JP7163128B2 - Power converter and control system - Google Patents

Description

The present invention relates to a power conversion device and control system for railway vehicles.

A traction motor of a railroad vehicle has an electric motor operation for accelerating the vehicle and a power generation operation for decelerating the vehicle.

There are two types of brakes for railway vehicles: mechanical brakes that suppress the rotation of wheels by frictional force, and electric brakes that are generated by the traction motor. In general, the electric brake has a range in which it cannot operate depending on the vehicle speed and traction. Therefore, as disclosed in Patent Literature 1, it is common to use the mechanical braking force as the force obtained by subtracting the force that can be borne by the electric brake from the braking force necessary for the vehicle.

JP-A-9-135501

On the other hand, with the advancement of semiconductor power converters in recent years, electric brakes have become more sophisticated. There are systems that work as well. In such a system, the time and force with which the wheel tread is in contact with the brake shoe is negligible and, in particular, the brake shoe does not scrape the wheel tread. In addition, when the electric brake suddenly becomes unable to operate, a response delay occurs until the mechanical brake operates and begins to bear the braking force.

The object of the present invention, which has been made in view of such circumstances, is to clean (polish) the tread surface of a wheel in a system in which the electric brake operates up to a very low speed, only by changing the control of the electric brake without changing the control of the mechanical brake. ) and to provide a power converter and a control system capable of speeding up the responsiveness of the mechanical brake.

In order to solve the above problems, a power conversion device according to the present invention is a power conversion device that controls a main motor mounted on a railroad vehicle, and is a power conversion device that generates a torque command that is a command for the output torque of the main motor. a command generation unit for outputting an electric braking force feedback signal indicating a lower value than the actual electric braking force calculated from the value of the current flowing through the traction motor when the speed of the railway vehicle is equal to or higher than a threshold; and an electric braking force notification unit that outputs an electric braking force feedback signal indicating the value of the electric braking force when the speed of the railway vehicle is less than the threshold value .

Furthermore, in the power converter according to the present invention, the electric braking force notification unit multiplies the electric braking force by a coefficient of 0.5 or more and less than 1 when the speed of the railway vehicle is equal to or higher than the threshold value . It is characterized by outputting an electric braking force feedback signal indicating a value.

Further, in order to solve the above problems, a control system according to the present invention is a control system comprising the power conversion device and a mechanical brake control device, wherein the mechanical brake control device responds to the electric brake force feedback signal by Based on this, the mechanical braking force required for braking the railway vehicle is calculated, and a mechanical braking force command indicating the mechanical braking force is output to the brake device that presses the brake shoe against the wheel tread according to the mechanical braking force command. Characterized by

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to implement|achieve the cleaning of the tread of a wheel at the time of braking of a railway vehicle, and the improvement of the response of a mechanical brake.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the power converter device and control system which concern on one Embodiment of this invention.

An embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 1 is a diagram showing an example of a railway vehicle 1 in which a mechanical brake and an electric brake operate in a blended manner during braking.

The control system 2 includes a power conversion device 10 and a mechanical brake control device 20, and performs coordinated control of electric braking that obtains braking force by operating the main motor 40 as a generator and mechanical braking that uses frictional force. Although FIG. 1 shows an example in which one power converter 10 includes two power converters 12 , one power converter 10 may include one power converter 12 .

The power converter 10 outputs electric power to the main motor 40 and controls the main motor 40 . The power converter 10 includes a torque command generator 11 , power converters 12 ( 12 - 1 and 12 - 2 ), and an electric brake force notifier 13 .

The mechanical brake control device 20 operates the brake device 50 to brake the wheels 30 . The mechanical brake control device 20 includes an electric brake force calculator 21 and a mechanical brake force command calculator 22 .

When a braking command is input from a main controller (master controller), the electric braking force calculation unit 21 calculates the electric braking force required to brake the railroad vehicle 1 by operating the main electric motor 40 as a generator. , the electric braking force command is output to the torque command generation unit 11 and the mechanical braking force command calculation unit 22 .

The torque command generation unit 11 generates a torque command, which is a command for the output torque of the traction motor 40, based on the vehicle speed of the railcar 1 and the electric braking force input from the electric braking force calculation unit 21, and generates electric power. Output to the conversion unit 12 .

The power conversion unit 12 has a power semiconductor element, and by switching the power semiconductor element, converts the collected DC power into three-phase AC power and outputs the three-phase AC power to the traction motor 40 . At that time, the power conversion unit 12 controls the main electric motor 40 so that the output torque of the main electric motor 40 matches the torque command input from the torque command generation unit 11 .

The traction motor 40 is mounted on the truck 60 . The rotational force generated by the main electric motor 40 is transmitted to the wheels 30 via gears and axles (not shown).

