JP3915952B2 - Inverter control device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular inverter control apparatus that controls an AC motor for propulsion and braking that is installed in a vehicle for transporting passengers and cargo such as a railway vehicle.
[0002]
[Prior art]
For example, an electric brake system in which a motor called a regenerative brake or a power generation brake bears a braking force is conventionally used in a railway vehicle.
However, the electric brake method was terminated when the vehicle speed was around 10 km / h, and the extremely low speed range until the stop was switched to the mechanical brake method.
This is because it was difficult to obtain a reliable braking force at an extremely low speed in the DC motor control system, but the AC motor was driven by the inverter controller, and the AC motor including the braking force was By improving the accuracy of torque control and improving control characteristics for idling and sliding, it has become possible to obtain an electrically reliable braking force up to extremely low speeds.
[0003]
A conventional electric brake discontinuing method is shown in FIG.
FIG. 6 shows a state in which a constant braking force is applied until the vehicle stops.
In a switching section between the electric brake and the mechanical brake, a reduction pattern is provided so that the electric brake force becomes zero at a predetermined speed. From the state where all the constant braking force is covered by the electric brake, the mechanical brake is started up and the braking force is adjusted so as to compensate for the reduction of the electric brake. Adjustment of the mechanical brake force is usually performed by a mechanical brake control device.
[0004]
In the electric brake discontinuation, the control is stopped in accordance with the speed at which the electric brake force becomes zero along the reduction pattern shown in FIG.
The conventional method is to increase the mechanical braking force after the vehicle is stopped to ensure safety during the stop.
Therefore, as shown in FIG. 7, the conventional control device is provided with a censoring speed fboff detector 21 that inputs the detected vehicle speed and outputs an electric brake censoring signal, and issues an electric brake force command for the censoring speed. The reduction pattern generating unit 22 to be reduced, the electric brake force command, and the low priority selection unit 23 that takes low priority of the pattern are included.
[0005]
[Problems to be solved by the invention]
However, the conventional apparatus has the following problems.
The first problem when switching the brake system from electric brake to mechanical brake during braking of the vehicle is ride comfort.
The electric brake force command reduction pattern described above is means for smoothly switching between the electric brake and the mechanical brake. However, the brake force command is often varied during braking, and the stop position is adjusted and the vehicle is stopped with a smooth ride. At this time, riding comfort may be impaired due to a difference in response characteristics between the electric brake system and the mechanical brake system.
[0006]
The second problem of switching the brake system is a change in characteristics due to wear of the mechanical brake and a burden of maintenance work. The wear of the brake shoe changes the time from when the operation command is issued until the braking force is applied. This disturbs the consistency with the electric brake and also becomes a factor that hinders the ride comfort. In order to maintain the riding comfort, it is necessary to frequently replace the brake shoes.
[0007]
Further, in the method in which the electric brake is applied until the vehicle stops, speed detection accuracy becomes a problem. There is no problem if the mechanical brake is applied when the speed is almost zero, but if there is an error in the detected speed and there is a sudden stop when the mechanical brake is started, the ride comfort will be significantly worsened. .
For example, in the case of a generator type in which the speed sensor converts the rotation speed into a frequency and a voltage amplitude, the voltage amplitude decreases as the rotation speed decreases, and this voltage is the voltage detection sensitivity of the speed calculation unit. When the speed becomes below, zero speed is detected regardless of speed. This is the minimum detection speed error.
[0008]
Even in a speed sensor that can always output the number of pulses per rotation at a constant peak value, in order to lower the minimum detection speed value, the pulse count time must be lengthened, and the detected value is the actual speed of the vehicle. There are also factors that are delayed in time. This is a delay error.
[0009]
There is also a method of applying the mechanical brake by predicting the time from the minimum detection speed to the stop, but if an external condition that increases the deceleration compared to the flat section, such as an ascending slope section, is applied, the mechanical brake is There may be a state where the vehicle moves backward before acting and suddenly stops at a speed. Recession must be prevented for security reasons.
The present invention was devised in view of the above points, and its object is to solve these drawbacks, to operate an electric brake until the vehicle stops, and to operate the mechanical brake after the vehicle stops. Thus, the present invention provides a vehicle inverter control device that can suppress deterioration in ride comfort and brake shoe wear due to switching between an electric brake and a mechanical brake.
[0010]
[Means for Solving the Problems]
In other words, the means to achieve that purpose is
1) In claim 1,
An inverter control device for a vehicle that controls the propulsive force and braking force of an AC motor for a vehicle, uses an electric brake until stopping, and uses a mechanical brake during stopping,
A speed detector that detects the vehicle speed or the rotation speed of the AC motor corresponding to the vehicle speed is provided, and a deceleration detector that obtains the speed change per unit time (deceleration) from this speed signal is provided. There is an error calculator that calculates the deviation (error) between the corresponding pre-determined reference deceleration and the actual deceleration, and a time-limit device (timer) that can vary the operating time according to the magnitude of the error. The timing of outputting the mechanical brake operation command from the electric brake signal at the timing of electric brake discontinuation using the speed signal as input is delayed, and if the deceleration is different from a predetermined value, the magnitude of the error According to the vehicle inverter, the delay time of the operation command given to the mechanical brake device is made variable from the timing of stopping the electric brake. A motor controller.
