TWI613456B - Electric Quantity Display System For Electric Vehicles - Google Patents

Abstract

The invention relates to a power display system for an electric vehicle, which provides a power message according to the following procedure: (A) the power of the battery is turned on, the first timer starts counting; (B) determining whether the timing of the first timer is less than the first The predetermined time, if yes, execute (B1) to read the voltage of the battery, display the power according to the relationship between the open circuit voltage and the power, and then return to (B), if not, execute (C); (C) determine whether the voltage of the battery is greater than Predetermined voltage, if yes, execute (C1) to display the electric quantity 100%, then return to (B), if not, execute (D): (D) the second timer starts counting; (E) judge the load voltage corresponding to the electric quantity relationship table Whether the corresponding power is less than the displayed power, if yes, execute (F), if not, execute (G); (F) determine whether the second timer is greater than the second predetermined time, and if so, execute (F1) to read the battery. The voltage is displayed according to the relationship between the load voltage and the amount of power, and then (G) is executed. If not, the process returns to (E); and (G) the second timer returns to zero, and then returns to (B).

Description

Electric vehicle power display system

The present invention relates to a power display system for an electric vehicle, and more particularly to a power display system suitable for an electric motor vehicle.

Most of the electric vehicles currently on the market use lead-acid batteries as the power source. In addition, the display method of the battery power can be divided into two types: "Battery Management System (BMS)" and "Normal Voltage Display". Electric vehicles with lower selling prices cannot be imported into the battery management system due to cost factors. Only low-cost common voltage display mechanisms can be used to display the information of the remaining battery (SOC: State-of-Charge). For the example of displaying the remaining battery state by ordinary voltage, since the battery has the difference between the load voltage and the open circuit voltage (OCV: Open Circuit Voltage), if only one of the judgment mechanisms is adopted, it is easy to cause the remaining power to be misaligned, not Very ideal.

For example, if the system uses the open circuit voltage as the judgment of the battery's capacity, it is accurate when it is turned on, but after a period of load operation, because of the same battery detection voltage, the open circuit voltage corresponds to the amount of power There must be a lot of power corresponding to the load voltage, so the system's power display device will display an indication lower than the actual remaining power, resulting in less confidence of the rider, resulting in the design can not provide driving while driving. Trust the reference remaining battery (SOC) information.

In addition, if the system uses the load voltage as the judgment of the battery's capacity, but because the remaining power (SOC) information is from 100% to 0%, the relative open circuit voltage segment is larger than the load voltage segment, which is easy to misjudge. Therefore, at the time of power-on, the system's power display device displays high residual power (SOC) information, but after a period of driving, the system's power display device displays low residual power (SOC) information due to the load, which easily leads to the driver's booting. The error message of the time caused the motor car to run out of power, causing inconvenience to the driver. Therefore, the above two conditions are not very satisfactory, and there is still room for improvement.

Because of this, in the spirit of active invention and creation, we have thought of a "electricity display system for electric vehicles" that can solve the above problems, and finally completed the present invention after several research experiments.

The present invention is directed to the improvement of a battery power display device without a built-in battery management system (BMS) design. Generally, the open circuit voltage value obtained when the system is powered on is a reference to the remaining power (SOC) information, especially in In a lead-acid battery, although it is not possible to confirm how long the battery stops outputting in this system, the remaining amount of electricity (SOC) detected at this time is not as high as the so-called open circuit voltage due to the voltage rise, and the remaining power obtained at this time ( SOC) may be underestimated, but because the general Cavaliers will not ride immediately after turning off the system power after a ride, there is a chance to get the correct remaining power (SOC), so the invention realizes the boot in the power display system. When the system is open circuit voltage detection.

In addition, the present invention sets the relationship between the read load voltage and the remaining power (SOC) for the calculation of the remaining power (SOC) at the time of riding, wherein the reading of the updated remaining power (SOC) is not performed until the return voltage is reached. The function of increasing the remaining power (SOC) is to operate the customer without performing a system shutdown when charging. Press, the system only updates the value lower than the current remaining power (SOC) value after a period of power on, so if the rider recharges the power in the state that the system has not been turned off, it will cause The charging completion still cannot be updated to the correct remaining power (SOC). Therefore, the present invention adds a reset voltage (RVC) mechanism. When the system reads that the system voltage exceeds a predetermined voltage, the voltage is greater than the normal open circuit voltage. The maximum value, the predetermined voltage can usually be set when the battery charger is switched from the constant current to the constant voltage transition point (also known as the transition voltage value) as the set reference value of the reset voltage (RVC) to solve this special case. .

For the above purpose, the electric quantity display system of the electric vehicle of the present invention comprises: a battery, a voltage detecting unit for detecting the battery, two timers, a display unit, an electrically connected battery, a voltage detecting unit, The control chip of the two timers and the display unit, the control chip stores a relationship table of the open circuit voltage corresponding to the battery and a relation table of the load voltage of the battery.

