JPS61210802A - Regenerative brake control system of ac electric railcar - Google Patents

Abstract

PURPOSE:To shorten a costing period during which a brake force is not operated by storing gate phase shift signal values of main and field converters at nonvoltage zone entering time, and applying a gate phase shift signal stored after escaping from the nonvoltage zone. CONSTITUTION:When a signal that a nonvoltage zone approaches is output from a nonvoltage zone prenotifying unit 13 during regenerative braking operation, the gate phase shift signal values of field and main converters 6, 3 at that time are stored in a brake controller 12. The converter 6 is flywheel- operated. Then, when the fact that the car enters to the nonvoltage zone is detected by a voltage detector 9, the converter 3 is freewheel-operated. When the fact that the car again enters to a voltage application zone is detected by the detector 9, the stored gate phase shift signal value is applied to the converters 6, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a regenerative braking control method when an AC electric vehicle in regenerative braking operation passes through a no-voltage section of a power supply line.

[Prior art and its problems]

When applying braking to a running AC electric car, in order to effectively utilize the kinetic energy of this AC electric car, a braking method is used that converts this kinetic energy into electrical energy and regenerates it to the power source through so-called power regenerative braking operation. It is becoming widely used.

However, when performing such power regenerative braking operation, braking force is obtained only when the load that can be regenerated is connected to the power supply system. It must be absolutely avoided that the AC electric vehicle in question passes by while operating under regenerative braking.

Therefore, in general, regenerative braking operation is canceled when the vehicle approaches this no-voltage zone within a certain distance, and regenerative braking operation is restarted after passing through the no-voltage zone.In this case, the regenerative braking force is Since the rise of the regenerative braking force is made gradual in order to prevent the regenerative braking force from failing or causing an overcurrent in the main motor circuit, there are safety problems such as a longer braking distance.

[Purpose of the invention]

This invention improves riding comfort as well as safety by minimizing the period during which regenerative braking is released when passing through a non-voltage section of a power supply line, and by smoothing the build-up of braking force when re-braking. It is an object of the present invention to provide an excellent regenerative braking control method for an AC electric vehicle. [Summary of the Invention] The present invention provides a system that, when receiving a signal predicting a no-voltage section of a power supply line during regenerative braking operation, At this point, the gate phase shift signal value of the main converter that supplies the armature current to the separately excited DC motor for driving the AC electric vehicle, and the gate phase shift signal value of the field converter that supplies the exciting current of this motor. is memorized and a gate phase shift signal is applied to the first field converter to cause the converter to operate in freewheel mode, thereby attenuating the field current, reducing the armature current accordingly, and then When entering the no-voltage section, a gate phase shift signal is applied to the main converter as well, which causes the converter to operate in freewheel mode. If you escape from the no-voltage section here, the field current and armature current of the motor will quickly rise by applying the previously memorized gate phase shift signal to each of the main converter and field converter. Since regenerative braking force can be obtained again, the idle running period during which no braking force is applied can be shortened, solving safety problems and improving ride comfort.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the present invention, and the content of the present invention will be explained below with reference to FIG.

In Fig. 1, AC power from feeder line 1 is drawn into the AC electric car by a pantograph and applied to the primary winding of main transformer 2. A voltage section is provided.

A main converter 3 composed of a semiconductor switching element such as a thyristor is connected to the secondary winding of the main transformer 20, and the DC power obtained from the main converter 3 is passed through a smoothing reactor 4 to an AC electric vehicle. is given to five armatures of separately excited DC motor 5 for driving. Also main transformer 2
A field converter 6, which is also composed of a thyristor or the like, is connected to another secondary winding of , and from this field converter 6 to the field winding 5F of the separately excited DC electric motor Mk5. An excitation current is provided. Excitation current I flowing through this field winding 5F
6 is a current transformer 8, and the above-mentioned armature current I3 flowing through the armature 5λ is detected by the current transformer 7 and transmitted to the brake control device 12.
is input. Further, a voltage detector 9 is provided on the secondary winding of the main transformer 2 to which the field converter 6 is connected, and a voltage detector 10 is provided on the DC side of the main converter 3. Furthermore, reference numeral 11 is a brake command device, and reference numeral 13 is a no-voltage interval prediction device, and these signals are also input to the brake control device 12.

Brake command device 1 to decelerate an AC electric car that is running in a row.
When a command for regenerative braking operation is input from 1 to the brake control device 12, this brake control device 12 applies an appropriate gate phase shift signal to the field converter 6 and the main converter 3 to control the AC electric vehicle. Convert kinetic energy to electrical energy and create armature 5A
This electrical energy is regenerated from the main converter 3, the main transformer 2, and the power supply line 1 to a power source (not shown). In such power regenerative braking, the armature current generator 3 is detected by a current transformer 7, the exciting current generator 6 is detected by a current transformer 8, and negative feedback is sent to the brake control device 12, and the detected amount is used as a brake command. The gate phase shift signals to the main converter 3 and the field converter 6 are adjusted to match the command value from the device 11, thereby increasing or decreasing the values of the armature current generator 3 and the excitation current generator 6. The required braking force is obtained in the same manner as in the conventional system.

