JPS5937642B2 - electric car control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electric vehicle control device that controls switching of regenerative braking current to falling air braking force in the final step of regenerative braking.

FIG. 1 shows a simplified diagram of a drive morph circuit during regenerative braking of an electric vehicle.

In the figure, 1 is an AC overhead line, 2 is a current collector, 3 is a transformer, 4 is a silice type inverter device (hereinafter referred to as an inverter), 5 is a reactor, 6 is a drive motor, 7 is a field winding, and 8 is a 9 is an excitation device, 9 is a current detector, Ed is an inverter output voltage, EM is an electromotive force of a drive motor, and IM is a brake current.

FIG. 2 is a simplified block diagram of a conventional embodiment for controlling the regenerative brake circuit.

In the figure, 4 and 9 indicate the same things as in Figure 1, VM is the brake current detection value output from the detector 9 corresponding to the brake current IM, and Vp is the brake current limit value corresponding to the brake current limit value Ip. The pattern, ANDl, is an AND that outputs when both people's powers are aligned.

The circuit, NOT, is a NOT circuit that outputs an output with the opposite logic to the input, 10 is a current limit value comparator that outputs a stage advance command 10a when IM<IP (VM<VP) is established under the input conditions, and 11 is a current limit value comparator that outputs a stage advancement command 10a when there is an input. a clock generator that outputs a predetermined clock signal 11a; 12 is a counter that advances a count each time the clock signal 11a is input through an AND1 circuit and outputs a step number signal 12a corresponding to the count;
13 is a phase command device which extracts an inverter phase control command value previously set in an internal memory corresponding to the step number signal 12a and commands the inverter 4 to receive a phase command value 13a; A coincidence detector that compares separately commanded regenerative brake final step number signals and outputs a coincidence signal 14a when the two match;
5 is the minimum brake current pattern V corresponding to the brake current detection value vM and the separately commanded minimum brake current setting value IC.
A current rise detector 16 outputs a current rise detection signal 15a when vM>vo holds by comparing c, and a cutoff command device 16 gives a cutoff command 16a to the air brake cutoff device 17 when inputted.

Next, the operation will be explained.

The brake current detection value VM and the current limit value Pakun VP are compared by the current limit value comparator 10, and when VM<Vp is established, the gear advance command 10a is issued and the clock generator 11 outputs the clock signal 1.
1a comes out.

When the gate of the AND1 circuit is open, the clock signal 11a is inputted to the counter 12 via the AND circuit, and the count number is increased by one step each time the clock signal is input, and the counter 12 outputs the step. The number signal 12a advances sequentially.

In response to the progression of the step number signal, the phase command device 13 outputs a phase command value 13a to the inverter 4, and the inverter output voltage Ed is controlled in a stepwise manner.

When the step advance control progresses and the step number signal 12a and the regenerative brake final step number signal SL match, a match signal 14a is output from the match detector 14 and the gate of the AND1 circuit is closed via the NoTl circuit, so that the clock signal 11a is output from the counter 1.
2 is no longer input, and the step progression stops at the final step of the regenerative brake.

Figure 3 shows the operating waveforms of the brake current IM, inverter output voltage Ed, and step number signal S in the above advancement control, where Ip and SL are the same as those in Figure 2, and t indicates time. ing.

Next, in FIG. 2, the brake current detection value VM and the minimum brake current setting value IC are compared in the brake current judgment device 15, and if VM>Va is established, the output 16a is output from the cutoff command device 16, and the air brake cutoff device 17 is applied and the air brake is cut off, but when the gear advance control advances and reaches the regenerative brake final step SL, the gear advance stops as described above.

Then, the inverter voltage becomes constant and the brake current IM attenuates due to a decrease in the superpower EM of the drive motor due to a decrease in speed. 15a disappears, and the shutoff command 16a to the air brake shutoff device 11 disappears, so the air brake starts up.

Figure 4 shows the fall of the regenerative brake current and the rise of the air brake when advancing to the final step of the regenerative brake. In the figure, IM, IP, and Ia are the same as in Figure 2, and t
is the time, BC is the air brake force, and TB is the total braking force of the regenerative brake and air brake, but since the air brake Bc starts after the brake current IM reaches Ia, the total brake force TB is shown in the shaded area. A depression occurs.