[0011]
2) In claim 2,
An inverter control device for a vehicle that controls the propulsive force and braking force of an AC motor for a vehicle, uses an electric brake until stopping, and uses a mechanical brake during stopping,
A speed detector that detects the vehicle speed or the rotation speed of the AC motor corresponding to the vehicle speed is provided, and a deceleration detector that obtains the speed change per unit time (deceleration) from this speed signal is provided. There is an error calculator that calculates the deviation (error) between the corresponding pre-determined reference deceleration and the actual deceleration, and a time-limit device (timer) that can vary the operating time according to the magnitude of the error. , The timing of outputting the mechanical brake operation command from the electric brake signal at the timing of electric brake discontinuation using the speed signal as input is delayed, and a plurality of braking force commands are sampled within a unit time for determining the deceleration. And a brake force command change detection unit that calculates the ratio between the average value and the sample value of the final brake force command. A deceleration correction unit that multiplies this ratio by the deceleration obtained from the speed change of the unit time interval is provided, and with this corrected deceleration, the delay time of the operation command given to the mechanical brake device can be changed from the electric brake stop timing This is an inverter control device for a vehicle characterized in that it is configured as described above.
[0012]
3) In claim 3,
For magnetic levitation vehicles in which the AC motor is a linear motor and equipped with a magnetic levitation vehicle equipped with a speed sensor that does not have a speed conversion part of the rotation mechanism, and an electric brake is used until stopping and a mechanical brake is used during the stop. An inverter control device,
A speed detector that detects the vehicle speed is provided, and a deceleration detector that obtains the speed change per unit time (deceleration) from this vehicle speed signal is provided. An error calculation unit that calculates the deviation (error) from the deceleration is provided, and a time limit device (timer) that can vary the operation time according to the magnitude of the error is provided. This timer activates the mechanical brake from the timing at which the electric brake is discontinued. The timing to output the command is delayed, sampling of the multiple braking force commands and the average value are obtained within the unit time for determining the deceleration, and the average value and the sample value of the final braking force command A brake force command change detection unit is provided to calculate the ratio, and a deceleration correction unit is provided to multiply the deceleration obtained from the speed change at the unit time interval by this ratio. Is a vehicle inverter control device, wherein a delay time of the operation command to be given to the mechanical brake device from abort timing was such that variable electric brake drives out deceleration.
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In the operation of the inverter control device when the electric brake is discontinued, the inverter operation is stopped after the electric brake force is reduced within a predetermined time by a predetermined method. Ideally, the vehicle decelerates while the electric brake is reduced, and the mechanical brake is applied at the time when the vehicle speed becomes zero. Strictly speaking, the provision of this region changes the braking force, but is conventionally referred to as jerk control and is a method for smoothly stopping.
[0014]
Considering the minimum detection speed, assuming that the electric brake is stopped when the vehicle speed passes the predetermined electric brake stop speed, the time until the vehicle speed becomes zero is the deceleration immediately before the stop. Proportional. Therefore, the mechanical brake is operated at the time set by the timer from the time when the abort speed is detected.
[0015]
When the gradient condition is added, the deceleration changes even for the same braking force command.If the detected deceleration is larger than the reference deceleration assumed in the flat section, the timer operation time is shortened and the assumption is made. If it is smaller than the deceleration, the timer operation time is lengthened. This time period corresponds to the predicted time from the electric brake stop speed until the vehicle stops.
[0016]
In addition to the gradient condition, if the vehicle is to be stopped smoothly and at a fixed position, the brake force command may be frequently changed immediately before stopping. When the deceleration is calculated from the speed signal, the deceleration includes an averaging error as shown in FIG. In order to correct the error included in this deceleration, the braking force command value is sampled more finely than the unit time for calculating the deceleration, and the ratio between this average value and the final sampling value is used as the correction amount. Multiply The operation time of the timer is set with the corrected deceleration, and the method of operating the time is the same as described above.
A specific example of the vehicle inverter control device of the present invention as described above will be described below.
[0017]
FIG. 1 is a block diagram showing an embodiment of the first aspect of the present invention, and FIG. 2 is a block diagram showing an embodiment of the second and third aspects of the present invention.
