JP2003037902A - Drive controller for electric rolling stock and slip control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase average acceleration and improve riding comfort, by reducing the influence of a delay in speed estimation, in a controller for driving and controlling a main motor by means of a variable voltage variable frequency(VVVF) inverter while estimating a motor speed in a speed-sensorless manner. SOLUTION: In the drive controller for an electric rolling stock, the speed of the main motor 4 is estimated in the speed-sensorless manner by a torque control means 2, so that an estimated speed ωrh can be obtained and so that a gate command to the VVVF inverter 1 can be generated in such a manner that the output torque of the main motor 4 follows a torque command value; slip control for correcting a torque command in accordance with the estimated speed ωrh is exercised by a slip control means 3; the estimated speed ωrh of the main motor 4, which serves as the output of the means 2, is input into an estimated-speed correcting means 7; the estimated speed ωrh is corrected to compensate for the delay of the speed estimation in this stage; and the slip control is exercised based on a corrected estimated speed ωrhcmp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device and an idling control method for an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, as a drive control device for an electric vehicle equipped with a VVVF inverter, one for an electric railway shown in FIG. 6 is known. This conventional electric vehicle drive control device is provided with a speed detector PG, and has a VVVF inverter 1
An induction motor (IM) 4 is connected to the. VVV
The F inverter 1 is a voltage source inverter having a widely known configuration. The rotor of the induction motor 4 is connected to the wheels 5 via gears, joints and the like (not shown). As a result, the induction motor 4 is rotationally driven by the electric power from the VVVF inverter 1, the rotational force of the induction motor 4 is transmitted to the wheels 5, the wheels 5 rotate, and the vehicle is driven by the adhesive force between the wheels 5 and the rails 6. Be promoted.

In the case of this conventional example, the VVVF inverter 1
The torque control unit 2 is provided as a control circuit of the above. The torque control unit 2 is divided into a vector control unit, a PWM control unit, and the like in detail, but here, the torque control unit 2 is generally referred to as a torque control unit. Since the processing function of the torque control unit 2 is widely known, its details are omitted.

Further, in this conventional example, a speed detector PG is provided for detecting the rotation speed of the electric motor 4, and the torque control section 2 controls the torque based on the speed detected by the speed detector PG. To do.

In the electric vehicle, a propulsive force is obtained by a force generated between the wheel 5 and the rail 6, that is, an adhesive force. FIG. 8 shows an example of the relationship between the slip velocity and the tangential force coefficient. The slip speed here indicates the difference between the peripheral speed of the wheel 5 and the forward speed of the axle, and does not indicate the slip speed of the induction motor 4. The tangential force coefficient is a coefficient obtained by dividing the adhesive force by the load applied to the rail 6 from the wheel 5 called wheel load. That is, the tangential force coefficient is proportional to the adhesive force, assuming that the wheel load is constant. It can be seen from FIG. 8 that the adhesive force has a maximum value. Therefore, when accelerating and decelerating the electric vehicle with high acceleration, it is essential to maintain an appropriate sliding speed so that the operating point is near the maximum of the adhesive force.

Generally, the characteristic of the adhesive force coefficient greatly changes depending on the condition of the road surface. When wet, such as in the rain, it is slippery and its adhesive strength is lower than when it is dry. When a constant motor torque exceeding the maximum adhesive force is applied, the rotor speed increases and the rotor diverges. This is called idling (during braking, the opposite phenomenon occurs, called gliding). This idling or gliding state is not preferable because the adhesive force of the vehicle, that is, the vehicle propulsion force decreases. Therefore, when idling occurs, it is necessary to quickly reduce the motor torque and re-adhere. This series of controls is called "idling control".

The structure of a general idle control section 3 is as shown in FIG. 9, and its waveform is as shown in FIG. The idling control unit 3 receives a speed ωr (sensor output when a speed sensor is provided) or ωrh (an estimated speed when a speed sensor is not described, which will be described later). The acceleration calculator 13 pseudo-differentiates the input speed to obtain the acceleration and outputs it. In the hysteresis comparator 14, when the calculated acceleration exceeds the predetermined value α, it is considered that the vehicle is in the idling state, and the idling flag is turned on. Further, when the acceleration is below the predetermined value β, it is determined that the vehicle is in the adhesive state, and the idling flag is turned off. When the idling flag is on, the switcher 15 selects the output of the torque current throttle calculation unit 16,
Output.

