JPH0847105A - Protecting apparatus for electric motor vehicle driving system - Google Patents

Abstract

PURPOSE:To suppress the generation of an excess pulsation due to excess pulsating torque or pulsating torque by detecting the vibration of a specific frequency generated corresponding to the pulsating torque generated from a main motor by a vibration sensor installed at a vibration generating part, and limiting the rotary force of a main motor. CONSTITUTION:Vibrations sensors 16a, 16b are provided in a structural member in which a main motor 4 or a gear 5 for causing a vibrating to occur at a pulsating torque is locked with truck frame 7 and a driving force or a braking force is transmitted such as positional vicinities 14a, 14b to be operated with driving reaction force. The vibration of a specific frequency generated due to the pulsating torque generated from the main motor is detected by the sensors 16a, 16b, the detected signal is compared with the reference value set by a reference value level generator 20 by a comparator 19. A pattern generator 21 limits the rotary force of the main motor based on the compared result. Thus, the generation of a large vibration due to the excess pulsating torque or the pulsating torque can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective device for an electric vehicle drive system, and more particularly to a pulsating torque or pulsating torque in an electric vehicle drive system using a three-phase squirrel cage induction motor and a variable voltage variable frequency inverter. The present invention relates to a protection device for an electric vehicle drive system capable of suppressing drive system vibration.

[0002]

2. Description of the Related Art An induction motor drive system in which an induction motor is used as an electric motor for driving a railway vehicle and is driven by a variable voltage variable frequency inverter (hereinafter abbreviated as an inverter), a so-called inverter type electric vehicle, is easy to maintain. It has many advantages such as improved reliability and downsizing, and its practical application is progressing rapidly.

By the way, in an induction motor driven by an inverter, a relatively low order pulsating torque is generated due to the influence of time harmonics contained in the output of the inverter. Technical Report of the Institute of Electrical Engineers of Japan [(II Part) No. 287] p.11; Showa 63
December 2012] and the like.

Further, in an inverter type electric vehicle used in an AC electrification section, a so-called main conversion device in which a converter for converting an AC power supply voltage into a DC and an inverter are combined has been put into practical use. In this induction motor drive system for an AC electric vehicle, the DC output voltage of the converter contains a pulsating component with a frequency double that of the input AC power source, so when the inverter frequency approaches this pulsating frequency,
The beat phenomenon occurs in the electric current of the motor and the pulsating torque of double frequency of the AC power source is generated.
70, No. 7 (1988-7) p. 16 and the like.

[0005]

As described above, the induction motor driven by the inverter generates pulsating torque, but the frequency of the pulsating torque and the characteristic of the drive shaft system including the main motor, gear device, wheel shaft, etc. When the frequency matches, the torsional resonance of the shaft system occurs, excessive torque is applied to the shaft, and the shaft,
There is a problem that the life of shaft joints, gears, etc. may be shortened or damaged.

Further, vibrations corresponding to the pulsating torque are induced in the main electric motor and the gear device, and the vibrations are transmitted to the bogie frame that locks the main electric motor and the gear device, and further, the vehicle body traction connecting the car body and the bogies. There is also a problem that it is transmitted to each part of the vehicle body via a device etc. and resonates with the natural frequency component included in the vibration transmission path, resulting in damage to equipment due to excessive vibration and deterioration of riding comfort due to vibration and noise. .

It is an object of the present invention to provide an electric vehicle drive system protection device capable of suppressing the occurrence of excessive pulsating torque in an electric vehicle drive system or excessive vibration due to the pulsating torque.

[0008]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention transmits a driving force or a driving force to each wheel shaft by transmitting the power generated by a vehicle to a wheel shaft through a driving device including a main electric motor and a gear device. In an electric vehicle that obtains a braking force, a driving force (braking force) near the position where the main motor or gear device of the drive device connected to each wheel shaft is locked to the bogie frame or to the vehicle body.
A vibration sensor is installed on a part of a member provided along a transmission path of a driving force or a braking force including a vehicle body towing device, and the vibration sensor is used to identify the pulsating torque generated by the main motor. It is characterized in that the vibration of the frequency can be detected and can be used for limiting the rotational force of the main motor.

