JPH01133310A - Transformer for vehicle - Google Patents

Abstract

PURPOSE:To prevent a current pulsation due to direct current biasing magnetization without installing an AC reactor, by providing a first magnetic substance between an input side coil and an output side coil and further providing a second magnetic substance between the output coil and a transformer iron core. CONSTITUTION:In a transformer for a motor vehicle, a first magnetic substance 13a is inserted between an input side coil 6 and an output side coil 7 to form an iron core with a void divided into five and a second magnetic substance 13b forms an iron core with a void inserted between the output side core 7 and a yoke iron core 5c. On the other hand, a voltage received from a trolley wire 1 through a pantagraph and a breaker 3 is input to the input side coil 6 of a transformer 4A and transformed and then output on the output side coil 7 of the transformer 4A for the motor vehicle. Since the output of the output side coil 7 increases in its magnetic flux quantity because the iron cores 13a and 13b with a void are exist, self inductance of the output side coil 7 of the transformer 4A becomes large. Therefore, inductance capable of preventing a current pulsation can be obtained without connecting an AC reactor to the vehicle transformer 4A.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pulse width modulation control conversion device (hereinafter referred to as PWM
The present invention relates to a vehicle transformer used in a vehicle driving electrical system that performs power supply and regeneration control using a power conversion device such as a converter.

[Prior Art] Fig. 5 is a configuration diagram showing a conventional external iron type vehicle transformer. In the figure, (5) is an iron core, and the main iron core (5
a) Leg cores (5b) located on both sides of this main core (5a) and having a width W, and a yoke core (5) having @W by combining these main cores (5a) and leg cores (5b).
c). (6) is the input winding placed in the space surrounded by the iron core (5), (7) is the iron core (5)
The output winding is divided into two parts in the space surrounded by the output winding (6) and placed on both sides of the input winding (6). The outside iron type vehicle transformer (4) includes an iron core (5), an input winding (6), and an output winding (7).

Figure 6 shows, for example, the proceedings of the 1988 Electrical and Information Related Societies Federation Conference, pages 2-62 to 2-65, section 10-3 r.
This is a circuit diagram partially showing a block diagram of a vehicle operating electrical system using the above-mentioned vehicle transformer, shown in "Application of VVVF Control to AC Trains"; in the figure, (1) is
・The trolley wire (2) is the pantograph that is in contact with this trolley wire (1), and (3) is connected to this pantograph (2) and the input winding (6) of the vehicle transformer (4). The circuit breaker (8) is four AC reactors each connected to the output winding (7) which is divided into four windings in this usage example, and (9) is the AC reactor (9) connected to the output winding (7) which is divided into four windings. A PWM converter connected to the output winding (7), (
1o) is the capacitor connected to the output side of this PWM converter (9), (11) is the VVVF inverter connected to the output side of this capacitor (1o), and (12) is the output side of this VVVF inverter (11). A three-phase induction motor (IM) connected to the

A vehicle operation electrical system using a conventional vehicle transformer (4) is configured as described above, and the voltage received from the trolley wire (1) via the pantograph (2) and circuit breaker (3) is used for the vehicle. It is input to the input side winding (6) of the transformer (4), is transformed, and is then transferred to the output side winding (7) of the vehicle transformer (4).
is output to. The output of this output winding (7) is supplied to a PWM converter (9) through an AC reactor (8), where the single-phase AC is converted to DC. This direct current is smoothed by a capacitor (1o) and then fed to a VVVF inverter (11), where the direct current is converted into three-phase alternating current. This three-phase AC is a three-phase induction motor (IM).
The power is transmitted to the wheels (not shown) of the vehicle.

A direct current component may be generated in the trolley wire (1) due to variations in polarity of the pantograph disconnection arc, variations in the firing angle of other cyrisk phase control wheels, or other causes. At this time, the iron core (5) of the vehicle transformer (4) receives a biased magnetic effect due to this DC component, and during a certain electrical angle period,
Causes magnetic saturation.

FIG. 7 is an explanatory diagram showing the magnetic field distribution of the conventional vehicle transformer (4), and shows an example of the calculation results of the magnetic field when the iron core (5) is not subject to magnetic saturation due to DC bias magnetization. In addition, (1
4) is the magnetic flux line.

When the PWM converter (9) is operated under the above-mentioned conditions, during the above-mentioned electrical angle period, the current in the output winding (7) of the vehicle transformer (4), that is, the PWM converter (9)
The input current is large and causes current pulsations. There is a risk that the PWM converter (9) may be damaged due to this current pulsation. The above situation was experimentally confirmed and illustrated in the waveform diagrams of FIGS. 8 and 9.

