JP6969902B2 - Vehicle power supply - Google Patents

Description

Embodiments of the present invention relate to a vehicle power supply.

The railcar is equipped with a main converter for supplying AC power to the electric motor and a power supply device for the vehicle for supplying AC power to the lighting and air conditioning devices in the railcar. Since the vehicle power supply unit has an isolation transformer that outputs 60 Hz AC power, its weight and volume increase. Therefore, for the purpose of miniaturization and high efficiency of the power supply device for vehicles, a resonance inverter that converts DC power supplied from the overhead wire into high-frequency AC power and an isolated transformer that transforms the AC power output from the resonance inverter. A vehicle power supply device including a rectifier that converts AC power transformed by the isolated transformer into DC power has been developed.

Japanese Unexamined Patent Publication No. 2006-25591

By the way, in the resonance inverter provided in the power supply device for a vehicle, the resonance frequency is adjusted so as to be soft switching in order to reduce the loss. However, when the isolation transformer provided in the vehicle power supply is a tertiary winding type transformer, when the load part connected to the secondary winding or the load part connected to the tertiary winding stops, the isolation transformer Since the inductance component changes, the resonance frequency of the resonance transformer shifts, resulting in hard switching, and the loss in the resonance transformer may worsen.

The vehicle power supply device of the embodiment includes a resonant inverter, a transformer, a first rectifier, a first load unit, a first resistor, a second rectifier, a second load unit, and a second resistor. .. The resonance inverter has a switching unit that converts DC power supplied from the overhead wire to the vehicle into AC power, and a resonance circuit that reduces switching loss in the switching unit. The transformer has a primary winding to which AC power is supplied from a resonant inverter, a secondary winding that outputs AC power isolated and transformed from the primary winding, and AC power isolated and transformed from the primary winding. Has a tertiary winding, which outputs. The first rectifier converts the AC power output from the secondary winding into DC power. The first load unit is provided in the vehicle and is driven by the DC power output from the first rectifier. The first resistor is connected in parallel to the first load section and has a larger resistance value than the first load section . The second rectifier converts the AC power output from the tertiary winding into DC power. The second load unit is provided in the vehicle and is driven by the DC power output from the second rectifier. The second resistor is connected in parallel to the second load section and has a higher resistance value than the second load section .

FIG. 1 is a diagram showing an example of a configuration of a vehicle power supply device according to the present embodiment.

Hereinafter, the vehicle power supply device according to the present embodiment will be described with reference to the attached drawings.

FIG. 1 is a diagram showing an example of a configuration of a vehicle power supply device according to the present embodiment. As shown in FIG. 1, the vehicle power supply device 2 according to the present embodiment includes a step-up chopper unit 3, a filter capacitor 4, a resonance inverter 5, a high-frequency isolated transformer 6, a first rectifier 7, and a filter capacitor 8. It has a three-phase inverter 9, a three-phase load unit 10, a second rectifier 11, a DC load unit 12, a secondary output side resistor 13, and a tertiary output side resistor 14.

The boost chopper unit 3 boosts the voltage of DC power supplied from an overhead wire to a railroad vehicle (an example of a vehicle) via a pantograph 1 to a preset voltage. Then, the step-up chopper unit 3 outputs the boosted DC power to the filter capacitor 4. The DC power supplied from the overhead wire includes ripples of a specific frequency (for example, 300 Hz) caused by the substation, but the boost chopper unit 3 removes the ripples contained in the DC power and is supplied from the overhead wire. It absorbs voltage fluctuations of DC power and supplies stable DC power to the filter capacitor 4.

In the present embodiment, the step-up chopper unit 3 includes a step-up reactor 31, a switching element 32, and a backflow prevention diode 33. The step-up reactor 31 is composed of a coil or the like and stores electric power supplied from the overhead wire. The switching element 32 is composed of a semiconductor switch or the like, and is chopper-controlled by a control unit (not shown) to repeatedly turn on and off, and the electric power stored in the step-up reactor 31 is applied to the GND side or the load unit side (three-phase load unit 10 and DC load). Unit 12) Discharges to the side. The backflow prevention diode 33 is a diode that prevents the backflow of current from the load portion side to the overhead wire.

The filter capacitor 4 removes high frequency components from the DC power output from the step-up chopper unit 3 and outputs the filter capacitor 4.

The resonance inverter 5 converts the DC power output from the filter capacitor 4 into AC power (for example, 5 KHz AC power), and outputs the AC power to the high-frequency isolation transformer 6. Further, the resonance frequency of the resonance inverter 5 is adjusted so as to be soft switching. In the present embodiment, the resonant inverter 5 has a switching unit and a resonant circuit. The switching unit converts DC power into AC power by repeating on / off. The resonant circuit reduces the switching loss in the switching section. Specifically, the resonant circuit stores electric power that vibrates at a resonant frequency close to the switching frequency in the switching unit.

In the present embodiment, the resonance inverter 5 is supplied with DC power that is boosted by the step-up chopper unit 3 and whose high-frequency components are removed by the filter capacitor 4, but it is not necessary to boost the DC power supplied from the overhead wire. Moreover, when the high frequency component contained in the DC power is small, the DC power may be supplied from the overhead wire and converted into the AC power without going through the step-up chopper unit 3 and the filter capacitor 4.