[0009]

That is, the pulsating torque or the vibration of the specific frequency caused by the pulsating torque increases or decreases substantially corresponding to the magnitude of the driving force or the braking force, and does not occur without the driving force or the braking force.

Further, the vibration of a specific frequency caused by the pulsating torque is generated near the position where the main motor is locked to the bogie frame, near the position where the gear device is locked to the bogie frame, and the driving force or the braking force. It has been clarified by experimental results so far that it is remarkably recognized in members along the transmission path, for example, a car body traction device, and induces excessive vibration by resonating with the natural frequency component of each part. There is.

Therefore, a vibration sensor is installed at one or more places of the vibration generating portion to detect the vibration of a specific frequency caused by the pulsating torque, and the detected signal is compared with a preset reference value signal. It is possible to predict the occurrence of excessive vibration, and to limit the pulsating torque or vibration of a specific frequency due to pulsating torque to below the reference value by limiting the rotational force of the main motor based on the comparison result. You can

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a protection device for an electric vehicle drive system according to the present invention will be described below with reference to the accompanying drawings.

1 and 2 are explanatory views showing an embodiment of a protection device for an electric vehicle drive system according to the present invention, and the construction of mechanical parts such as a trolley and a drive device shown in both figures is a general electric vehicle. 2 is a schematic structural diagram of FIG. Reference numeral 1 is a pantograph, 2 is an inverter circuit for converting the DC power supplied from the pantograph 1 into AC power having a variable voltage and a variable frequency, and supplying the AC power to a main motor 4 incorporated in a carriage 3. A squirrel cage induction motor is used. Further, the driving force or braking force generated by the main electric motor 4 is transmitted to the wheel shaft 6 via the gear device 5 and further transmitted to the bogie frame 7 via a publicly known axle box supporting device (not shown). The driving force or braking force transmitted to the bogie frame 7 is rotatably provided between the lateral beam 8 of the bogie frame 7 and the center pin 10 fixed to the vehicle body 9, as shown in the schematic structure of FIG. The vehicle body 9 is configured to be transmitted via a vehicle body towing device 11 and tow the vehicle body 9.
Reference numeral 12 is a main motor mounting leg for mounting the main motor 4 on the bogie frame 7, and 13 is a gear box suspension device for elastically supporting the gear device 5 on the bogie frame 7. The reaction force of the force or braking force acts.

The vibration detection circuit 15 includes a vibration sensor 16a.
16c, a bandpass filter 17 and a waveform shaper 18. The vibration sensors 16a to 16c detect vibration generated due to pulsating torque and convert the vibration into an electric signal, and a piezoelectric acceleration converter or the like which has been widely used in the past can be used. Further, the vibration sensors 16a to 16c are located near a position (14a or 14b) where the main motor 4 or the gear device 5 in which vibration due to the pulsating torque is likely to be generated is locked to the bogie frame 7 and a driving reaction force acts, or a vehicle body towing device. One of the structural members such as 11 to which the driving force or the braking force is transmitted
Or installed in multiple places.

The electric signals detected by the vibration sensors 16a to 16c are input to the band-pass filter 17, only the specific frequency component caused by the pulsating torque is extracted, and the waveform is shaped by the waveform shaper 18 to obtain the vibration detection signal.

The installation positions of the vibration sensors 16a to 16c and the set frequency of the bandpass filter 17 are excessive vibrations due to resonance in relation to the frequency of the pulsating torque generated in the electric vehicle drive system and the natural frequency of each member. It is desirable to confirm and determine the place and frequency where the noise occurs by confirming in advance by simulation calculation or experiment.

