JP2980426B2 - AC electric vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC electric vehicle control device.

[0002]

2. Description of the Related Art As an AC electric vehicle control device that takes in AC power from an AC overhead wire, converts the AC power into DC, and drives an electric vehicle, a device having a configuration shown in FIG. 4 is conventionally known.

[0003] This conventional AC electric vehicle control device is a PWM control device.
It includes a converter / VVVF inverter system, and includes a pantograph 1, a main transformer 3 provided between the pantograph 1 and the wheels 3 for transforming a high-voltage AC received by the pantograph 1, a contact AC. Contactors 4-1 and 4-2; 5-1 and 5-2, a charging resistor 6 for preventing overcurrent during charging of a large-capacity smoothing capacitor.
1, 6-2, single-phase input PWM converter 6-1, 6-
2, large-capacity smoothing capacitors 7-1 and 7-2, three-phase output VVVF inverters 9-1 to 9-4, and V
Induction motor 10-driven by VVF inverter
1 to 10-4.

Here, contactors 5-1 and 5-2 for charging the smoothing capacitors 7-1 and 7-2 and resistors 6-1 and 6 are provided.
Explaining the operation of -2, generally, when charging a capacitor with a DC voltage, if there is no impedance between the charging power supply and the capacitor, a large current flows at the start of charging,
Each device may be damaged. However, since the large-capacity smoothing capacitors 7-1 and 7-2 need to be charged when the apparatus is started, a large current may flow. Therefore, when charging the smoothing capacitors 7-1 and 7-2, the contactors 5-1 and 5-2 for charging the capacitors connected to the charging resistors 6-1 and 6-2 for suppressing the charging current are closed. To charge the smoothing capacitors 7-1 and 7-2, and after the voltage between both ends of the smoothing capacitors 7-1 and 7-2 reaches a certain value, the contactors 4-1 and 4-2 are closed and the converter 8-
1, 8-2 and the control of the inverters 9-1 to 9-4 are started.

The PWM converters 6-1 and 6-2
Controls the converter input current so that the voltage of each of the smoothing capacitors 7-1 and 7-2 becomes constant. Each of the VVVF inverters 9-1 to 9-4 controls the induction motor 10-.
1 to 10-4 are torque-controlled with variable voltage and variable frequency outputs.

The reason that the converter and the inverter are divided into two groups and controlled independently of each other is that when a part of the device belonging to one group fails, only the failed group is opened and the normal group is opened. This is because the operation is continued by the motors belonging to the group, and the reduction of the motor output in the event of a failure is minimized.

[0007]

However, in such a conventional AC electric vehicle control device, the contactor connected to the secondary winding side of the main transformer is a contacted type, so that maintenance work is required. There was a problem that took time and effort.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is maintenance-free by making the AC contactor for the charging resistor connected to the secondary winding of the main transformer contactless. It is an object of the present invention to provide an AC electric vehicle control device that can achieve the above.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a single-phase AC power is input, and a switching element and an anti-parallel diode are provided on each winding of a main transformer having at least two windings on a secondary side. In an AC electric vehicle control device having an AC-DC converter to which a large-capacity smoothing capacitor is connected via a bridge-connected converter, at least one of the secondary winding outputs of the main transformer has a contact switch and a reverse blocking. A first charging circuit of the smoothing capacitor connected in parallel with a solid state switch is inserted, and the remaining number of secondary winding outputs of the main transformer is the same as the number of windings in which the first charging circuit is inserted. The polarity of the second charging circuit of the smoothing capacitor, in which a contact switch and a reverse blocking type semiconductor switch are connected in parallel, is opposite to that of the first charging circuit. In which was inserted into.

In the above-mentioned AC electric vehicle control device, a charging resistor for each of the smoothing capacitors can be inserted in series on the reverse blocking type semiconductor switch side of each of the first charging circuit and the second charging circuit. .

