JP6363944B2 - Power converter and control method of power converter - Google Patents

Description

  The present invention relates to a power conversion device that converts input power into predetermined power and outputs the power, and a control method for the power conversion device.

  Conventionally, in the control of a power converter that is mounted on a railway vehicle and that converts input power into predetermined power and outputs it, the control response is required. Mainly, the motor current is decomposed into excitation and torque components. Thus, a vector control system that performs independent control is used. Among them, a frequency type vector control method is generally used in which a wheel rotation speed is detected using a speed detection sensor or a speed estimation technique, and inverter output frequency control is performed based on the detected rotation speed (for example, , See Patent Document 1).

  However, in the frequency vector control method as in the prior art described above, it is important to accurately grasp the wheel rotation speed in real time, but the detected value abnormality due to failure of the speed detection sensor, disconnection of wiring, etc. If a sudden speed drop erroneous detection due to wheel sticking (axle sticking) occurs, it becomes difficult to detect the wheel rotation speed and the control may become unstable.

  In addition, the wheel sticking that is one of the causes of the abnormality in the speed detection of the railway vehicle, that is, the failure that the wheel does not rotate is a serious problem. It is necessary to carry out vehicle stoppage and wheel inspection, etc., when it is determined whether or not the wheels are stuck.

  Therefore, by comparing multiple axle rotation speeds and detecting the occurrence of speed deviation and the state where the speed detection sensor output is “zero”, the abnormality of the speed detection system is detected, and the cause of the abnormality is the axle sticking (wheel sticking ) Or other technologies have been proposed (see, for example, Patent Document 2).

JP 2000-312403 A JP-A 63-64860

  However, the technique described in Patent Document 2 detects the sticking of the axle when the speed detection sensor output becomes “zero”, but only with this detection condition, that is, only the speed information, It is difficult to determine whether the axle has stuck or whether a failure has occurred in various devices such as a speed detection sensor or an oscillator. For this reason, it is easy to erroneously detect the occurrence of the axle sticking, and even if it is erroneously detected, it is necessary to stop the vehicle and perform an axle inspection operation or the like.

  Here, when the wheel sticking occurs, it is necessary to stop the vehicle immediately, but it is not necessary when a failure occurs in various devices such as a speed detection sensor and an oscillator. Therefore, it is important to accurately and promptly determine whether or not wheel sticking has occurred.

  The present invention has been made in view of such circumstances. In addition to the output of the speed detection sensor, the current state output to the electric motor that drives the axle is monitored, so that the wheel can be It is an object of the present invention to provide a power conversion device and a method for controlling the power conversion device capable of accurately and quickly discriminating whether sticking has occurred or abnormality has occurred in various devices.

To achieve this object, the present invention provides an electric motor for driving a vehicle, an axle that is driven by the electric motor and supports a wheel, a rotational frequency detecting means for detecting a rotational frequency of the axle, and a current of the electric motor Current detecting means, and control means for controlling the current of the electric motor based on the rotation frequency output from the rotation frequency detecting means, wherein the control means is the rotation frequency input from the rotation frequency detecting means. And the rotation frequency monitoring means for outputting a monitoring result when the rotation frequency satisfies a predetermined condition, and when the monitoring result is input from the rotation frequency monitoring means, the rotation frequency monitoring means is input from the current detection means. performs a detection value is compared with a preset target value, based on the comparison result, determines the wheel fixation has a adhesion determination means for outputting a determination result, wherein the wheel The rotation frequency detecting means detects the rotation frequency of each axle, the rotation frequency monitoring means detects the maximum value and the minimum value of each rotation frequency, and the minimum value is the first value. It further has sticking detection means for outputting the monitoring result when the threshold value is 1 or less or zero and when the maximum value is more than the second threshold value, and the rotational frequency monitoring means is monitored by the sticking detection means. When the result is output, it further has a fixed axle detection means for detecting and outputting the axle information whose rotation frequency is the minimum value, and the rotation frequency monitoring means is the rotation output from the rotation frequency detection means. An axle condition branching unit that receives the frequency and outputs the rotation frequency to the sticking detection unit and the sticking axle detection unit is further provided, and the axle condition branching unit is output from the stuck axle detection unit. The rotation frequency other than the axle specified based on the feedback information out of the rotation frequencies input from the rotation frequency detection means is fed back and the determination result output from the sticking determination means. Is provided to the sticking detection means and the sticking axle detection means .