The vibration detection signal obtained by the vibration detection circuit 15 is input to the comparator 18 and compared with the reference value set by the reference value level generator 20. A pattern generator 21 receives the output from the comparator 19 and outputs a limit signal for limiting the driving force or the braking force in response to the output. Further, 22 is an amplifier, which is a limit signal from the pattern generator 21 and a current command value I _P for vehicle acceleration.
And the main motor current I _M detected by the DC transformer DCCT
Is input to output a gate signal to the inverter circuit 2. The inverter circuit 2, the comparator 19, the reference value level generator 20, the pattern generator 21, and the amplifier 22 constitute an inverter controller as the main controller 23.

Next, the first aspect of the present invention constructed as described above
The operation of the protection device for the electric vehicle drive system according to the embodiment will be described based on an example of operation waveforms shown in FIG. FIG. 3 shows a representative example of the operation waveforms of each part in the powering state from the start of the electric vehicle to the predetermined vehicle speed, and (a) in the figure shows the vibration detection signal obtained from the vibration detection circuit 15 as an inverter The operating waveforms of the vibration detection signal, the inverter frequency and the main motor current when the protective device of the present invention is not operated without returning to the control system are shown, and (b) shows the case when the protective device is normally operated. The operation waveforms are shown for comparison. According to the figure, when the protection device for the electric vehicle drive system of the present invention is not activated (FIG. 3 (A)), the inverter frequency also increases in response to the increase in vehicle speed and is included in the main motor generated torque. The frequency of the pulsating torque varies correspondingly (6n times the inverter frequency), but the frequency of the pulsating torque and the characteristic of the drive shaft system are specific when the inverter frequency reaches point A in a specific area (a) of FIG. The frequencies match,
It resonates and generates an excessive vibration detection signal.

On the other hand, in the case of FIG. 3B in which the protective device for the electric vehicle drive system of the present invention is normally operated, the vibration detection signal obtained from the vibration detection circuit 15 at the point B near the resonance point is the reference. The reference value set by the value level setter 20 is reached and the comparator 19 produces an output signal. In response to this, the pattern generator 21 outputs a limiting signal for limiting the driving force, and the limiting signal is input to the amplifier 22. Then, the pulsating torque is reduced because the driving force of the traction motor 4 is reduced by reducing the traction motor current command value I _P for accelerating the vehicle, and excessive vibration caused by this can be suppressed. Further, due to the decrease in the driving force, the vehicle acceleration also slightly decreases, but since the acceleration continues, the resonance point is exceeded at point (c) in FIG. 3 and the output signal of the comparator 19 is released, so that the driving force becomes a predetermined value. It is restored and vehicle acceleration continues.

As described above, in the embodiment of the present invention, it is possible to suppress the excessive vibration induced in the drive shaft system due to the pulsating torque included in the torque generated by the main motor 4, so that the electric vehicle can be suppressed. In addition to avoiding damage and shortening of life due to excessive vibration of the equipment that makes up the
It is possible to suppress deterioration of riding comfort due to noise.

FIG. 4 is a control block diagram showing a second embodiment of the protection device for the electric vehicle drive system of the present invention. The present embodiment is different from the embodiment of FIG. 1 in that the protection device for an electric vehicle drive system of the present invention is applied to an induction motor drive system for an AC electric vehicle. That is, the induction motor drive system for an AC electric vehicle employs the main transformer 41 whose primary side is connected to the pantograph 1 and the converters 42a and 42b which are connected to its secondary side.
Inverter circuit 2, comparator 19, reference level generator 2
0, the pattern generator 21 and the amplifier 22 constitute a main controller 43 for controlling the driving force or braking force of the main motor 4. In this case, the AC power supply supplied from the pantograph 1 is converted into DC by the converters 42a and 42b, but since the DC output voltage of the converters 42a and 42b contains the pulsating component of the double frequency of the input AC power supply, When the inverter frequency approaches this pulsation frequency, a beat phenomenon occurs in the main motor current, etc., and pulsating torque with twice the frequency of the AC power supply is generated, and vibrations corresponding to this are induced in each part of the drive shaft system. It In the protection device for the electric vehicle drive system of the present invention, the vibration caused by the pulsating torque is detected by the vibration detection circuit 15, and when the vibration detection signal exceeds the set reference value level, the driving force or the braking force is exceeded. Since the limiting signal is output and the driving force or the braking force is immediately reduced, it is possible to suppress the excessive pulsating torque and the vibration caused thereby, and to achieve the same effect as that of the first embodiment. In addition to the above, it is possible to suppress the generation of an excessive main motor current due to the beat phenomenon, and it is possible to avoid the system stoppage due to the overcurrent and the damage of the control element in the main control device 43.