FIGS. 8(a) and 8(b) are waveform diagrams of the input voltage, input current, and output current of the vehicle transformer (4) during normal operation when there is no DC component in the trolley wire (1). In this case, the value of the AC reactor (8) is 1.1 mH.

Figures 9(a) and (b) show that under the same conditions as above,
Trolley 1! FIG. 2 is a waveform diagram of the input voltage, input current, and output current of the vehicle transformer (4) in DC biased magnetization where a DC component exists in (1). As shown in Figure 9(b),
The output current causes large current pulsations during a certain electrical angle period.

By the way, the above phenomenon can be sufficiently suppressed by increasing the capacity of the AC reactor (8>).

Figures 10 and 11 show the output current of the vehicle transformer (4) under normal conditions and DC biased magnetization when the value of the AC reactor (8) is 2.7 ml under the same conditions as above. FIG.

As explained above, a vehicle transformer (4
) magnetic saturation occurs in the iron core (5) of the vehicle transformer (4), reducing the reactance of the vehicle transformer (4) and increasing current pulsation. In order to compensate for this decrease in reactance, the AC reactor (8) is connected to the vehicle transformer (4) to suppress the current pulsation.
connection has been considered essential.

[Problems to be Solved by the Invention] In the vehicle operation electrical system using the conventional vehicle transformer (4) as described above, an AC reactor (8) is installed to suppress current pulsation due to DC biased magnetization. I needed to. However, installing the AC reactor (8) occupies the installation space under the floor of the vehicle, resulting in problems such as narrowing the installation space for other electrical equipment and increasing the weight of the vehicle.

This invention was made to solve the above-mentioned problems, and aims to provide a vehicle transformer that can suppress current pulsation due to DC biased magnetization without installing an AC reactor (8).

[Means for Solving the Problems] The vehicle transformer according to the present invention has an input winding connected to a power source, and an output winding directly connected to a power converter that converts single-phase alternating current to direct current. , a first magnetic body provided between the input side winding and the output side winding, and a second magnetic body provided between the output side winding and the transformer core. It is something.

[Function] In the present invention, the first magnetic body provided between the input side winding and the output side winding, and the second magnetic body provided between the output side winding and the transformer core. Due to the ampere turn formed by the current flowing through the output side winding of the magnetic material,
A magnetic flux passing through the first magnetic body and the second magnetic body is generated to suppress current pulsation due to DC biased magnetism.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, and in the figure, (5) to (7) are completely the same as those in a conventional vehicle transformer. (13a) is a first magnetic body, which in this embodiment is inserted between the input winding (6) and the output winding (7), and is divided into, for example, a five-piece core with an air gap. , (13b) is a second magnetic body, which in this embodiment is an iron core with a gap inserted between the output side winding (7) and the yoke iron core (5c). In addition, (4^) is an outer iron type vehicle transformer consisting of an iron core (5), an input side winding (6), an output side winding (7), and an iron core with a gap (13a) and (13b). It is.

FIG. 2 is a circuit diagram partially showing a block diagram of a vehicle operating electrical system using the above embodiment.
) to (3), (5) to (7), and (9) to (12) are exactly the same as those in the vehicle operating electrical system described above. The PWM converter (9) is a vehicle transformer (4^
) is directly connected to the output winding (7) of the

The vehicle operating electrical system using the above embodiment is constructed as described above, and is connected from the trolley wire (1) to the pantograph (
2) and the voltage received via the circuit breaker (3) is the input side winding 1 of the vehicle transformer (4^)! (6), is transformed and output to the output winding (7) of the vehicle transformer (4^). The output of this output winding (7) is directly supplied to a PWM converter (9), where single-phase alternating current is converted to direct current. This direct current is smoothed by a capacitor (10) and then fed to a VVVF inverter (11), where the direct current is converted into three-phase alternating current. This three-phase alternating current drives a three-phase induction motor (IM), and its power is transmitted to the wheels (not shown) of the vehicle.

FIG. 3 is a diagram showing the magnetic field distribution of the above example,
An example of the calculation results of the magnetic field when the iron core (5) is magnetically saturated due to DC bias magnetization is shown. Note that (14) is a line of magnetic flux.

Due to the presence of the air-gapped cores (13a) and (13b), the amount of magnetic flux has increased as shown in Figure 3, so the self-inductance of the output winding (7) of the vehicle transformer (4^) has increased. Therefore, an inductance that can suppress current pulsation can be obtained without connecting an AC reactor to the outside of the vehicle transformer (4^).

The core with a gap (13a) inserted between the input side winding (6) and the output side winding (7) is divided into, for example, five pieces and the gap size is increased, but this is due to leakage reactance. This is a measure to prevent the value from becoming too excessive. On the other hand, the gapped iron core (13b) inserted between the output side winding (7) and the yoke iron core (5c) is inserted into the yoke iron core (5c) without being divided.
) to leave a small gap between them.

