JPS588672B2 - Hatsuden Brake Kisei Giyosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power generation brake control device using a vernier chopper device.

FIG. 1 shows an outline of the main circuit during power generation brake control when a vernier chopper type power generation brake control device is used.

The configuration of the vernier chopper device, its operating principle, etc. are already well known, so a description thereof will be omitted.

In conventional dynamic brake control devices of this kind, even if an attempt is made to apply dynamic braking at low speeds, the main circuit current (armature current) does not rise due to the characteristics of the DC series traction motor that is being controlled, and the dynamic braking is activated. The problem is that it cannot generate force.

This is because even if an attempt is made to apply a dynamic brake during low-speed rotation, the induced voltage EM due to the residual magnetic flux of the main motor is extremely low, several volts or less. S7
Even if all are short-circuited, the chopper parallel resistance value still remains, so the current is limited by this resistance, and the main motor is unable to raise the current due to self-excitation phenomenon, and when trying to ignite the chopper. Also, the gate firing pulse given to the main thyristor 16 of Chotupa is approximately 50 μs to 150 μs.
This is because the current flowing through the main thyristor 16 does not reach the thyristor's latching current value while this gate pulse is being applied, and the main thyristor 16 cannot sustain firing. It is something.

This is due to the actance L of the main circuit, which includes the armature 10 of the main motor, the series field 12, the main smoothing reactor 14, the main resistor 18, and the short-circuit switch circuit parallel to it. The gradient is di/dt=EM/L
This is because di/dt becomes extremely small when the induced voltage EM in the armature winding is low.

FIG. 2 is a block diagram showing a conventional electric power braking device using a vernier chopper device.

As shown in the figure, the main components of this conventional device include a brake command device 20, a brake current pattern generator 22, a current detector 24, a comparator amplifier 26, and a phase shifter 2.
8. Equipped with a gate amplifier circuit 30, a thyristor 32 of a vernier chopper device, and a DC current transformer 36, and generates a brake current (ip) corresponding to the current of the main circuit 34 under power generation control when a brake command is issued. This (ip) is generated and compared with the main circuit current to determine the conduction angle of the thyristor.

The brake current pattern generator 22 is a brake command device 2
When a brake operation command signal is given from 0 and the power generation brake main circuit 34 is turned on and the main circuit current (IA) flows, this is detected by the DC current transformer 36 (ia)L, and the current detector 24 Only when it is detected that this current (ia)∝(IA) is greater than a predetermined value and a pattern generation command is given, a brake current pattern (ip) is generated and applied to the comparator amplifier 26.

The phase shifter 28 determines the conduction angle (γ) according to the output level of the comparison amplifier 26 and supplies it to the gate amplifier circuit 30. Therefore, the current (IA) of the main circuit 34 is controlled by the thyristor 32 and its conduction angle. (γ) to control the generated braking force.

Control of the main motor in the high and medium speed ranges is possible with the conventional dynamic brake control device described above, but in the low speed range, the main circuit current does not rise, so the current detector 24
does not operate, therefore, the output pattern (ip) is not supplied from the pattern generator 22 and the conduction angle (γ) does not open, so the thyristor 32 is not conductive and can only be controlled.

Therefore, an object of the present invention is to provide a vernier chopper power generation brake device that performs power generation brake control operation even in a low speed range.

In order to achieve the above object, in the present invention, when a brake operation command signal is given from the brake command device 20, the rotational speed of the main motor at that time is compared with a reference value,
When the rotation speed is below the reference value, the comparison amplifier 26 outputs a minimum output limit corresponding to or equal to the rotation speed;
In addition, a brake initial speed detector that outputs a continuous pulse generation command signal is installed in the gate amplifier circuit, and the gate amplifier circuit 30 is replaced with a multi-gate amplifier circuit, and the continuous pulse generation command signal is outputted to the multi-gate amplifier circuit. is configured to supply as a control input.

As a result, according to the present invention, the thyristor is forcibly driven to close the main circuit, achieving dynamic braking control even in the low speed range, which was not possible with conventional devices.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 3 is a block diagram showing an embodiment of a power generation brake control device using a vernier chopper according to the present invention.

This embodiment differs from the conventional device shown in FIG. 2 in that a brake initial speed detector 38 is installed and a multi-gate amplifier circuit 31 is used.

The brake initial speed detector 38 detects a minimum output limit pattern (IP
m) to the input terminal of the comparator amplifier 26, and a continuous pulse generation command (CPIS) to the multi-gate amplifier circuit 31, and these signals continue to be output until the brake command is turned off.

In this embodiment, since the lowest output limit pattern (ipm) is supplied to the ratio amplifier 26, the main circuit current (ia) is small and the amplifier 26 is output, phaser 2
8 outputs a signal representing the angular flow angle (γ) to the multi-gate amplifier circuit 31.

Note that instead of supplying the lowest limit pattern (ipm) to the input terminal of the amplifier 26, a lowest limit output command signal is supplied to the amplifier 26 to force the limit pattern output of a certain level pattern from within the amplifier 26. It may be made to occur.

An example configuration of the multi-gate amplifier circuit 31 is shown in FIG.

This circuit 31 includes a square wave oscillator 311, an amplifier 312,
Gate transformer 313, phase inversion circuit 314, amplifier 3
15, gate transformer 316, and gate transformer 3
It is equipped with diodes and the like to combine the outputs of 13,316.