The bandpass filter 17 in the second embodiment is set to a band including at least twice the frequency of the AC power supply.

[0023]

According to the present invention, the excessive pulsating torque generated by the main motor and the excessive vibration induced in each part of the drive system due to the excessive pulsating torque can be suppressed, so that the electric vehicle drive system is damaged. It is possible to avoid a decrease in the life and the life of the drive system, and the reliability of the drive system is significantly improved. Further, by suppressing excessive pulsating torque or vibration resulting from this, deterioration of riding comfort due to vibration and noise can be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a protection device for an electric vehicle drive system according to the present invention.

FIG. 2 is an explanatory view of a vehicle body towing device in the embodiment of FIG.

FIG. 3 is a waveform diagram illustrating an operation during power running in the embodiment of FIG.

FIG. 4 is a control block diagram showing another embodiment of the protection device for the electric vehicle drive system according to the present invention.

[Explanation of symbols]

15 ... Vibration detection circuit, 16a to 16c ... Vibration sensor, 1
7 ... bandpass filter, 18 ... waveform shaper, 19 ... comparator,
20 ... Reference level generator, 21 ... Pattern generator, 2
2 ... Amplifier, 23, 43 ... Main controller.

Claims (7)

[Claims] 1. A drive system for an electric vehicle including a main control device for controlling a rotational force of a main electric motor and an electric carriage having the main electric motor and a gear device mounted thereon, which is caused by a pulsating torque generated by the main electric motor. Then, the first means for detecting the vibration of the specific frequency induced in the drive system, the second means for comparing the output signal of the first means with the reference value signal, and the output signal of the first means. A protection device for an electric vehicle drive system, comprising: a third means for limiting a rotational force of the main electric motor based on a comparison result with a reference value signal. 2. The electric vehicle drive system according to claim 1, wherein the main control device for controlling the rotational force of the main electric motor comprises a variable voltage variable frequency inverter, and the main electric motor is a three-phase squirrel-cage induction motor. Protective device. 3. The electric machine according to claim 1, wherein the main control device for controlling the rotational force of the main electric motor comprises a converter and a variable voltage variable frequency inverter, and the main electric motor is a three-phase squirrel-cage induction motor. Car drive system protection device. 4. The vibration detecting means according to claim 1, wherein a vibration sensor for converting the vibration into an electric signal, and a vibration component of a specific frequency corresponding to the pulsating torque generated by the main motor are extracted from the electric output of the vibration sensor. And a protection device for an electric vehicle drive system including a bandpass filter. 5. The electric vehicle drive according to claim 3, wherein the bandpass filter installed in the vibration detecting means for extracting a vibrational component of a specific frequency is set to a band including a frequency twice as high as the AC voltage input to the converter. System protector. 6. The electric vehicle drive system protection device according to claim 1, wherein one or more vibration sensors as the first means are installed near a portion where a main motor or a gear device is locked to a bogie frame. . 7. The vibration sensor as the first means according to claim 1, wherein one or more vibration sensors are installed in a part of a member provided along a transmission path of a driving force or a braking force including a vehicle body towing device. Electric vehicle drive system protection device.