U.S. patent application number 10/428861 was filed with the patent office on 2003-10-30 for protecting device of electromobile.
Invention is credited to Ikkai, Yasufumi, Kondo, Yasuhiro, Tamaki, Satoshi.
Application Number | 20030202298 10/428861 |
Document ID | / |
Family ID | 16933621 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030202298 |
Kind Code |
A1 |
Tamaki, Satoshi ; et
al. |
October 30, 2003 |
Protecting device of electromobile
Abstract
A protecting device of electromobile has control device to
control the rotating speed of a motor on the basis of an
accelerator signal, a brake signal, and output signals from an
encoder sensor, a CS sensor, and a phase current detector, which
includes a device for detecting interruption of input of the output
signals and outputting detecting signal, a device for stopping
supply of electricity to the motor in response to the detecting
signal of the detecting device, a device for detecting a value of a
phase current of the motor and outputting a detecting signal when
the phase current is abnormal, and a device for stopping supply of
electricity to the motor in response to the detecting signal of the
phase current detecting device.
Inventors: |
Tamaki, Satoshi;
(Hirakata-shi, JP) ; Ikkai, Yasufumi; (Kobe-shi,
JP) ; Kondo, Yasuhiro; (Hirakata-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
16933621 |
Appl. No.: |
10/428861 |
Filed: |
May 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10428861 |
May 5, 2003 |
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09583018 |
May 30, 2000 |
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6580239 |
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09583018 |
May 30, 2000 |
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08874485 |
Jun 13, 1997 |
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6131057 |
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08874485 |
Jun 13, 1997 |
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08676418 |
Jul 8, 1996 |
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08676418 |
Jul 8, 1996 |
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08307053 |
Sep 16, 1994 |
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Current U.S.
Class: |
361/23 |
Current CPC
Class: |
B60L 50/51 20190201;
B60L 7/14 20130101; B60L 2240/427 20130101; B60L 2240/12 20130101;
Y02T 10/642 20130101; Y02T 10/64 20130101; B60L 2240/421 20130101;
B60L 2240/423 20130101; B60L 3/0046 20130101; B60L 58/15 20190201;
B60L 3/06 20130101; Y02T 10/7005 20130101; B60L 2240/429 20130101;
B60L 2240/425 20130101; B60L 3/04 20130101; Y02T 10/70 20130101;
B60L 2240/547 20130101; B60L 2240/549 20130101; B60L 2250/26
20130101; B60L 3/0023 20130101; B60L 3/0061 20130101; B60L 2220/14
20130101 |
Class at
Publication: |
361/23 |
International
Class: |
H02H 005/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 1993 |
JP |
5-232076 |
Claims
What is claimed is:
1. A protecting device of an electromobile having a control device
to control a rotating speed of a motor on the basis of a control
signal of the motor, which comprises: a detecting means for
detecting interruption of input of the control signal of the motor
and outputting a detecting signal; and a stopping means for
stopping supply of electricity to the motor in response to the
detecting signal of the detecting means.
2. The protecting device as claimed in claim 1, wherein the control
device controls the rotating speed of the motor on the basis of an
accelerator signal and a brake signal, and the detecting means is a
detecting means for detecting interruption of input of the
accelerator signal and outputting the detecting signal.
3. The protecting device as claimed in claim 1, wherein the control
device controls the rotating speed of the motor on the basis of an
accelerator signal, a brake signal, and an output signal from an
encoder sensor set in the motor, and the detecting means is a
detecting means for detecting interruption of input of the output
signal from the encoder sensor and outputting the detecting
signal.
4. The protecting device as claimed in claim 1, wherein the control
device controls the rotating speed of the motor on the basis of an
accelerator signal, a brake signal, and an output signal from a CS
sensor set in the motor, and the detecting means is a detecting
means for detecting interruption of input of the output signal from
the CS sensor and outputting the detecting signal.
5. The protecting device as claimed in claim 1, wherein the control
device controls the rotating speed of the motor on the basis of an
accelerator signal, a brake signal, and an output signal from a
phase current detector set in the motor, and the detecting means is
a detecting means for detecting interruption of input of the output
signal from the phase current detector and outputting the detecting
signal.
