JP4643391B2 - Electric vehicle control device - Google Patents

Description

The present invention relates to an electric vehicle control equipment.

  In an electric vehicle control device that performs vector control of an induction motor that does not have a speed sensor, almost no motor induced voltage is generated at extremely low speeds. Estimation becomes difficult. Therefore, the estimated speed cannot be used to determine whether the electric vehicle is moving backward or forward at extremely low speed.

FIG. 7 is a control block diagram of the reverse determination in the conventional electric vehicle control apparatus. In FIG. 7 , 22 is a Q-axis induced voltage calculation unit, 23 is a Q-axis induced voltage reference calculation unit, 24 is a timer, 25 is a comparator, 26 is a rising detector, 27 is an absolute value integrator, and 29 is an RS flip-flop. , 30 is a changeover switch, and 31 is a change rate limiter.

In the electric vehicle control device, the deviation is obtained by the difference between the Q-axis induced voltage reference and the Q-axis induced voltage, and after a predetermined time integration, the backward movement is determined by the magnitude. In other words, the backward detection is performed by utilizing the fact that the error between the reference value of the Q-axis induced voltage and the calculated value is large during the backward movement and is small during the forward movement. However, there is a problem that an error may become large even when stopped or slightly advanced, and it is difficult to make a highly accurate determination.
JP 11-285300 A JP 2003-9600 A Kazuaki Yuki, Osamu Yamazaki, Toshiaki Yamada, Ikuo Yasuoka, "Slow speed restart method in speed sensorless vector control for trains", IEEJ Industrial Application Division Conference 3-10.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an electric vehicle control technique capable of accurately detecting a reverse and performing a reverse activation control.

The invention of claim 1 includes a VVVF inverter that converts a direct current supplied from an overhead wire into a desired voltage and frequency, and an induction motor that does not have a speed sensor and runs an electric vehicle using the output of the VVVF inverter as a power source. In the electric vehicle control device, a direct current application means for supplying a direct current from the VVVF inverter to the induction motor only during a minute period immediately after the start of the VVVF inverter in response to an activation command from the outside, Based on the current flowing through the induction motor or the voltage applied to the induction motor, a reverse detection index calculating means for calculating a reverse detection index for detecting reverse, and based on the reverse detection index, the induction motor rotates. a rotation direction determining means for determining the direction in which, the computed backward detection index is retracted detection of the backward detection index calculating means When the set value is exceeded, the electric vehicle control device issues a batch reverse start command to all the other electric vehicle control devices that are being knitted. When the reverse detection index exceeds the reverse detection second set value, the reverse control is performed. A reverse command means for issuing a single reverse start command to the VVVF inverter controlled by the detected electric vehicle control device is provided.

According to a second aspect of the present invention, in the electric vehicle control device according to the first aspect, the reverse detection index calculating means decomposes the direct current supplied by the direct current applying means into a D-axis current and a Q-axis current, The Q-axis voltage is calculated using the Q-axis current command, and the reverse detection index is calculated based on the Q-axis voltage.

The invention according to claim 3 is the electric vehicle control device according to claim 1 or 2 , further comprising means for estimating the speed of the electric vehicle based on the reverse detection index calculated by the reverse detection index calculation means. Is.

According to a fourth aspect of the present invention, in the electric vehicle control device according to any one of the first to third aspects, a DC voltage applying means for applying a DC voltage to the induction motor is provided instead of the DC current applying means for causing a direct current to flow through the induction motor. The reverse detection index calculating means calculates a reverse detection index based on a current flowing through the induction motor by applying the DC voltage.

According to the present invention, it is possible to accurately retracted detected, providing electric vehicle control equipment which can retract start control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (First Embodiment) FIG. 1 is a block diagram of an electric vehicle control apparatus according to a first embodiment of the present invention. In FIG. 1, 1 is a VVVF inverter, 2 is a current sensor, 3 is a coordinate conversion unit, 4 is a voltage command calculation unit, 5 is an index calculation integrator, 6 is a reverse detection unit, 7 is an induction motor (IM), and 8 is Wheel, 9 is a filter capacitor, 10 is a filter reactor, 11 is a pantograph, and 13 is a reverse activation command section.

