Illlll|l||l|||||l|||l|||||||||l|Illll|l||||H|l||||||||||||||||llllllllllll
`US005623104A
`
`United States Patent
`
`[191
`
`[11] Patent Number:
`
`5,623,104
`
`Suga
`
`[45] Date of Patent:
`
`Apr. 22, 1997
`
`[54] APPARATUS FOR TESTING POWER
`PERFORMANCE OF ELECTRIC MOTOR
`FOR ELECTRIC VEHICLE
`
`5,262,717
`
`11/1993 Bolegoh .
`
`FOREIGN PATENT DOCUMENTS
`
`[75]
`
`Inventor: Hiroshi Suga, Toyoake, Japan
`
`[73] Assignee: Toyota Jidosha Kabushiki Kaisha,
`Toyota, Japan
`
`[21] Appl. No.: 593,971
`
`[22]
`
`Filed:
`
`Jan. 30, 1996
`
`[30]
`
`Foreign Application Priority Data
`
`Mar. 10, 1995
`
`[JP]
`
`Japan .................................... 7-051385
`
`Int. Cl.5 ...................................................... .. G01L 3/00
`[51]
`[52] U.S. Cl.
`..................................... 73/862.18; 73/862.17;
`73/117
`
`[58] Field of Search .......................... .. 73/862.18, 862.17,
`73/862.09, 117, 117.1; 364/551.01
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`8/1975 Knoop et al.
`...................... .. 73/862.18
`3,898,875
`3/1981 Ono et al.
`73/862.18
`4,257,261
`
`5/1983 Ono ...................................... 73/862.18
`4,382,388
`4,422,040 12/1983 Raider et al. .
`4,442,708
`4/1984 Gable et al.
`....................... .. 73/862.18
`4,672,288
`6/1987 Abbondanti.
`4,860,231
`8/1989 Ballard et a1.
`4,965,513
`10/1990 Haynes et al.
`
`.
`.
`
`6/1984
`59-104571
`6/1984
`59—l11071
`9/1991
`3—212194
`4—348289 12/1992
`6-66653
`3/1994
`
`Japan .
`Japan .
`Japan .
`Japan.
`Japan.
`
`Primary Examiner—Richard Chilcot
`Assistant Examiner—Rona1d Biegel
`Attorney, Agent, or Firm—Ob1on, Spivak, McClelland,
`Maier & Neustadt, P.C.
`
`[57]
`
`ABSTRACT
`
`A test motor 2 is controlled by a controller 7 in accordance
`with travelling pattern (i.e. vehicle speed) data of an electric
`vehicle. A load motor 3 is controlled by a controller 9 in
`accordance with a load pattern. A host controller 10 gener-
`ates the load pattern based on the vehicle speed pattern and
`factors of the electric vehicle, and synchronously outputs the
`vehicle speed pattern and the load pattern to the controller 7
`and 9, respectively. Data detected by a torque sensor 4 or
`other measuring element are input to the host controller 10
`to generate a two-dimensional map showing the relationship
`between the motor efficiency and motor output, or between
`the motor efliciency and revolution speed. Since the load
`pattern is generated and input in advance without using
`feedback control,
`test results can be obtained with high
`accuracy.
`
`6 Claims, 10 Drawing Sheets -
`
`
`
` HOST
`CONTROLLER
`
`LOAD PATTERN
`
`GENERATION
`
`
`
`11
`
`Page 1 of 15
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`FORD 1454
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`Page 1 of 15
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 1 of 10
`
`5,623,104
`
`Bo:
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`Page 2 of 15
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`4541DROF
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`Page 2 of 15
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`FORD 1454
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`

`
`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 2 of 10
`
`5,623,104
`
`START
`
`INPUT VEHICLE SPEED DATA BASED
`ON TRAVELLING PATTERN DATA
`
`CALUCULATE ACCELERATION DATA
`FROM MOMENT TO MOMENT
`
`
`
`
`CALUCULATE TORQUE FOR LOAD MOTOR BASED
`ON RUNNING RESISTANCE, TIRE DIAMETER,
`VEHICLE WEIGHT, GEAR RATIO, ETC.