The high frequency isolation transformer 6 is a tertiary winding type transformer. Specifically, the high-frequency isolated transformer 6 includes a primary winding 61 to which AC power is supplied from the resonance inverter 5, and a secondary winding 62 to output AC power isolated and transformed from the primary winding 61. It has a primary winding 61 and a tertiary winding 63 that outputs an isolated and transformed AC power. Since the high frequency isolation transformer 6 is insulated between the primary winding 61 and the secondary winding 62 and the tertiary winding 63, the high frequency isolation transformer 6 functions as an isolated AC / AC converter.

The first rectifier 7 converts the AC power output from the secondary winding 62 of the high-frequency isolation transformer 6 into DC power again and outputs the AC power. The filter capacitor 8 removes the high frequency component of the DC power output from the first rectifier 7 and outputs it. In the present embodiment, the vehicle power supply unit 2 has a filter capacitor 8, but has a filter capacitor 8 when the high frequency component contained in the DC power output from the first rectifier 7 is small. It doesn't have to be.

The three-phase inverter 9 is a load unit (an example of a first load unit) provided in a vehicle such as a railroad vehicle and driven by DC power output from the first rectifier 7. Specifically, the three-phase inverter 9 converts the DC power output from the filter capacitor 8 into AC power having a preset voltage and outputs the DC power to the three-phase load unit 10. The three-phase load unit 10 (an example of the first load unit) is a lighting or air conditioning device for a vehicle such as a railroad vehicle, and is a load unit driven by AC power output from the three-phase inverter 9. The secondary output side resistor 13 (an example of the first resistor) is connected in parallel to the three-phase inverter 9 and the three-phase load unit 10.

The second rectifier 11 converts the AC power output from the tertiary winding 63 of the high-frequency isolation transformer 6 into DC power again and outputs the AC power. The DC load unit 12 (an example of the second load unit) is a control unit or the like that controls the entire vehicle, is provided in a vehicle such as a railroad vehicle, and is a load unit driven by DC power output from the second rectifier 11. Is. The tertiary output side resistor 14 (an example of the second resistor) is connected in parallel to the DC load unit 12.

Next, with reference to FIG. 1, the operation when an abnormality occurs in the load portion of the vehicle power supply device 2 according to the present embodiment will be described.

For example, when an abnormality such as a failure occurs in at least one of the three-phase inverter 9 and the three-phase load unit 10 and the output destination of the DC power from the first rectifier 7 becomes unloaded, the inductance of the high-frequency isolation transformer 6 The ingredients change. As a result, the resonance frequency of the resonance inverter 5 deviates from the preset frequency, resulting in hard switching and a large loss in the resonance inverter 5.

Therefore, in the present embodiment, as described above, the vehicle power supply device 2 has a secondary output side resistor 13 connected in parallel to the three-phase inverter 9 and the three-phase load unit 10. As a result, even if an abnormality occurs in at least one of the three-phase inverter 9 and the three-phase load unit 10, the AC power output from the first rectifier 7 is supplied to the secondary output side resistor 13, and the high-frequency isolated transformer 6 is used. Since the change in the inductance component of the above can be suppressed, the soft switching can be maintained and the loss in the resonance inverter 5 can be reduced.

Further, even when an abnormality such as a failure occurs in the DC load unit 12 and the output destination of the DC power from the second rectifier 11 becomes a no-load state, the inductance component of the high frequency isolation transformer 6 changes. As a result, the resonance frequency of the resonance inverter 5 deviates from the preset frequency, resulting in hard switching and a large loss.

Therefore, in the present embodiment, as described above, the tertiary output side resistor 14 is connected in parallel to the DC load unit 12. As a result, even if an abnormality occurs in the DC load unit 12, the DC power output from the second rectifier 11 is supplied to the tertiary output side resistor 14, and the change in the inductance component of the high-frequency isolation transformer 6 can be suppressed. The soft switching can be maintained and the loss in the resonance inverter 5 can be reduced.

Further, in the present embodiment, the resistance value of the secondary output side resistor 13 is made larger than the resistance value of the three-phase load unit 10. As a result, when no abnormality has occurred in the three-phase inverter 9 and the three-phase load unit 10, the amount of power supplied from the first rectifier 7 to the secondary output side resistor 13 increases, so that the secondary output side resistor 13 increases. Can suppress the heat generated by the inverter. Further, in the present embodiment, the resistance value of the tertiary output side resistor 14 is made larger than the resistance value of the DC load unit 12. As a result, when no abnormality has occurred in the DC load unit 12, the amount of power supplied from the second rectifier 11 to the tertiary output side resistor 14 increases, so that the heat generated by the tertiary output side resistor 14 can be suppressed.