[0011]

According to the AC electric vehicle control device of the present invention, when charging the smoothing capacitor at the time of starting, in each of the first charging circuit and the second charging circuit, the ON / OFF of the reverse blocking type semiconductor switch which is a non-contact switch. By controlling the amount of current flowing through the smoothing capacitor, a large current can be prevented from flowing through this smoothing capacitor.

In each charging circuit, by inserting a charging resistor together with a reverse blocking semiconductor switch,
The large current that flows when the semiconductor switch is turned on can be further suppressed, and the flow of the large current when the smoothing capacitor is charged can be more reliably suppressed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
In this embodiment, portions common to the circuit configuration of the conventional example shown in FIG. 4 are denoted by the same reference numerals. The AC electric vehicle control device of this embodiment transforms a high-voltage AC power supply received by the pantograph 1 by the main transformer 3 in the same manner as the conventional example, and the main transformer 3 has one of two secondary windings. An AC contactor 4-1 as a contact switch for constituting a first charging circuit and a reverse blocking semiconductor such as a thyristor for playing a role of an AC contactor for a charging resistor in parallel with the contactor. The switch 11-1 is inserted.

The other secondary winding of the main transformer 3 has an AC contactor 4-2 as a contact switch so as to form a second charging circuit, and a thyristor so as to be parallel to the contactor. Such a reverse blocking type semiconductor switch 11-2 is inserted, and the reverse blocking type semiconductor switch 11-2 of the second charging circuit is used to prevent the magnetization of the smoothing capacitors 7-1 and 7-2. , Is connected to the reverse blocking semiconductor switch 11-1 of the first charging circuit so as to have a reverse polarity.

The gates of the reverse blocking semiconductor switches 11-1 and 11-2 are connected to the gate control circuit 1
2 and the smoothing capacitors 7-1 and 7-
2 to control the amount of current applied to each.

Next, the operation of the AC electric vehicle control device having the above configuration will be described.

As shown in FIG. 2, the smoothing capacitor 7-
When the main circuits 1 and 7-2 are charged, the reverse blocking semiconductor switches 11-1 and 11-2 are controlled in phase by the gate control circuit 12 in synchronization with the AC input power supply from the start-up time A of the main circuit. In this phase control, the phase angle is gradually widened, and charging is performed while limiting an instantaneous change in voltage applied to both ends of the smoothing capacitors 7-1 and 7-2. This control prevents an instantaneous large current at the start of charging of the smoothing capacitors 7-1 and 7-2, and protects the device.

When the voltage between both ends of the smoothing capacitors 7-1 and 7-2 reaches a predetermined value and the charging is completed at point B, the phase control of the reverse blocking semiconductor switches 11-1 and 11-2 is performed. At the same time, the AC contactors 4-1 and 4-2, which are contact switches, are both closed, and the VVVF inverter 9 is closed.
Preparations for operations -1 to 9-4 are started.

Thereafter, the PWM converters 8-1, 8-2,
The VVVF inverters 9-1 to 9-4 start control, and the AC power input from the main transformer 3 is applied to the converter 8-
1, 8-2 and inverters 9-1 to 9-4.
Is converted into phase AC power, and the induction motors 10-1 to 10-4
Drive.

Here, by setting the reverse blocking semiconductor switches 11-1 and 11-2 for charging the capacitors to have opposite polarities, the magnetic bias phenomenon of the main transformer 3 is prevented. That is, the charging of the smoothing capacitor 7-1 by the semiconductor switch 11-1 of the first charging circuit is performed by positive half-wave rectification of the AC power supply input from the main transformer 3, so that the main transformer 3 The polarity of the semiconductor switch 11-2 of the second charging circuit may be opposite to the polarity of the semiconductor switch 11-1 of the first charging circuit, and charging may be performed by negative half-wave rectification. Thereby, the magnetic bias of the main transformer 3 can be suppressed.

