JPS6055829A - Charger of electric motor vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric vehicle charging device, and more particularly to an on-vehicle charging device for charging the battery of an electric vehicle.

BACKGROUND OF THE INVENTION A battery, which is an energy source for driving an electric vehicle, needs to be charged, for example, after the vehicle has finished traveling in preparation for the next trip. Conventional electric vehicle charging equipment cannot properly measure the charging current Q when charging, and there is a risk of undercharging or overcharging.If charging is insufficient, the next For example, if an electric vehicle is driven for a certain period of time, it will not be able to travel a predetermined distance.On the other hand, if overcharging continues, the battery life will be shortened.

OBJECT OF THE INVENTION The present invention has been made in view of the above background. An object of the present invention is to provide an electric vehicle charging device that integrates the amount of discharge current of a battery, calculates the amount of charging current that should be charged to the battery based on the integrated value, and charges only the calculated value. It is to provide.

Structure of the Invention The present invention includes: (1) a means for calculating the discharge current amount of the battery as the electric vehicle travels; (1) A charging device for an electric vehicle, including a charging means that performs charging according to the result of the calculation means.

Effects of the Invention Since the present invention is constructed as described above, the amount of charging current to charge the battery is calculated based on the amount of discharging current of the battery, and charging can always be performed with the most appropriate amount of current. In addition, overcharging and undercharging can be prevented.

The above-described structure and features of the present invention will become clearer from the following description of embodiments with reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a diagram showing an example of a charging circuit to which an embodiment of the present invention is applied. This charging circuit is also used as a drive circuit for electric vehicles. First, the operation of this circuit will be briefly explained. When the electric vehicle is running (when the electric vehicle is running), the main switch 1 is turned on, and the battery 2, main switch 1, electric motor 3, smoothing coil 4, chopper circuit 5, battery current detection shunt 6, and battery 2 circuit A current flows through. At this time, the chopper circuit 5 controls the electric motor n30 rotation speed and the like.

To further charge the battery 2, connect 200V, for example, A and C to the charger input terminal 7 and turn on the charging contactor 13. As a result, the battery 2 is charged with current by electromagnetic induction between the primary coil 8 and the secondary coil (smoothing coil) 4. That is, during a positive half cycle, current flows through the circuit of the secondary coil 4, motor 3, diode 9, battery 2, battery current detection shunt 6, cyrisk 10, and secondary coil 4. On the other hand, in the case of a negative half cycle, the secondary coil 4, diode 11, battery 2, battery current detection shunt 6, thyristor 12, and 11 currents 'iJi flow through the circuit of the secondary coil 4.

In the case of the positive half cycle and the negative half cycle, charging of the battery 2 is controlled by controlling the thyristors 1013 and 12.

According to this invention, the Nylister 10 (15) is controlled by the control means.
and 12, and according to the discharge current m of the battery 2,
The battery 2 is charged with a predetermined amount of current.

FIG. 2 is a block diagram of a control means for controlling the circuit shown in FIG. 1.

In FIG. 2, the control means includes a CPLI 21 that executes various calculations and controls, a ROM 22 that stores a program of operation of the CI-'U 21, and calculation data Ab of the CPU 21.
The CPIJ 21, which includes a RAM 2S for temporarily storing predetermined input data, etc., is supplied with at least the following signals via an input interface 24. ■Signal from real time clock 25. As will be explained later, this signal is the fi 1. Measurement between t1,
Used to know the current time. ■Signal from input key 26. This signal includes, for example, a J signal indicating the time when the electric automatic mode is to be used next. ■Charging outlet connection signal. This is a signal indicating that an AC power source is connected to the input terminal 7 of the charger described above. ■Signal that represents the battery voltage and battery voltage.

Each of these signals is converted into a digital signal by the A/D converter 27 Mj! given. ■Overtemperature detection signal @. This signal is given when the moisture content of the battery 2 (FIG. 1) increases too much due to charging.

