JP3345336B2 - Method and apparatus for controlling reverse phase electric brake of electric vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system using an electric brake of an electric vehicle propulsion control device, and more particularly to a reverse-phase electric brake system in which a braking force is obtained by switching from a forward brake to a reverse power running with a decrease in speed. The present invention relates to a method for detecting zero speed in a negative-phase electric brake for detecting that the speed of an electric vehicle has become zero.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of an electric vehicle provided with an inverter connected to a power supply and an induction type linear motor driven by the output of the inverter, which is described in Japanese Patent Application Laid-Open No. Hei 2-17805. is there.

In FIG. 5, 7 is an overhead line, 8 is a pantograph provided between the overhead line 7 and the electric vehicle, and 9 and 10 are overhead lines 7.
, A filter reactor and a filter capacitor for filtering the noise of the current supplied to the electric vehicle via the pantograph 8, 11 is an inverter, and 14 is fV
(Frequency-voltage) An adder that subtracts a predetermined slip frequency fs input during braking from the output of the converter 21 and outputs the result. The frequency 15 that receives the output of the adder 14 and controls the frequency of the inverter 11 A control device 16 is a phase sequence control device that receives the output of the adder 14 and controls the phase sequence of the AC voltage supplied from the inverter 11 to the linear motors 26A to 16D described later. 19 is a wheel, and 20 is a wheel. And a pulse generator 21 for generating a pulse signal having a frequency corresponding to the wheel speed, an fV (frequency-voltage) converter 21 and a voltage pattern generator 22 for generating a voltage pattern based on an input brake command value. , 23 are reference value generators for comparison, 24 is a voltage pattern generator 22
Are compared with the reference value output from the reference value generator 23 to generate an output, 25 is a voltage control device that controls the voltage of the inverter 11 based on the output of the comparator 12, and 26A to 29D are The induction type linear motor is controlled by the inverter 11.

In the conventional reverse-phase electric brake of the control system shown in FIG. 5, the inverter frequency is controlled to be lower than the rotor frequency (corresponding to the vehicle speed) by the slip frequency fs when the brake is operated, and the low-speed inverter is operated. When the frequency becomes zero (0) Hz, the phase sequence of the three-phase alternating current is switched to generate a thrust in a direction opposite to the traveling direction, thereby obtaining a braking force.

FIG. 5 shows a conventional example of an electric vehicle provided with an induction motor instead of a linear motor as a power source. In FIG. 5, reference numeral 1 denotes a speed detector for detecting the speed of the electric vehicle, and 3 and 4 denote pulse generators 13 to be described later.
The PGA signal and the PGB signal output from the wire 7 are overhead wires,
8 is a pantograph provided between the overhead wire 7 and the electric vehicle, 9 is a filter reactor for filtering a current supplied from the overhead wire 7 to the electric vehicle via the pantograph 8, 10 is a filter capacitor, 11 is an inverter, and 12A and 12B are induction. The electric motor 13 is a PGA signal 3 which is a pulse signal of a frequency corresponding to the rotation speed of the PGA signal 3 in conjunction with the induction motor 12B.
And a pulse generator that generates a PGB signal 4 and outputs it to the speed detector 1. The other components are almost the same as those in the conventional example shown in FIG.

In this conventional example, a PGA signal 3 and a PGB signal 4 output from a pulse generator 13 interlocked with an induction motor 12B are input to a speed detector 1, and the speed detector 1 uses the input signals to control the electric vehicle. The speed information representing the speed is generated and output to the adder / subtractor 14. Adder / subtractor 14
During braking, an output signal is generated by subtracting the slip frequency fs from the speed information, and the output signal is input to the frequency control device 15 and the phase sequence switching device 16.

[0007] The inverter 11 is controlled by outputs of a frequency control device 15 and a phase sequence switching device 16.

The speed information generated by the speed detector 1 is obtained on the basis of the output signal of the pulse generator 13. FIG. 3 shows the PGA signal 3 and the PGB signal 4 which are the output signals of the pulse generator 13. .

The speed information is a signal period T of the pulse generator 13 and is expressed as follows. Wheel diameter: ΦD (mm) Speed: v (Km / h) Number of pulses of pulse generator: P (pulse / rotation) T (second) = (π × D × 10 ⁻⁶ × 3600) / (vxP)

[0010]

In the conventional control method as described above, the speed v is small and the signal period T of the pulse generator 13 is long at a low speed just before the stop. In this case, the number of pulses per rotation of the pulse generator 13 must be increased. For this reason, the inexpensive low-resolution pulse generator 13 normally used has a speed of zero (0 km / h).
Can not accurately detect the stop time of the system. Therefore, in order to improve the speed detection accuracy, a high-performance product having a large number of output pulses must be adopted as the pulse generator, and the resources of the counter for measuring the period T must be increased. There has been a problem that manufacturing costs have soared.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a stable and accurate zero-speed braking stop by a negative-phase electric brake can be obtained by using an existing inexpensive pulse generator. The purpose is to:

[0012]

SUMMARY OF THE INVENTION The present invention uses an existing inexpensive (low-resolution) pulse generator to discriminate two signals having different phases (PGA signal and PGB signal) output from the pulse generator. By doing
When the phase sequence of the signals changes, braking is stopped by detecting zero speed (0 km / h).