`
`
`
`
`GENERATE REVOLUTION SPEED
`PATTERN FOR TEST MOTOR
`
`’
`
`GENERATE TORQUE PATTERN FOR LOAD MOTOR
`
`SYNCHRONIZED WITH THE REVOLUTION
`
`
`
`SPEED PATTERN FOR TEST MOTOR
`
`3101
`
`S102
`
`S103
`
`S104
`.
`
`I
`
`S1 05
`
`SYNCHRONOUSLY CONTROL BOTH
`TEST MOTOR AND LOAD MOTOR
`
`.
`
`S106
`
`INPUT AND ANALIZE MEASURED DATA
`
`5107
`
`-311
`
`Fig. 2
`
`Page 3 of 15
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`FORD 1454
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`Page 3 of 15
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 3 of 10
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`5,623,104
`
`100012001400
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`
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`
`VEHICLE SPEED [km/h]
`
`Page 4 of 15
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`FORD 1454
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`Page 4 of 15
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 4 of 10
`
`5,623,104
`
`600800100012001400
`
`400
`
`200
`
`Fig.4
`
`[sec]
`
`Page 5 of 15
`
`.
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`FORD 1454
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`Page 5 of 15
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 5 of 10
`
`5,623,104
`
`TIME
`
`
`
`(B)MOTOR2
`
`SPEED
`
`a:
`
`O I
`
`- O E 3
`
`5
`
`Page 6 of 15
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`FORD 1454
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`Page 6 of 15
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`FORD 1454
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`

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`U.S. Patent
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`Apr. 22, 1997
`
`Sheet 6 of 10
`
`5,623,104
`
`POWERING
`
`
`
`0MOTOROUTPUT
`
`REGENERATION
`
`QL
`
`
`
`
`
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`MOTOR EFFICIENCY E
`
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`
`Page 7 of 15
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`E
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`‘
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`FORD 1454
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`Page 7 of 15
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 7 of 10
`
`5,623,104
`
`POWERING
`
`
`
`0MOTOROUTPUT
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
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`1%UPHILLGRADIENTINLA#4
`
`IIIIIIIIIIIIIIIIIIII
`IIIIIIIIIIIIIIIIIIII
`IIIIIIIIIIIIIIIIIIII
`IIIIIIIIIIIIIIIIIIII
`IIHIIIIIIIIIIIIIIIII
`IIIIIIIIIIIIIIIIIIII
`
`IIIIIIIIIIIIIIIIIIII
`
`IIEIIIIIIIIIIIIIIIII
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`ZIEHIIIIIIIIIIIIIIII
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`
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`MOTOR EFFICIENCY
`
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`
`O O (
`
`5
`
`Page8of15
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`FORD1454
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`Page 8 of 15
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`FORD 1454
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`

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`Page 9 of 15
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 9 §f 10
`
`5,623,104
`
`TORQUE [Nm]
`
`MOTOR EFFICIENCY [%]
`D
`
`~
`
`V
`
`Fig.9
`
`"T 2.,
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`REVOLUTION SPEED [rpm]
`
`Page 10 of 15
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`FORD 1454
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`FORD 1454
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`

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`U.S. Patent
`
`Apr. 22, 1997
`
`Sheet 10 of 10
`
`5,623,104
`
`
`
`
`
`REVOLUTIONSPEED[rpm]
`
`Fig.10
`
`[um] anouoi uoxow
`
`Page 11 of 15
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`«
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`FORD 1454
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`Page 11 of 15
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`FORD 1454
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`

`
`1
`APPARATUS FOR TESTING POWER
`PERFORMANCE OF ELECTRIC MOTOR
`FOR ELECTRIC VEHICLE
`
`BACKGROUND OF THE INVENTION
`
`5,623,104
`
`2
`
`order to reduce the time delay, the accuracy of the micro-
`computer must be improved, which results in increased cost.