Each of the above-mentioned signals is input to CP tJ 21, and CP (
) 21 outputs predetermined operation and control data based on these signals. That is, the CPIJ 21 outputs the following signal via the output interface 28. ■Signal given to remaining capacity meter.

This signal indicates the state of charge of the battery.
(not shown). (2) Control signals for the thyristors 10 and 12, and the im signal control the charging current amount, charging time, etc. of the battery 2.

■Charging contactor closing signal. This signal 1 (charging contactor 13 is turned on and charging starts. ■ Display output signal. This signal is used to send various time display data, charging display data, etc. to the de-C spray 32. Since the signals 6 and 2 are output as digital signals from the output interface 28, D
,/' A comparator 929 converts the analog signal (2"
g', and -C is output.

In addition, in this example, since the CPtJ 21 was also used as the CPU for controlling the power of the electric vehicle, the CPLJ
21 is a chopper circuit 5 (FIG. 1) based on signals input and output via an interface 30 for control during transport.
Control Performs the necessary controls for the senka process. Therefore, when an interrupt pulse is input from the interrupt pulse generator 3'1, the battery 2, which is a feature of the present invention, is
The charging control is performed.

Note that it is of course possible to provide a separate CPU for the battery charging device to perform control operations.

FIG. 3 is a flow diagram showing a subroutine for calculating the discharge current of the battery 2 (FIG. 1) as the electric vehicle (not shown) travels. FIG. 4 is a diagram for explaining the calculation method for calculating the discharge current. As shown in FIG. 4, in this example (- indicates the change in the amount of battery current due to discharge on a 1-hour axis) and the area concaved by "battery current" is shown.

The operation of the control means shown in FIG. 2 to calculate the discharge current will be described with reference to FIGS. 3 and 4. As described above, the discharge current calculation flow in the control means shown in FIG. 2 is executed as an interrupt processing program in the control program at the time of execution. That is, an interrupt signal is provided from the interrupt pulse generator 31 to the CPU 21 at every time T1.

Based on this applied interrupt signal, the CPU 21 executes a discharge current calculation processing program every T1 time.

First, when an interrupt signal is input, the CPU 21 reads the battery current IBn in response to the signal. For example, in FIG. 4, the battery current IB is read. Then, a short time after reading IB, the battery current IB(n+1) is read again. For example, read I 8 z. The time Δ[ has a very short interval C, and it is considered that the change in battery current IB, →lB2 during this time Δt changes almost linearly. Therefore these IB
Based on n, T13(n+1), Δt-, fli electric'
The area Sn (for example, the area S (see FIG. 4)) representing the R flow rate is calculated according to the following formula.

Sn = [(IBn + IB (n + I)) Δ
t]/2 roughly claimed area 3 n is △ff1 (A=1
”'t/△1 and calculate the amount of current for 1 hour.
85). Then, upon inputting the interrupt signal, the discharge current calculated for each time 1゛1, S+n (=A
S11) is stored in the RAM 23, and the remaining capacity is calculated based on it, and the remaining capacity is 6 Wj jt
1 (not shown) (Stellaf 36, 37).

The interrupt signal from the interrupt pulse generator 31 (Fig. 2) is generated when the key switch of the electric vehicle is turned off. , that is, the discharge end time is stored in AM23 as F. Then, the process proceeds to the charging control routine to be explained next.

FIG. 5 is a flowchart for explaining the charging control operation of the control stage (not shown in FIG. 2). The charging control operation by this control means will be explained with reference mainly to FIG. 2 and FIG. 5.

When the charging control routine starts, charging terminal 7 (Fig. 1)
The CPU 21 waits for the AC power source to be connected to the charging terminal 7, and when the AC power source is connected to the charging terminal 7, the CPU 21 reads the current time from the real time clock 25. Then, wait for the charging start switch (not shown) to be turned on (step S11~
S13).

When the charging start switch is turned on, the CPU 21 determines whether or not the battery 2 has been charged once.

That is, it is determined whether the electric vehicle has charged the battery 2 after driving. If the battery has been charged once,
The previous charging end time is read (step S18).

