A STOP CONTROL SYSTEM USING ELECTRIC BRAKE OF ELECTRIC RAIL CAR

Technical Field

The present invention relates to a stop control system using an electric brake of an electric railway vehicle, and more particularly, to a stop control system which stops an electric railway vehicle only through the electric brake in all speed ranges.

B ackgro und Art

Recently, since the railway vehicles, in particular, the subway becomes important means for a popular traffic, while it has been more and more required for high reliability operation of the electric railway vehicle so as to increase the convenience of the passengers and secure the safety, it is possible to manage the electric railway vehicle more stably and economically with the capacity improvement of the electric railway vehicle along with the development of the electric power, electronic devices, and a control technology. ^" '

Conventionally, the operation and stopping of the electric railway vehicle were performed in such a manner that the electric railway vehicle begins to drive by the starting of an inverter, which was a propulsion control device for the electric railway vehicle, and stops when it arrives at a station.

In the conventional operational manner of the electric railway vehicle as described above, the electric railway vehicle was operated to perform speed reduction control through an electric brake manner in the range of high and middle speed such as by about

5km/h while it was operated at the maximum speed, and the electric railway vehicle finally stopped at the low speed range below 5km/h by instantly employing a disc friction

manner by air pressure.

The conventional electric brake method performs a vector control by using an encoder for detecting positions of an electric motor. However, since the encoder method generates about 60 to 100 pulse per one rotation, it was not possible to perform minute vector control at the low speed. As a result, a brake method employing the electric brake and the air brake instantly has been used.

Thus, the brake system for the electric railway vehicle such as railway vehicle for a subway employs a dual-purpose brake system combining a brake method using electricity with a brake method using air. •

Disclosure of Invention

Technical Problem

However, since the conventional brake method for the electric railway vehicle employs a combined electric brake and air brake method, it becomes a principal cause of the noise produced from the electric railway vehicle. Also, dust is produced and dispersed due to the friction of the disc-brake shoe at the time of braking the electric railway vehicle to thereby cause environmental pollution. _. Moreover, in. the conventional electric and air brake method, since the air brake method was employed when the speed of the electric railway vehicle was below 5km/h, there also occurred problems that noise was produced from the compressor and it was difficult to maintain and repair the device, and safety accident could be brought about because the air piping could be damaged due to worn out. Accordingly, the present invention was devised to solve such conventional problems, and an object of the present invention is to provide a stop control system which stops an

electric railway vehicle only through the electric brake in all speed ranges.

Technical Solution

To achieve the above object, the present invention provides a stop control system using an electric brake, comprises an inverter- for controlling speed of the motor by converting direct current inputted through a pantograph into alternative current, a pulse width modulation PWM control section for controlling voltage and frequency of an input circuit of an traction motor by producing a gate pulse of the inverter, a vector control section for determining inverter voltage and inverter frequency by means of the speed of the motor and current signal, an operation control section for performing operation command for reverse driving, regeneration, and stop of the electric railway vehicle, a brake controller for performing a parking brake for the electric railway vehicle, and a speed detection section for detecting the speed of rotor for controlling the motor.

Advantageous Effects

Therefore, the present invention realizes a full electric brake method capable of performing the precision control at the low speed range.

Further, it is possible to suppress the discharge of the dust and environment contaminating materials and generation of the noise by removing the air brake method.

Brief Description of the Drawings

FIG. 1 is a diagrammatical view showing the construction of a stop control system using an electric brake for the electric railway vehicle according to the present invention; FIG. 2 is a graphic view showing an electric brake stop control of the full range according to the conventional method; FIG. 3 is a graphic view showing the stop control using the electric brake according to the improved method of the present invention;

FIG. 4 is a graphic view showing the stop control at the speed reduction at low speed of the electric railway vehicle according to the present invention. <Explanation on numerals of principal portions of the drawings> 10: operation control section

20: brake controller 30: vector control section 40: pulse width modulation control section 50: power conversion section 60: speed detection section

Best Mode for Carrying Out the Invention

Hereinafter, the preferred embodiment of the present invention will be described in detail with reference to the appended drawings.

At first, the electric railway vehicle applied of the subordinate control method of the electric brake according to the present invention has an advantage that it can reduce the adjustment work burden to realize the stable stop control. Accordingly, it is possible to remove the noise and the dust by using the full electric brake as brake method for the electric railway vehicle till the speed of the electric railway vehicle becomes to be zero state. It is necessary to provide an inverter for controlling the motor in order to perform

the full electric brake, and the inverter performs the functions from the start to the stop, and the final maintenance of the stop state is accomplished by using an assistant brake.

The present invention provides effective brake method for performing the full electric brake by using the inverter control method. FIG. 1 is a diagrammatical view showing the basic construction of a vector control for the electric railway vehicle for the stop control of the full electric brake according to the present invention.

In the drawing, an inverter 50 is a propulsion inverter for supplying the driving power to the electric railway vehicle. The inverter operates to transform the direct current voltage (about DC 1500V) inputted through a pantograph disposed at the upper end of the electric railway vehicle into alternative current voltage after it passes through a filter and a condenser disposed in ^' series and in parallel and supply to thereby control the torque and speed of the motor IM. The inverter 50 for controlling the voltage inputted to the motor is constructed of the following elements described below. A pulse width modulation PWM control section 40 is to produce gate pulse of the inverter 50 to thereby control the voltage and frequency of the input circuit of a traction motor, and it receives commands of voltage | V | , phase angle δ and frequency Fj _nv from a vector control section 30, and receives direct current voltage E from the front end of the inverter 50 to thereby devise to improve the precision degree for controlling the voltage of the inverter 50.