  The electric vehicle control apparatus shown in FIG. 1 operates as follows. After starting the VVVF inverter 1, the VVVF inverter 1 supplies a three-phase DC excitation current to the induction motor 7 as a DC excitation current supply means. The current sensor 2 detects the U-phase and W-phase currents of the three-phase DC excitation current, and the coordinate conversion unit 3 decomposes the detected currents into the D-axis current and the Q-axis current. This is sent to the voltage command calculation unit 4. The voltage command calculation unit 4 calculates the Q-axis voltage using the Q-axis current Iq and the Q-axis current command Iq *, and sends the calculation result to the index calculation integrator 5. The index calculation integrator 5 integrates an index including the rotation direction information of the induction motor 7 using the Q-axis voltage calculated by the voltage command calculation unit 4 and sends the result to the reverse detection unit 6. The reverse detection unit 6 determines whether or not the index obtained by the index calculation integrator 5 exceeds the reverse detection set value. If the index exceeds the reverse detection set value, it determines that the index is reverse and outputs a reverse determination signal to the reverse activation command unit 13.

  Immediately after starting the VVVF inverter 1 of the electric vehicle, when the VVVF inverter 1 supplies DC current to the induction motor 7 as DC excitation current supply means, the Q-axis voltage of the induction motor 7 is The AC waveform starts from a negative value first, and when moving forward in the power running direction, the AC waveform starts from a positive value. As the reverse speed increases, the amplitude of the AC waveform increases and the value of the index calculated by the index calculation integrator 5 also increases. Therefore, when the index exceeds the reverse detection set value, the reverse detection unit 6 detects the reverse. can do. Therefore, when the induction motor 7 is started, an index for determining forward / backward movement is calculated, and the electric vehicle control device detects the index, whereby accurate determination of forward / backward movement can be made.

  As described above, according to the electric vehicle control apparatus of the first embodiment, the Q-axis voltage including the information on the traveling direction generated by supplying the DC excitation current from the VVVF inverter to the induction motor immediately after the start is integrated. Then, an index for determining forward or backward is created based on the positive / negative sign, and when the index exceeds the reverse detection set value, the reverse is detected, and the reverse start control of the VVVF inverter can be performed by accurately detecting the reverse.

  In the electric vehicle control apparatus of the above embodiment, the direct current excitation current is supplied to the induction motor 7 only for a very short time immediately after the VVVF inverter 1 of the electric vehicle is started, and the index calculation integrator 5 displays the index in the short time for the direct current excitation. It is preferable to complete the integration. Thereby, it is possible to prevent the DC excitation current from affecting the stop start and coasting restart not only during reverse start but also during normal start. The configuration for supplying the DC excitation current to the induction motor 7 only for a very short time immediately after the VVVF inverter 1 is started is as follows.

  FIG. 2 shows an inverter drive circuit in the electric vehicle control apparatus of the first embodiment. In the main circuit, the panda graph 11 and the wheel 8 are connected to a DC overhead line. The direct current taken from the direct current wire through the pantograph 11 is fed to the inverter 1 through the filter reactor 10 and the filter capacitor 9. The inverter 1 converts this DC power into desired voltage AC power, supplies it to the induction motor 7, and drives it. The control circuit 40 that controls the inverter 1 employs a speed sensorless vector control system that does not detect the number of revolutions of the induction motor 7, and the induction motor 7 is controlled by a vector control method on the DQ rotational coordinate system, which is a well-known technique. Control. The control circuit 40 will be described below.

  The start command Gst given to the control circuit 40 is a signal for instructing the operation and stop of the inverter 1 and is separately instructed from the outside. The start command Gst is a command to operate the gate so that the inverter 1 outputs torque from the induction motor 7 when it is 1, and to stop the gate of the inverter 1 when Gst is 0. The DC excitation period setting unit 45 maintains Flg_DC = 1 for a predetermined time from the time when the activation command Gst becomes 1, and outputs Flg_DC = 0 otherwise. The period of Flg_DC = 1 is a period in which direct current excitation described later is performed.