This time is stored in the RAM 23 as described later. Then, from the read time, it is determined whether or not the unused time, which is the time from the time of charging once to the present, is longer than, for example, 240 hours. Electric car batteries generally have 1
It is said that if a battery is left unused for 24 hours, it will spontaneously discharge by about 1%. Therefore, if you leave it for 240 hours, the battery will be approximately 1
This will result in a 0% discharge. In this example, the leaving time is 2.
When the natural discharge of the battery exceeds 10% after 40 hours, the battery is charged (step S19).

If the left time is shorter than 240 hours, full charge is displayed on the display means (not shown) (step S20), and the routine returns to the beginning.

In step S14, if the battery 2 has not been charged even once after driving the electric vehicle, the next step S1
In step 5, it is determined whether the standing time is 120 hours or more. That is, it is determined whether the electric vehicle has been left for more than 120 hours since it was last used until the current charging time. If the left time is 120 hours or more, RAM23
The CPU 21 reads the amount of discharge current stored in the CPU 21 and corrects the usage of the discharge current based on the standing time. That is, the discharge current amount Sm (see FIG. 3) is corrected on the assumption that 1% spontaneous discharge occurred during the 24 hours of standing time (steps S16 and S27). In this way, in this embodiment, in addition to the amount of discharge current accompanying the running of the electric vehicle, if the left time is longer than a predetermined time, the amount of natural discharge current during the left time is corrected. This has the advantage that the amount of discharge current can be determined more accurately.

Next, in step S21, it is determined whether or not charging is being performed for the 10th time. If charging is not the 10th time, step S22
．． If S23 is executed and charging is the 10th time, step S24. S25 is executed. More specifically, when charging is not the 10th time, the CPU 21 stores the number of charging times in the RAM.
C=Sm×1.2, where C is the amount of charging current to be charged. i.e. 1
For normal charging other than the 0th time, set "Charging current amount" to "
The amount of discharge current is determined to be 120%.

On the other hand, every 10th charge, reset the number of charges (
In step S24), a charging current amount C' different from the normal charging is determined as C'=Sm×1.4. That is, 10
As a supplementary charge every time the second charge is performed, the "charging current amount" is "
discharge current amount x 140%.

In this way, if the amount of charging is increased and supplementary charging is performed every 10th time, for example, there is an advantage that the life of the battery 2 is extended.

Note that such supplementary charging is not limited to every 10th time, but may be performed at other times.

Next, determine whether or not to start charging battery 2 immediately. If not, set the charging start time so that charging ends immediately before the next time you start using the electric vehicle, as described below. decide.

That is, in step S27, the user inputs the start time of the next use of the electric vehicle using the input key 26 (FIG. 2). Next, the CPU 21 calculates a charging time from the amount of charging current to be charged, and calculates and sets a charging start time from the input use start time. Note that the relationship between the charging current amount and the charging time is written, for example, in a data table in the ROM, and calculations are performed based on it (step S28).

The CPU 21 determines whether or not the charging start time has arrived in units of a predetermined time ΔT, and when the charging start time has come, the charging contactor 13 is turned on to start charging (step S2
9-S31).

The charging current amount during charging is calculated in the same manner as the calculation of the discharge current slope described above. That is, the area surrounded by the charge Wffi current fJz J n at a predetermined time and the charge current ff1l (+++1) 61 hours after that time is calculated. This calculation is performed according to the following formula.

Sn'-((ln+I (n+1))Δbi) ,,'
2 and the area S' n is 3' II = 3' n
+S' (+1-1) is accumulated sequentially, and the total charging current amount is accumulated and stored in RAM. Note that, like the calculation of the discharge current amount, the charging current amount is calculated by measuring the discharge current amount (area sn) for Δ out of 11 hours. Therefore, the time interval Δ[′ for charging current detection is
In the case of current detection, it is better to make the CP relatively longer than Δt.
The control operation of U21 is simplified and convenient.

