JPH077808A - Inverter drive system for AC / DC trains - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an inverter drive system for an AC / DC electric train, which can reduce the size of the converter without increasing the current capacity of the converter even if the voltage varies greatly in the AC section. [Configuration] DC power from the trolley line 10 in the DC section and AC power from the trolley line 10 in the AC section are switched to either DC power stepped down by the transformer 13 and AC / DC converted by the converter 24 and variable by the inverter 16. In the inverter drive system of the AC / DC train that converts the voltage and the variable frequency into three-phase AC power and supplies it to the three-phase induction motor, the DC voltage is changed from the rated DC voltage of the train line 10 in the DC section by the phase control of the converter 24. It is characterized by a high and constant value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter drive system for an AC / DC train that uses a three-phase induction motor as a main motor of the AC / DC train and controls a variable voltage and a variable frequency by an inverter.

[0002]

2. Description of the Related Art FIG. 2 is, for example, published on page 190 of the book "Railway Mechanism Drawing" published by Grand Prix Publishing Co., Ltd. (3 Fukuromachi, Shinjuku-ku, Tokyo) (September 10, 1987, first edition). FIG. 10 is a circuit diagram showing an inverter drive system for a conventional AC / DC train. In the figure, 10 is an overhead train line (hereinafter abbreviated as overhead line), to which a predetermined DC voltage is applied in the DC section and a predetermined AC voltage of a single-phase commercial frequency is applied in the AC section. 11 is a pantograph that takes in power from the overhead line 10, 12 is a changeover switch that switches between DC power and AC power from the overhead line 10, 13 is a transformer for a rectifier that steps down the AC voltage of the overhead line 10, and 14 is a transformer A converter that is connected to the secondary side of 13 and performs AC / DC conversion, and is a rectifier with a single-phase full-wave diode connection. 15 is the DC power from the overhead wire 10 in the DC section and the converter in the AC section
A converter for converting DC power from 14 and 16 are inverters for converting DC power from overhead line 10 in the DC section or DC power from converter 14 in the AC section into three-phase AC power of variable voltage and variable frequency. , Connect a three-phase induction motor as a load. Reference numeral 17 is a reactor that blocks the harmonic current generated in the inverter 16.

Next, the operation will be described. In the DC section, the changeover switch 12 is connected to the right terminal of the figure, the converter 15 is connected to both terminals on the outer side of the figure, and the DC power taken from the overhead wire 10 is variable voltage and variable frequency three-phase AC power with the inverter 16. Converted to and supplied to the three-phase induction motor of the load. Also, in the AC section, the changeover switch 12 is connected to the terminal on the left side of the figure, the converter 15 is connected to both terminals on the inside of the figure, and single-phase, commercial frequency AC power taken from the overhead line 10 is stepped down by the transformer 13. The converter 14 converts it into DC power, and the inverter 16 converts it into three-phase AC power of variable voltage and variable frequency, which is supplied to the three-phase induction motor. The voltage and frequency output from the inverter 16 are controlled according to the rotation speed of the three-phase induction motor, so that the inverter 16 can be efficiently operated in a wide speed range.

[0004]

The conventional inverter drive system for an AC / DC train is constructed as described above, and the DC voltage applied to the inverter 16 is, for example, an overhead line in the DC section.
1500V of 10 rated DC voltage, converter 14 in AC section
The rated DC voltage of 1650V is increased by 10% in the AC section to reduce the current capacity of the converter 14 to reduce the current capacity of the converter 14, but the DC voltage of the converter 14 is reduced due to the large voltage fluctuation in the AC section. If you want a converter
There was a technical problem that the current capacity of 14 could not be made small and could not be made compact.

The present invention has been made in order to solve the above-mentioned problems, and the inverter's current capacity of the converter does not increase even if the voltage fluctuation is large in the AC section, and the inverter can be miniaturized. The purpose is to obtain a drive system.