6. A protecting device of an electromobile having a control device
to control a rotating speed of a motor on the basis of an
accelerator signal and a brake signal, which comprises a current
detecting means for detecting a value of a phase current of the
motor and outputting a detecting signal, and a stopping means for
stopping supply of electricity to the motor when the phase current
of the motor is abnormal on the basis of the detecting signal of
the current detecting means.
7. A protecting device of an electromobile having a control device
to control a rotating speed of a motor using a primary battery as a
power source on the basis of an accelerator signal and a brake
signal, which comprises a current detecting means for detecting a
value of a current of the primary battery and outputting a
detecting signal, and a stopping means for stopping supply of
electricity to the motor when the current of the primary battery is
abnormal on the basis of the detecting signal of the current
detecting means.
8. A protecting device of an electromobile having a control device
to control a rotating speed of a motor using a primary battery as a
power source on the basis of an accelerator signal and a brake
signal, which comprises a voltage detecting means for detecting a
value of a voltage of the primary battery and outputting a
detecting signal, and a current limiting means for limiting a
current fed to the motor by a decreasing amount of the voltage of
the primary battery on the basis of the detecting signal of the
detecting means.
9. A protecting device of an electromobile having a control device
to control a rotating speed of a motor using a primary battery as
the power source on the basis of an accelerator signal and a brake
signal, which comprises a voltage detecting means for detecting a
value of a voltage of the primary battery and outputting a
detecting signal, and a current limiting means for controlling a
field-weakening current fed to the motor on the basis of the
detecting signal of the detecting means when the voltage of the
primary battery is abnormally increased, thereby reducing a
regenerative amount from the motor to the primary battery.
10. A protecting device of an electromobile having a control device
to control a rotating speed of a motor using a primary battery as a
power source on the basis of an accelerator signal and a brake
signal, and a control battery to supply electricity to the control
device, which comprises a voltage detecting means for detecting a
value of a voltage of the control battery and outputting a
detecting signal, and a stopping means for stopping supply of
electricity to the motor on the basis of the detecting signal of
the detecting means when the voltage of the control battery is
abnormally decreased.
11. A protecting device of an electromobile having a control device
to control a rotating speed of a motor on the basis of an
accelerator signal and a brake signal, which comprises a detecting
means for detecting overheat of the motor and outputting a
detecting signal, and a controlling means for stopping or limiting
supply of electricity to the motor in response to the detecting
signal of the detecting means.
12. A protecting device of an electromobile having an inverter
driving a motor and a control device to control a rotating speed of
the motor on the basis of an accelerator signal and a brake signal,
which comprises a detecting means for detecting overheat of a
switching element of the inverter and outputting a detecting
signal, and a controlling means for stopping or limiting supply of
electricity to the motor in response to the detecting signal of the
detecting means.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a protecting device for a
fail-safe purpose in case of a failure, an accident, etc. in an
electromobile incorporating a synchronous motor therein as a power
source.
[0002] The development of electromobiles has been rapidly
progressed from the viewpoint of countermeasures against
environmental problems, and the power source of an increasing
number of the recent electromobiles has been replaced with an
alternating current motor from a direct current motor because of
its advantageous points such as maintenance easiness and the like.
Particularly, a synchronous motor using a magnet as a rotor is
highly efficient, and therefore eagerly fitted for use in the
electromobiles. While the synchronous motor of this kind has
conventionally been widely used in the factory automation or
industrial field, the basic controlling system of the synchronous
motor used in electromobiles is almost the same as in the factory
automation or industrial usage.
[0003] However, because of the undeniable fact that human lives are
exposed to a high risk in vehicles, it is necessary to take all
possible fail-safe measures.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is therefore to provide
a protecting device of an electromobile designed to secure safety
in case of an emergency or abnormality.
[0005] In accomplishing these and other objects, according to a
first aspect of the present invention, there is provided a
protecting device of an electromobile having a control device to
control a rotating speed of a motor on the basis of a control
signal of the motor, which comprises:
[0006] a detecting means for detecting interruption of input of the
control signal of the motor and outputting a detecting signal;
and
[0007] a stopping means for stopping supply of electricity to the
motor in response to the detecting signal of the detecting
means.
