CN202486293U - Electric vehicle power detection device - Google Patents

Abstract

The utility model discloses a power detecting device for an electric car. The power detecting device for the electric car comprises a sensor, a polarity conversion unit and a power displaying unit, wherein the sensor is used for measuring the current passing from an anode end of a battery of the electric car to a ground end, and outputting an analog voltage signal in proportion to the current magnitude to the polarity conversion unit; the output analog voltage signal is a positive voltage analog signal during charging, and the output analog voltage signal is a negative voltage analog signal during discharging; the polarity conversion unit is used for converting the measured negative analog voltage signal into the positive analog voltage signal and then outputting to the power displaying unit; and the power displaying unit is used for processing and operating the voltage signal and displaying the current condition of the power of the electric car. The power detecting device in the utility model has a compact structure, and is rationally designed; some parts are arranged by connecting, therefore, the relatively accurate real-time power of the electric car can be obtained, which enables users to use easily; meanwhile, the power detecting device has the function of manually discharging, thus, the convenience of further measuring accurate power is provided.

Description

Electric vehicle power detection device

technical field

The utility model relates to the technical field of electric vehicle measurement and control, in particular to an electric vehicle power detection device. the

Background technique

At present, the electric vehicle power display used in the market generally uses the output voltage change of the battery to judge the power of the battery. Because the discharge voltage of the battery is related to the discharge current, that is, the discharge voltage of the battery changes with the discharge load, because the load unit works When the battery has enough power, the voltage will be high, and if the power is low, the voltage will be low. When the load unit is not working, the voltage is virtual. Therefore, this method cannot accurately reflect the battery power. the

To sum up, it is necessary to invent a device that can realize real-time detection of electric vehicle power. The detection result is relatively accurate and can provide necessary help for the use of the vehicle owner. the

Utility model content

In view of this, the purpose of the utility model is to provide an electric vehicle power detection device which is simple in structure, easy to install, and can provide real-time power of the electric vehicle more accurately. the

The purpose of this utility model is achieved by the following technical solutions:

This kind of electric vehicle power detection device includes a sensor, a polarity conversion unit and a power display unit;

The sensor is used to measure the current flowing from the negative terminal of the electric vehicle battery to the ground terminal, and output an analog voltage signal proportional to the magnitude of the current to the polarity conversion unit. When charging, the output is a positive voltage analog signal, and when discharging, the output is negative. Voltage analog signal, the polarity conversion unit is used to convert the measured negative analog voltage signal into positive and output to the power display unit, the power display unit processes and calculates the voltage signal and displays the current power status of the electric vehicle. the

Further, the device also includes a manual discharge unit, the manual discharge unit includes a discharge control switch, one end of the discharge control switch is connected to the positive pole of the electric vehicle battery, and the other end is connected to the ground after a discharge resistor is connected in series. the

Further, a voltmeter for indicating the discharge voltage is connected in parallel with the discharge resistor. the

Further, a follower circuit is provided between the polarity conversion unit and the power display unit. the

Further, the sensor is a balanced Hall current sensor. the

The beneficial effects of the utility model are:

The utility model has a relatively compact structure and a reasonable design. By connecting and arranging several parts, a more accurate real-time power of the electric vehicle can be obtained, which is beneficial to the use of the car owner; at the same time, the utility model has a manual discharge function, which provides a convenient way for further measuring the accurate power. convenient. the

Other advantages, objectives and features of the present utility model will be set forth in the following description to some extent, and to some extent, based on the investigation and research below, it will be obvious to those skilled in the art, or can be Get teaching from the practice of the utility model. The objectives and other advantages of the utility model can be realized and obtained by the following description and claims. the

Description of drawings

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

Fig. 1 is the module connection schematic diagram of the present utility model;

Fig. 2 is a schematic diagram of connection in use of the utility model. the

Detailed ways

Preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the utility model, rather than limiting the protection scope of the utility model. the

As shown in the figure, the electric vehicle power detection device of the present utility model is used for the power detection of the vehicle-mounted battery of the electric vehicle. The positive pole of the vehicle-mounted battery is generally connected with the charger and the electric unit of the whole vehicle, and the negative pole can be regarded as connected to the public ground terminal; The utility model includes a sensor 1, a polarity conversion unit 2 and a power display unit 3; wherein,