Further, in the present embodiment, the vehicle power supply device 2 is secondary to the three-phase inverter 9 and the three-phase load unit 10 when no abnormality has occurred in at least one of the three-phase inverter 9 and the three-phase load unit 10. A switch capable of disconnecting the parallel connection of the output side resistor 13 may be provided. As a result, it is possible to prevent power from being supplied from the first rectifier 7 to the secondary output side resistor 13 when no abnormality has occurred in the three-phase inverter 9 and the three-phase load unit 10, so that the secondary output side can be prevented from being supplied. The heat generated by the resistor 13 can be suppressed.

Specifically, when the control unit (not shown) of the vehicle power supply unit 2 does not detect an abnormality in at least one of the three-phase inverter 9 and the three-phase load unit 10, it controls a switch to control the three-phase inverter. The parallel connection of the secondary output side resistor 13 to 9 and the three-phase load unit 10 is disconnected. On the other hand, when the control unit detects an abnormality in at least one of the three-phase inverter 9 and the three-phase load unit 10, the control unit controls the switch to reduce the secondary output side resistor 13 to the three-phase inverter 9 and the three-phase load. Connect in parallel to the unit 10.

Alternatively, when at least one of the three-phase inverter 9 and the three-phase load unit 10 has not detected an abnormality, the administrator of the vehicle power supply device 2 operates a switch to operate the three-phase inverter 9 and the three-phase load unit 10. The parallel connection of the secondary output side resistor 13 with respect to 10 is disconnected. On the other hand, when an abnormality of at least one of the three-phase inverter 9 and the three-phase load unit 10 is detected, the administrator operates a switch to set the secondary output side resistor 13 to the three-phase inverter 9 and the three-phase load. Connect in parallel to the unit 10.

Further, in the present embodiment, the vehicle power supply device 2 may be provided with a switch capable of disconnecting the parallel connection of the tertiary output side resistor 14 to the DC load unit 12 when no abnormality has occurred in the DC load unit 12. good. As a result, it is possible to prevent power from being supplied from the second rectifier 11 to the tertiary output side resistor 14 when no abnormality has occurred in the DC load unit 12, so that the heat generated by the tertiary output side resistor 14 can be further suppressed. can.

Specifically, when the control unit (not shown) of the vehicle power supply unit 2 does not detect an abnormality in the DC load unit 12, the switch is controlled so that the tertiary output side resistance 14 is parallel to the DC load unit 12. Disconnect. On the other hand, when the control unit detects an abnormality in the DC load unit 12, it controls a switch to connect the tertiary output side resistor 14 to the DC load unit 12 in parallel.

Alternatively, when the abnormality of the DC load unit 12 is not detected, the administrator of the vehicle power supply device 2 operates a switch to disconnect the parallel connection of the tertiary output side resistor 14 to the DC load unit 12. On the other hand, when an abnormality in the DC load unit 12 is detected, the administrator operates a switch to connect the tertiary output side resistor 14 to the DC load unit 12 in parallel.

Further, in the present embodiment, the first rectifier 7 and the second rectifier 11 are Schottky barrier diodes using SiC. As a result, even if an abnormality occurs in at least one of the three-phase inverter 9 and the three-phase load unit 10 or the DC load unit 12 and the resonance inverter 5 becomes hard switching, the loss in the resonance inverter 5 can be reduced. Can be done.

As described above, according to the vehicle power supply device 2 according to the present embodiment, when an abnormality occurs in at least one of the three-phase inverter 9, the three-phase load unit 10, and the DC load unit 12, the high-frequency isolation transformer 6 Since the change in the inductance component of the above can be suppressed, the soft switching can be maintained and the loss in the resonance inverter 5 can be reduced.

Although embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Pantograph 2 Vehicle power supply 5 Resonant inverter 6 High-frequency isolated transformer 7 First rectifier 9 Three-phase inverter 10 Three-phase load part 11 Second rectifier 12 DC load part 13 Secondary output side resistance 14 Third output side resistance 61 Primary winding 62 Secondary winding 63 Tertiary winding

Claims (3)

A resonant inverter having a switching unit that converts DC power supplied from an overhead wire to a vehicle into AC power, and a resonance circuit that reduces switching loss in the switching unit.
A primary winding to which AC power is supplied from the resonance inverter, a secondary winding that outputs AC power that is insulated and transformed from the primary winding, and an AC power that is insulated and transformed from the primary winding are output. With a transformer, which has a tertiary winding,
A first rectifier that converts AC power output from the secondary winding into DC power,
A first load unit provided in the vehicle and driven by DC power output from the first rectifier, and a first load unit.
A first resistor that is connected in parallel to the first load section and has a higher resistance value than the first load section.
A second rectifier that converts AC power output from the tertiary winding into DC power, and
A second load unit provided in the vehicle and driven by DC power output from the second rectifier, and a second load unit.
A second resistor that is connected in parallel to the second load section and has a higher resistance value than the second load section.
A power supply for vehicles equipped with. A first switch capable of disconnecting the parallel connection of the first resistor to the first load unit when no abnormality has occurred in the first load unit.
The vehicle power supply device according to claim 1, further comprising a second switch capable of disconnecting the parallel connection of the second resistor to the second load unit when no abnormality has occurred in the second load unit. The vehicle power supply device according to claim 1 or 2 , wherein the first rectifier and the second rectifier are Schottky barrier diodes using SiC.

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