The square wave oscillator 311 generates a continuous pulse generator command signal (C
PIS) is being input, the phase shifter 28 continuously repeats pulses during the pulse section representing the reverse flow angle (γ) and outputs them to the amplifier 312 and phase inversion circuit 314, and the command signal (CPIS) is output. If it does not exist, the flow angle (
γ) Only one pulse (single pulse) is output when the signal arrives.

Therefore, as shown in FIG. 7, when the brake initial speed detector 38 is producing an output, that is, when the lowest output limit pattern (ipm) is input to the amplifier 26,
The output of the amplifier 26 causes the phase shifter 28 to set the minimum conduction angle (γm
in) signal is output, and when the continuous pulse generation command signal (CPIS) is applied to the gate amplifier circuit 31, as shown in FIG. Therefore, it has the same width as the minimum flow angle (γmin).

Therefore, the thyristor is definitely turned on.

On the other hand, when a brake command is issued in a medium or high speed range, there is no continuous pulse command signal (CPIS) and the seventh
As shown in FIG. b, a single pulse is generated only at the rising edge of the output pulse of the phase shifter 28.

In this case, since the main circuit current is constant, complete conduction of the thyristor is achieved with only a single pulse.

Note that instead of the configuration in which the gate amplifier circuit 31 has a predetermined width (γmin) by combining pulses as described above,
A configuration in which the AND section of the output of the phase shifter 28 and the pulse generation command (CPIS) is directly amplified can be considered, but this would increase power consumption and increase the size of the device, which would be uneconomical.

FIG. 4 shows a modification of the embodiment shown in FIG.

In this embodiment, AND gates AND1 and AND2 are installed in the output circuit of the brake initial speed detector 38, and these gates are controlled by the output of the inverter 25 which receives the output of the current detector 24 as input.

Therefore, in this example, the above-mentioned (Fig. 3)
The operation is performed, the thyristor 32 is turned on, the main circuit current (■A, ia) increases, the current detector 24 outputs a pattern generation command signal, and the brake current pattern (ip) is input to the amplifier 26. After that, the minimum output limit pattern (ipm) and continuous pulse generation command signal (CP
IS) is cut off, and the aforementioned low-speed region forced drive operation is canceled.

Note that a normally closed relay may be installed in place of the AND gates AND1 and AND2, and this may be controlled by the output of the current detector 24.

Alternatively, the detector 28 may be deenergized by the output of the current detector 24.

FIG. 5 is a block diagram showing still another embodiment of the device of the present invention.

In this embodiment, the output of the comparison amplifier 26 is input to the level comparator 4.
0 and the output value rises above the low-speed region forced drive level, that is, the thyristor 32 is turned on due to the above-mentioned low-speed region forced drive, and the main circuit current (IA, ia) increases. Then, when the current detector 24 generates an output and the pattern generator 22 generates a pattern output (ip), the reset command device 12 is energized and the brake initial speed detector 38 is deenergized. ing.

As described above, according to the configuration of the present invention, the thyristor is forcibly driven in the low speed range, a sufficiently large current is supplied to the brake main circuit, and a generated braking force can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional power generation brake circuit using a vernier chopper, and FIG. 2 is a block diagram showing a conventional power generation brake control device. FIG. 3, FIG. 4, and FIG. 5 are block diagrams each showing an embodiment of the power generation brake control device of the present invention, and FIG. FIG. 2 is a block diagram showing more specifically a part of the device shown in FIG. FIG. 7 is a waveform diagram showing output waveforms of each part of the apparatus shown in FIGS. 3, 4, and 5. In addition, in the drawings, the same reference numerals indicate the same or equivalent members. 10...Armature, 12...Series winding field,
14... Smoothing reactor, 16... Thyristor, 18... Resistor, S1 to S7...
... Switch, 20 ... Brake command device, 2
2... Brake current pattern generator, 24...
...Current detector, 25...Inverter, 2
6... Comparison amplifier, 28... Phase shifter,
30...Gate amplifier circuit, 31...
Multi-gate amplifier circuit, 32... Main circuit, 3
6...DC current transformer, field...brake initial speed detector, AND1, AND2...and gate, 40...level comparator, 42.・・・・・・
・Reset device, 311... Square wave oscillator, 31
2,315...Amplifier, 313,316...
...Gate transformer, 314...Phase inversion circuit.

Claims (1)

[Claims] 1. A vernier chopper consisting of a DC series motor, a smoothing reactor, a resistor, a thyristor chopper device connected in parallel to one section of the resistor, a plurality of switches arranged to sequentially short-circuit other sections of the resistor, etc. A control device for a type dynamic brake circuit includes a comparator amplifier for variable control of the conduction rate of the thyristor chopper device, a phase shifter for outputting a chopper conduction angle signal corresponding to the output level of the comparator amplifier, and a phase shifter for outputting a chopper conduction angle signal corresponding to the output level of the comparator amplifier. a brake initial speed detector that operates at an initial speed when a dynamic brake is commanded to generate a minimum conduction rate limit pattern output that energizes the comparator amplifier and makes its output equal to or higher than a predetermined conduction angle; A power generation brake control device comprising a multi-gate amplifier that outputs a pulse-on pulse having a width equivalent to the output signal pulse section of the phase shifter when receiving a command signal from a speed detector.