The torque current throttle calculation unit 16 gradually increases the torque command correction amount, which is the output, so as to suppress idling and lead to re-adhesion. In the subtractor 17, the torque command
By subtracting the torque command correction amount from Tm *, the corrected torque command Tm * cmp also gradually decreases. As a result, idling is suppressed and re-adhesion occurs.

When the acceleration calculated by the acceleration calculation unit 13 decreases and the idling flag is turned off by the hysteresis comparator 14, the switching unit 15 causes the torque holding value calculation unit 2 to operate.
Let the output from 1 be that output.

The torque holding value calculation unit 21 calculates the motor torque according to the equations (1) and (2) based on the torque command Tm * and the maximum idle speed ΔF which is the output of the maximum idle speed calculation unit 18. To match the hold value TmHold,
Calculate the correction amount TmHoldcmp to the torque command. here,
a and b are adjustment gains.

[0011]

[Equation 1] TmHold = a × ΔF + b (1) TmHoldcmp = Tm * −TmHold (2) The maximum idling speed calculation unit 18 outputs the maximum reference speed difference as the maximum idling speed ΔF while the idling flag is ON. To do. Here, the reference speed difference represents a difference between the speed ωr and the calculation speed of the reference speed calculation unit 19.

The torque holding value calculation unit 21 holds the correction amount for the torque command for a predetermined time and then gradually decreases the correction amount to zero.

The idling control by the idling controller 3 will be described with reference to the waveform example of FIG. In order to simplify the explanation, the idling control is divided into the following five areas.

The torque command Tm * is not corrected by the normal region / idle control.

This is an area that the control side recognizes as being in the adhesive state.

When the acceleration exceeds the predetermined value α,
The idling flag is turned on, assuming the idling state.

Torque throttle area -The area where the idling flag is on.

In terms of control, the torque command Tm * is corrected in the direction of reducing the torque by recognizing that it is in the idling state.

When the acceleration falls below a predetermined value β,
It is regarded as re-adhesion for control, and the idling flag is turned off.

Torque return area-After determining the readhesion, the torque command Tm * cmp is returned to a predetermined value.

The torque command is maintained at a predetermined value near the adhesion limit due to concern about the torque holding region and the recurrence of idling.

The torque command correction amount is reduced so that the torque command correction amount in the torque recovery region / idling control unit 3 becomes zero.

By the above-mentioned slip control, it is possible to reduce the thrust reduction due to slip and obtain a high average acceleration even in a slippery condition.

The above is an example of the drive control device for the electric vehicle to which the vector control with the speed sensor using the speed detector PG is applied, but in recent years, the railway vehicle to which the speed sensorless vector control without the speed detector is applied. Is being developed. FIG. 7 shows an example of a conventional electric vehicle drive control device to which the speed sensorless vector control is applied.

In the configuration of the second conventional example, V is set so that the motor torque matches the torque command Tm * without using the speed detector (PG) for detecting the speed, that is, the rotor frequency.
Control the VVF inverter. In the speed sensorless vector control, the speed is estimated (the estimated speed ωrh) without using the detected speed ωr. This speed estimation is executed by the torque control unit 2. However, in the speed estimation calculation, "(Development of speed sensorless vector control for electric train (second method) -evaluation of high-speed region-", H13 National Congress 5 -261) is used.

[0026]

However, in a drive control device for an electric vehicle to which such a speed sensorless vector control system is applied, idling control is performed based on the estimated speed ωrh, but the speed is estimated. Therefore, the estimation delay occurs. Due to the influence of the delay in the speed estimation, the release of the torque throttle region of the idling control, that is, the timing of turning off the idling flag is delayed. In the torque throttle region, the rotor re-adheres from the idling state, so that the rotor frequency, that is, the speed, sharply decreases. The estimated speed generally tends to follow slowly as the speed changes sharply. Due to the delay in the timing of turning off the idling flag, the throttle amount of torque increases. As a result, the average acceleration may be reduced and the riding comfort may be deteriorated.