The present invention also includes an axle supporting a wheel driven by an electric motor, rotational frequency detection means for detecting a rotational frequency of the axle, current detection means for detecting a current of the electric motor, and the rotational frequency detection means. A control means for controlling the electric current of the electric motor based on the output rotation frequency, the method for controlling the power converter, wherein the rotation frequency input from the rotation frequency detection means is monitored, and the rotation frequency A rotation frequency monitoring step for outputting a monitoring result when a predetermined condition is satisfied, and a detection value input from the current detection means when a monitoring result is input from the rotation frequency monitoring means. to compare the target value, based on the comparison result, it determines the wheel fixation, possess the adhesion determination step of outputting a determination result, wherein the rotating frequency detecting means, a plurality of vehicles The rotation frequency monitoring step detects a maximum value and a minimum value of each rotation frequency, and when the minimum value is less than or equal to a first threshold value or zero, the maximum value is A sticking detection step of outputting the monitoring result when the value is equal to or greater than a second threshold, wherein the rotation frequency monitoring step includes the axle information for which the rotation frequency is a minimum value when the monitoring result is output. The rotation frequency monitoring step further receives a rotation frequency output from the rotation frequency detection means, and the rotation frequency monitoring step outputs the rotation frequency to the fixation detection step and the fixation axle detection step. An axle condition branching step for providing the axle condition branching step, wherein the axle condition branching step feeds back the axle information and the determination result, and the rotation obtained in the rotational frequency detection step. Of the wave number, the rotation frequencies other than the axle which is specified based on said feedback information, there is provided a control method of the power converter to be provided to the fixed sensing step and the fixing axle detection step.

  According to the present invention, even when the vehicle is running, it is possible to quickly and accurately determine whether wheel sticking has occurred or abnormality has occurred in various devices.

It is a front view showing an outline of a railcar carrying a power converter concerning Embodiment 1 of the present invention. It is a structure circuit diagram of the power converter device shown in FIG. It is a block diagram which shows the structure of the automatic control apparatus shown in FIG. It is a block diagram which shows the structure of the rotational frequency monitor shown in FIG. It is a block diagram which shows the structure of the sticking discriminator shown in FIG. It is a flowchart which shows the process of the power converter device which concerns on Embodiment 1. FIG. (A) is a figure which shows the operation | movement simulation result when wheel sticking generate | occur | produces, (b) is a figure which shows the operation simulation result when speed detection sensor abnormality generate | occur | produces. It is a block diagram which shows the structure of the rotational frequency monitor and sticking discriminator which concern on Embodiment 2. FIG.

  Next, a power converter according to an embodiment of the present invention and a control method thereof will be described with reference to the drawings. In addition, embodiment described below is the illustration for demonstrating this invention, and this invention is not limited only to these embodiment. Therefore, the present invention can be implemented in various forms without departing from the gist thereof.

(Embodiment 1)
FIG. 1 is a front view schematically showing a railway vehicle equipped with the power conversion device according to the first embodiment, FIG. 2 is a circuit diagram of the power conversion device shown in FIG. 1, and FIG. 3 is an automatic control shown in FIG. 4 is a block diagram showing the configuration of the rotational frequency monitor shown in FIG. 3, FIG. 5 is a block diagram showing the configuration of the sticking discriminator shown in FIG. 3, and FIG. It is a flowchart which shows the process of the power converter device which concerns on form 1.