`
`SUMMARY OF THE INVENTION
`
`This invention was conceived in view of the above-
`
`10
`
`This invention relates to an apparatus for testing electric
`mentioned problems and it is an object of the invention to
`motor performance, and more particularly to an apparatus
`provide an apparatus for testing the power performance of
`for testing the power performance of an electric motor for an
`an electric motor which realizes highly accurate and effec-
`electric vehicle.
`tive testing of a test motor.
`.
`.
`In order to achieve the object, a test apparatus of the
`Generally: When eValuat1n8 the Pertorrnance oranelectric
`invention carries out apower performance test of an electric
`motor (hereinafter referred to as a test motor) on a test
`motor for an electric vehicle by driving an electric motor to
`bench» Perrorrnance testing is carried out under tWo diderent
`he mounted on an electric Vehicle and a Ioad motor con-
`evaluation circumstances,
`i.e. evaluation under constant
`i5 nected to the electric motor. The test apparatus comprises
`conditions (With constant reVolution and constant torque)
`electric motor control means for controlling the electric
`and CVa1Uati0I1 Under aCCC1eI‘atIOIl/deCC1eI'3.tiOII 0pefati0I1S.
`motor in accordance with a predetermined travelling pattern
`Test driVing With acceleration/deceleration olierations fur‘
`of the electric vehicle, load motor control means for con-
`ther includes a sirnple driVing Pattern and arnode simulating
`troiiing the ioad motor in accordance with a predetermined
`for actual travel of a vehicle. Under the simulation mode, the
`loaa pattern, and main control Ineans for synchronously
`Inotor revolution IS controlled so
`the Vehicle Speed 20
`controlling an operation timing of the electric motor control
`indicates a Predeterrnined running Pattern (for example:
`means and the ioad motor controi means
`LA#4 mode based on actual driving in Los Angeles, Calif),
`In this structure, the main controller synchronously con-
`wlllll? gellelatlllg ll teslstllllce collespolldlllg toiall acllllll
`trols the electric motor control means and load motor control
`llllllllllg leslstallce llslllg 9‘ load motor‘
`Controlling or the running resistance is carried out by 25 means in accordance with apredetermined speed pattern and
`computing a load on the vehicle based on the revolution of
`a predetermined ioad pattern, respectiveiy, rather than using
`the test rnotor (i-e- Vehicle speed) and outputting the coin‘
`a conventional feedback control to determine a torque for
`puted
`Value to the load motor. The load motor has 3.
`the load motor_ Accordingly’ Control delay arising from a
`computing unit for calculating the running resistance in its
`feedbackldelay is obviated, and also, errors in torque com-
`control sYstern-
`30 mand values caused by detection error in acceleration can be
`Conventionally, several techniques are known for calcu-
`avoided. Consequently, accurate test results of the power
`lating running resistance. One technique is to calculate a
`performance of the motor are obtained.
`load from a load map which is preset in response to a vehicle
`The apparatus for testing the performance of the eiectric
`speed. In this case, the test bench should be provided with
`motor further comprises means for generating the Ioad
`an element haVing an inertia equiValent to the Vehicle inertia 35 pattern based on the travelling pattern and various factors of
`(e-g- a hYWheel) and resistance equivalent to the Vehicle
`the electric vehicle. By simply setting the travelling pattern
`sPeed is aPPlied to the test apparatus as a load
`and the values of the electric vehicle factors, the load pattern
`Alternatively, load may be calculated based on a feedback
`is automatically generated and performance tests under
`speed/acceleration of the load motor, vehicle weight, air
`various travelling conditions are easily realized without
`resistance factor, etc. When carrying out a performance test 40 complicated process for generating the load pattern.
`on a test bench using this technique, feedback speed and
`The apparatus for testing the performance of the eiectric
`acceleration of the load motor must be accurately measured
`motor further comprises detection means for detecting at
`to ProVide an aPProPriate load in accordance With the
`least torque, revolution speed, driving electric current and
`measurement result-
`driving voltage, and map generation means for generating a
`Japan Laid Open (Kokai) H3-212194 discloses a structure 45
`two-dimensional map showing the relationship between the
`of outputting a speed command (torque command) to the test
`output torque of the electric motor and the motor efiiciency
`motor in accordance with a travelling schedule of the
`based on the detected values.