The present invention has been made in view of the above-mentioned conventional technical problems, and does not use a speed detector, but controls the drive of the main electric motor by the VVVF inverter while estimating the electric motor speed. The purpose is to reduce the influence of delay in speed estimation, improve average acceleration, and improve riding comfort.

[0028]

The invention according to claim 1 is the VV
The VF inverter, the main motor connected to the VVVF inverter, and the speed of the main motor are estimated without using a speed detector to obtain an estimated speed, and the output torque of the main motor follows the torque command value. Na said VVVF
In a drive control device for an electric vehicle comprising torque control means for generating a gate command for an inverter, and idling control means for performing idling control for correcting the torque command based on the estimated speed, an output of the torque control means is provided. Estimated speed is input, and an estimated speed correction unit that corrects the estimated speed so as to compensate for a delay in speed estimation is provided, and the idling control unit is based on the corrected estimated speed that is the output of the estimated speed correction unit. It is characterized in that idling control is performed.

According to a second aspect of the present invention, in the drive control device for an electric vehicle according to the first aspect, the estimated speed correction means is
It is characterized in that it has a filter means having a reverse transfer characteristic from the actual speed to the estimated speed, using the estimated speed as an input.

According to a third aspect of the present invention, in the drive control device for an electric vehicle according to the first aspect, the estimated speed correction means is
An estimated speed correction amount storage means for storing in advance an estimated speed correction amount for correcting the delay of the speed estimation; and an addition means for adding the output of the estimated speed correction amount storage means and the estimated speed. It is a feature.

According to a fourth aspect of the present invention, a VVVF inverter and a main motor connected to the VVVF inverter,
Torque control means for estimating the speed of the main electric motor without using a speed detector to obtain an estimated speed and for generating a gate command for the VVVF inverter so that the output torque of the main electric motor follows a torque command value; A idling control method in a drive control device for an electric vehicle comprising idling control means for performing idling control for correcting a torque command based on the estimated speed, wherein the estimated speed output from the torque control means is input, It is characterized in that the estimated speed is corrected so as to compensate for the delay in the estimation, and the corrected estimated speed is input to the idling control means to perform the idling control.

In the present invention, the estimated speed of the main motor, which is the output of the torque control means, is input, the estimated speed is corrected so as to compensate for the delay in speed estimation, and idling control is performed based on this corrected estimated speed. As a result, the influence of the delay in the speed estimation is improved, the excessive torque is narrowed down by the idling control, the average acceleration is improved, and the riding comfort is improved. If the estimated speed correction value is taken out from the storage means that is stored in advance, it is not necessary to sequentially calculate the correction amount of the estimated speed, and the load of control calculation processing can be reduced.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first exemplary embodiment of the present invention. The drive control device for an electric vehicle according to the present embodiment is different from the second conventional example shown in FIG.
The estimated speed correction unit 7 is newly provided, and the estimated speed correction unit 7 is provided.
Corrects the estimated speed ωrh obtained by the torque control unit 2 and supplies the corrected estimated speed ωrhcmp to the idling control unit 3 so that the idling control unit 3
Is characterized by performing idling control based on this corrected estimated speed ωrhcmp. Note that the other components are shown with the same reference numerals as the components common to the conventional example shown in FIG. 7.

The idling control method according to the first embodiment will be described. The estimated speed ωrh, which is one of the outputs of the torque control unit 2, is input to the estimated speed correction unit 7. The estimated speed correction unit 7 is set as follows. As a characteristic of the estimated speed ωrh estimated by the torque control unit 2, the transfer function from the actual speed ωr to the estimated speed ωrh is shown in FIG.
It is assumed that they are as shown in (a) and (b). In this frequency characteristic, the higher the band is, the more the gain is attenuated, and the phase is delayed.

Therefore, the characteristic of the speed estimation system is approximated by the following equation (3). The input of the transfer function is the rotor frequency ωr, and the output is the rotor frequency estimated value ωrh. However, ωest = 62.8 [rad / s].

[0036]

[Equation 2] In order to improve the delay of speed estimation, an inverse system of speed estimation system is introduced. However, since the inverse system of the equation (3) cannot be realized, it is realized by the equation (4) in which a low-pass filter that attenuates in the high frequency range is combined. Here, ωf = 31
It is set to 4.2 [rad / s].