The vector control section 30 is to determine the voltage and the frequency of the inverter by receiving the inputted speed and current signal of the traction motor, and it detects the electric current *" / ^v , ^{' w} applied to the motor IM from the inverter 50 so as to improve the precision degree of the electric current control to thereby remove the offset of the electric current, resulting in the suppress of the torque pulsation.

An operation control section 10 is to perform the operation commands such as reverse driving, regeneration, and stop and the like in the electric railway vehicle, and it sends commands of a magnetization current I _dp and a torque current I _qp to the vector, control section 30 by means of a notch commands P, B, and sends a command of brake torque B _TC to a brake controller 20, and receives a brake torque feedback B _TF from the brake controller 20.

The brake control section 20 indicates the operation of the assistant air brake (or hydraulic) method when the electric railway vehicle is stopped by the electric brake, and the result of the assistant brake operation is feedbacked and sent to the operation control section 10 to thereby realize the optimum state of the system operation.

A speed detection section 60 comprises a speed detection circuit for controlling the motor IM by receiving the speed of the electric railway vehicle from a speed sensor.

The speed detection section 60 detects the speed of the rotor of the motor IM to thereby improve the precision degree of the speed detection at low speed and correct the speed at the minimal range of the speed pulse.

Hereinafter, the operation of the stop control system using the electric brake of the electric railway vehicle of the present invention as constructed above will be described in detail below.

First, according to the reverse driving or regeneration command of the operation control section 10, a predetermined torque is required, and then the vector control section

30 increases the voltage/frequency to output required traction force to thereby supply it to the pulse width modulation control section 40, and then the supplied signal is transferred to the inverter 50 to thereby drive the traction motor IM.

. The vector control section 30 adjusts the output to the pulse width modulation control section 40 by receiving the value ^w , ^w , ^{' w*} of the detected current applied to

the motor IM and the detected speed from the speed detection section 60 so as to feedback the traction force and the speed produced from the traction motor IM.

Also, the vector control section 30 performs the feedback of the current and the frequency as vector control to cope with the command value of the operation control section 10, to thereby perform the feedback control continuously till it reaches the value of the command. While a usual encoder is used as a speed sensor for the precision control, since the encoder for the electric railway vehicle is used under poor surroundings with much vibrations and impacts, there is a limitation for the products having a high frequency to be used due to low durability. Accordingly, in the present invention, while the usual encoder has been used to improve the precision degree of the speed detection and control at the low speed range in particular, a multiplier (with more than four multiply ratio) is engaged to increase the switching frequency and the period of the pulse width modulation to thereby realize the precise control at the low speed. Of course, if the motor having a resolver at the inside is used as a speed detection sensor, it becomes possible to perform the precise control without the separate magnification device.

FIG. 2 is a graphic view showing the speed and the brake force of the joint use of the conventional electric brake and the air brake, in which the brake forces of the electric brake and the air brake are concurrently operated at the low speed range wherein the speed is reduced below a predetermined level. In other words, if a predetermined operation is performed for the brake of the electric railway vehicle, the operation of the electric brake is started, and the air brake is also started at low speed range of below 5 km/h. In this instant, since the brake force of the air brake doubly increases at the region in which the brake force of the electric brake is reduced, it can be easily understood that a blending region in which the electric brake and the air brake coexist substantially remains,

and the final stop operation is accomplished only by the brake force of the air brake without the brake force of the electric brake. .

Meanwhile, according to a method shown in FIG. 3 applied to the present invention, differing from a method shown in FIG. 2, the brake force of the air brake is produced at the minimal from the point when the brake force of the electric railway vehicle starts to decrease to stop the electric railway vehicle, the operation of the air brake at this time is simply for the prevention of the rolling, it is not related to the substantial brake. In other words, since the electric railway vehicle becomes to stop only by the brake force of the electric brake till the electric railway vehicle finally stops substantially, the blending region in which the electric brake and the air brake coexist does not exist in real.

FIG. 4 is a graphic view showing the stop control when the electric railway vehicle performs speed reduction at low speed. As shown in the drawing, when the stop signal is detected, command of the torque current Iq _p is sent to output full brake force,, so that the speed of the electric railway vehicle becomes to decrease, and when it arrives ^t predetermined low speed region (below 5 km/h), the command value of the torque current is gradually decreased to reduce the brake force of the electric brake. After the electric railway vehicle becomes to stop, the brake is performed by means of the hydraulic/air brake. While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. Also, it is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

KR2006/005549

Industrial Applicability

As described above, according to the stop control system using the electric brake of the electric railway vehicle of the present invention, it is possible to improve the driving feelings by employing full electric brake till the electric railway vehicle stops to brake the electric railway vehicle and remove the noise and extend the exchange period by reducing the wear of the brake shoe. Also, the present invention devises to reduce a jerk ratio, which generates the jerking, by the highly precise detection of the stop by means of the pulse control of the speed detection, after realizing the vector control with reduced speed, and to improve the entrainment feelings with the control of high reliability.