JP2010161925A - Device for controlling electric rolling stock and method of controlling electric power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress a specified frequency component generated in a retrace line current. <P>SOLUTION: The rotational angular speed ωr of a motor is detected, a torque correction command ΔT* is operated on the basis of a specified frequency component included in the ωr, a d-axis voltage correction command dVd*, a q-axis voltage correction command dVq*, a q-axis current correction command dIq*, and an angular speed correction command dω1* are operated on the basis of the torque correction command ΔT*, and these correction commands are added to a d-axis voltage command, a q-axis voltage command, a q-axis current command, and an angular speed command respectively to control a DC current of a first power converter. By this, the specified frequency component included in the DC current is canceled, and the specified frequency component is effectively suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric vehicle control device using a power converter for driving an induction motor, and an electric vehicle including the control device.

  In a railway vehicle, electric power is supplied to the power converter by an overhead line and a track, and a return current flows on the track. On the other hand, in order to detect the presence of an electric vehicle, a safety device or the like installed on the ground uses the track as a track circuit. For this reason, if the return current includes a fault current having the same frequency component as the AC signal used by the track circuit, the safety device may malfunction. For this reason, the fault current is strictly regulated and needs to be suppressed below the regulation value. Since the return current flowing in the track and the overhead current flowing in the filter reactor have the same value, the following is unified to the overhead current unless particularly distinguished.

  As a technique for suppressing the fault current, there is a technique described in Patent Document 1, for example. This is a technique for suppressing the retrace current by correcting the extracted current command value based on the specific frequency component of the motor current.

JP 2002-186287 A

In a railway vehicle, the rotational speeds of wheels and motors change due to disturbance from the track and the like. When the mechanical output of the motor changes, the electric power received from the overhead line also changes, so a fault current is generated.
In the prior art, since the specific frequency component of the motor current is suppressed, the fluctuation of the motor torque that is substantially proportional to the motor current can be suppressed, but the fluctuation of the mechanical output of the motor that is the product of the torque and the rotational speed cannot be suppressed. . For this reason, the fault current cannot be effectively suppressed.

  An object of the present invention is to effectively suppress fault currents caused by fluctuations in the mechanical output of a motor.

  In the present invention, when a DC voltage is converted into an AC voltage based on a current command and an electric motor is driven, a rotational speed determination unit that detects or estimates the rotational speed of the motor, and a specific frequency component from the detected or estimated rotational speed. A filter for extracting; a generating unit that outputs a correction current command for controlling the motor torque so that the motor output is constant based on the output of the filter; and a motor control unit that controls the AC voltage command based on the correction current command. It is characterized by that.

  According to the present invention, since the mechanical output of the motor can be controlled to be constant, the power received from the overhead line can be made constant. Therefore, it is possible to effectively suppress the fault current caused by the fluctuation of the machine output of the motor.

It is a block diagram of the 1st Embodiment of this invention. It is principle explanatory drawing of the 1st Embodiment of this invention. It is operation | movement explanatory drawing of the 1st Embodiment of this invention. It is a block diagram of the 2nd Embodiment of this invention. It is a block diagram at the time of applying the power receiving part of this invention to an alternating current vehicle.

Hereinafter, the first embodiment of the present invention will be described in detail with reference to FIGS.
The present embodiment is an example of an electric vehicle for railway use, and is applied here to a vehicle that is supplied with DC power. That is, as shown in FIG. 1, the DC power received from the overhead line by the current collector 1 is removed from the high frequency component by the filter reactor 2 and the filter capacitor 3 and supplied to the first power converter 4.

  In the first power converter 4, a DC power source is converted into an AC power source, the converted AC power source is supplied to a motor (induction machine) 5, the motor 5 is rotationally driven, and wheels arranged on a vehicle carriage. 7 is rotated. The rotation of the motor 5 is detected by a rotation speed detector 6.