  A railway vehicle 100 shown in FIG. 1 drives a vehicle body 10, an axle 12 disposed at a predetermined position of the vehicle body 10, wheels 12 a and 12 b disposed on both sides of the axle 12, and the axle 12. An electric motor 11, a power conversion device 1 installed under the floor of the vehicle main body 10, a speed detection sensor 3 disposed on the axle 12, and a pantograph 14 installed on the upper portion of the vehicle main body 10 and collecting current from the overhead line 13. And.

  Normally, two or four electric motors 11 are generally connected to one power converter 1, but in the first embodiment, as an example, each of four axles 12 has 1 each. A case where a total of four motors 11 are connected to each other will be described. Moreover, the speed detection sensor 3 is individually connected to each axle 12.

  The power conversion device 1 collectively controls the rotation speeds of the plurality of electric motors 11 by controlling the electric power and frequency supplied to each electric motor 11. An automatic control device 2 having a function of monitoring and comparing the rotational speed of each axle 12 using a signal received from each speed detection sensor 3 is disposed inside the power conversion device 1. This automatic control device 2 is connected to each speed detection sensor 3 by an electric wire or the like.

  As shown in FIG. 2, the power conversion apparatus 1 includes a converter unit 101 and an inverter unit 102. The AC voltage collected from the overhead line 13 via the pantograph 14 is transmitted to the converter unit 101 via the transformer 15. The converter unit 101 converts an AC voltage into a DC voltage and transmits the converted voltage to the inverter unit 102. The inverter unit 102 converts a DC voltage into an AC voltage and performs drive control of each electric motor 11. The electric power converter 1 and each electric motor 11 are electrically connected by electric wires or the like, and the electric current flowing between them can be detected by the electric motor current detection sensor 4. Further, the motor current detection sensor 4 and the automatic control device 2 are connected by an electric wire or the like, and the automatic control device 2 can receive the motor current detection value Imf of the motor current detection sensor 4.

  As shown in FIG. 3, the automatic control device 2 includes a frequency converter 20, a motor current target value calculator 21, a rotation frequency monitor 30, and a sticking discriminator 40. The frequency converter 20 receives signals PFr1 to PFr4 output from the respective speed detection sensors 3 as input signals (FIG. 6, S101), and converts these pulse signals PFr1 to PFr4 into rotation frequency information Fr1 to Fr4 ( FIG. 6, S103). For example, the motor current target value calculator 21 calculates a control target of the motor current according to preset vector control and outputs the result as a motor current target value Imp.

  As shown in FIG. 4, the rotational frequency monitor 30 includes a sticking detector 31 and a sticking axle detector 32 that receive the rotational frequency information Fr1 to Fr4 output from the frequency converter 20 as input signals. The rotation frequency information Fr1 to Fr4 corresponds to the rotation frequency of each axle 12.

  The sticking detector 31 detects, for example, the minimum and maximum values in the input rotational frequency information Fr1 to Fr4 (FIG. 6, S104), and the minimum value is “below a predetermined threshold rotational frequency or no signal (wheel rotation None) ”(FIG. 6, S105: YES) and the maximum value is“ above a predetermined threshold rotation frequency ”(FIG. 6, S106: YES) The sticking detection signal Pre-Ad is output (S107 in FIG. 6). On the other hand, if the minimum value exceeds a predetermined threshold rotation frequency (FIG. 6, S105: NO), and the maximum value is less than the predetermined threshold rotation frequency (FIG. 6, S106: NO), the steps shown in FIG. Return to S101.

  When the sticking axle detector 32 receives the sticking detection signal Pre-Ad output from the sticking detector 31, the sticking axle detector 32 detects the axle having the minimum rotation frequency information and outputs it as sticking axle information (FIG. 6, S108). To do.

  5, the sticking discriminator 40 receives the motor current target value Imp output from the motor current target value calculator 21 and the motor current detection value Imf output from the motor current detection sensor 4 as input signals (FIG. 6). , S102), and a discriminator 42 that receives the comparison result signal ΔIm output from the comparator 41 as an input signal.

