peripheral circuits; The voltage acquisition module (2) includes a controllable switch S1, a controllable switch S2, a controllable switch S3, a controllable switch S4, and a capacitor C, a first A/D converter and a first single-chip MCU; wherein the controllable One end of the switch S1 and the controllable switch S2 are connected in parallel to the battery pack, and the other end is connected in parallel to the capacitor C; one end of the controllable switch S3 and the controllable switch S4 are connected in parallel to the capacitor C, and the other end is connected to the capacitor C. On an A/D converter; the controllable switch S1, the controllable switch S2, the controllable switch S3, the controllable switch S4 and the first A/D converter also communicate with the first single-chip microcomputer through the control line respectively MCU connected; The current acquisition module (3) includes a Hall current sensor, a second A/D converter, and a second single-chip MCU connected in sequence; wherein, the Hall current sensor is connected in series between the storage battery pack and the load; The temperature acquisition module (4) includes a DS18B20 digital temperature sensor and a third single-chip MCU connected in sequence; wherein, the DS18B20 digital temperature sensor is placed close to the battery pack; The battery balancing module (5) includes a plurality of balancing units, and each balancing unit is connected in parallel with a battery cell, and each balancing unit includes a resistor R and a balancing switch K; wherein, each balancing The switches K are all driven by PWM signals to be closed or opened. 2. The electric vehicle battery management device according to claim 1, characterized in that, the voltage acquisition module (2), current acquisition module (3), temperature acquisition module (4), battery equalization module (5) and GPS The /GPRS modules (6) are all connected to the DSP controller (1) through the internal communication CAN bus. 3. The electric vehicle battery management device according to claim 1, wherein when the first single-chip microcomputer MCU controls both the controllable switch S1 and the controllable switch S2 to be closed, the storage battery pack is The capacitor C is charged; when the first single-chip MCU controls both the controllable switch S3 and the controllable switch S4 to be closed, and further controls the controllable switch S1 and the controllable switch S2 to be turned off , realizing the voltage acquisition of the storage battery pack. 4. The electric vehicle battery management device according to claim 1, wherein the Hall current sensor comprises a magnetic core, a Hall element and a conductor; wherein the conductor is connected in series between the load and the battery; the The magnetic core is sleeved on the outer surface of the conductor, and performs magnetic induction with the Hall element; the Hall element is connected to the second A/D converter.