`VehiC1C,
`outputting to the 103d motor 3. I'CSiStaIICC
`The map generation means may generate a tw0_djmen_
`(torque) corresponding to traVelling conditions at the reed‘
`sional map showing the relationship .between the revolution
`back sPeed and acceleration Each of the operations are 50
`speed of the electric motor and the motor efliciency based on
`controlled by a microcomputer.
`the detected values
`However, in the former technique using a flywheel, the
`By generating atwo_dimensionaI map containing ar,hysi_
`mechanical strength of the test bench must be reinforced in
`cai Value of the efficiency,
`the tendency of the motor
`order to mount the flywheel, which causes the test apparatus 55 performance is easiiy understood_
`to become llllgel as well as more expellSlVe'
`Other objects and advantages will be apparent from the
`On the other hand: in calculating a load based on the
`detailed description of the embodiment with reference to the
`feedback speed and acceleration of the load motor (in the
`drawings
`latter technique), it is difiicult to detect an acceleration with
`high accuracy due to the influence of discrete errors in no
`digital systems and the influence of noise in analogue
`systems. The detection errorin acceleration may provide an
`unrealistic load value and prevent
`the providing of an
`appropriate running resistance.
`Furthermore, presence of time delay is inevitable during 65
`the measurement of the fedback speed and acceleration, and
`it adversely affects reproduction of the measured value. In
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`_
`_
`_
`_
`FlG- l is a scheniatic diagrarn or a test aPParatus in
`accordance With the inVent1on-
`FIG. 2 is a flowchart showing operations of the test
`aPParatus or FlG- 1-
`FIG. 3 illustrates a travelling pattern of LA#4 used in the
`embodiment.
`
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`3
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`4
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`5,623,104
`
`FIG. 4 illustrates a torque pattern used in the embodiment
`which corresponds to the travelling pattern of FIG. 3.
`FIG. 5 illustrates a revolution speed and a torque which
`are output from the host computer 10 to the test motor and
`load motor, respectively.
`FIG. 6 shows evaluation results for a 0% uphill gradient
`obtained by the test apparatus in accordance with the
`embodiment, mapped on a two-dimensional map of motor
`efliciency vs. motor output.
`FIG. 7 shows evaluation results for a 1% uphill gradient
`obtained by the test apparatus in accordance with the
`embodiment.
`
`FIG. 8 shows another display example of evaluation
`results mapped on a graph with torque vs. revolution speed.
`FIG. 9 shows still another display example of evaluation
`results showing torque, revolution speed and motor elli-
`ciency.
`FIG. 10 shows evaluation results obtained by a conven-
`tional test apparatus.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`FIG. 1 shows a system structure in accordance with one
`embodiment of the invention. A test motor 2 and a load
`motor 3, which are mechanically connected to each other
`through a coupling shaft, are set on a test bench 1. A torque
`sensor 4 is provided on the coupling shaft to detect an output
`torque of the test motor 2. An inverter 6 is connected to the
`test motor 2 and an inverter 8 is connected to the load motor
`3. Switching operation of the invertor 6 is controlled by a
`controller 7 which serves as an electric motor controlling
`means, while switching operation of the inverter 8 is con-
`trolled by a controller 9 which serves as a load motor control
`means. The inverters 6 and 8 are connected to a DC power
`source 11 and convert
`the direct current
`to alternating
`current to drive the respective motors 2 and 3. The control-
`lers 7 and 8 are connected via a dedicated data bus 12 to a
`host controller 10 which serves as a high order main
`controlling means to generally control the two motors. The
`host controller 10 comprises a motor interface unit, a mea-
`surement control unit, and a display analysis unit which
`functions as a map generation unit 10b as will be described
`below. The host controller 10 outputs a high-speed sync
`signal at an electrically constant time period from the motor
`interface unit and supplies it via the dedicated data bus 12 to
`the controllers 7 and 9 for a synchronizing operation com-
`mand. Since the controllers 7 and 9 generate their own
`control signal based on the sync signal, the synchronism of
`the motors 2 and 3 are assured. The high-speed sync signal
`provides an operation command at a shorter time period than
`the mechanical time constant of both the motors 2 and 3,
`which allows various driving patterns ranging from a simple
`pattern to a complicated operation pattern.