  The comparator 41 compares the motor current target value Imp with the motor current detection value Imf, and outputs the comparison result signal ΔIm to the discriminator 42 (S109 in FIG. 6).

  Based on the received comparison result signal ΔIm, the discriminator 42 determines whether wheel sticking has occurred or whether the devices such as the speed detection sensor 3 have failed (FIG. 6, S110). Specifically, for example, the discriminator 42 determines whether or not the comparison result signal ΔIm is equal to or greater than a certain threshold and the sticking detection signal Pre-Ad is input, and if the condition is satisfied ( FIG. 6, S110: YES) The sticking occurrence signal Ad is output (FIG. 6, S112).

  On the other hand, when the comparison result signal ΔIm is less than the threshold value and the sticking detection signal Pre-Ad is input (FIG. 6, S110: NO), the device failure signal PGD is output (FIG. 6, S111), It returns to step S101 shown in FIG.

  That is, when the comparison result signal ΔIm is less than the threshold value and the sticking detection signal Pre-Ad is not input (FIG. 6, S105: NO or S106: NO), the process returns to step S101 shown in FIG. Yes.

  When the sticking occurrence signal Ad is output (FIG. 6, S112), in order to immediately reduce the load on the axle 12, the drive control of each electric motor 11 is stopped and an emergency stop operation process (FIG. 6, S113) is performed. When the equipment failure signal PGD is output (S111 in FIG. 6), the emergency stop operation processing is not performed and the process returns to step S101. However, the equipment is repaired at any time, for example, at the end of traveling.

  Next, in Embodiment 1, the result of the operation simulation when the wheel sticking occurs is described with reference to FIG. 7A, and the result of the operation simulation when the speed detection sensor abnormality occurs Will be described with reference to FIG.

  FIG. 7A shows the motor current target value Imp and the motor current detection value Imf with respect to time time [s]. In this simulation, it is assumed that the wheel sticking occurs on only one axle out of all four axles when the vehicle is coasting. In this simulation, the motor current target value Imp is raised after the sticking detection signal Pre-Ad is output. Furthermore, a change in the motor current detection value Imf was observed with the rise of the motor current target value Imp.

  From FIG. 7 (a), when the motor current target value Imp starts to rise, the motor current detection value Imf also starts to rise, but due to the occurrence of wheel sticking, the control frequency of the power converter and the axle rotation frequency are widened. As a result, it can be seen that the motor current detection value Imf does not follow the motor current target value Imp.

  FIG. 7B shows the motor current target value Imp and the motor current detection value Imf with respect to time time [s], as in FIG. 7A. Although the simulation conditions are the same as those in FIG. 7A, a state in which all four axles are rotating normally is simulated.

  From FIG. 7B, when the motor current target value Imp starts to rise, the motor current detection value Imf also starts to rise. However, since all four axles are rotating normally, the motor current target value Imp is normal depending on the control frequency of the power converter. Further, it is understood that the motor current detection value Imf substantially follows the motor current target value Imp by controlling the axle rotation frequency.

  From the results of FIG. 7A and FIG. 7B, it is possible to accurately detect whether or not the wheel sticking has occurred by comparing the motor current target value Imp with the motor current detection value Imf. I understand.

  As described above, the power conversion apparatus according to the present invention monitors the rotational speed of each of the four axles 12 and compares the target value of the current flowing through each motor 11 with the detected value. That is, according to the present invention, since the axle on which the wheel is stuck is detected by using both the output signal from the speed detection sensor 3 and the motor current, the speed detection sensor 3 is kept in a state where the vehicle 100 continues to travel. Therefore, it is possible to accurately determine whether there is an abnormality in various devices such as an oscillator and an oscillator, or whether the wheels are stuck, and erroneous detection can be prevented. In addition, since it is a method that does not depend on the abnormal duration of the speed information, an instantaneous determination is possible.