In step 838, the liquid temperature of the battery 2 being charged is detected, and if the liquid temperature becomes extremely high, charging is stopped (step 539).

Furthermore, it is determined whether or not the gassing voltage (a voltage at which hydrogen gas is generated as charging progresses), and if the voltage of the battery 2 reaches the preset gassing voltage 1y, above ←=, the CP
tJ 21 Hasairista 10. 12 (Fig. 1) to limit the charging current. 1, that is, the terminal current is limited (steps 340, 841>.And when the charging current usn' reaches the predetermined charging current amount C,
Release the charging contactor 13 to end charging,
The charging end time is stored in 1 (AM23) and the operation ends. Note that this charging end time is set at step 818, for example.
Used in.

In addition, in this embodiment, the charging end time is set to be immediately before the next time the user uses the electric vehicle, so especially in the winter, the battery liquid temperature increases L/.
This has the advantage that the traveling type r1 can be increased with one charge.

It is assumed that the CPU 21, which performs charging control, etc., is always energized regardless of whether the key switch of the electric vehicle is on/off or the charging switch is on/off.

In this embodiment, the charging time is calculated and set from the required charging current M (Fig. 5 (step 828), but at that time, the relationship between the charging current amount j and the "time for the battery to reach the gassing voltage" is also determined). By storing the data in the data table of the ROM 22 (FIG. 2), the battery life can also be measured.

That is, the relationship between the amount of charging current and the time required to reach the battery's gassing voltage generally exists as shown in FIG. In other words, when the battery is normal, there is a proportional relationship between the predetermined charging current and the time the battery reaches the gassing voltage (6th
In the figure, it is indicated by c'9). Therefore, if the battery reaches the gassing voltage (indicated by a in FIG. 6) in a very short time after the start of battery charging, it can be determined that the battery life has expired. By displaying the fact that the battery life has expired on a display means (not shown), it is possible to accurately know when it is time to replace the battery.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main circuit for charging and charging an electric vehicle to which the present invention is applied. FIG. 2 is a block diagram of a control circuit system according to one embodiment of the present invention. FIG. 3 is a reference to FIG.
It is a diagram. FIG. 4 is a diagram for explaining a method of calculating the amount of discharge current. FIG. 5 is a flowchart for explaining the charging control 1llI¥ of the control means based on FIG. 2. FIG. 6 is a diagram for explaining the battery 1 setting. In the figure, 2 is the battery, 4 is the secondary coil of the charger, and 7 is the battery.
is the input terminal of the charger, 8 is the primary coil of the charger, 10.
12 is a thyristor for controlling the amount of charging current; 13 is a charging contactor; 21. - 22 is a CPU that is the central part of the system that integrates the amount of discharged N current, calculates the amount of charging current, etc.
A ROM 23 stores the U's dynamic program, etc.
Accepting RAM for temporary memory of the evening -0

Claims (4)

[Claims] (1) An on-vehicle charging device for charging the battery of an electric mortar WJ vehicle, comprising a discharge current amount integrating means for integrating the discharge current layer of the battery as the electric vehicle travels, and an integrating means for the integrating means. A charging device for an electric vehicle, comprising means for calculating a charging current range to charge the battery based on the value, and charging means for charging the battery according to Jζ and the result of the calculation means. (2) The discharge current amount integrating means further includes means for measuring the time while the electric vehicle is left unattended, and thereby calculates the discharge current due to spontaneous discharge and calculates the discharge current amount integrated value. The electric vehicle charging device according to claim 1, which includes means for correcting. (3) The charging means responds to the time at which use of the electric vehicle is to be started, determines a charging start time so that charging is completed immediately before the use start time, and sends a signal to start charging at the charging start time. The electric vehicle recharging system according to claim 1 JJm or claim 2, including means for outputting
fi device. (4) The calculation means calculates the charging current amount by multiplying the integrated value by a predetermined coefficient, and the predetermined coefficient is multiplied by a relatively high coefficient every predetermined number of times of charging. An electric vehicle charging device according to any one of claims 1 to 3.