`The host controller 10 further includes a load pattern
`generation unit 10a for calculating a load pattern from the
`various vehicle factors in the travelling mode, details of
`which will be described below.
`
`A measure unit 13 is provided to detect various param-
`eters such as a revolution speed, electric current and voltage
`of the test motor 2. The detection signals from the measure
`unit 13 as well as a detection signal from a torque sensor 4
`are supplied to the host controller 10. The display analysis
`unit of the host controller 10 calculates an efliciency of the
`test motor 2 based on the detection signals, and generates
`
`and outputs a two-dimensional map of the relationship
`between the revolution speed and the eificiency (or between
`the motor output and the efiiciency) .
`The operation of the test apparatus will now be described
`with reference to the flowchart of FIG. 2.
`
`Vehicle speed pattern data is input to the host controller 10
`using traveling mode data (S101). In the embodiment, LA#4
`mode shown in FIG. 3 is used. The host controller 10
`calculates an acceleration data from moment to moment
`
`based on the vehicle speed pattern data (S102). More
`particularly, the acceleration data is obtained by time- dif-
`ferentiating the travelling pattern in FIG. 3. After calculating
`the acceleration pattern in S102,
`the host controller 10
`calculates a torque, which is to be Supplied to the load motor
`3, based on the running resistance, tire diameter, vehicle
`weight, and gear ratio of the vehicle on which the test motor
`is mounted (S103). The torque is calculated using the
`following equation:
`
`Output torque =running resistance+acceleration/deceleration resis-
`tance
`1
`The running resistance is obtained by either of the fol-
`lowing methods.
`
`(A) Mapping Method
`
`Running resistance values corresponding to each of a
`number of vehicle speeds are input
`in advance, and a
`running resistance at a given vehicle speed is obtained by
`linear interpolation.
`'
`
`(B) Calculation Method I
`
`Running resistance values corresponding to each of a
`number of vehicle speeds are input in advance, and the
`constants in the following equation are determined to obtain
`an approximation curve.
`
`20
`
`25
`
`30
`
`35
`
`40
`
`Running resistance:A+BV+CV2
`
`45
`
`where A, B and C represent constants and V represents
`vehicle speed.
`
`(C) Calculation Method H
`
`Traveling resistance is calculated in accordance with the
`following equation.
`
`Traveling resistance=1/z * CD * S * p(V/5.6)2+gpW
`
`where V is vehicle speed, CD is air resistance coefficient, S
`is projected front area of vehicle, p is air density, p is rolling
`resistance coefficient, W is vehicle weight, and g is the
`acceleration of gravity.
`The present invention is characterized in that the host
`controller 10 generates a torque in advance which is to be
`provided. to the load motor 3, and either method among
`(A)—(C) can be used to obtain the traveling resistance.
`Acceleration/deceleration resistance may be calculated
`from the following equation.
`
`50
`
`55
`
`60
`
`65
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`Acceleration/deceleration resista.nce=W/g * dV/dt
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`After calculating the torque to be sent to the load motor
`efiiciency or causality of energy loss. Comparing this plot
`with the evaluation results shown in FIG. 6, the advanta-
`3, the host controller 10 generates a revolution speed pattern
`which is to be supplied to the test motor 2 (S104). The
`geous effect of the test apparatus of the invention will be
`apparent.
`revolution speed pattern is generated based on the vehicle
`speed pattern data input in the step S101. As has been
`Although the evaluation result of FIG. 6 is on the assump-
`described,
`in the embodiment,
`the vehicle speed pattern
`tion of a 0% uphill gradient in LA#4, the test apparatus of
`shown in FIG. 3 is generated based on LA#4 mode. Then, a
`the present invention can easily be applied to any traveling
`torque pattern which synchronizes with the vehicle speed
`pattern because vehicle speed pattern and torque pattern are
`pattern of the test motor 2, is generated for the load motor
`calculated and provided to the host controller in advance.