[0037]

[Equation 3] The estimated speed correction unit 7 calculates the equation (5), corrects the estimated speed ωrh and outputs ωrhcmp.

[0038]

[Equation 4] FIGS. 3A and 3B show frequency characteristics of the estimated speed ωrmcmp corrected by the inverse system from the actual speed. It can be seen that the attenuation of the gain and the delay of the phase are improved as compared to the characteristics without correction by the inverse system shown in FIGS. 2A and 2B.

The above-mentioned structure has the following effects. The estimation delay can be improved by inserting a filter having characteristics similar to the inverse system of the velocity estimation system in series with respect to the estimated velocity ωrh, and the estimated velocity ωrhcmp that quickly follows the actual velocity can be obtained. Based on this,
When the idling control is performed, the excessive torque throttling in the torque throttling region is improved, and the average acceleration and the riding comfort can be improved.

An example showing that excessive torque throttling is improved will be described with reference to FIG. Fig. 4 shows the relationship between the motor torque and the slip speed (slip speed is the difference between the peripheral speed of the wheel and the forward speed of the axle, and the tangential force, that is, the thrust is determined according to this slip speed). It is shown. 6A shows the result of idling control of a drive control device for an electric vehicle to which the vector control with speed sensor shown in the first conventional example of FIG. 6 is applied, and FIG. The result of applying the speed sensorless vector control shown in the conventional example of No. 2 is shown. In the method with a speed sensor shown in FIG. 9A, torque throttling is properly performed after idling, and the locus of the operating point is small. On the other hand, in the speed sensorless method of FIG.
Since the release of the idling flag is delayed, the torque is reduced to near 0. For this reason, the average acceleration of the vehicle may be reduced or the riding comfort may be deteriorated.

On the other hand, in the case of the present embodiment, since the speed sensorless vector control in which the speed estimation delay is corrected is performed, the idling flag is improved by improving the speed estimation delay as shown in FIG. The timing of resetting is also appropriate, and an operating point locus equivalent to that of the first conventional example using the speed sensor shown in FIG. As a result, in the present embodiment, the average acceleration and the riding comfort can be improved.

Although the drive control device of the above embodiment is applied to an electric vehicle having an induction motor as a main motor, the drive control device is not limited to the induction motor and may be a permanent magnet synchronous motor (PM) or a permanent magnet. The same can be applied to a speed sensorless vector control system using another electric motor such as a magnet reluctance synchronous motor (PRM). Although the electric railway is taken as an example, when applied to electric vehicles such as electric vehicles,
Similar effects can be obtained.

Next, a drive control device for an electric vehicle according to a second embodiment of the present invention will be described with reference to FIG. Second
This embodiment differs from the first embodiment shown in FIG. 1 in the functional configuration of the estimated speed correction unit 70. Since the other components are common to those of the first embodiment shown in FIG. 1, they will be described using the same reference numerals as those in FIG.

In the case of the second embodiment, the estimated speed correction unit 70 is composed of an estimated speed correction amount storage unit 9 and an adder 10. The estimated speed correction amount storage unit 9 includes a counter 11 and an estimated speed correction amount table 12. The counter 11 receives the idling flag from the idling control unit 3, counts up when the idling flag is on, and clears the count when the idling flag is off. Here, the operation is performed with an integer count Cnt, and the following equation is calculated for each control.

[0045]

[Equation 5] Cnt = Cnt + 1 if idling flag = on Cnt = 0 if idling flag = off The speed correction amount storage table 12 stores a correction amount Δωrhcmp (k) for correcting the speed estimation delay in advance. , Outputs a value according to the count Cnt of the counter 11. Since the counter 11 has a value only during the period in which the idling flag = on in which the idling state is recognized, the counter 11 sets a delay in speed estimation occurring in the torque throttle region, that is, a speed difference.

With the above configuration, the drive control device for the electric vehicle of the second embodiment operates as follows. When it is recognized as idling on control, the torque is narrowed down and the rotor decelerates rapidly. At this time, the estimated speed ωrh has a delay in estimation. Therefore, delay of speed estimation in this area in advance,
In other words, the value of the speed stored as time series data Δ
The effect of estimation delay is reduced by adding ωrhcmp (k) to the estimated velocity ωrh.