As described above, the conventional brake system has a drawback that the total braking force drops when switching between the regenerative braking force and the air brake in the final regenerative braking step.

This invention was made to eliminate the above drawbacks.
When the regenerative brake advances to the final step, the air brake cut-off command is turned off to start up the air brake, and at the same time, the output of the field winding excitation device is throttled down to reduce the regenerative braking current, thereby increasing the regenerative braking force and the air braking force. The purpose of the present invention is to provide an electric vehicle control device that can smoothly switch.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is a block diagram showing an embodiment of the present invention. In the figure, the same reference numerals as in FIG. If present, it is a field narrowing command device that issues a field narrowing command 18a to the excitation device 8.

Next, the present invention will be explained in detail.

However, the explanation of the same parts as the conventional one will be omitted.

When the regenerative brake advances to the final step number SL, a coincidence signal 14a is output and the gate of the AND1 circuit is closed via the NOT□ circuit to stop the progression, and the gate of the AND2 circuit is also closed, so that the input of the cut-off command 16 is The air brake shutoff device 17 becomes inoperable and the air brake is activated.

Further, the coincidence signal 14a is input to the field narrowing command unit 18, so that the field narrowing down command 18a is sent to the excitation device 8.
Since the electromotive force EM of the drive motor is attenuated, the regenerative brake current is lowered.

Figure 6 shows the number of steps 81 in the advance control of the final step of regenerative braking, the inverter output voltage Ed, the output IF of the excitation device 8, the brake current IM, and the air brake force B.
c, shows the operating waveform of the total braking force TB, SL, I
p and t are the same as before.

In the above embodiment, it is also possible to have a predetermined time constant for narrowing down the output of the field narrowing command device 18, so that the falling characteristic of the output ■F of the exciter can be made to correspond to the rising characteristic of the air brake force Bc. By setting , it is possible to smoothly shift from regenerative braking to air braking at the final step of regenerative braking, and it is possible to eliminate a drop in the total braking force TB.

As described above, when the regenerative brake advances to the final step, the present invention stops the advancing operation to keep the inverter output constant, reduces the field excitation, reduces the brake current at a predetermined time constant, and Since the air braking force is increased, it is possible to smoothly transition from regenerative braking to air braking when the final number of regenerative braking steps is reached.

[Brief explanation of the drawing]

Figure 1 is a simplified connection diagram showing the regenerative brake circuit of an electric vehicle.
Figure 2 is a block diagram showing a conventional electric vehicle control device;
Figures a"c and 4a-c are operation waveform diagrams of various parts to explain the operation of the conventional device, Figure 5 is a block diagram showing an embodiment of the present invention, and Figure 6a = f is a 5 is an operation waveform diagram of each part for explaining the operation of the device shown in FIG. 5. In the figure, vM is a brake current detection value, Vp is a brake current limit value button, ANDl, AND2 are AND circuits, N
0T1 is a NOT circuit, 10 is a current limit value comparator, 11 is a clock generator, 12 is a counter, 13 is a phase command device, 14
15 is a coincidence detector, 15 is a current rise detector, 16 is a cutoff command, 17 is an air brake cutoff device, and 18 is a field narrowing command. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A clock generator that outputs a rank signal when there is an advance command, a counter that advances the count every time the upper clock signal is input and outputs a step number signal of a digital value, and a thyristor type inverter device that corresponds to the step number signal. a phase commander that outputs a phase control signal; a coincidence detector that outputs a coincidence detection signal when the step number signal matches a preset final step number signal; and a coincidence detection signal that receives the first clock signal and the coincidence detection signal. is input through the NOT circuit and the first AND circuit stops the above clock signal.The brake current detection value VM is compared with a preset minimum brake current setting value VO, and when VM>Va is established, a current rise detection signal is generated. a rise detector, a cut-off command device that issues an operation command to the air brake cut-off device when there is an input; a second AND circuit that turns off the input of the current detection signal to the cut-off command circuit if there is the coincidence detection signal;
An electric vehicle control device comprising a field narrowing command device that issues a command to narrow down the output to an excitation device of a field winding when the coincidence detection signal is input.