Further, the present invention uses an existing inexpensive (low-resolution) pulse generator, and switches from control of an actually measured speed to control of a predicted speed as the speed of the electric vehicle decreases.
It detects a zero speed (0 km / h) and performs stable braking stop.

[0014]

[0015] Also, with the speed reduction,
Switch to reverse powering to obtain the braking force.
In the rake control method, based on the signal from the speed detector
The electric car traveled in a direction different from the direction
In this case, when the phase between the two signals output from the speed detector changes, the speed is set to zero and the braking is stopped.

Also, in a negative-phase electric brake control method for an electric vehicle which obtains a braking force by switching from forward braking to reverse driving with a decrease in speed, in a low-speed range where speed detection accuracy is reduced by the resolution of a speed detector, actual measurement is performed. The speed detection is switched to predictive control, and zero speed is predicted and detected to stop braking.

Further, based on the speed detected by the speed detector at the switching time of switching the speed detection to the prediction control, the speed of the electric vehicle to predict when to become zero, the braking stops at that point It is assumed that.

[0018]

Also, in a negative-phase electric brake control device for an electric vehicle that obtains a braking force by switching from forward braking to reverse powering with a decrease in speed, an induction motor, an inverter for controlling the operation of the induction motor, and an induction motor are provided. A pulse generator that generates an output signal having a frequency corresponding to the rotation speed in conjunction therewith, a speed detector that detects the speed of the electric vehicle based on the output signal of the pulse generator, and a pulse detector based on the output signal of the pulse generator. A speed estimator for detecting the speed of the electric vehicle at a predetermined cycle and predicting the speed of the electric vehicle thereafter until the speed becomes zero based on the detected speed; and an output of the speed detector or the speed prediction. A control device for controlling the inverter based on the output of the electric vehicle; and an output of the speed detector and the speed according to the speed of the electric vehicle. A speed signal switch for selectively inputting one of the outputs of the measuring instruments to the control device, wherein the speed signal switch outputs the output of the speed detector when the speed of the electric vehicle is higher than a predetermined value. Input to the control device,
When the speed of the electric vehicle becomes equal to or less than a predetermined value, an output of the speed predictor is input to the control device.

[0020]

Further , the control device controls the output frequency of the inverter based on the output signal of the speed detector, and the control device determines the output phase sequence of the inverter based on the output signal of the speed detector. And a phase sequence switching device for controlling.

Further , the apparatus further comprises an adder / subtractor for generating an output signal by subtracting a slip frequency from the speed information during braking, and outputting the output signal to the frequency control device and the phase sequence switching device.

Further, advancement of the electric vehicle based on the two output signals of the pulse generator detects the backward, forward /
It further comprises a classification detector for stopping the braking operation of the inverter when the reverse operation is switched.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a schematic block diagram of an electric propulsion control apparatus according to Embodiment 1 of the present invention, and has a configuration in which a phase relationship between a PGA signal 3 and a PGB signal 4 output from a pulse generator 13 is shown. Except for having a classification detector 2 that classifies
The configuration is almost the same as the above-described conventional example shown in FIG.

The classification detector 2 includes a pulse generator 13
The PGA signal 3 and the PGB signal 4, which are output signals of the electric vehicle, are input, and a forward / reverse signal indicating forward / reverse of the electric vehicle is generated from these signals and output to the inverter 11. That is, as shown in FIG.
The PGA signal 3 and the PGB signal 4 having different phases from each other are generated. For example, if the phase of the PGA signal 3 is ahead of the phase of the PGB signal 4, the classification detector 2 determines that the vehicle is moving forward and outputs a forward signal. If this relationship is reversed, it is determined that the vehicle is traveling backward and a reverse signal is generated.