  The control circuit 40 is given a magnetic flux command and a torque command. The current command calculation unit 41 calculates and outputs an excitation current command Id * and a torque current command Iq * with respect to the magnetic flux command and the torque command. When Flg_DC = 1, the torque current command Iq * = 0 and the excitation current command Id * = α (α is a predetermined set value). The current detector 2 detects the phase currents Iu and Iw of the electric motor 7, and the coordinate conversion unit 3 converts them into DQ axis currents Id and Iq on the DQ axis coordinate system. In the voltage command calculation unit 4, PI control is performed so that the excitation current command Id * and the torque current command Iq * from the current command calculation unit 41 and the DQ axis actual currents Id and Iq from the coordinate conversion unit 3 coincide with each other. Current control is realized by, for example, calculating and outputting the D-axis voltage command Vd * and the Q-axis voltage command Vq *. The DQ axis voltage commands Vd *, Vq * are converted into three-phase voltage commands Vu *, Vv *, Vw * by another coordinate conversion unit 42 and input to the PWM circuit 43. The PWM circuit 43 controls the switching element of the inverter 1 by, for example, a known triangle wave comparison PWM control so that a voltage that matches the three-phase voltage command from the coordinate conversion unit 42 is output.

  The speed estimator 44 receives the DQ axis voltage commands Vd * and Vq * and the actual DQ axis currents Id and Iq as inputs, and estimates and outputs the speed of the induction motor 7, that is, its rotational speed.

  The switch 47 switches the output according to the DC excitation period flag Flg_DC. When Flg_DC = 1, 0, and when Flg_DC = 1, the estimated speed in the speed estimation unit 44 is output as the final estimated speed ωrh. The slip frequency reference calculation unit 46 calculates the slip frequency reference ωs * based on the DQ-axis current command values Id * and Iq * from the current command calculation unit 41, for example, and outputs it.

ωs * = R2 / L2 × Iq * / Id * (1)
Here, R2 is a secondary resistance, and L2 is a secondary inductance.

  The adder 48 adds the final speed estimation value ωrh and the slip frequency reference ωs *, and outputs the result as the inverter frequency ω1. The inverter frequency ω1 is input to the integrator 49. The integrator 49 integrates the input ω1 and calculates the phase angle θ of the rotating coordinate system D axis from the stationary coordinate system A axis. This phase angle θ is used in the coordinate conversion units 3 and 42.

  With the above configuration, a direct current can be applied to the induction motor 7 for a predetermined period immediately after the start command Gst is input, that is, immediately after Gst = 1. As described above, while Flg_DC = 1, the current commands are Id * = α, Iq * = 0, and the estimated speed value ωrh = 0. Further, since the slip frequency reference calculation unit 16 is Iq * = 0, the output is also 0 from the equation (1). Therefore, the inverter frequency ω1 that is the output of the adder 48 is also zero. Thereby, a direct current can be applied to the induction motor 7 from the inverter 1.

  (Second Embodiment) Next, an electric vehicle control system according to a second embodiment of the present invention will be described. FIG. 3 is a block diagram of the first group control unit in the electric vehicle control system according to the second embodiment of the present invention. Compared to the first embodiment shown in FIG. As the set values to be compared with the index output from the index calculation integrator 5, the first set value for backward detection and the second set value for reverse detection are set, and the index output from the index calculation integrator 5 is set to the first and second values. A comparison is made between the set value and the magnitude relationship to output a reverse detection signal, and a new reverse detection unit number adder 12 is provided. The reverse detection unit number adder 12 adds the number of control units detected reverse in one train, and issues a reverse start command from the reverse start command unit 13 to the VVVF inverter 1 based on the addition result.