When the iron core (5) is saturated, the air-gapped iron core (13b)
This is to reduce the magnetic resistance of the magnetic circuit that circulates through the magnetic field and to increase the self-inductance as much as possible.

FIG. 4 is a block diagram showing another embodiment of the present invention, and in the figure, (5) to (7) are completely the same as those in a conventional vehicle transformer. (13a) is a first magnetic body, which in this embodiment is inserted between the input winding (6) and the output winding (7), and is divided into, for example, a five-piece core with an air gap. , (5C) is a yoke core that is integrated with the second magnetic body, and in this embodiment, the yoke core (
The width (=W + ) of 5C) is larger than the width (=W) of the leg core (5b).

In addition, <4B) is an iron core (5C) equipped with a yoke iron core (5C).
), an input winding (6), an output winding (7), and a core with a gap (13a).

When the leg core (5b) is magnetically saturated, the magnetic permeability of the yoke core (5c) is larger than that of the leg core (5b). Therefore, this yoke core (5C) can be used as a substitute for the voided core (13b) shown in Fig. 1 to obtain the same effect, and the vehicle transformer (4B) is better than the vehicle transformer (48). This has the effect of reducing the number of parts.

[Effects of the Invention] As explained above, the present invention includes a first magnetic body provided between the input side winding and the output side winding, and a first magnetic body provided between the output side winding and the transformer iron core. Since the magnetic body is provided with a second magnetic body, current pulsation due to direct current biased magnetization can be suppressed.

Therefore, by using the vehicle transformer of the present invention, a vehicle operating electrical system using a PWM converter can be constructed without installing an AC reactor. Moreover, the installation space under the floor of the vehicle is not occupied and the installation space for other electrical equipment can be expanded, which has the effect of reducing the weight of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a circuit diagram showing a partial block diagram of a vehicle driving electrical system using an embodiment of the invention, and Fig. 3 is a circuit diagram showing an embodiment of the invention. An explanatory diagram showing the magnetic field distribution of the embodiment, FIG. 4 is a block diagram showing another embodiment of the invention, FIG. 5 is a block diagram showing a conventional vehicle transformer, and FIG. 6 is a conventional vehicle transformer. Figure 7 is an explanatory diagram showing the magnetic field distribution of a conventional vehicle transformer, and Figure 8 is a diagram showing a conventional vehicle transformer in normal operation. FIG. 9 is a waveform diagram showing the operation of a conventional vehicle transformer in direct current biased magnetism. FIG. 10 is another waveform diagram showing the operation of the conventional vehicle transformer during normal operation. FIG. 11 is another waveform diagram showing the operation of a conventional vehicle transformer in DC biased magnetization. In the figure, (1) is the trolley wire, (2) is the pantograph, (4^), (4B) is the outside iron type vehicle transformer, (5
) is the iron core, (6) is the input side winding, (7) is the output side winding,
(9) is a PWM converter, and (13a) and (13b) are cores with voids. In addition, the same reference numerals in each figure indicate the same or equivalent parts in Figure 1, vehicle transformer 5 cost 1υ 6 human power Iriri winding light 13b 1-2 J, RI I 擾j (? W field E I) (
, 4 branches (=) Figure 3 Ga Sai π Line Figure 4 Hitting/Hayatsu m Transformation 5 company 1 (6 people n ii East ° 1'' Empty To 柤 fk 7 Output 41, rising 138 Item 41 (F1) Wang 4 Fu, (Maenhi 43e Shi8-) Figure 5 Figure 6 Figure 7 Figure 6 Figure 10 (Sei Hayabusa cod) Figure 11 (Direct angle ＾h)

Claims (4)

[Claims] (1) An input winding connected to a power supply, an output winding connected directly to a power converter that converts single-phase AC to DC, and a winding installed between the input winding and the output winding. The first
and a second magnetic body provided between the output side winding and the transformer core, the first magnetic body and the second magnetic body suppressing current pulsations due to DC bias magnetization. A vehicle transformer characterized by suppressing. (2) The vehicular transformer according to claim 1, wherein the first magnetic body and the second magnetic body are cores with a gap. (3) The first magnetic body is a core with an air gap, and the second magnetic body is integrated with a yoke core that constitutes a yoke portion of the transformer core, so that the width of the yoke core is the same as that of the transformer. 2. The vehicle transformer according to claim 1, wherein the width of the leg core is wider than the width of the leg core constituting the leg portion of the core. (4) A vehicle transformer according to claim 1, 2, or 3, wherein the first magnetic body is divided into a plurality of pieces.