Next, the operation of the first embodiment will be described. Until the speed of the electric vehicle is equal to or higher than the predetermined speed, the speed detector 1 measures the period T of the speed information based on the PGA signal 3 or the PGB signal 4 input from the pulse generator 13, and as a result, Is output to the adder / subtractor 14. Further, the classification detector 2 includes a pulse generator 1
Based on the PGA signal 3 and the PGB signal 4 input from 3, a forward signal indicating forward movement is output to the inverter 11. Therefore, the control of the inverter 11 at this time is as shown in FIG.
As in the case of the conventional example, the control is performed by the output signals of the frequency control device 15 and the phase sequence switching device 16. Note that the frequency control device 15 and the phase sequence switching device 16 constitute a control device of the present invention that controls the inverter 11 based on the output of the speed detector 1.

When the speed of the electric vehicle falls below the predetermined speed due to the activation of the electric brake, and it becomes difficult to measure the period T shown in FIG. 3, the forward / backward movement obtained by the classification detector 2 is obtained. When the signal becomes different from the traveling direction at the time of activation of the electric brake (for example, at the time of switching from forward to reverse), the braking is stopped by regarding the speed as zero (0 km / h).

Second Embodiment FIG. 2 is a block diagram showing a main part of an electric propulsion control device according to a second embodiment of the present invention. In the second embodiment, a speed estimator 5 is provided in parallel with a speed detector 1. The PGA signal 3 and the PGB signal 4 which are output signals from the pulse generator 13 are input to the speed detector 1 and the speed estimator 5. These output signals are output by the speed signal switch 6. It is switched and selectively input to the inverter 11. That is, the speed signal switch 6 is switched so that the output of the speed detector 1 is input to the adder / subtractor 14 when the speed is equal to or higher than the predetermined speed, and the output of the speed predictor 5 is output to the adder / subtractor 14 when the speed is lower than the predetermined speed.

The speed estimator 5 includes a pulse generator 13
The speed of the electric vehicle is constantly calculated based on the PGA signal 3 or the PGB signal 4 from the vehicle, and at each time until the speed becomes zero after that, taking into account the deceleration obtained as the rate of change of the speed. The speed is calculated and predicted, and such speed calculation and prediction are performed in a predetermined cycle.

The other configuration of the second embodiment is the same as that of the first embodiment shown in FIG.

Next, the operation of the second embodiment will be described. When the speed of the electric vehicle is medium or high speed exceeding a predetermined value, the speed detector 1 measures the period T of the speed information based on the PGA signal 3 or the PGB signal 4 input from the pulse generator 13, and The signal is input to the adder / subtractor 14 via the speed signal switch 6. In addition, the classification detector 2
Based on the PGA signal 3 or the PGB signal 4 input from the pulse generator 13, a forward signal indicating forward travel is output to the inverter 11. Therefore, the control of the inverter 11 at this time is performed in the same manner as in the first embodiment of FIG.

When the speed of the electric vehicle is reduced to a predetermined speed or less by the activation of the electric brake, and it becomes difficult to measure the period T shown in FIG. The output of the speed predictor 5 provided in parallel with the speed detector 1 is input to the adder / subtractor 14. In this case, when the period T of the speed information becomes longer than the predetermined calculation period due to the decrease in the speed v, when the next calculation period is reached,
The predicted speed at that time (the next calculation cycle) calculated in the previous calculation cycle is input from the speed predictor 5 to the adder / subtractor 14.
If the cycle T of the speed information is smaller than the predetermined calculation cycle, the speed calculation is repeated for each predetermined calculation cycle, and the calculated speed is input to the adder / subtracter 14 each time. The adder / subtractor 14 subtracts the slip frequency fs from the speed information input from the speed estimator 5 and outputs the result to the frequency control device 15 and the phase sequence switching device 16, whereby the inverter 11 is controlled.

In this way, when the output of the adder / subtractor 14 becomes zero, the frequency controller 15
1 is also controlled to zero, and therefore the induction motor 12
Since A and 12B are deenergized, braking is stopped. That is, the speed information is switched by the speed signal switch 6 to the output of the speed predictor 5 that constantly predicts the speed based on the PGA signal 3 or the PGB signal 4, and the output of the speed predictor 5 becomes zero ( (0 km / h), braking is stopped.

In addition to the above-described operation of the speed estimator 5, the classification detector 2 operates in the same manner as described in the first embodiment. Therefore, when the speed of the electric vehicle is reduced to the predetermined speed or less by the activation of the electric brake and it becomes difficult to measure the period T shown in FIG. 3, the forward / reverse signal obtained by the classification detector 2 Is stopped at a point in time when it is different from the traveling direction at the time of activation of the electric brake (for example, at the time of switching from forward to reverse), assuming that the speed is zero (0 km / h). Since the braking stop based on the output of (1) occurs earlier than the braking stop based on the output of the classification detector 2, the braking stop by the classification detector 2 is complementary to the braking stop by the speed predictor 5, and If the braking stop by the speed predictor 5 does not work well for the reason, it has a fail-safe meaning and enhances safety.