  The electric vehicle control system according to the present embodiment includes the electric vehicle control device shown in FIG. 3 as the first group control unit, and other control units of the second group to the fourth group are mounted during one train. , Each controls the VVVF inverter 1 in charge and drives the induction motor 7. The electric vehicle control device shown in FIG. 3 is for the first group control unit, and each of the control units of the second group to the fourth group does not include the backward detection unit number adder 12; Or the function is bypassed. In addition, the control units communicate with each other, and the second to fourth group control units add the determination signals detected by the reverse detection unit 6 mounted on each control unit to the number of reverse detection units of the first group control unit. And a reverse start command unit 13 receives a simultaneous reverse control command from the reverse start command unit 13 of the first group control unit.

  FIG. 4 is a diagram showing operation waveforms for backward detection. In FIG. 4, 14 represents a reverse detection index, 15 represents a first set value for reverse detection, and 16 represents a second set value for reverse detection. In the reverse detection unit 6 provided in each control unit in one organization, when the reverse detection index 14 exceeds the first reverse detection set value 15, it is determined that the reverse is detected. When each of the control units after the second group control unit determines that the vehicle is moving backward beyond the first detection value 15 for reverse detection, the control unit transmits a reverse determination signal to the first group control unit. The reverse detection unit number adder 12 adds the number of control units determined to be reverse. When the output result of the reverse detection unit number adder 12 exceeds the settable number of detections, the reverse activation command unit of all other control units in the knitting from the reverse activation command unit 13 of the first group control unit. A simultaneous reverse start command is issued to 13. In addition, when the control unit of each group determines that the index of the index calculation integrator 5 in the own unit has exceeded the reverse detection second set value 16, the reverse detection unit is configured to start backward independently instead of simultaneous reverse start. 6 issues a backward activation command to the backward activation command unit 13 of the own unit. The VVVF inverter 1 starts reverse activation control that receives a reverse activation command from the reverse activation command unit 13.

  The configuration of the inverter drive circuit having the function of applying a direct current from the inverter 1 to the induction motor 7 only for a certain period immediately after the start-up is shown in FIG. 2 as in the first embodiment. Is.

  According to the present embodiment, if each of the VVVF inverters 1 that are detected to reversely perform reverse start without considering the variation of the index for each vehicle, the behavior of the induction motor 7 is different, which causes a deterioration in riding comfort. Considering the variation of the index for each vehicle, the behavior of all the induction motors 7 is made uniform by simultaneous reverse activation, so that stable reverse activation can be performed. However, when the electric vehicle is retreating greatly, it is possible to quickly move forward by individually starting the retreat immediately after detecting retreat.

  (Third Embodiment) FIG. 5 is a block diagram showing the configuration of a first group control unit in an electric vehicle control system according to a third embodiment of the present invention. In FIG. 5, reference numeral 17 denotes an index average value calculator, which has the configuration of FIG. In the present embodiment, the first group control unit is provided with this index average value calculator 17, and the other components are the same as those in the first embodiment shown in FIG. Are denoted by common reference numerals.

  In this embodiment, four groups of control units are mounted during one train, and the electric vehicle control device shown in FIG. 5 is for the first group control unit, and the second group to the fourth group. Each of the control units does not include the index average value calculator 17 or bypasses its function. In addition, the control units communicate with each other, and the second to fourth group control units output the Q-axis voltage obtained by the voltage command calculation unit 4 to the index average value calculator 17 of the first group control unit, Further, the reverse detection unit 6 receives the index average value from the index average value calculator 17 of the first group control unit.

  In the index average value calculator 17 shown in FIG. 6, 17-1 is a first group index calculator, 17-2 is a second group index calculator, 17-3 is a third group index calculator, and 17-4 is a fourth group index calculator. , 18 represents an average value calculator. The first group index computing unit 17-1, the second group index computing unit 17-2, the third group index computing unit 17-3, and the fourth group index computing unit 17-4 integrate the Q voltage of the corresponding group for a predetermined time to obtain an index. Ask. The average value calculation part 18 calculates | requires the average value of the parameter | index of each control unit, and transmits to the reverse detection part 6 of an own group control unit, and the reverse detection part 6 of each 2nd-4th group control unit. During the knitting, all control units perform reverse detection in the reverse detection unit 6 using this index average value in the same manner as in the first embodiment, and perform reverse activation control when reverse activation is detected.