In the present invention, when the no-voltage section prediction device 13 issues a signal informing that the no-voltage section of the power supply line approaches during regenerative braking operation as described above, first the field converter at that point The gate phase shift signal value of 6 and the gate phase shift signal/value of the main converter 3 are stored inside the brake control device 12, and the field converter 6 is continuously operated in a freewheel operation. 6 is given a gate phase shift signal. For this reason, the excitation current I6 is attenuated to reduce the induced voltage of the separately excited DC motor 5 operating as a generator, and the armature current 3 is also rapidly attenuated accordingly. When entering the no-voltage section, this armature current I3 is approximately zero.

That is, the time or position at which the no-voltage section prediction signal is issued is appropriately selected so that the exciting current generator 6 has almost disappeared when the AC electric vehicle enters the no-voltage section.

When the voltage detector 9 detects that the voltage-free zone has entered in this state, a gate phase shift signal is sent from the brake control device 12 to the main converter 3 to cause the main converter 3 to perform freewheel operation. In the no-voltage section, both converters 3 and 6 are in a freewheeling state.

When the voltage detector 9 detects that the AC electric vehicle has escaped from the no-voltage section of the feeder line and entered the energized section again, this detection signal causes the gate of the main converter 3 to Since the gates of the converters 6 are given the respective gate phase shift signal values stored when the signal predicting the no-voltage section is received, the currents in both converters 3 and 6 quickly rise, resulting in regenerative braking. Operation will resume.

FIG. 2 is a diagram of the operating state of each part when passing through a no-voltage section by the embodiment circuit shown in FIG. 1, and FIG.
is the effective value of the feed line voltage, FIG. 2 (b) is the no-voltage section prediction signal, and FIG. 2 (c) is the output signal of the voltage detector 9.
2) shows the armature current I3, and FIG. 2(E) shows the exciting current 6, respectively.

As shown in FIG. 2, when the approach of one no-voltage zone is output from the no-voltage zone prediction device 13, the field converter 6 becomes freewheeling, the excitation current I6 attenuates, and at the same time Armature electric current 3 is also attenuated. When passing through the no-voltage section and entering the energized section, the main converter 3 and the field converter 6 are given the previous gate phase shift signal.
The armature current I3 and the excitation current I6 quickly rise to a predetermined regenerative braking operating state again.

FIG. 3 is an operating waveform diagram of each part during regenerative braking operation in the example circuit shown in FIG. 1, and FIG.
Figure 3 (b) shows the AC input voltage waveform from the main converter 3.
Figure 3 (c) shows the DC output voltage waveform of the field converter 6.
In the figure, β is the output control phase by the main converter 3 gate phase shift signal, and α is the DC output voltage waveform.
indicates the output control phase by the gate phase shift signal of the field converter 60.

FIG. 4 is also a main converter output characteristic diagram during regenerative braking operation, and shows the relationship between output current and output voltage using the output control phase β by the gate phase shift signal as a parameter.

〔Effect of the invention〕

According to this invention, the armature of a separately excited DC motor that drives an AC electric car is equipped with a main converter, and the field winding is equipped with a field converter to control armature current and excitation current. If an AC electric vehicle that is running regenerative braking approaches a non-voltage section of the feeder line, it will memorize the gate phase shift signals of both converters at that time and re-wheel the field converter. The excitation current and armature current are controlled to rapidly attenuate, and when the no-voltage section is entered, the main converter is also freewheeled in preparation for re-energization, and when the energized section is re-entered, both conversions are performed. The above-mentioned stored gate phase shift signal is applied to the regenerative braking force to quickly start up the regenerative braking force. With this control method, it is possible to minimize the period during which the regenerative braking force is lost when passing through the five non-electrified sections of the power supply line during regenerative braking operation, so the so-called idle running period (or idle running distance) can be minimized. ) and () to a small value to minimize safety hazards, and as shown in Figure 2, by smoothing current changes, braking force starts and falls smoothly, improving ride comfort. It is possible to exhibit the effect that there is no risk of worsening the condition.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
The figure is a diagram of the operation state of each part when passing through a no-voltage section in the example circuit shown in Figure 1. Figure 3 is an operation waveform diagram of each part during regenerative braking operation in the example circuit shown in Figure 1. Figure 4 is a main converter output characteristic diagram during regenerative braking operation. DESCRIPTION OF SYMBOLS 1... Power supply line, 2... Main transformer, 3... Main converter, 4... Smoothing reactor, 5... Separately excited DC motor,
5A... Armature, 5F... Field winding, 6... Field converter, 7° 8... Current transformer, 9.10... Voltage detector, 11... - Brake command device, 12... Brake control device, 13... No-voltage section prediction device. Figure 11 Figure 2 Figure 4! ! 1

Claims (1)

[Claims] In the AC electric vehicle that runs while controlling the armature current of a separately excited DC motor using a main converter that converts AC power to DC power, and controlling the excitation current of the separately excited DC motor using a field converter, When the AC electric vehicle receives a signal predicting a no-voltage section of the power supply line during regenerative braking operation, it stores the gate phase shift signal values of the main and field converters at this time, and also stores the gate phase shift signal values of the main and field converters at this time A gate phase shift signal that causes the converter to perform freewheel operation is applied to the main converter, and when the electric vehicle enters a no-voltage section, a gate phase shift signal that causes the converter to perform freewheel operation is applied to the main converter. A regenerative braking control system for an AC electric vehicle, characterized in that when the electric vehicle enters a charged section of a power supply line again, the stored gate phase shift signal values are applied to the main and field converters.