[0036]

As described above, according to the present invention, by using the conventional inexpensive pulse generator having low-speed accuracy variation at low speed, the reverse-phase electric power with high stopping accuracy up to zero speed (0 km / h) is obtained. It is possible to obtain a brake system at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an electric propulsion control device according to a first embodiment of the present invention.

FIG. 2 is an enlarged block diagram showing a main part of an electric propulsion control device according to a second embodiment of the present invention.

FIG. 3 is a waveform diagram of an output signal of a pulse generator.

FIG. 4 is a block diagram showing a schematic configuration of a conventional electric propulsion control device.

FIG. 5 is a block diagram showing a schematic configuration of another conventional electric propulsion control device.

[Explanation of symbols]

1 speed detector, 2 classification detector, 3 PGA signal, 4
PGB signal, 5 speed predictor, 6 speed signal switch,
7 overhead wire, 8 pantograph, 9 filter reactor, 10 filter capacitor, 11 inverter, 1
2A, 12B induction motor, 13 pulse generator, 14 adder / subtractor, 15 frequency control device, 16 phase sequence switching device, 20 wheels, 21 fV (frequency-voltage) converter, 22 voltage pattern generator, 24 comparator, 25 voltage control devices, 26A, 26B, 26C, 2
6D linear motor.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI H02P 5/41 302 B60L 13/02 M (58) Field surveyed (Int.Cl. ⁷ , DB name) B60L 7/00 103 B60L 9/18 B60L 13/03 H02P 3/00 H02P 3/20 H02P 5/41 302

Claims (7)

(57) [Claims] 1. A negative-phase electric brake control method for an electric vehicle, which obtains a braking force by switching from forward brake to reverse power running with a decrease in speed, in a direction different from a designated direction based on a signal from a speed detector. If the electric vehicle has proceeded
Between the two signals output from the speed detector
A negative-phase electric brake control method for an electric vehicle, wherein when a phase is changed, the speed is set to zero and braking is stopped. 2. When the vehicle speed decreases, the vehicle moves backward from the forward brake.
Negative-phase electric brake of an electric car that obtains braking force by switching to power running
In the control method, the speed is determined by the resolution of the speed detector.
In the low-speed range where detection accuracy is reduced, speed detection by actual measurement
Switch to predictive control and predict zero speed to stop braking and stop
A method for controlling a reverse-phase electric brake of an electric vehicle. 3. An off-state in which the speed detection is switched to predictive control.
Based on the speed detected by the speed detector at the time of
And predict when the speed of the electric car will be zero,
The reverse-phase electric brake control method for an electric vehicle according to claim 2 , wherein braking is stopped at a point . (4)As the speed decreases, go backward from the forward brake
Negative-phase electric brake of an electric car that obtains braking force by switching to power running
In the key control device, An induction motor, An inverter that controls the operation of the induction motor; In conjunction with the induction motor, a circuit corresponding to the rotation speed
A pulse generator for generating a wave number output signal, Based on the output signal of the pulse generator,
A speed detector for detecting speed, A predetermined cycle is determined based on the output signal of the pulse generator.
The speed of the electric car is detected during the period, and based on the detected speed
And predict the subsequent speed of the electric vehicle until it reaches zero.
Speed estimator, Based on the output of the speed detector or the output of the speed predictor
A control device for controlling the inverter based on the The output of the speed detector and the speed according to the speed of the electric car
One of the outputs of the degree predictor Is selectively input to the control device.
Speed signal switch With The speed signal switch switches the speed of the electric vehicle to a value greater than a predetermined value.
Input the output of the speed detector to the control device
When the speed of the electric car falls below a predetermined value,
Characterized in that an output of a degree predictor is input to the control device.
To be Reverse-phase electric brake control device for electric vehicles. (5)The control device includes: Based on the output signal of the speed detector,
A frequency control device for controlling the output frequency; Based on the output signal of the speed detector,
A phase sequence switching device that controls the output phase sequence It is characterized by having
Claim 4 Negative phase electric brake control of electric car
apparatus. 6. The brake system according to claim 6 , wherein, when braking, the slip frequency is adjusted to the speed.
Subtract from the information to produce an output signal,
Adder / subtractor that outputs to the frequency controller and phase sequence switching device
The reverse-phase electric whistle rake control device for an electric vehicle according to claim 4, further comprising: 7. The two output signals of the pulse generator.
Forward / reverse of the electric vehicle based on the signal
Stop the braking operation of the inverter when the operation is switched
The reverse-phase electric brake control device for an electric vehicle according to claim 4, further comprising a classification detector .