  The generation state of the AC power source by the power converter 4 will be described. Based on the AC voltage commands Vu *, Vv *, and Vw * from the AC voltage command generation unit 109 in the motor control unit 120, the AC voltage of the variable frequency variable voltage. And the motor 5 is controlled. The motor control unit 120 uses the rotation speed ωr detected by the rotation speed detector 6 that detects the rotation speed of the motor 5 and the d-axis current command Id * and the q-axis current command Iq * that are current command values given from the outside. Is supplied to the vector controller 106, and an AC voltage command is obtained from the AC voltage command generator 109. Although the specific configuration of the motor control unit 120 will be described later, in this example, the noise suppression signal generated by the noise suppression unit 105 is added to the output of the vector control unit 106. The noise suppression unit 105 is controlled by the output of the correction current command creation unit 121.

  Next, a more specific control of the rotational drive of the motor 5 will be described. The first power converter 4 sends a voltage from the motor control unit 120 to the motor 5 based on the AC voltage commands Vu *, Vv *, Vw *. Supply. The rotational speed detector 6 is a detector for detecting the rotational speed of the motor 5 and obtaining the rotational speed ωr. The torque command creating unit 101 inputs the d-axis current command Id * and the second q-axis current Iq2 output from the subtractor 113, and calculates the torque command T * based on Expression (1).

However, L2, M, and P are motor constants of the motor 5, L2 is a secondary self-inductance, M is a mutual inductance, and P is the number of poles of the motor 5.
In the filter 102, the rotational angular velocity ωr of the motor 5 detected by the rotational velocity detector 6 is input, and the rotational angular velocity fluctuation component Δωr is output using a filter that extracts a specific frequency band.
The correction current command creation unit 121 includes a torque correction command creation unit 103 and a q-axis current operation amount creation unit 104. A specific frequency band Δωr is extracted by the filter 102 from the rotational speed ωr of the motor 5 detected by the rotational speed detector 6, and the extracted specific frequency band Δωr is supplied to the torque correction command creating unit 103. The torque correction command creation unit 103 calculates the torque correction command ΔT *, and the q-axis current manipulation amount creation unit 104 determines the q-axis current manipulation amount ΔIq.

  Specifically, the torque correction command creation unit 103 calculates a torque correction command ΔT * from the rotational angular velocity ωr of the motor 5, the rotational angular velocity fluctuation component Δωr, and the torque command T * by Equation (2).

  The q-axis current manipulated variable creating unit 104 calculates the q-axis current manipulated variable ΔIq from Equation (3) using the torque correction command ΔT * and the d-axis current command Id *.

The electric motor control unit 120 determines the AC voltage commands Vu *, Vv *, and Vw * so as to correct the torque according to the correction amount of the supplied torque correction command ΔT *.
That is, in the noise suppression unit 105, from the q-axis current operation amount ΔIq, the first angular velocity command ω11 *, the d-axis current command Id *, and the q-axis current command Iq * output from the vector control unit 106, Equation (4) From the equations (5), (6), and (7), the q-axis current correction command dIq *, the angular velocity correction command dω1 *, the d-axis voltage correction command dVd *, and the q-axis voltage correction command dVq * are respectively obtained. Calculate.

R2, Rσ, and lσ are motor constants of the motor 5, R2 is a secondary resistance, Rσ is a primary conversion winding resistance, and lσ is a primary conversion leakage inductance. T1 and T2 are control time constants, and S is a Laplace operator.
When the q-axis voltage correction command dVq * is corrected to compensate for the q-axis current manipulated variable ΔIq, the q-axis current correction command dIq * is compensated to suppress fluctuation due to constant current control, and the slip angular velocity fluctuations are reduced. The angular velocity correction command dω1 * is compensated for the suppression, and the d-axis voltage correction command dVd * is compensated for the fluctuation of the d-axis current.

  In the vector control unit 106, the d-axis current command Id *, the q-axis current command Iq *, and the rotation angular velocity ωr are input, and the first d-axis voltage command Vd * and the first The q-axis voltage command Vq * and the first angular velocity command ω11 * are calculated.

  The integrator 107 adds a first angular velocity command ω11 *, which is the output of the vector control unit 106, and an angular velocity correction command dω1 *, which is the output of the noise suppressing unit 105, by the adder 112, thereby adding a second angular velocity command ω12 *. Is supplied, and the supplied second angular velocity command ω12 * is integrated to output the phase θ.