[0008] According to a second aspect of the present invention, there
is provided the protecting device as described in the first
aspect,
[0009] wherein the control device controls the rotating speed of
the motor on the basis of an accelerator signal and a brake signal,
and
[0010] the detecting means is a detecting means for detecting
interruption of input of the accelerator signal and outputting the
detecting signal.
[0011] According to a third aspect of the present invention, there
is provided the protecting device as described in the first
aspect,
[0012] wherein the control device controls the rotating speed of
the motor on the basis of an accelerator signal, a brake signal,
and an output signal from an encoder sensor set in the motor,
and
[0013] the detecting means is a detecting means for detecting
interruption of input of the output signal from the encoder sensor
and outputting the detecting signal.
[0014] According to a fourth aspect of the present invention, there
is provided the protecting device as described in the first
aspect,
[0015] wherein the control device controls the rotating speed of
the motor on the basis of an accelerator signal, a brake signal,
and an output signal from a CS sensor set in the motor, and
[0016] the detecting means is a detecting means for detecting
interruption of input of the output signal from the CS sensor and
outputting the detecting signal.
[0017] According to a fifth aspect of the present invention, there
is provided the protecting device as described in the first
aspect,
[0018] wherein the control device controls the rotating speed of
the motor on the basis of an accelerator signal, a brake signal,
and an output signal from a phase current detector set in the
motor, and
[0019] the detecting means is a detecting means for detecting
interruption of input of the output signal from the phase current
detector and outputting the detecting signal.
[0020] According to a sixth aspect of the present invention, there
is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor on the basis
of an accelerator signal and a brake signal, which comprises a
current detecting means for detecting a value of a phase current of
the motor and outputting a detecting signal, and a stopping means
for stopping supply of electricity to the motor when the phase
current of the motor is abnormal on the basis of the detecting
signal of the current detecting means.
[0021] According to a seventh aspect of the present invention,
there is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor using a
primary battery as a power source on the basis of an accelerator
signal and a brake signal, which comprises a current detecting
means for detecting a value of a current of the primary battery and
outputting a detecting signal, and a stopping means for stopping
supply of electricity to the motor when the current of the primary
battery is abnormal on the basis of the detecting signal of the
current detecting means.
[0022] According to an eighth aspect of the present invention,
there is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor using a
primary battery as a power source on the basis of an accelerator
signal and a brake signal, which comprises a voltage detecting
means for detecting a value of a voltage of the primary battery and
outputting a detecting signal, and a current limiting means for
limiting a current fed to the motor by a decreasing amount of the
voltage of the primary battery on the basis of the detecting signal
of the detecting means.
[0023] According to a ninth aspect of the present invention, there
is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor using a
primary battery as the power source on the basis of an accelerator
signal and a brake signal, which comprises a voltage detecting
means for detecting a value of a voltage of the primary battery and
outputting a detecting signal, and a current limiting means for
controlling a field-weakening current fed to the motor on the basis
of the detecting signal of the detecting means when the voltage of
the primary battery is abnormally increased, thereby reducing a
regenerative amount from the motor to the primary battery.
[0024] According to a tenth aspect of the present invention, there
is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor using a
primary battery as a power source on the basis of an accelerator
signal and a brake signal, and a control battery to supply
electricity to the control device, which comprises a voltage
detecting means for detecting a value of a voltage of the control
battery and outputting a detecting signal, and a stopping means for
stopping supply of electricity to the motor on the basis of the
detecting signal of the detecting means when the voltage of the
control battery is abnormally decreased.
[0025] According to an eleventh aspect of the present invention,
there is provided a protecting device of an electromobile having a
control device to control a rotating speed of a motor on the basis
of an accelerator signal and a brake signal, which comprises a
detecting means for detecting overheat of the motor and outputting
a detecting signal, and a controlling means for stopping or
limiting supply of electricity to the motor in response to the
detecting signal of the detecting means.
[0026] According to a twelfth aspect of the present invention,
there is provided a protecting device of an electromobile having an
inverter driving a motor and a control device to control a rotating
speed of the motor on the basis of an accelerator signal and a
brake signal, which comprises a detecting means for detecting
overheat of a switching element of the inverter and outputting a
detecting signal, and a controlling means for stopping or limiting
supply of electricity to the motor in response to the detecting
signal of the detecting means.