`3 (S105). The torque may be calculated by either of the
`For example, FIG. 7 shows an evaluation result of a 1%
`above-mentioned methods (A) to (C), and an example of the 10 uphill gradient in LA#4. This test result can be obtained by
`generated torque pattern is illustrated in the lower half of
`simply correcting the torque pattern given to the load motor
`FIG. 4. In FIG. 4, the upper half is a vehicle speed pattern
`for a 0% uphill gradient.
`for the test motor 2 represented by a revolution speed (the
`FIG. 8 illustrates more evaluation results showing amotor
`pattern itself is therefore the satire as that of FIG. 3), while
`efficiency distribution for each given time, with revolution
`the lower half is a torque pattern for the load motor 3 which 15
`speed as a horizontal axis and output torque as a Vertreal
`is synchronized with the vehicle speed pattern. The synchro-
`aXis- Although a three'd_imer1_srona1 gralrhre is generahy used
`nized vehicle speed pattern and torque pattern are output via
`for exlnessmg the relanorlshlp among the _reVo1ut1on speed
`the data bus 12 to the test motor 2 and load motor 3,
`torque and eeee1eneY=
`8 tW°'d1men51°na1tY “Presses
`respectively (S106). FIG. 5 shows anexample of the vehicle
`the relauonshlp by plotting the ?,fi‘},°1.en°y with dlfferem
`speed pattern and torque pattern output from the host 20 C019“ I:?r,,e.a°h levels.‘ The reglon a 1.5 p1f.)tt,?‘.1 In red’ the
`controller 10. FIG. 5(A) is a vehicle speed pattern output to
`retrgrlon b dlstéflotteq 1n,f)(rr,‘,Htge’1fl:: {region rrc
`15 P1°“""rr‘r“
`the test motor 2 (actually to the controller 7), and FIG. 5(B)
`Zgriccgrcilnis dgcrggiégg in tr: grief ornrgde :3;/r'r:1r;ee;,1é110V:
`is a torque pattern output to the load motor 3_ (actually to the
`and yepoW_greenr Thus, the eflicrerrcy distribution or the
`controller 9)‘ Both patterns are §y“°hr°mZe‘_1 w,1th each 25 motor is graphically expressed as isobaric lines and is easily
`other, and therefore, control delay In feedback is dissolved.
`and Visually analyzed If abnormal Color distribution appears
`In step 5107: Various data are detected by the torque
`on the graph, it is determined that there is something wrong
`sensor 4 and other measurement unit 13 while controlling I
`with the motor aud the motor ouu be quickly checked and
`the test motor 2 and toad motor 3 in the synchronized
`redesigned. Similar to FIG. 6, each data point may bear a
`manner. The detected data are input to the display analysis
`number showing the order of the measurement,
`unit of the host controller 10 for data analysis (S107). 30
`FIG. 9 shows another graph showing the evaluation
`Analysis includes a calculation of the efliciency of the test
`results. The horizontal axis represents time and the vertical
`motor 2 and a mapping of the relationship between the
`axis represents revolution speed, torque, and efficiency. In
`efiiciency and motor output or between the efliciency and the
`this graph, the relationships between revolution speed and
`motor revolution speed or motor electric current (or voltage)
`times hetween outPut torque and time and hetween em‘
`on a two-dimensional map. The efliciency is obtained using 35 orenoy and time are rnoorporated in the same tWo‘dtmen'
`“E f°“°“““g “‘t“a“°“-
`f§.‘3’€$ ?§§ie§§§‘ if §§s”c.‘li‘2.§‘§5‘ v3i1i“§;c%“L‘i‘f.2§‘§§“§Eli
`basis. Therefore, it is easily and quickly determined which
`pattern legds to thp redpcgid elflicienqrlr
`al
`r
`Eficiency:Z(T*N)[Z(I*V)
`ee pre erre
`examp es 0
`sp aying t e ev uation
`results have been shown above. However, since one of the
`where T represents torque, N is revolution speed, I is
`features of the invention ‘is to create the two-dimensional
`electrical ouuour, and V is vo1rage_
`map Containing a PhYsrea_1 amountror motor eflierenolfi other
`FIG. 6 shows an example of the relationship between the
`display methods are also included in the scope of_the present
`oaloulatoo ofiioiopoy and motor output mapped on a two_
`dimensional map. The horizontal axis represents a motor 45 mventten a_5 101135 as they Show the relatlenshlp between
`output (kw) and the vertical axis represents an eflicrerrcy
`motor efficiency and other parameters such as torque or
`(%). Although it is not shown in the figure, each data point
`re‘;?]1r}r1:t°r: Ztrjgfigpd rs_
`ggtghiesIEEEIZCSES :nIr1ruiI:::r mdlcztmg the Order In W130? the
`1. An apparatus for testing the power performance of an
`.