Controlling the chip and providing a message to the display unit to display the battery power according to the following actuation process: (A) the battery power is turned on, the first timer starts counting; (B) determining whether the first timer is less than a first predetermined time Time, if yes, execute step (B1) to read the voltage of the battery, and the display unit displays the electric quantity according to the relationship table of the open circuit voltage corresponding quantity, and then returns to step (B), if not, execute step (C); (C) Whether the voltage of the battery is greater than a predetermined voltage, if yes, executing step (C1), the display unit displays the power amount of 100%, and then returns to step (B), if not, executing step (D): (D) the second timer starts timing; (E) determining whether the amount of electricity corresponding to the load corresponding to the load voltage is less than the amount of power displayed by the display unit, if yes, executing step (F), if not, executing step (G); (F) determining the second timer Whether the timing is greater than a second predetermined time, if yes, executing step (F1) to read the voltage of the battery, and the display unit displays the power according to the relationship table of the corresponding voltage of the load voltage, and then performing step (G), and if not, returning to the step ( E); and steps Step (G) The second timer is reset to zero, and then returns to step (B).

Therefore, the power display system of the present invention can provide a more accurate battery remaining power, in addition to having a reset voltage (RVC) mechanism and using both the open circuit voltage and the load voltage as the remaining battery power (SOC). Driver's reference.

The first predetermined time may be set to 0.5 seconds or other similar time, and the second predetermined time is 60 seconds or the like.

The predetermined voltage may be a transition voltage value when the battery is switched from a constant current to a constant voltage during charging.

The display unit can be a liquid crystal display device or a pointer meter. The control chip has a digital/analog signal conversion unit. The battery power is displayed on the pointer meter after the digital/analog signal conversion unit.

The above control chip does not have the function of a battery management system (BMS).

10‧‧‧Battery

15‧‧‧Voltage detection unit

20‧‧‧First timer

25‧‧‧ second timer

30‧‧‧Display unit

40‧‧‧Control chip

A, B, B1, C, C1, D, E, F, F1, G‧ ‧ steps

L‧‧‧Load voltage vs. electricity

O‧‧‧ Open circuit voltage corresponding to the relationship between electricity

P‧‧‧Transition voltage value

Figure 1 is a graph showing the relationship between the open circuit voltage and the load voltage of the battery.

Figure 2 is a schematic diagram of charging completion of a battery, switching from a constant current to a constant voltage.

FIG. 3 is a schematic structural diagram of a power display system according to a preferred embodiment of the present invention.

4 is a flow chart according to a power display system in accordance with a preferred embodiment of the present invention.

Please refer to FIG. 1 for the relationship between the open circuit voltage and the load voltage of the battery. The horizontal axis of FIG. 1 is the remaining power of the battery, and the vertical axis is the voltage of the battery, wherein the line O indicates the opening of the battery. The road voltage corresponds to the relationship between the electric quantities, and the line L represents the relationship between the load voltage of the battery and the electric quantity of the battery. The rated voltage of the battery illustrated in Fig. 1 is 14.7 volts. As shown in FIG. 1, when the voltage measured by the battery is the same, the line L indicates that the corresponding remaining power is significantly higher than the remaining power corresponding to the line O.

Please refer to FIG. 2 for the charging of the battery, the charging is completed by the constant current switching to the constant voltage. The charging time of the horizontal axis of the battery in FIG. 2 is the voltage and current respectively, and the line V of FIG. 2 is the voltage variation line. , indicating that the battery increases with time, its voltage increases, when it increases to the transition voltage value P, it will not increase, it will become a constant voltage; in addition, line A is the current change line, indicating that the battery is charged When the time increases, the current system does not increase, it is a constant current. When the battery is fully charged and the line V becomes a constant voltage, the current of the line A will gradually become smaller. Therefore, when the battery is charged, it is mainly divided into two. In the phase, the first half is a constant current and the second half is a constant voltage.

Please refer to FIG. 3 and FIG. 4 , which are respectively a schematic diagram of a power display system and a flow chart according to a power display system according to a preferred embodiment of the present invention. The electric quantity display system of the electric vehicle of the embodiment includes a battery 10, a voltage detecting unit 15 electrically connected to the battery 10, a first timer 20, a second timer 25, a display unit 30 and a control chip. 40. The control chip 40 electrically connects the battery 10, the voltage detecting unit 15, the first timer 20, the first timer 25, and the display unit 30, controls the wafer 40, and stores a relationship table of the open circuit voltage corresponding to the battery 10 and a The load voltage of the battery 10 corresponds to the amount of power. In the present embodiment, the control wafer 40 does not have the function of a battery management system (BMS).