  The rotation coordinate conversion unit 108 performs rotation coordinate conversion using the motor current detection values Iu, Iv, Iw and the phase θ detected by the current detector 10, and outputs a d-axis current Id and a first q-axis current Iq1. . The d-axis current Id and the first q-axis current Iq1 output from the rotation coordinate conversion unit 108 are supplied to the subtractor 113, and the q-axis current correction command dIq * input from the noise suppression unit 105 is subtracted to obtain the d-axis The current Id and the second q-axis current Iq2 are output.

  The first d-axis voltage command Vd1 *, which is the output of the vector control unit 106, and the d-axis voltage correction command dVd *, which is the output of the noise suppression unit 105, are added by the adder 110 to obtain a second d-axis voltage. This is supplied to the AC voltage command generator 109 as a command Vd2 *. Similarly, the adder 111 adds the first q-axis voltage command Vq1 * output from the vector control unit 106 and the q-axis voltage correction command dVq * output from the noise suppression unit 105 to obtain the second The q-axis voltage command Vq2 * is supplied to the AC voltage command creating unit 109.

  The AC voltage command generation unit 109 adds the first d-axis voltage command Vd1 * that is the output of the vector control unit 106 and the output of the adder 110 that adds the d-axis voltage correction command dVd * that is the output of the noise suppression unit 105. The second d-axis voltage command Vd2 *, the first q-axis voltage command Vq1 * output from the vector control unit 106, and the q-axis voltage correction command dVq * output from the noise suppression unit 105 are added. The second q-axis voltage command Vq2 * and the phase θ, which are the outputs of the device 111, are input, the rotation coordinate conversion is performed, and AC voltage commands Vu *, Vv *, Vw * are output.

Next, the operation principle of the present embodiment will be described with reference to FIG. FIG. 2 shows a block diagram relating to fluctuations in the overhead wire voltage caused by fluctuations in the rotation speeds of the wheels 7 and the motor 5 due to disturbance from the track or the like.
Due to the rotational angular velocity fluctuation component Δωr of the motor 5, the mechanical output of the motor 5 varies by ΔPm1 and ΔPm. Focusing on the output of the motor 5 and the input of the first power converter 4 and assuming the conversion efficiency of the motor 5 and the first power converter 4 to be η, the input of the first power converter 4 varies by ΔPe.
Since the input of the first power converter 4 is the product of the voltage Ecf across the filter capacitor 3 and the input current, the input current varies by ΔIdc with respect to the input variation ΔPe. The fluctuation ΔIdc of the input current becomes the fluctuation ΔIs of the overhead wire current through the power reception filter. That is, the fluctuation of the machine output causes the fluctuation of the overhead wire current ΔIs. Therefore, the torque is controlled so that the machine output does not fluctuate even when the rotation speed of the motor 5 fluctuates. That is, the machine output fluctuation ΔPm2 due to the torque is canceled out by the machine output fluctuation ΔPm2 due to the torque, thereby suppressing the machine output fluctuation ΔPm and the overhead current fluctuation ΔIs causing the fault current. .

Next, the operation of the present embodiment will be described based on the above principle.
The rotational angular velocity fluctuation component Δωr is assumed to be a waveform 201 shown in FIG.
The waveform of the torque correction command ΔT * becomes the waveform 202 of FIG. 3 according to Equation (2) in order to control the motor power to be constant. ΔT * is converted into a q-axis current manipulated variable ΔIq of the waveform 203, and an AC voltage command is output to the first power converter 4.

Since the first power converter 4 controls the voltage according to the given AC voltage command, the waveform 204 of the torque fluctuation amount ΔT becomes a waveform 205 of the motor power change amount ΔPm as shown in FIG.
When the motor power change amount ΔPm is 0, the change amount ΔIdc of the current flowing into the first power converter 4 is 0, and the noise component due to the rotation speed of the motor 5 is the output current of the first power converter 4. Not converted. For this reason, since the overhead wire current ΔIs becomes ΔIs = 0 in a steady state where the voltage across the filter capacitor is constant from ΔIdc = 0, it is possible to suppress the frequency component that affects the security device from the overhead wire current Is. Note that a waveform 206 in FIG. 3 is a waveform of ΔIs.