In FIG. 1, 1 is an electric brake stop speed detection unit, 2 is a deceleration detection unit that calculates vehicle deceleration from the change in speed per unit time, and 3 is a predicted deceleration value and an actual reduction for a braking force command. An error calculation unit that outputs an estimated value of the time from the start of electric brake discontinuation until the vehicle speed becomes zero based on an error from the speed, 4 is a timer that can vary the time limit setting, and 5 is a switch that controls the operation timing of the mechanical brake , 8 is a speed detector for detecting the speed of the AC motor.
[0018]
While the speed is high, the electric brake signal that is the output of the electric brake cutoff speed detector 1 is on. When the vehicle speed passes the electric brake cutoff speed, the electric brake signal is turned off. The timer 4 receives a turn-off of the electric brake signal, and outputs a signal for turning on the mechanical brake force command after a time set by the output of the error calculation unit 3.
[0019]
The error calculation unit 3 inputs the braking force command and the deceleration calculated by the deceleration detection unit 2, and outputs a set value of the delay time of the mechanical brake operation timing from the electric brake discontinuation timing.
FIG. 3 shows an example of input / output characteristics.
In FIG. 3, the horizontal axis represents a braking force command, and the solid line represents a delay time set from a preset reference deceleration characteristic. It is assumed that the reference deceleration characteristics have been adjusted for changes in vehicle body mass, such as the boarding rate. The actual deceleration corresponding to a change in the external condition such as the gradient deviates from the reference deceleration as indicated by a broken line or a one-dot chain line. This deviation amount is an error of deceleration, and is proportional to the correction amount of time limit.
If the vertical axis represents the deceleration deviation, the magnitude relationship between the delay time and the deviation is reversed, so in FIG. 3, the vertical axis arrows are shown alternately.
[0020]
FIG. 4 shows the deceleration and the timed action state to be corrected. When the deceleration is large due to an ascending slope, a state in which the mechanical brake force command is output in a time Δt-a shorter than the reference time Δt is shown.
[0021]
When stopping at the target position, it is often the case that the deceleration is increased or decreased by a driving operation. If the brake force command is changed immediately before the electric brake breaking speed, the deceleration changes within a unit time for calculating the deceleration, as shown in FIG.
The unit time for the deceleration calculation here is an integer (≧ 1) times the pulse count time mentioned in the problem to be solved by the invention.
To increase the accuracy of the detected deceleration, the unit time shown in FIG. 5 is increased, but this increases the frequency of being affected by the change in the brake force command.
In the case of FIG. 5, the theoretical deceleration A before the change of the braking force command and the theoretical deceleration B after the change are mixed within the unit time, and the calculation result is a deceleration X (deceleration) that is neither A nor B. Speed A> Deceleration X> Deceleration B)
If the electric brake is discontinued when the deceleration X is obtained, the mechanical brake cannot be applied at an appropriate timing.
[0022]
The embodiment of FIG. 2 considers that it corresponds to a change in deceleration within a unit time for the deceleration calculation. Compared with the embodiment of FIG. 1, the brake force command change detector 6 and the deceleration correction Part 7 is provided.
A factor that increases the unit time for calculating the deceleration is that the pulse count time for speed detection is long. FIG. 2 shows the embodiment of FIG. 2 when the speed / output (pulse) frequency conversion ratio of the speed sensor is small or when the speed sensor itself outputs a value converted into a digital quantity, and the update cycle is long. Is effective.
[0023]
Most speed sensors currently in practical use have a rotation mechanism, and convert this rotation speed into an output frequency. However, since the speed sensor of a magnetically levitated vehicle propelled and braked by a linear motor does not have a mechanism for converting the relative speed between the track and the vehicle body into the number of revolutions, the speed-to-output frequency conversion ratio can be increased. Not easy.
That is, the embodiment of FIG. 2 is extremely effective in the inverter control device for a magnetically levitated vehicle.
[0024]
The brake force command change detection unit 6 has a function of sampling values precisely within a unit time, as indicated by a black circle in the brake force command diagram of FIG. 5, and the average value in synchronization with the end of the unit time. And the value of the ratio between the final sample value.
At this time, the deceleration X is obtained as the deceleration. The deceleration X can be corrected to the deceleration B by multiplying the deceleration X by the value of the ratio that is the output of the brake force command change detection unit 6 by the correction calculation unit 7. Since the deceleration B is a value immediately before the start of the electric brake discontinuation operation, the timer 4 described with reference to FIG. 1 can apply the mechanical brake force command at the timing when the vehicle speed becomes substantially zero. Even if the relationship of deceleration A <deceleration B is satisfied, it can be easily estimated that there is no need to change the operation of the braking force command change detection unit 6.
[0025]
【The invention's effect】
As described above, according to the present invention, even if the electric brake is applied until the vehicle stops, the riding comfort is not impaired, and the riding comfort can be impaired even when the braking force is changed immediately before the electric brake is stopped. Furthermore, the same ride comfort improvement effect can be obtained even in a system in which the brake control, which has been performed by the driver in the past, is automatically operated and the brake force is finely moved, which is extremely useful in practice. .