`.
`’
`. presse as t.1me'Sequence a a on
`electric motor for an electric vehicle by driving the electric
`twodlmenslonal map’ Smce the Vehicle Speed for the test 50 motor to be mounted on the electric vehicle and a load motor
`motor 2 and torque for the load motor 3 are calculated in
`Connected to the electric motor comprising.
`,
`advance and are output in a synchronized manner, control
`_
`’
`'_
`delay is substantially eliminated. Furthermore,
`reduced
`elecmc niotor control means for °°““°“‘.“s the e1ect.nc
`accuracy in the acceleration detection is avoided and highly
`m°t°r to aeoordanee Wlth ‘fl Predetennined travelling
`accurate data can be obtained in a short time period as well 55
`£23285; afiegg0‘:::t;Cerg::1rig1:0:a$gc§:::g:Eprgigggf
`as eas detection of the center of
`avit of the motor out ut.
`’
`Generally, motoris designed so thgat a periphery ofthe cerriter
`load motor Control means for Controlling the toad motor
`of gravity is optimally designed. By obtaining the evaluation
`in aeeordanee With a Predetermmed toad Pattern? and
`results as shown in FIG. 6, the scope of the optimal design
`main control means for synchronously controlling the
`is easily set.
`operation timing of the electric motor control means
`FIG. 10 shows an example of test results obtained by a
`and the load motor control means.
`conventional test apparatus, for comparison, where the h0ri-
`2. The apparatus according to claim 1, further comprising
`zontal axis represents motor revolution speed (rpm) and the
`means for generating the load pattern based on the travelling
`vertical axis represents motor torque (Nm). Dots in the chart
`pattern and factors of the electric vehicle.
`are measuring points, and motor efficiency is calculated at 65
`3. The‘ apparatus according to claim 2, wherein said load
`each of the measuring points. In such a conventional test
`pattern is an addition of a running resistance and an accel-
`eration/deceleration resistance of the electric vehicle.
`apparatus, it is difiicult to know a tendency of the motor
`
`40
`
`60
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`4. The apparatus according to claim 3, wherein the
`acceleration/deceleration resistance is calculated based on
`the acceleration obtained by time-differentiating a vehicle
`speed of the travelling pattern.
`5. The apparatus according to claim 1, further comprising:
`
`6. The apparatus according to claim 1, fuither comprising:
`
`detection means for detecting at least a torque, revolution
`speed, driving electric current, and driving voltage of
`
`5
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`the electric motor; and
`
`detection means for detecting at least a torque, revolution
`speed, driving electric current, and driving voltage of
`the electric motor; and
`
`map generation means for generating a two-dimensional
`map showing the relationship between the output and 10
`efiiciency of the electric motor based on the detected
`values.
`
`In-an generation means for generating a twwdinlensionnl
`map showing the relationship between the revolution
`speed and efliciency of the electric motor based on the
`
`detected Values-
`
`*
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`*
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`*
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`*
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`*
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