  As described above, according to the control apparatus for an electric vehicle in the present embodiment having the configuration shown in FIG. 1, the frequency component Δωr affecting the safety device is detected from the rotational speed ωr of the motor 5, and the torque is calculated using the detected value. By controlling the correction command ΔT *, it is possible to prevent the occurrence of the fluctuation ΔIs of the overhead line current that affects the security device without providing a detector for directly detecting the overhead line current.

In the present embodiment, a control method for correcting, for example, the d-axis voltage, the q-axis voltage, the q-axis current, and the angular velocity based on the q-axis current operation amount ΔIq is adopted. As a result, the q-axis current operation amount ΔIq Alternatively, any control method may be used as long as the numerical value of the torque correction command ΔT * can be corrected.
Further, since a component of ± 10 Hz of the frequency used by the security device is generally regulated, the component extracted by the filter 102 needs to include ± 10 Hz of the frequency used by the security device. Specifically, the frequencies used in the security device are 25 Hz, 30 Hz, 50 Hz, 60 Hz, 83.3 Hz, 100 Hz, and 120 Hz, and the filter 102 is a security device used in the line section where the vehicle travels. In response, extract components of at least one frequency range from 15 Hz to 35 Hz, 20 Hz to 40 Hz, 40 Hz to 60 Hz, 50 Hz to 70 Hz, 73.3 Hz to 93.3 Hz, 90 Hz to 110 Hz, 110 Hz to 130 Hz. is required.

  Further, in the configuration shown in FIG. 1, only one motor 5 is shown, but a configuration in which a plurality of motors 5 are connected in parallel is also possible. In this case, an average angular velocity may be obtained from the obtained plurality of velocity sensor signals, and the average angular velocity may be used instead of the rotational angular velocity ωr.

  Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 4, portions corresponding to those already described in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this example, instead of providing the rotational speed detector 6 (FIG. 1) described in the first embodiment, a speed estimation unit 301 is provided as shown in FIG. Various methods have been proposed as the speed estimation method in the speed estimation unit 301. For example, in the present embodiment, the d-axis current Id, the first q-axis current Iq1, the second d-axis voltage command Vd2 *, And a second q-axis voltage command Vq2 * are input, and a speed estimation method is used in which the rotational angular speed estimated value ωr ^ is calculated using Equation (8).

However, ω1 is the frequency of the first power converter 4.
The rotational angular velocity estimation value ωr ^ is input to the filter 102, the q-axis current manipulated variable creating unit 104, and the vector control unit 106 instead of the rotational angular velocity ωr described in the first embodiment. Other parts are configured in the same manner as in FIG. 1 described in the first embodiment.

In the present embodiment, the speed calculation method using the formula (8) is used, but any estimation method may be used as long as the speed can be estimated.
Since the rotational angular velocity estimated value ωr ^ is estimated based on the speed electromotive force, the rotational angular velocity estimated value ωr ^ includes a rotational angular velocity fluctuation component Δωr as in the first embodiment. For this reason, even if there is no speed detector 6 or in the configuration of the present embodiment, the same effect as in the case of the first embodiment can be obtained.

  In the above description, an example of an electric vehicle that receives direct current has been described. However, the present invention can also be applied to an electric vehicle that receives alternating current. That is, in the first embodiment shown in FIG. 1 or the second embodiment shown in FIG. 4, the second power receiving unit 41 shown in FIG. 5 is used instead of the first power receiving unit 11. Also good.

  That is, as the second power receiving unit 41, AC power received from the overhead line by the current collector 1 is transformed to a low voltage by the main transformer 42, and the transformed AC power is converted to DC by the second power converter 43. Convert. In this case, the capacitor 44 controls the output voltage to be constant.

  When the electric vehicle shown in FIG. 1 or FIG. 4 is provided with the second power receiving unit 41 having such a configuration, when the rotational speed of the wheel 7 and the motor 5 fluctuates due to disturbance from a track or the like, the mechanical output of the motor 5 Fluctuates, and the input and output currents of the first power converter 4 also fluctuate. In the case of an AC overhead line, the second power converter 43 controls the voltage across the capacitor 44 to be constant, so that the output current fluctuation component of the first power converter 4 passes through the main transformer 42. Spill to rail.