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the first aspect of the present invention.
FIG. 2 is a block diagram showing an embodiment of the second and third aspects of the present invention.
FIG. 3 is a characteristic example of an error calculation unit which is a part of the present invention.
FIG. 4 is an explanatory diagram of changes in deceleration and variable states of mechanical brake operation timing.
FIG. 5 is an explanatory diagram of a change in deceleration and a detection error of deceleration.
FIG. 6 is an example of how to use a conventional electric brake and mechanical brake.
FIG. 7 is a block diagram relating to brake control of a conventional inverter control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric brake cutoff speed detection part 2 Deceleration detection part 3 Error calculation part 4 Timer 5 Switch 6 Brake force command change detection part 7 Deceleration correction part 8 Speed detection part 21 Ending speed fboff detection part 22 Reduction pattern generation part 23 Low level Priority section

Claims (3)

Controlling propulsion and braking force of the AC motor in a vehicle, and, using an electric brake to stop, the stopping is vehicle inverter controller for using the mechanical brake, and a predetermined control only electric brake A speed detector for detecting the vehicle speed or the rotational speed of the AC motor corresponding to the vehicle speed in the vehicle inverter control device having a function of preventing transmission of a brake force command to the mechanical brake device when power is obtained And an electric brake discontinuation speed detecting section for detecting that the vehicle speed is equal to or lower than a predetermined speed by inputting a speed signal output from the speed detecting section, and a speed change per unit time from the speed signal. a deceleration detection unit for obtaining a (deceleration) provided false a deviation (error) between the actual deceleration with reference deceleration to be predicted based on the braking force command An arithmetic unit is provided, timed apparatus capable of varying the operating time according to the size of the deviation (the timer) is provided, this timer, receives the output of the abort speed detection unit of the electric brake, with a predetermined timed machine vehicle inverter control apparatus, characterized in that to release the transmission blocking state of the braking force command to the brake device. Controlling propulsion and braking force of the AC motor in a vehicle, and, using an electric brake to stop, the stopping is vehicle inverter controller for using the mechanical brake, and a predetermined control only electric brake A speed detector for detecting the vehicle speed or the rotational speed of the AC motor corresponding to the vehicle speed in the vehicle inverter control device having a function of preventing transmission of a brake force command to the mechanical brake device when power is obtained An electric brake discontinuation speed detecting section for detecting that the vehicle speed is equal to or lower than a predetermined speed by inputting a speed signal output from the speed detecting section, and a speed change per unit time from the speed signal. a deceleration detection unit for obtaining a (deceleration) is provided, a deviation (error) between the actual deceleration with reference deceleration to be predicted based on the braking force command error The calculation unit is provided, timed apparatus capable of varying the operating time according to the size of the deviation (the timer) is provided, this timer, receives the output of the abort speed detection unit of the electric brake, with a predetermined timed machine It is intended to release the transmission blocking state of the braking force command to the brake device, further, a plurality of times sampling within the unit of deceleration calculating time sample value of the braking force command unit time trailing edge of the deceleration calculating A brake force command change detection unit that calculates a ratio to the average value obtained is provided, and a deceleration correction unit that multiplies the deviation that is the output of the error calculation unit using the brake force command change detection unit output as a correction amount , The vehicle inverter control device characterized in that the corrected deviation amount is used as the operation time of the time limiter . For magnetic levitation vehicles in which the AC motor is a linear motor and equipped with a magnetic levitation vehicle equipped with a speed sensor that does not have a speed conversion part of the rotation mechanism, and an electric brake is used until stopping and a mechanical brake is used during the stop. An inverter control device that includes a speed detection unit that detects a vehicle speed and inputs a speed signal output from the speed detection unit to detect that the vehicle speed has become equal to or lower than a predetermined speed. detector and the velocity change amount per unit time from the velocity signal and a deceleration detection unit for obtaining a (deceleration) provided, deviation of the actual deceleration with the reference deceleration to be predicted based on the braking force command ( an error calculation unit for obtaining an error) is provided, timed apparatus capable of varying the operating time according to the size of the deviation (the timer) is provided, this timer is out of abort speed detection unit of the electric brake Receiving, which releases the transmission inhibit state of the braking force command to the mechanical brake device with a predetermined time limit, further the deceleration calculating a sample value of the braking force command unit time trailing edge of the deceleration calculating A brake force command change detection unit that calculates a ratio with an average value obtained by sampling a plurality of times within a unit time of the output, and the output of the error calculation unit using the brake force command change detection unit output as a correction amount A linear motor-driven inverter control apparatus for a vehicle, characterized in that a deceleration correction unit for multiplying the deviation is provided, and the corrected deviation amount is used as an operation time of the time limiter .

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