BRIEF DESCRIPTION OF THE DRAWING
[0027] These and other objects and features of the present
invention will become clear from the following description taken in
conjunction with the preferred embodiments thereof with reference
to the accompanying drawings, in which:
[0028] FIG. 1 is a schematic structural diagram of an electromobile
provided with a protecting device of one embodiment of the present
invention; and
[0029] FIG. 2 is a block diagram of a control device of the
electromobile.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Before the description of the present invention proceeds, it
is to be noted that like parts are designated by like reference
numerals throughout the accompanying drawings.
[0031] Preferred embodiments of the present invention will be
described with reference to the drawings.
[0032] In FIG. 1, there is indicated the concept of a system of an
electromobile having a protecting device of one embodiment of the
invention incorporated therein. The electromobile uses a
synchronous motor under the field-weakening control.
[0033] As shown in FIG. 1, the electromobile carries out
appropriate operations or calculations including the
field-weakening control within a control device 1 when an
accelerator signal, an accelerator switch signal interlocking with
the accelerator signal and a brake signal are inputted to the
control device 1. In consequence, a motor 3 is commutated via a PWM
(pulse width modulation) inverter 2. The motor 3 is connected to
driving wheels (rear wheels) 6 via a transmission 4 and an axle 5.
An electromobile body 7 is started to move as the motor 3 is
rotated.
[0034] The electricity is supplied to the motor 3 from a primary
battery 8. A current and a voltage of the primary battery 8 are
monitored at the control device 1 with the use of a current
detector 9 and an isolator 10, respectively. At the same time, the
control device 1 monitors a voltage of a control battery 11 in
receiving electricity from the control battery 11. In the circuit
structure of FIG. 1, while a three-phase alternating current is
supplied to the motor 3 from the PWM inverter 2, the phase current
of the motor 3 is inputted to the control device 1 by current
detectors 12, 13. The phase current is thus controlled, and
moreover monitored as to whether the motor 3 is normal or
abnormal.
[0035] When the motor 3 is rotated, an encoder sensor 14 and a CS
sensor 15 both connected mechanically to a motor shaft 3a are
rotated, generating outputs to the control device 1. Accordingly,
the speed of the motor 3 and the positional data of a rotor of the
motor 3 are provided. Reference numeral 16 represents front
wheels.
[0036] The CS sensor, i.e., commutation sensor 15 detects the
position of magnetic poles of the rotor of the synchronous motor 3
thereby to determine to which coils the electricity is
supplied.
[0037] The encoder sensor 14 is a detecting means for detecting the
rotating position of the rotor, and outputs pulse trains of two
phases in general, namely, A-phase and B-phase pulses shifted
90.degree. from reference pulses (Z-phase pulses; one pulse per one
360.degree. rotation). Owing to the shift of the phase, the encoder
sensor 14 can detect the rotating direction of the rotor. Moreover,
the encoder sensor 14 detects the rotating angle of the rotor by
counting the pulse trains.
[0038] The rotating angle and the rotating speed are detected in a
manner as will be detailed hereinbelow.
[0039] For instance, supposing that 1000 pulses are generated per
one rotation of the motor 3 when only the leading edges of the
A-phase and B-phase pulses are counted, the 500th pulse counted
from the Z-phase pulse corresponds to the fact that the rotor is at
the 180.degree. phase. The speed of the motor 3 is detected by
counting the number of A-phase or B-phase pulses within a fixed
time interval. For example, the motor 3 is rotated twice in one
second if 2000 pulses are counted in one second, that is, the motor
3 is rotated at 120 rpm.
[0040] The CS sensor 15 may be considered to be substantially
unnecessary so long as outputs can be obtained from the encoder
sensor 14, because the output signal of the encoder sensor 14
itself indicates the rotating angle of the rotor. However, since
the encoder signal becomes effective only after the reference
Z-phase pulse is inputted, the current to the coils is commutated
in accordance with the output of the CS sensor until the Z-phase
pulse is inputted, and the commutating timing of the current to the
motor 3 is produced based on the Z-phase pulse after the Z-phase
pulse is inputted.