  For this reason, in order to suppress the disturbance by the fluctuation | variation of the machine output of the motor 5, the output current fluctuation | variation component of the 1st power converter 4 must be suppressed. Therefore, similarly to the DC electric vehicle shown in FIG. 1 or 4, control is performed so as to suppress the mechanical output fluctuation of the motor 5.

  In the case of an AC electric vehicle, the operation of the second power receiving unit 41 is assumed that the fluctuation component ΔIdc of the output current of the first power converter 4 is 0, similarly to the DC electric vehicle shown in FIG. Since the voltage across the capacitor 44 is constant, the output current fluctuation component of the second power converter 42 becomes zero. Since the second power converter 42 converts an alternating current into a direct current, the input current fluctuation component of the second power converter 42 becomes an alternating current with zero. This alternating current flows out to the overhead line through the main transformer 41. Therefore, it is possible to suppress the fault current flowing out to the overhead line due to fluctuations in the rotational speeds of the wheel 7 and the motor 5 due to disturbance from the track or the like.

However, in the case of an AC electric vehicle, in the second power converter 43, the output fluctuation is the fluctuation of the input side current, that is, the amplitude of the AC current. That is, since the input current is amplitude-modulated by the output fluctuation, when the power supply frequency is Fs, the component of the frequency F1 of the output fluctuation is the input current,
Is converted to a frequency component of | Fs ± F1 |. For this reason, when the component of the frequency Fh is suppressed by the overhead wire current, it is necessary to suppress the output fluctuation of the frequencies | Fs + Fh | and | Fs−Fh |, and the filter 102 needs to extract these frequency components. . Usually, since it is necessary to suppress the range of ± 10 Hz of the frequency used in the security device, when the frequency used in the security device is Fh ′, the filter 102 is at least from | Fs-Fh′−10 | Hz to | Fs-Fh ′. It is necessary to extract a range up to +10 | Hz or | Fs + Fh'-10 | Hz to | Fs + Fh '+ 10 | Hz. Specifically, the frequencies used in the security device are 25 Hz, 30 Hz, 83.3 Hz, 100 Hz, and 120 Hz, and the filter 102 is 15 Hz depending on the security device used in the line where the vehicle travels. To 35 Hz, 65 Hz to 85 Hz, 20 Hz to 40 Hz, 80 Hz to 100 Hz, 23.3 Hz to 43.3 Hz, 123.3 Hz to 143.3 Hz, 40 Hz to 60 Hz, 140 Hz to 160 Hz, 30 Hz to 50 Hz, 150 Hz to 170 Hz, 50 Hz to 70 Hz , It is necessary to extract a component in at least one frequency range in the range from 170 Hz to 190 Hz.

  DESCRIPTION OF SYMBOLS 1 ... Current collector, 2 ... Filter reactor 3 Filter capacitor, 4 ... 1st power converter, 5 ... Motor, 6 ... Rotational speed detector, 7 ... Wheel, 11 ... Current detector 1st power receiving part, 41 ... Second power receiving unit, 42 ... main transformer, 43 ... second power converter, 44 ... capacitor, 101 ... torque command creating unit, 102 ... filter, 103 ... torque correction command creating unit, 104 ... q-axis current operation Quantity creating unit 105 ... Noise suppressing unit 106 ... Vector control unit 107 ... Integrator 108 ... Rotating coordinate conversion unit 109 109 AC voltage command creating unit 120 ... Motor control unit 121 ... Correction current command creating unit 301: Speed estimation unit

Claims (1)

In a control device for an electric vehicle that drives a motor by converting a DC voltage into an AC voltage based on a current command,
A detector for detecting the rotational speed of the electric motor;
A filter for extracting a specific frequency component from the detected rotational speed;
A generating unit that outputs a correction current command for controlling the motor torque so that the motor output becomes constant based on the output of the filter;
An electric vehicle control device comprising an electric motor control unit that controls the AC voltage command based on the correction current command.

Images