  The configuration of the inverter drive circuit having the function of applying a direct current from the inverter 1 to the induction motor 7 only for a certain period immediately after the start-up is shown in FIG. 2 as in the first embodiment. Is.

  According to the present embodiment, even if a different index is generated for each vehicle, the reverse determination can be performed based on the same reference by using the average value of the index by all the control units.

  In each of the above embodiments, a DC current is applied from the inverter to the induction motor in a very short time immediately after startup. However, the present invention is not limited to this, and a DC voltage is applied to the induction motor during the period. It is also possible to adopt a configuration in which control is similarly performed by detecting a direct current flowing through the induction motor.

The block diagram of the electric vehicle control apparatus of the 1st Embodiment of this invention. The block diagram of the inverter drive circuit in the said embodiment. The block diagram of the electric vehicle control apparatus of the 2nd Embodiment of this invention. The figure which shows the relationship between an integration parameter | index, a backward detection 1st setting value, and a backward detection 2nd setting value in the said embodiment. The block diagram of the electric vehicle control apparatus of the 3rd Embodiment of this invention. The block diagram of the average parameter | index calculator in the said embodiment. The block diagram of the conventional electric vehicle control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 VVVF inverter 2 Current sensor 3 Coordinate conversion part 4 Voltage command calculation part 5 Index calculation integrator 6 Backward detection part 7 Induction motor 8 Wheel 9 Filter capacitor 10 Filter reactor 11 Pantograph 12 Backward detection unit number adder 13 Reverse start command part 14 Reverse detection index 15 Reverse detection first set value 16 Reverse detection second set value 17 Index average value calculator 18 Group 1 index calculator 19 Group 2 index calculator 20 Group 3 index calculator 21 Group 4 index calculator 22 Average value Computer 40 Control circuit 41 DC excitation period setting section

Claims (4)

A VVVF inverter for converting a direct current supplied from an overhead wire into a desired voltage and frequency;
In an electric vehicle control device including an induction motor that does not have a speed sensor and runs an electric vehicle using the output of the VVVF inverter as a power source,
DC current applying means for supplying a DC current from the VVVF inverter to the induction motor only during a very short period immediately after starting the VVVF inverter in response to an external start command;
Based on the current flowing through the induction motor in the minute period or the voltage applied to the induction motor, a reverse detection index calculating means for calculating a reverse detection index for detecting reverse,
Rotation direction determination means for determining a direction in which the induction motor is rotating based on the reverse detection index ;
When the reverse detection index calculated by the reverse detection index calculating means exceeds the reverse detection first set value, the electric vehicle control device issues a collective reverse start command to all the other electric vehicle control devices in the knitting, and the reverse operation A reverse command means for issuing a single reverse activation command to the VVVF inverter controlled by the electric vehicle control device that detects the reverse when the detection index exceeds the reverse detection second set value;
An electric vehicle control device comprising: In the electric vehicle control device according to claim 1,
The reverse detection index calculating means decomposes the DC current supplied by the DC current applying means into a D-axis current and a Q-axis current, calculates a Q-axis voltage using a Q-axis current and a Q-axis current command, and converts it into a Q-axis voltage. An electric vehicle control device which calculates a reverse detection index based on the above. In the electric vehicle control device according to claim 1 or 2,
An electric vehicle control device comprising means for estimating the speed of the electric vehicle based on the reverse detection index calculated by the reverse detection index calculating means . In the electric vehicle control device according to any one of claims 1 to 3,
In place of the direct current application means for applying a direct current to the induction motor, a direct current voltage application means for applying a direct current voltage to the induction motor is provided,
The electric vehicle control device, wherein the reverse detection index calculating means calculates a reverse detection index based on a current flowing through the induction motor by applying the DC voltage .

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