Sensor 1 is used to measure the current flowing from the negative terminal of the electric vehicle battery to the ground terminal, and output an analog voltage signal proportional to the current to the polarity conversion unit 2. The output is a positive voltage analog signal when charging, and the output is negative when discharging. Voltage analog signal, polarity conversion unit 2 is used to convert the measured negative analog voltage signal into positive and output to the power display unit 3, the power display unit processes and calculates the voltage signal and displays the current power status of the electric vehicle. In this embodiment, the sensor is a balanced Hall current sensor. the

As a further improvement, a follower circuit is provided between the polarity conversion unit 2 and the power display unit 3, and the follower circuit includes an operational amplifier U2, and the non-inverting terminal of U2 is used as the signal input terminal and the signal output terminal of the polarity conversion unit The inverting terminal of U2 is connected with the output terminal, and its output terminal is connected with the signal input terminal of the power display unit. By setting the follower circuit, the characteristics of high input impedance and low output impedance can be used to improve measurement accuracy and load capacity. the

As a further improvement, the device also includes a manual discharge unit, the manual discharge unit includes a discharge control switch K1, one end of the discharge control switch K1 is connected to the positive pole of the electric vehicle battery, and the other end is connected in series with a discharge resistor R1 and then grounded. A voltmeter V1 for indicating the discharge voltage is connected in parallel with the resistor R1. the

The working principle of the utility model is as follows:

Charging process: when the charger charges the battery, a charging current I2 (set as I _2a ) flows through the balanced Hall current sensor, and the current sensor outputs a positive analog voltage signal proportional to the current to the signal polarity conversion circuit. The signal polarity conversion circuit keeps the polarity unchanged, and then sends it to the power display unit through U2, and the power display unit counts the current value. When the charging current I2 changes (set as I _2b ), the timing of the previous period is t ₁ , timing I _2b again...;

When the charger fully charges the battery, that is, the output voltage of the current sensor is close to zero (the minimum current calibration of the charger fully charging the battery), the total charge Q _charge = t ₁ ×I _2a +t ₂ × I _2b ...+t _n ×I _2n ;

Discharging process: I1 is the current flowing through the battery when using electricity. When the vehicle has a useful electric current I1 (set as I _1a ), I _1a flows through a balanced Hall current sensor, and the output of the current sensor is proportional to the current The negative analog voltage signal is sent to the signal polarity conversion circuit, and the signal polarity conversion circuit changes the polarity to positive, and then sends it to the power display part through the follower U2, and the power display part counts the current value, and the total power discharged _Qdischarge =t ₁ ×I _1a +t ₂ ×I _1b ...+t _n ×I _1n ; thus the remaining power Q= _Qcharge -Qdischarge is _obtained .

If the vehicle is idle for a long time, the battery will self-discharge, which will change the original remaining power. At this time, manually discharge through the discharge control switch K1, discharge resistor R1, and voltmeter V1. When it reaches the displayed voltage of V1 It is 10.5n (V), and n is the number of batteries. At this time, charge E1 to get accurate battery power. In turn, the mileage that the vehicle can complete at a certain set speed can be calculated at the current power level. the

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present utility model without limitation. Although the utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the utility model can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions shall be covered by the claims of the present utility model. the

Claims (5)

1. Electric vehicle power detection device, characterized in that: the electric vehicle power detection device includes a sensor, a polarity conversion unit and a power display unit; The sensor is used to measure the current flowing from the negative terminal of the electric vehicle battery to the ground terminal, and output an analog voltage signal proportional to the magnitude of the current to the polarity conversion unit. When charging, the output is a positive voltage analog signal, and when discharging, the output is negative. Voltage analog signal, the polarity conversion unit is used to convert the measured negative analog voltage signal into positive and output to the power display unit, the power display unit processes and calculates the voltage signal and displays the current power status of the electric vehicle. 2. The electric vehicle power detection device according to claim 1, characterized in that: the device also includes a manual discharge unit, the manual discharge unit includes a discharge control switch, one end of the discharge control switch is connected to the electric vehicle The positive pole of the battery is grounded after connecting a discharge resistor in series with the other end. 3. The electric vehicle power detection device according to claim 2, wherein a voltmeter for indicating the discharge voltage is connected in parallel with the discharge resistor. 4. The electric vehicle power detection device according to claim 1, wherein a follower circuit is arranged between the polarity conversion unit and the power display unit. 5. The electric vehicle power detection device according to claim 1, wherein the sensor is a balanced Hall current sensor.

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