  Further, in the present invention, since the speed of the axle 12 is not used for vector control, the electric motor 11 is controlled only by the speed of the axle with no wheels fixed. For this reason, the electric motor 11 is controlled using the speed (control speed) of the axle that is rotating normally. At this time, the power conversion device 1 outputs a frequency and voltage at which the motor 11 can output a necessary torque based on the control speed, and the difference between the output frequency of the power conversion device 1 and the rotation frequency of the axle 12 (slip frequency). ), The motor 11 is controlled so that a current equal to the motor current target value Imp flows. Therefore, the motor current target value Imp is equal to the motor current detection value Imf for an axle in which no wheel sticking occurs.

  On the other hand, for the axle on which the wheel is stuck, there is a large difference between the output frequency of the power converter 1 and the actual axle rotation frequency, and the slip frequency increases. At this time, the electric motor 11 tries to output a torque corresponding to the slip frequency, and the torque of the electric motor 11 is proportional to the motor current. Therefore, the slip frequency increases, and the electric power converter 1 tries to control the motor current. It will flow beyond the target value. Therefore, by comparing the electric motor current target value Imp and the electric motor current detection value Imf, it is possible to accurately determine whether the wheel sticking has occurred or the speed detection or the like has failed. Further, it is possible to specify the axle where the wheel sticking occurs from the rotation speed monitoring result.

  In the first embodiment, the case where the frequency converter 20 is disposed and the rotational frequency detection means according to the present invention is configured by the speed detection sensor 3 and the frequency converter 20 has been described. For example, when the speed detection sensor 3 outputs rotation frequency information, the frequency converter 20 is not necessarily provided. In this case, the speed detection sensor 3 corresponds to the rotational frequency detection means according to the present invention.

  Further, in the first embodiment, the case where the emergency stop operation process is performed by stopping the drive control in order to immediately reduce the load on the axle when the wheel sticking is detected has been described. The load on the axle may be reduced by another method such as “reducing the amount of current output to the motor”.

(Embodiment 2)
Next, Embodiment 2 according to the present invention will be described with reference to the drawings. FIG. 8 is a block diagram illustrating configurations of a rotation frequency monitor and a sticking discriminator according to the second embodiment. The main difference between the power conversion device according to the second embodiment and the power conversion device according to the first embodiment is the configuration of the rotation frequency monitor and the sticking discriminator. In the second embodiment, detailed description of the same configuration and the same process as in the first embodiment is omitted.

  The difference between the rotational frequency monitor 30 according to the second embodiment and the rotational frequency monitor according to the first embodiment is that the rotational frequency monitor 30 is provided with an axle condition branching device 33. The signal output from the sticking discriminator 40 is fed back to the axle condition branching device 33.

  The axle condition branching unit 33 uses the axle information on the occurrence of wheel sticking output from the sticking axle detector 32, the sticking occurrence signal Ad, and the equipment failure signal PGD to send the axle information on which the abnormality has occurred to the sticking detector 31. The output is not made, and the sticking detection of the axle where the wheel sticking is not generated is not affected. It should be noted that the axle condition branching device 33 may perform a process of discarding the rotational frequency of the axle in which the wheel sticking occurs and replacing it with the maximum rotational frequency of all four axles instead of the above process.

  Note that the rotation frequency monitor 30 and the sticking discriminator 40 in the configuration examples shown in the first and second embodiments can be easily realized by software processing using a microcomputer, for example.

  DESCRIPTION OF SYMBOLS 1 ... Power converter device, 2 ... Automatic control device, 3 ... Speed detection sensor, 4 ... Electric motor current detection sensor, 10 ... Vehicle main body, 11 ... Electric motor, 12 ... Axle, 20 ... Frequency converter, 21 ... Electric motor current target value Arithmetic unit, 30 ... rotational frequency monitor, 31 ... stuck detector, 32 ... stuck axle detector, 33 ... axle condition branching device, 40 ... stuck discriminator, 41 ... comparator, 42 ... discriminator, 100 ... railroad vehicle

Claims (4)