The current controlled by the reverse blocking semiconductor switches 11-1 and 11-2 for charging the capacitors may exceed the current value during normal operation when charging the smoothing capacitors 7-1 and 7-2. However, there is no high heat because the power is supplied only for a short time required for charging. Therefore, the ratings of the semiconductor switches 11-1 and 11-2 are higher than the ratings of the elements constituting the converter or the inverter. And a small device can be used, and a large-scale element cooling mechanism is not required.

FIG. 3 shows a circuit configuration of another embodiment of the present invention. This second embodiment includes a first charging circuit,
An inverted-element semiconductor switch 1 is provided for each of the second charging circuits.
It is characterized in that charging resistors 13-1 and 13-2 are provided in series with 1-1 and 11-2. In the case of this embodiment, one smoothing capacitor 7 and one VVVF inverter 9 are used to simplify the circuit configuration. However, this can be configured similarly to the first embodiment. It is.

The charging resistor 13-
1, 13-2, the smoothing capacitor 7
, The instantaneous current flowing when the gates of the semiconductor switches 11-1 and 11-2 are opened at the start of charging can be more reliably suppressed, and the safety of the main circuit is improved. .

The present invention is not limited to the above-described embodiment. In particular, when the main transformer 3 has three or more secondary windings, the first charging circuit and the second charging circuit The same operation and effect can be obtained by inserting the same number of charging circuits. Further, the inverted element type semiconductor switch is not limited to a thyristor, and another semiconductor switch element having similar characteristics can be used.

[0026]

As described above, according to the present invention, each of the secondary windings on the secondary side of the main transformer is a reverse element type semiconductor switch which is a non-contact switch in the charging circuit of the smoothing capacitor when the main circuit is started. In order to control the charging current to the smoothing capacitor by controlling the gate of this semiconductor switch, the current control during charging of the smoothing capacitor is performed by a contact switch as in the past. As a result, the size of the apparatus can be reduced, and maintenance-free operation can be achieved.

Further, by inserting a charging resistor in series with the reverse element type semiconductor switch of each charging circuit, it is possible to more reliably suppress an excessive current flowing when charging the smoothing capacitor.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of one embodiment of the present invention.

FIG. 2 is a waveform chart showing the operation of the inverted element type semiconductor switch in the embodiment.

FIG. 3 is a circuit block diagram of another embodiment of the present invention.

FIG. 4 is a circuit block diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pantograph 2 Wheel 3 Main transformer 4-1 and 4-2 AC contactor 7,7-1,7-2 Smoothing capacitor 8,8-1,8-2 PWM converter 9,9-1-1-9-4 VVVF Inverter 10-1 to 10-4 Induction motor 11-1, 11-2 Inverted element type semiconductor switch 12 Gate control circuit 13-1, 13-2 Charging resistor

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ikuo Yasuoka 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant (72) Inventor Rei Miyazaki 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Plant (56) References JP-A-63-186505 (JP, A) JP-A-61-81178 (JP, A) JP-A-4-72880 (JP, U) JP-A-58-49591 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) H02M 7/00-7/98

Claims (2)

(57) [Claims] 1. A single-phase AC power is input to a main transformer having at least two windings on a secondary side via a converter in which a switching element and an anti-parallel diode are bridge-connected to each of the windings. In an AC electric vehicle control device having an AC-DC converter connected to a capacitance smoothing capacitor, a contact switch and a reverse blocking semiconductor switch are connected in parallel to at least one of the secondary winding outputs of the main transformer. A first charging circuit of the smoothing capacitor is inserted, and the remaining number of secondary winding outputs of the main transformer is the same as the number of winding outputs in which the first charging circuit is inserted. A second charging circuit of the smoothing capacitor in which a contact switch and a reverse blocking semiconductor switch are connected in parallel with each other so that the polarity of the second charging circuit is opposite to that of the first charging circuit. AC electric vehicle control apparatus according to symptoms. 2. The AC electric vehicle control device according to claim 1, wherein a charging resistor for each of the smoothing capacitors is inserted in series on the reverse blocking type semiconductor switch side of each of the first charging circuit and the second charging circuit. An AC electric vehicle control device, characterized in that: