JPS62268302A - Auxiliary power unit system for rolling stock - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle equipped with a 4M (pulse width modulation) inverter that supplies power to an AC load from a DC power supply supplied from an overhead contact line or third rail. related to auxiliary power supply systems.

[Conventional technology]

Normally, electric vehicles must obtain all power sources, such as vehicle drive power, cooling/heating power, lighting power, battery charger, and control power, from overhead contact lines or the third rail. In the case of a DC train, the voltage of these overhead contact lines is 600cm DC.
~1500 V, and as high as 3000 V DC, all vehicle power supplies are powered by this DC 600 V~300 V.
Must be obtained from the 0 V overhead contact line or third rail.

Figure 6 is a circuit diagram showing a conventional example of a power supply system that uses a main inverter to obtain power for vehicle cooling. It is driven by

The main PWM inverter 2 is connected to a starting device 4 which is connected to the overhead contact line 3 and configured with a filter switch, etc., and between the starting device 4 and the main PWM inverter 2, an inverter 2 flowing to the overhead contact line 3 side is connected. A smoothing capacitor 5 is connected in parallel for suppressing input harmonic current.

In the figure, reference numeral 6 denotes an auxiliary power supply device for obtaining control power for the inverter 2, and this is connected to the output side of the starting device 4 of the main power supply circuit.

FIG. 7 shows an example of the basic circuit of the auxiliary power supply device 6, which includes an auxiliary PWM inverter 61 that converts direct current to alternating current, and an auxiliary PWM inverter 61 that is insulated from the main power circuit and that changes the alternating current voltage of the inverter 61 to a required voltage. A rectifier 63 is connected to this inverter 61 via an isolation transformer 62 that steps down the voltage up to .

In this way, the main voltage of the rectifier 63 is adjusted by the PWM 1tdH output of the inverter 61, and the DC output of the rectifier 63 is converted to a DC/AC converter (not shown) as necessary.
However, in order to obtain two or more types of power, various types of alternating current and direct current can be obtained by providing multiple secondary windings of the transformer 62 or providing taps. .

[Problem that the invention seeks to solve]

In the conventional auxiliary power supply circuit shown in FIGS. 6 and 7, the semiconductor elements used in the auxiliary PWM inverter 61 for the auxiliary power supply are the same as the elements of the main PWM inverter 2, for example, 2500 V or more. A high-voltage self-extinguishing element with a withstand voltage of Generally, high voltage self-extinguishing elements of 2500 V or higher include GTO Cyrisk, but these elements are large current elements and are expensive.

If such an element is applied to an inverter for a small capacity auxiliary power supply, the auxiliary power supply device 6 will become very expensive and large.

In addition, the power of the auxiliary power supply device 6 can be directly connected to the main PW of the main power supply circuit.
Since it is taken from the same DC main circuit as M inverter 2, the auxiliary P
A failure of the WM inverter 61 directly affects the operation of the main PWM inverter 2, reducing the reliability of the entire power supply circuit.

Furthermore, the protection measures against failure of the auxiliary PWM inverter 61 are the same as those of the main PITM inverter 2, making the auxiliary power supply device 6 even more expensive.

The present invention eliminates the disadvantages of the conventional example and provides a vehicle auxiliary power system that is small and lightweight, inexpensive, and highly reliable for use in inverter-equipped vehicles.

[Means for solving problems]

In order to achieve the above object, the present invention provides an auxiliary power supply system for a vehicle using DC electricity that supplies power to an AC load from a DC power supply supplied from an overhead contact line or a third rail through a PWM inverter. Divide the smoothing capacitor connected to the side into two and connect them in series,
A primary winding of a transformer is connected between the AC terminals of at least two arms of the PWM inverter and a connection point of the capacitor, and an auxiliary power supply device is connected via the secondary winding of the transformer. The main points are as follows.

[Effect]

According to the present invention, the PWM inverter of the main power supply circuit turns on and off the semiconductor switches of two arms connected in series to generate a rectangular wave AC voltage at the AC terminals according to the input voltage of the inverter. Focusing on this, we stepped down this AC voltage via a transformer to obtain the necessary power supply voltage.

Since the auxiliary power converter is thereby connected to the secondary side of the transformer, the withstand voltage of the semiconductor element used in the converter can be freely selected.

In addition, since only a highly reliable transformer is connected to the main power circuit side, there is no risk that failure of the auxiliary power converter or the like will adversely affect the main inverter.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the auxiliary power supply system for a vehicle according to the present invention, in which the same components as in FIG. 6 showing the conventional example are given the same reference numerals.

The main power supply circuit is the same as the conventional example except for the smoothing capacitor connected to the DC side of the main PWM inverter 2. Reference numeral 1 is a taller as an AC load, which connects the starting device 4 to the overhead contact line 3. Although it is connected to the AC output side of the main PWM inverter 2 connected through the main PWM inverter 2, a detailed explanation thereof will be omitted since it is as described above. In addition, in the figure, 2L 2
Reference numeral 2 indicates a part of a semiconductor switch constituting the inharter 2.

In the present invention, the smoothing capacitor connected in parallel between the starting device 4 and the main PWM inverter 2 is divided into two parts.
．． 52, and these were connected in series.

The primary of the auxiliary transformer 71 is connected between the connection point A of these smoothing capacitors 51 and 52 and the AC terminal B of the first arm of the main four-unit inverter 2 (for example, the arm from the semiconductor switches 21 and 22 connected in series). Connect the windings. Similarly, the second
An auxiliary transformer 72 is connected between the AC terminal C of the arm and an auxiliary transformer 73 is connected between the AC terminal of the third phase arm. Note that the switching of the first, second, and third phases of the inverter arm operates in three phases, so these auxiliary transformers 71
.about.73 are the same operations shifted by 120 degrees.

Then, an auxiliary power supply bag N is attached to the secondary winding of each transformer 71 to 73.
8 and obtain the necessary power from its output terminals 91 and 92.

FIG. 2 is a circuit diagram showing an example of the auxiliary power supply device 8, which is connected to the transformers 71 to 73 and connected in parallel to each other in order to obtain a stable DC voltage for use as an auxiliary power source, such as an inverter control power source. diode rectifier 81~
83 and the converter 8 connected to these rectifiers 81 to 83
It was composed of 4. This converter 84 is a DC/DCC/type converter when a direct current power source is required for the output, and a DC/ACC/type converter when an alternating current power source is required.

Next, to explain the operation, the inverter 2 in FIG.
In the control inverter, between the AC terminal B of the inverter arm and the intermediate point A of the smoothing capacitors 51 and 52, there is a
An alternating current voltage having a peak value of 172 of the contact line voltage Ed as shown in a) is generated.

Time 1. Then, semiconductor switch 21 is turned off and semiconductor switch 22 is turned on. The capacitor voltage of the capacitor 52 is applied to the transformer 71 .

At t3, the same operation as at t is performed, at t4, the same operation as at t2 is performed, and thereafter the semiconductor switches 21 and 22 are alternately turned on and off in the same manner.

Similarly, the transformer 73 operates 120 degrees behind the transformer 72, and the transformer 73 operates 120 degrees behind the transformer 72.

When the secondary winding voltage of the transformer 7 is rectified by the diode rectifier 81, a smooth DC voltage proportional to the voltage of the overhead contact line 3 as shown in FIG. 3(b) is obtained. Since the value of this DC voltage fluctuates depending on the overhead line voltage and is not stable, it is stabilized through a converter such as 84.

FIG. 4 is a diagram showing a second embodiment of the present invention. The difference from FIG. 1 of the first embodiment is that the secondary windings of transformers 71 to 73 are connected in three phases, and The input is a three-phase input. FIG. 5 shows an example of the auxiliary power supply device 8 of this second embodiment, in which three-phase AC input is rectified by a diode rectifier 85. In the case of the second embodiment shown in FIG. 4, it is necessary that a voltage higher than the specified voltage is always generated at the output of the main PWH inverter 2, but unless the AC load is the AC motor for driving the vehicle, the main inverter is always There is no problem since there is output.

By the way, although the above embodiment has been shown in the case where the main PWM capacitor 2 is three-phase, it can be applied in the same manner to a single-phase inverter or a multi-phase inverter having three or more phases.
Even in operating conditions where the transformer 7 is stopped, one arm of the inverter connected to the transformer 7 only needs to be operated.
The efficiency of the entire power supply circuit can be improved.

〔Effect of the invention〕

As described above, in the vehicle auxiliary power system according to the present invention, since the auxiliary power converter is connected to the secondary side of the transformer, the semiconductor element used in the converter and its withstand voltage can be freely selected. Since it is possible to use low-cost elements that are most suitable for the auxiliary power supply device, it is possible to significantly reduce the cost, size, and weight of the auxiliary power supply device.

Furthermore, since only a highly reliable transformer is connected to the main circuit side, the reliability of the main circuit and the auxiliary power system as a whole is greatly improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the auxiliary power supply system for a vehicle according to the present invention, FIG. 2 is a circuit diagram showing an example of the auxiliary power supply device used in the embodiment of FIG. FIG. 4 is a circuit diagram showing another different embodiment of the present invention, and FIG.
A circuit diagram showing an example of an auxiliary power supply device used in the embodiment shown in the figure, FIG. 6 is a circuit diagram showing a conventional example, and FIG.
FIG. 2 is a circuit diagram showing details of an auxiliary power supply device used in the conventional example. 1... Cooler 2... Main PWM inverter 2L 22... Semiconductor switch 3... Tram line 4... Starting device 5...
Smoothing capacitor 5L 52...Smoothing capacitor 6
... Auxiliary power supply device 61 ... Auxiliary PWM inverter 62 ... Isolation transformer 63 ... Rectifier 71 -
73...Auxiliary transformer 8...Auxiliary power supply device 81~
83...Diode rectifier 84...Converter 85...Diode rectifier 9L 92...Output terminal

Claims (1)

[Claims] PWM from DC power source supplied from overhead contact line or third rail
In a vehicle auxiliary power supply system for a DC electric vehicle that supplies power to an AC load via an inverter, the PW
2 smoothing capacitors connected to the DC side of the M inverter
The PWM inverter is divided and connected in series, and the primary winding of a transformer is connected between the AC terminals of at least two arms of the PWM inverter and the connection point of the capacitor, and the secondary winding of the transformer is connected. An auxiliary power supply system for a vehicle, characterized in that an auxiliary power supply device is connected.