An electric motor for driving the vehicle;
An axle that is driven by the motor and supports the wheels;
Rotation frequency detection means for detecting the rotation frequency of the axle;
Current detection means for detecting the current of the motor;
Control means for controlling the current of the electric motor based on the rotation frequency output from the rotation frequency detection means;
With
The control means includes
Rotational frequency monitoring means that monitors the rotational frequency input from the rotational frequency detection means and outputs a monitoring result when the rotational frequency satisfies a predetermined condition;
When a monitoring result is input from the rotational frequency monitoring means, the detection value input from the current detection means is compared with a preset target value, and the wheel sticking is determined based on the comparison result. A sticking discrimination means for outputting a discrimination result;
Have
A plurality of the axles;
The rotational frequency detecting means detects the rotational frequency of each axle;
The rotational frequency monitoring means detects a maximum value and a minimum value of each rotational frequency, and when the minimum value is less than or equal to a first threshold value or zero, and when the maximum value is greater than or equal to a second threshold value, It further has a sticking detection means for outputting the monitoring result,
The rotational frequency monitoring means further includes a fixed axle detection means for detecting and outputting axle information in which the rotational frequency is a minimum value when a monitoring result is output from the sticking detection means,
The rotation frequency monitoring unit further includes an axle condition branching unit that receives the rotation frequency output from the rotation frequency detection unit and outputs the rotation frequency to the adhesion detection unit and the adhesion axle detection unit.
The axle condition branching unit feeds back the axle information output from the fixed axle detecting unit and the determination result output from the fixed determining unit, and out of the rotation frequency input from the rotational frequency detecting unit The rotation frequency other than the axle specified based on the feedback information is output to the sticking detection means and the sticking axle detection means.
The power converter characterized by the above-mentioned . The target value is a current target value calculated in advance by the control means,
The sticking discrimination means is
Comparison means for comparing the detection value input from the current detection means and the current target value, and outputting the comparison result;
When the comparison result output from the comparison means is greater than or equal to a predetermined threshold value, the wheel sticking detection information is output, and when the comparison result is less than the predetermined threshold value, the determination means for outputting equipment failure information;
Comprising comprising a power converter according to claim 1. An axle supporting a wheel driven by an electric motor, a rotational frequency detecting means for detecting a rotational frequency of the axle, a current detecting means for detecting a current of the electric motor, and a rotational frequency output from the rotational frequency detecting means. A control means for controlling the electric current of the electric motor, and a control method for a power conversion device comprising:
A rotational frequency monitoring step of monitoring the rotational frequency input from the rotational frequency detection means and outputting a monitoring result when the rotational frequency satisfies a predetermined condition;
When a monitoring result is input from the rotational frequency monitoring means, the detection value input from the current detection means is compared with a preset target value, and the wheel sticking is determined based on the comparison result. A sticking discrimination step for outputting a discrimination result;
I have a,
The rotational frequency detection means detects rotational frequencies of a plurality of axles,
The rotational frequency monitoring step detects a maximum value and a minimum value of each rotational frequency, and when the minimum value is less than or equal to a first threshold value or zero, and when the maximum value is greater than or equal to a second threshold value, A sticking detection step for outputting the monitoring result;
The rotational frequency monitoring step further includes a fixed axle detection step of detecting and outputting axle information in which the rotational frequency is a minimum value when the monitoring result is output,
The rotational frequency monitoring step further includes an axle condition branching step that receives the rotational frequency output from the rotational frequency detection means and provides the rotational frequency to the sticking detection step and the sticking axle detection step,
In the axle condition branching step, the axle information and the determination result are fed back, and the rotation frequency other than the axle specified based on the feedback information among the rotation frequencies obtained in the rotation frequency detection step. For the sticking detection step and the sticking axle detection step
A method for controlling a power conversion device. The sticking discrimination process
A comparison step of comparing the detection value input from the current detection means with the current target value, and outputting the comparison result;
When the comparison result is greater than or equal to a predetermined threshold, the wheel sticking detection information is output, and when the comparison result is less than the predetermined threshold, the device malfunction information is output; and
The control method of the power converter device of Claim 3 which has these.

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