When the idling control is performed on the basis of the estimated speed ωrhcmp in which the delay is corrected, the excessive torque throttling in the torque throttling region is improved, and the average acceleration and the riding comfort are improved. Further, the amount of calculation is smaller than that in the first embodiment, and the load on the processing device can be reduced.

[0048]

As described above, according to the present invention, the delay of the speed estimation system is corrected when the drive control of the main motor is performed without using the speed detector, so that excessive torque narrowing can be suppressed. It is possible to improve average acceleration and ride comfort.

[Brief description of drawings]

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

FIG. 2 is a graph of frequency characteristics of a speed estimation system when the inverse system characteristics are not applied.

FIG. 3 is a graph of frequency characteristics of a speed estimation system when the inverse system characteristics according to the above-described embodiment are applied.

[Fig. 4] Vector control method with speed sensor, speed sensorless vector control method (without inverse system characteristic application), speed sensorless vector control method (inverse system characteristic application)
Explanatory drawing which shows the operating point locus of speed difference versus torque at the time of idling control by each.

FIG. 5 is a block diagram of an estimated speed correction unit in the electric vehicle drive control device according to the second embodiment of the present invention.

FIG. 6 is a block diagram of a first conventional example.

FIG. 7 is a block diagram of a second conventional example.

FIG. 8 is a graph showing a relationship between a general sliding speed and a tangential force coefficient when dry and when wet.

FIG. 9 is a block diagram of a general idling control unit.

FIG. 10 is an explanatory diagram of torque behavior during general idling control.

[Explanation of symbols]

1 VVVF inverter 2 Torque control unit 3 Idling control section 4 induction motor 5 wheels 6 rails 7 Estimated speed correction unit 9 Estimated speed correction amount storage 10 adder 11 counter 12 Estimated speed correction amount table 13 Acceleration calculator 14 Hysteresis Comparator 15 Switch 16 Torque throttling calculator 17 Subtractor 18 Maximum idle speed calculation unit 19 Reference speed calculator 20 subtractor 21 Torque holding value calculator

Continued front page    F term (reference) 5H115 PA01 PC02 PG01 PI03 PU09                       PV09 QE14 QI23 QN06 QN09                       QN24 RB25 SE03 TO04                 5H576 AA01 BB09 CC01 DD02 DD04                       EE04 EE19 FF02 FF03 GG02                       GG04 HB01 JJ04 JJ05 JJ23

Claims (4)

[Claims] 1. A VVVF inverter, a main motor connected to the VVVF inverter, and the speed of the main motor are estimated without using a speed detector to obtain an estimated speed, and an output torque of the main motor is a torque command. A drive control device for an electric vehicle comprising: torque control means for generating a gate command for the VVVF inverter that follows a value; and idle control means for performing idle control to correct the torque command based on the estimated speed. The estimated speed that is the output of the torque control means is input, and an estimated speed correction means that corrects the estimated speed so as to compensate for the delay in the speed estimation is provided, and the slip control means is the output of the estimated speed correction means. A drive control device for an electric vehicle, wherein the idling control is performed based on a corrected estimated speed. 2. The electric vehicle drive control device according to claim 1, wherein the estimated speed correction means has a filter means having a reverse transfer characteristic from an actual speed to an estimated speed with the estimated speed as an input. A drive control device for an electric vehicle characterized by the above. 3. The electric vehicle drive control device according to claim 1, wherein the estimated speed correction unit stores an estimated speed correction amount storage unit that stores in advance an estimated speed correction amount that corrects a delay in the speed estimation. And a drive control device for an electric vehicle, comprising: an addition unit configured to add the output of the estimated speed correction amount storage unit and the estimated speed. 4. A VVVF inverter, a main motor connected to the VVVF inverter, and a speed detector to estimate the speed of the main motor without using a speed detector to obtain an estimated speed, and the output torque of the main motor is a torque command. Idling control in a drive control device for an electric vehicle including torque control means for generating a gate command for the VVVF inverter that follows a value and idling control means for performing idling control for correcting the torque command based on the estimated speed. A method, wherein the estimated speed output by the torque control means is input,
Correct the estimated speed so as to compensate for the delay in speed estimation, input the corrected estimated speed to the idling control means,
A slipping control method for a drive control device for an electric vehicle, comprising performing the slipping control.