[0006]

An inverter drive system for an AC / DC train according to the present invention uses a converter to step down DC power from a train line in a DC section and AC power from a train line in an AC section. In the one that switches to AC / DC converted DC power and converts it to a three-phase AC power of variable voltage and variable frequency by an inverter and supplies it to a three-phase induction motor, the DC voltage is controlled by the converter phase control. It is higher than the rated DC voltage of the wire and is a constant value.

[0007]

According to the present invention, since the DC voltage of the converter is controlled to be higher than the rated DC voltage of the electric power line in the DC section and is kept at a constant value by the phase control of the converter, the current capacity of the converter is maintained even if the voltage fluctuation is large in the AC section. It never grows.

[0008]

EXAMPLES Example 1. FIG. 1 is a circuit diagram showing an embodiment of the present invention. In the figure, 10 to 13 and 15 to 17 are the same as those described in the conventional art. Reference numeral 18 is a capacitor that functions as a filter, and 24 is a converter that is connected to the secondary side of the transformer 13 to perform AC-DC conversion, and is a rectifier with a single-phase full-wave connection of a thyristor. Reference numeral 31 is a voltage detector that detects the DC voltage of the inverter 16, and 32 is a phase controller that outputs a phase control signal corresponding to the DC voltage signal detected by the voltage detector 31.

This embodiment is constructed as described above, and in the DC section, the changeover switch 12 is connected to the right terminal of the figure, and the converter 15 is connected to both terminals on the outer side of the figure so that the DC power taken in from the overhead wire 10 is supplied. The inverter 16 converts the variable voltage and variable frequency into three-phase AC power and supplies the three-phase induction motor of the load. Also, in the AC section, the changeover switch 12 is connected to the terminal on the left side of the figure, the converter 15 is connected to both terminals on the inside of the figure, and single-phase, commercial frequency AC power taken from the overhead wire 10 is stepped down by the transformer 13. Then, the converter 24 converts the DC power. At this time, the DC voltage signal corresponding to the DC voltage of the converter 24 is detected by the voltage detector 31, and is input to the phase controller 32 to perform the phase control of the thyristor constituting the converter 24 with the phase control signal. Set the DC voltage of 5% to 20% higher than the rated DC voltage of the overhead line 10 in the DC section. The DC power converted by the converter 24 is further converted by the inverter 16 into three-phase AC power of variable voltage and variable frequency and supplied to the three-phase induction motor. Therefore, the current capacity of converter 24 does not increase even if the voltage fluctuation is large in the AC section.

[0010]

As described above, according to the present invention, the DC power from the trolley line in the DC section and the AC power from the lane in the AC section are both stepped down by the transformer and converted into direct current by the converter. In an inverter drive system for an AC / DC electric train that switches to a three-phase AC power of variable voltage / variable frequency by an inverter and supplies it to a three-phase induction motor, the DC voltage is controlled by the converter's phase control. Since the rated DC voltage is higher than the rated DC voltage and is constant, the current capacity of the converter does not increase even if the voltage varies greatly in the AC section, and the converter can be downsized.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional inverter drive system for an AC / DC train.

[Explanation of symbols]

 10 Overhead line 11 Pantograph 12 Changeover switch 13 Transformer 15 Converter 16 Inverter 24 Converter 31 Voltage detector 32 Phase controller

Claims (2)

[Claims] 1. A DC voltage from an electric train line in a DC section and an AC electric power from an electric line in an AC section are stepped down by a transformer and switched to DC power which is AC / DC converted by a converter, and a variable voltage is set by an inverter. In an inverter drive system for an AC / DC train that converts variable-frequency three-phase AC power and supplies it to a three-phase induction motor, the DC voltage is higher than the rated DC voltage of the train line in the DC section by the phase control of the converter. An inverter drive system for an AC / DC electric train, which is characterized by setting a constant value. 2. The inverter drive system for an AC / DC train according to claim 1, wherein the DC voltage of the converter is set to be 5% to 20% higher than the rated DC voltage of the train line in the DC section.