[0041] In other words, the commutating timing of the current to the
coils is fabricated with the use of outputs of the CS and encoder
sensors so as to control the motor 3. Moreover, a signal to show
the actual rotating speed of the motor 3 is generated to control
the speed of the motor 3.
[0042] Unless following signals are correctly inputted to the
control device 1 in the above-described system of the
electromobile, it is impossible to protect the electromobile not to
be endangered. As such, the protecting device is adapted to monitor
the following signals concurrently for the fail-safe driving: of
the electromobile by means of the built-in function in the control
device 1.
[0043] (A) to detect interruption of signals:
[0044] 1) accelerator signals
[0045] 2) output signals from the encoder sensor 14
[0046] 3) output signals from the CS sensor 15
[0047] 4) output signals from the phase-current detectors 12,13 of
the motor 3
[0048] (B) to detect currents:
[0049] 1) phase current of the motor 3
[0050] 2) current of the primary battery 8
[0051] (C) to detect voltages of batteries:
[0052] 1) voltage of the primary battery 8
[0053] 2) voltage of the control battery 11
[0054] (D) to detect overheat:
[0055] 1) motor 3
[0056] 2) switching element of the PWM inverter 2
[0057] In the embodiment, the control device 1 includes an
accelerator signal interruption detecting means 30, an encoder
sensor interruption detecting means 31, a CS sensor signal
interruption detecting means 32, a motor phase current sensor
signal interruption detecting means 33, a motor phase current
abnormality detecting means 34, a primary battery current
abnormality detecting means 35, a primary battery high voltage
detecting means 36, a primary battery low voltage detecting means
37, a control power supply voltage decrease detecting means 40, a
switching element overheat detecting means 41, a motor overheat
detecting means 42, an abnormality processing circuit 38 connected
to the above means 30-37 and 40-42, a current command control
circuit 43, a motor control circuit 39 connected to the abnormality
processing circuit 38 via the current command control circuit 43,
and a current command integrating means 44 which connects the
current command control circuit 43 and the abnormality processing
circuit 38, as shown in FIG. 2. These means 30-37, 40-42, and 44
and circuits 38, 39, 43 incorporated in the control device 1 of
FIG. 1 to fulfill the fail-safe function are described
hereinbelow.
[0058] The accelerator signal interruption detecting means 30
detects interruption of inputs of accelerator signals.
[0059] The encoder sensor interruption detecting means 31 detects
interruption of inputs of signals from the encoder sensor 14.
[0060] The CS sensor signal interruption detecting means 32 detects
interruption of inputs of signals from the CS sensor 15.
[0061] The motor phase current sensor signal interruption detecting
means 33 detects interruption of inputs of signals from the phase
current detectors 12, 13.
[0062] The motor phase current abnormality detecting means 34
detects abnormality of a value of the phase current of the motor
3.
[0063] The primary battery current abnormality detecting means 35
detects a value of the current of the primary battery 8.
[0064] The primary battery high voltage detecting means 36 detects
a value of the voltage of the primary battery 8.
[0065] The primary battery low voltage detecting means 37 detects a
value of the voltage of the primary battery 8.
[0066] The control power supply voltage decrease detecting means 40
detects a value of the voltage of the control battery 11.
[0067] The switching element overheat detecting means 41 detects
overheat of the switching element of the PWM inverter 2.
[0068] The motor overheat detecting means 42 detects overheat of
the motor 3.
[0069] The abnormality processing circuit 38 outputs a signal for
stopping control of the motor 3, that is, stopping the supply of
electricity to the motor 3 (the expression "stop control" means to
stop the supply of electricity to the motor, which applies to the
whole of the description below. If the control might be stopped,
the electromobile runs by inertia.) to the motor control circuit 39
via the current command control circuit 43 in response to the
detecting signal of one of the above detecting means 30-37 and
40-42. That is, the abnormality processing circuit 38 outputs a
signal for stopping control of the motor 3 when the phase current
of the motor 3 is abnormal on the basis of the detecting signal of
the motor phase current abnormality detecting means 34, a signal
for stopping control of the motor 3 when the current of the primary
battery 8 is abnormal on the basis of the detecting signal of the
primary battery current detecting means 35, a signal for limiting
the current fed to the motor 3 by the decreasing amount whereby the
voltage of the primary battery 8 is decreased on the basis of the
detecting signal of the primary battery low voltage detecting means
37, a signal for controlling the field-weakening current fed to the
motor 3 when the voltage of the primary battery 8 is abnormally
increased on the basis of the detecting signal of the primary
battery high voltage detecting means 36 thereby to reduce the
regenerative amount from the motor 3 to the primary battery 8, a
signal for stopping control of the motor 3 when the voltage of the
control battery 11 is abnormally decreased on the basis of the
detecting signal of the control battery voltage decrease detecting
means 40, a signal for stopping or controlling the supply of
electricity to the motor 3 in response to the detecting signal of
the motor overheat detecting means 42, and a signal for stopping or
controlling the supply of electricity to the motor 3 in response to
the detecting signal of the switching element overheat detecting
means 41.
[0070] The fail-safe control operation exerted by each means will
be discussed below.
[0071] The accelerator signal interruption detecting means 30
detects that inputting of accelerator signals is interrupted and a
signal indicating this condition is inputted in the abnormality
processing circuit 38, the supply of electricity to the motor 3 is
stopped via the current command control circuit 43, the motor
control circuit 39, and the PWM inverter 2, so that the abnormal
rotation of the motor 3 is prevented, thus securing the safety.
[0072] The encoder sensor interruption detecting means 31 detects
that inputting of output signals from the encoder sensor 14 is
interrupted and a signal indicating this condition is inputted in
the abnormality processing circuit 38, the supply of electricity to
the motor 3 is stopped via the current command control circuit 43,
the motor control circuit 39, and the PWM inverter 2, so that the
abnormal rotation of the motor 3 is prevented, and the safety is
secured. As one example of the concrete structure and operation for
the fail-safe function at detecting interruption of accelerator
signals or disconnection,
[0073] The CS sensor signal interruption detecting means 32 detects
that inputting of output signals from the CS sensor 15 is
interrupted and a signal indicating this condition is inputted in
the abnormality processing circuit 38, the supply of electricity to
the motor 3 is stopped via the current command control circuit 43,
the motor control circuit 39, and the PWM inverter 2, thereby to
prevent the abnormal rotation of the motor 3, with the safety
secured.
[0074] The motor phase current sensor signal interruption detecting
means 33 detects that inputting of the output signal from the phase
current detectors 12 or 13 is interrupted and a signal indicating
this condition is inputted in the abnormality processing circuit
38, the abnormal rotation of the motor 3 is prevented by stopping
the supply of electricity to the motor 3 via the current command
control circuit 43, the motor control circuit 39, and the PWM
inverter 2, so that the safety is secured.
[0075] The motor phase current abnormality detecting means 34
detects that the phase current of the motor 3 is turned abnormal
and a signal indicating this condition is inputted in the
abnormality processing circuit 38, the supply of electricity to the
motor 3 is stopped to prevent the abnormal rotation of the motor 3
via the current command control circuit 43, the motor control
circuit 39, and the PWM inverter 2, and the safety is secured.
[0076] The primary battery current abnormality detecting means 35
detects that the current of the primary battery 8 becomes abnormal
and a signal indicating this condition is inputted in the
abnormality processing circuit 38, the supply of electricity to the
motor 3 is stopped via the current command control circuit 43, the
motor control circuit 39, and the PWM inverter 2 to prevent the
abnormal rotation of the motor 3, thereby to secure the safety.
[0077] The primary battery low voltage detecting means 37 detects
that the voltage of the primary battery 8 is decreased and a signal
indicating this condition is inputted in the abnormality processing
circuit 38, the current fed to the motor 3 is limited by the
decreasing amount of the voltage via the current command control
circuit 43, the motor control circuit 39, and the PWM inverter 2.
Therefore, the motor 3 is slowed, decelerating the electromobile,
restricting the consumption of the primary battery 8, thus securing
the safety.
[0078] The primary battery high voltage detecting means 36 detects
that the voltage of the primary battery 8 is abnormally increased
and a signal indicating this condition is inputted in the
abnormality processing circuit 38, the field-weakening current fed
to the motor 3 is controlled via the current command control
circuit 43, the motor control circuit 39, and the PWM inverter 2,
thereby to reduce the regenerative amount from the motor 3 to the
primary battery 8. Accordingly, overcharging of the primary battery
8 is prevented, and the primary battery 8 is protected, and the
safety is secured. This field-weakening control is described in,
for example, "Flux-Weakening Regime Operation of an Interior
Permanent-Magnet Synchronous Motor Drive" by Thomas M. Jahns of
IEEE Transactions on Industry Applications, Vol. IA-23, No.4,
July/August 1987, and European Patent Publication No. 0 503 879 A2,
and a U.S. patent application filed on September 1994, entitled
"METHOD AND APPARATUS FOR CONTROLLING MOTOR", claiming three
priority rights based on Japanese Patent Application Nos. 5-232075,
5-232077, and 5-232080.
[0079] The control power supply voltage decrease detecting means 40
detects that the voltage of the control battery 11 is abnormally
decreased and a signal indicating this condition is inputted in the
abnormality processing circuit 38, the supply of electricity to the
motor 3 is stopped via the current command control circuit 43, the
motor control circuit 39, and the PWM inverter 2, the abnormal
rotation of the motor 3 resulting from the abnormality of the
control device 1 is prevented, thereby securing the safety.
[0080] The switching element overheat detecting means 41 detects
that the switching element of the PWM inverter 2 is overheated and
a signal indicating this condition is inputted in the abnormality
processing circuit 38, the supply of electricity to the motor 3 is
stopped or limited via the current command control circuit 43, the
motor control circuit 39, and the PWM inverter 2, and therefore,
the generation of heat from the switching element is restricted.
The switching element of the PWM inverter 2 is protected and the
safety is secured.
[0081] The motor overheat detecting means 42 detects that the motor
3 is overheated and a signal indicating this condition is inputted
in the abnormality processing circuit 38, the supply of electricity
to the motor 3 is stopped or limited via the current command
control circuit 43, the motor control circuit 39, and the PWM
inverter 2, and therefore the generation of heat from the motor 3
is suppressed and the motor 3 is protected, ensuring the
safety.
[0082] The concrete structure and operation for the fail-safe
function will now be described in detail hereinbelow.
[0083] [1] to Detect Interruption of Signals (to Detect
Disconnection):
[0084] (1) Accelerator Signals
[0085] Supposing that 5V represents the maximum speed in a system
wherein the level of accelerator signals changes from 0V to 5V, it
never happens that a signal larger than 5V is inputted. Therefore,
if it is detected by the means 30 that a value larger than 5V is
outputted during monitoring of the accelerator signals, the above
fail-safe control is carried out.
[0086] (2) Output Signals From the Encoder Sensor 14 and CS Sensor
15
[0087] If the encoder sensor and CS sensor signal interruption
detecting means 31, 32 detect that these signals from the sensors
14, 15 are not inputted, the control device 1 cannot recognize the
speed of the motor 3 and the position of the rotor. Therefore, the
above failsafe control is carried out.
[0088] (3) Detector of the Phase Current of the Motor 3
[0089] The change of output values of the phase current detector
12, 13 which results from the disconnection of a line of a power
source (+15V, -15V, GND) for driving the phase current detectors
12, 13 is monitored by the motor phase current sensor signal
interruption detecting means 33. The above fail-safe control is
carried out when the disconnection is detected by the motor phase
current sensor signal interruption detecting means 33.
[0090] [2] to Detect Currents:
[0091] (1) Phase Current of the Motor 3
[0092] When the motor phase current abnormality detecting means 34
detects that the output from one of the phase current detectors 12,
13 corresponds to a value not conceivable from the characteristic
viewpoint of the motor 3, the fail-safe control is carried out.
[0093] (2) Current of the Primary Battery 8
[0094] When the primary battery current abnormality detecting means
35 detects that the detected output from the current detector 12 or
13 corresponds to a value not conceivable from the characteristic
viewpoint of the primary battery 8, the fail-safe control is
carried out.