As shown in FIG. 4, the control chip 40 provides a message to the display unit 30 to display the power of the battery 10 according to the following operation flow: in step (A) the power of the battery 10 is turned on, and the first timer 20 starts counting. Next, the step (B) determines whether the timing of the first timer 20 is less than a first predetermined time. If it is less than the first predetermined time, the step (B1) is performed to read the voltage of the battery 10, and the display unit 30 corresponds to the open circuit voltage. Electricity The quantity relationship table shows the remaining power (SOC) of the battery 10, and then returns to step (B); if it is not less than the first predetermined time, step (C) is performed. In this embodiment, the first predetermined time is 0.5 seconds; the display unit 30 is a pointer meter, and the control chip 40 includes a digital/analog signal conversion unit, and the power of the battery 10 is controlled by the digital/analog signal of the control chip 40. The conversion unit is displayed on the pointer meter. In addition, the display unit 30 can also be a liquid crystal display device that directly displays digital information.

Next, the step (C) determines whether the voltage of the battery 10 is greater than a predetermined voltage. If it is greater than a predetermined voltage, the step (C1) is performed to display the remaining power (SOC) of the battery 10 by 100%, and then return to the step (B). If it is not greater than a predetermined voltage, then step (D) is performed. In the present embodiment, the predetermined voltage is the transition voltage value P when the battery 10 is switched from a constant current to a constant voltage when charging.

Then, the second timer 25 of the step (D) starts counting; then, the step (E) determines whether the amount of electric power corresponding to the relationship table of the load voltage corresponding to the electric quantity is smaller than the electric quantity displayed by the display unit 30, and if it is less than the electric quantity corresponding to the load voltage Step (F) is performed for the amount of power corresponding to the relationship table; if it is not less than the amount of power corresponding to the relationship table of the amount of power corresponding to the load voltage, step (G) is performed.

Next, the step (F) determines whether the timing of the second timer 25 is greater than a second predetermined time. If it is greater than the second predetermined time, the step (F1) is performed to read the voltage of the battery 10, and the display unit 30 depends on the load voltage. The corresponding power amount relationship table displays the remaining power (SOC) of the battery 10, and then performs step (G); if it is not greater than the second predetermined time, it returns to step (E). Next, the second timer 25 of step (G) is reset to zero, and then returns to step (B). In this embodiment, the second predetermined time is 60 seconds.

Therefore, the power display system of the present invention can provide a more accurate battery remaining power, in addition to having a reset voltage (RVC) mechanism and using both the open circuit voltage and the load voltage as the remaining battery power (SOC). Driver's reference.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

A, B, B1, C, C1, D, E, F, F1, G‧ ‧ steps

Claims (7)

A power display system for an electric vehicle includes: a battery; a voltage detecting unit electrically connected to the battery; and a second timer including a first timer and a second timer; a display unit; and a control chip, Electrically connecting the battery, the voltage detecting unit, the two timers and the display unit, wherein the control chip stores a relationship table between the open circuit voltage and the power amount of the battery, and a relationship table between the battery and the load voltage corresponding to the battery, the control The chip provides a message to the display unit to display the battery power according to the following actuation process: (A) the battery is powered on, the first timer starts counting; (B) determining whether the first timer is less than one. The first predetermined time, if yes, the step (B1) is performed to read the voltage of the battery, and the display unit displays the electric quantity according to the relationship between the open circuit voltage and the electric quantity, and then returns to the step (B). If not, the step (C) is performed. (C) determining whether the voltage of the battery is greater than a predetermined voltage, if yes, performing step (C1), the display unit displays the power amount of 100%, and then returns to step (B), if not, executing the step (D); (D) the second timer starts counting; (E) determining whether the amount of power corresponding to the load voltage corresponding to the power consumption is less than the amount of power displayed by the display unit, and if yes, performing step (F), if not Step (G) is performed; (F) determining whether the timing of the second timer is greater than a second predetermined time, and if yes, performing step (F1) to read the voltage of the battery, and the display unit corresponding to the load voltage The relationship table displays the power, then step (G) is performed, and if not, returns to step (E); (G) The second timer is reset to zero, and then returns to step (B). The electric power display system for an electric vehicle according to claim 1, wherein the first predetermined time is 0.5 seconds. The electric power display system for an electric vehicle according to claim 1, wherein the second predetermined time is 60 seconds. The electric quantity display system for an electric vehicle according to claim 1, wherein the predetermined voltage is a transition voltage value when the battery is switched from a constant current to a constant voltage when the battery is being charged. The electric power display system for an electric vehicle according to claim 1, wherein the display unit is a liquid crystal display device. The power display system for an electric vehicle according to claim 1, wherein the display unit is a pointer meter, and the control chip comprises a digital/analog signal conversion unit, wherein the battery is powered by the digital/analog signal. The conversion unit is displayed on the pointer meter. The electric power display system for an electric vehicle according to claim 1, wherein the control chip does not have a function of a battery management system (BMS).