The electric braking force notification unit 13 acquires or estimates the current value of the current flowing through the main electric motor 40, and calculates the actual electric braking force Fe from the current value. Then, the electric braking force notification unit 13 outputs to the mechanical brake control device 20 an electric braking force feedback signal indicating an electric braking force Fe' lower than the calculated electric braking force Fe. For example, the electric braking force notification unit 13 sets the value of the electric braking force Fe' to a value obtained by multiplying the electric braking force Fe by a coefficient K less than one. Here, the coefficient K is set to 0.5 or more (for example, 0.9) because the load of the electric brake is more important than that of the mechanical brake. That is, the electric braking force notification unit 13 outputs to the mechanical brake control device 20 an electric braking force feedback signal indicating a value lower than the electric braking force corresponding to the electric braking force command.

The electric braking force notification unit 13 does not always need to make the value indicated by the electric braking force feedback signal lower than the electric braking force Fe. For example, the electric braking force notification unit 13 outputs an electric braking force feedback signal indicating an electric braking force Fe′ lower than the electric braking force Fe only when the speed of the railway vehicle 1 is equal to or higher than the threshold, is less than a threshold value, an electric braking force feedback signal indicating the value of the electric braking force Fe may be output.

The mechanical braking force command calculation unit 22 calculates the mechanical braking force required for braking the railway vehicle 1 based on the electric braking force feedback signal input from the electric braking force notification unit 13, and the mechanical braking force indicating the mechanical braking force is calculated. A brake force command is output to the brake device 50 . Specifically, the mechanical braking force command calculating unit 22 calculates the difference between the electric braking force calculated by the electric braking force calculating unit 21 and the electric braking force Fe′ indicated by the electric braking force feedback signal as the mechanical braking force. and

The brake device 50 has a brake shoe 51 . The braking device 50 presses the brake shoe 51 against the tread surface of the wheel 30 with air pressure or hydraulic pressure in accordance with the mechanical braking force command input from the mechanical braking force command calculator 22 .

In modern inverter-controlled railway vehicles, the electric power converter can bear most of the electric braking force, so the mechanical brake does not operate, and as a result, the brake shoe often operates only momentarily just before stopping. Sometimes. At relatively high speeds, the mechanical brake operates and the brake shoe hits the wheel tread surface, cleaning the tread surface. and the cleaning effect of the tread cannot be obtained. As a result, noise may occur and the ride comfort may be affected.

On the other hand, the power conversion device 10 according to the present invention outputs the electric braking force feedback of the power conversion device 10 lower than the electric braking force command as described above. Therefore, the mechanical braking force calculated by the mechanical braking force command calculation unit 22 will never become 0, and the brake device 50 is operated to create a situation in which the brake shoe 51 is always in contact with the tread surface of the wheel 30. can be cleaned. Furthermore, even when the regeneration is disabled, the braking device 50 is already in operation, so delay in response of the braking device 50 can be prevented.

Also, the brake shoe 51 is preferably a cast iron brake shoe. Since the cast iron brake shoe is rougher than the synthetic brake shoe, by pressing the brake shoe 51 against the tread surface of the wheel 30, the tread surface of the wheel 30 can be cleaned and at the same time, the roughness of the tread surface can be kept moderate and the tread surface can be made into a mirror surface. can be prevented.

Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many modifications and substitutions may be made within the spirit and scope of the invention. Therefore, the present invention should not be construed as limited by the embodiments described above, and various modifications and changes are possible without departing from the scope of the appended claims. For example, it is possible to combine a plurality of configuration blocks described in the configuration diagrams of the embodiments into one, or divide one configuration block.

INDUSTRIAL APPLICABILITY The present invention is applicable to railway vehicles, and regardless of the installed function of the mechanical brake, it is possible to reproduce a certain function of the mechanical brake only by changing the function of the power converter.

1 Rail Vehicle 2 Control System 10 Power Conversion Device 11 Torque Command Generating Section 12 Power Conversion Section 13 Electric Brake Force Notification Section 20 Mechanical Brake Control Device 21 Electric Brake Force Calculation Section 22 Mechanical Brake Force Command Calculation Section 30 Wheel 40 Traction Motor 50 Brake Device 51 Brake shoe 60 Bogie

Claims (3)

A power conversion device for controlling a traction motor mounted on a railway vehicle,
a torque command generation unit that generates a torque command that is a command for the output torque of the main electric motor;
a power conversion unit that controls the main electric motor so that the output torque of the main electric motor matches the torque command;
When the speed of the railway vehicle is equal to or higher than a threshold, an electric braking force feedback signal indicating a lower value than the actual electric braking force calculated from the value of the current flowing through the traction motor is output , an electric braking force notification unit that outputs an electric braking force feedback signal indicating the value of the electric braking force when the speed is less than the threshold ;
A power conversion device comprising: The electric braking force notification unit outputs an electric braking force feedback signal indicating a value obtained by multiplying the electric braking force by a coefficient of 0.5 or more and less than 1 when the speed of the railway vehicle is equal to or higher than the threshold value. The power converter according to claim 1, characterized by: A control system comprising the power conversion device according to claim 1 or 2 and a mechanical brake control device,
The mechanical brake control device calculates a mechanical brake force required for braking the railway vehicle based on the electric brake force feedback signal, and controls a mechanical brake force command indicating the mechanical brake force according to the mechanical brake force command. A control system characterized by outputting to a brake device that presses the wheel against the tread of the wheel.

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