[0095] [3] to Detect Voltages of Batteries:
[0096] (1) Voltage of the Primary Battery 8
[0097] I) Decrease
[0098] When the primary battery low voltage detecting means 37
detects that the voltage of the primary battery 8 is decreased and
nothing other than the voltage of the primary battery 8 is
abnormal, the current of the motor 3 is limited by the decreasing
amount of the voltage thereby to lower the speed of the
electromobile under the above fail-safe control.
[0099] II) Increase
[0100] When the primary battery high voltage detecting means 36
detects that the voltage of the primary battery 8 is increased due
to the regeneration so much as deteriorates' the characteristic of
the primary battery 8, the field-weakening current is controlled
under the above fail-safe control, thereby to decrease the
regenerative amount.
[0101] (2) Voltage of the Control Battery 11
[0102] When the voltage of the control battery 11 is decreased, the
control device 1 erroneously may operate. In order to solve the
problem, the voltage of the control battery 11 is monitored by the
control power supply voltage decrease detecting means 40, and the
fail-safe control is carried out when the means 40 detects that the
voltage becomes abnormal.
[0103] [4] to Detect Overheat:
[0104] (1) The temperature of the motor 3 and the switching element
of the PWM inverter 2 is monitored with the use of a thermostat
which outputs the switching element temperature sensor signals to
the switching element overheat detecting means 41 and the motor
overheat detecting means 42. When the temperature is not lower than
a predetermined value, the supply of electricity to the motor 3 is
stopped under the fail-safe control.
[0105] (2) Instead of the above temperature measurement, the
current values fed to the motor 3, that is, current commands fed
from the abnormality processing circuit 38 to the motor control
circuit 39 via the current command control circuit 43 are
sequentially integrated by the current command integrating means 44
and the integrated values are inputted to the abnormality
processing circuit 38. The output of the motor 3 is controlled to
be decreased when the integrated value found by the current command
integrating means 44 exceeds a predetermined value.
[0106] In the case where an abnormality is brought about while the
field-weakening current is running, needless to say, the
field-weakening current should not be quickly dropped so as to
protect the primary battery 8.
[0107] In the protecting device, the supply of electricity to the
motor is stopped when inputting of accelerator signals is
interrupted, so that the abnormal rotation of the motor is
prevented and the safety is secured.
[0108] The supply of electricity to the motor is stopped when
inputting of output signals from the encoder sensor is interrupted,
so that the abnormal rotation of the motor is prevented and the
safety is secured.
[0109] The supply of electricity to the motor is stopped when
inputting of output signals from the CS sensor is interrupted, so
that the abnormal rotation of the motor is prevented and the safety
is secured.
[0110] The supply of electricity to the motor is stopped when
inputting of output signals from the phase current detector is
interrupted, so that the abnormal rotation of the motor is
prevented and the safety is secured.
[0111] The supply of electricity to the motor is stopped when the
phase current of the motor is abnormal, so that the abnormal
rotation of the motor is prevented and the safety is secured.
[0112] The supply of electricity to the motor is stopped when the
current of the primary battery is abnormal, so that the abnormal
rotation of the motor is prevented and the safety is secured.
[0113] The current fed to the motor is limited by the decreasing
amount whereby the voltage of the primary battery is decreased, and
the speed of the motor is lowered, so that the electromobile is
slowed down, with the consumption of the primary battery suppressed
and the safety secured.
[0114] The field-weakening current fed to the motor is controlled
when the voltage of the primary battery is abnormally increased,
thereby reducing the regenerative amount from the motor to the
primary battery, preventing overcharging of the primary battery and
securing the safety.
[0115] The supply of electricity to the motor is stopped when the
voltage of the control battery is abnormally decreased, so that the
abnormal rotation of the motor due to the abnormality of the
control device is prevented and the safety is secured.
[0116] The supply of electricity to the motor is stopped or limited
when overheat of the motor is brought about, so that the generation
of heat from the motor is restricted, the motor is protected,
thereby securing the safety.
[0117] The supply of electricity to the motor is stopped or limited
when the switching element of the PWM inverter is overheated,
thereby to suppress the generation of heat from the switching
element and protect the switching element, while the safety is
secured.
[0118] Although the present invention has been fully described in
connection with the preferred embodiment thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications are apparent to those skilled in the art. Such
changes and modifications are to be understood as included within
the scope of the present invention as defined by the appended
claims unless they depart therefrom.
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