JP2003047245A - Electric vehicle power supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce switching losses produced by switching devices in an electric vehicle power supply apparatus and to improve a conversion efficiency of the apparatus in a high frequency switching state. SOLUTION: An inverter circuit comprises four switching devices SA, SB, SC, and SD connected to a full bridge. The inverter circuit is controlled so as to have the switching devices SA, SB, SC, and SD turned on or off when voltages or currents applied to the switching devices SA, SB, SC, and SD are zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a DC / DC converter insulation circuit having a train line as an input, and a switching device switches at a constant frequency to prevent fluctuations in the input DC voltage and fluctuations in the load capacitance. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an electric vehicle that controls an output voltage at a constant level, and more particularly to a power supply device for an electric vehicle that reduces switching loss due to a switching device and enhances conversion efficiency of the device during high frequency switching.

[0002]

2. Description of the Related Art Conventionally, as one of electric power supply devices for electric vehicles, a DC / DC converter insulation circuit having a train line as an input is used, and a switching device switches at a constant frequency to cause fluctuations in input DC voltage. Power supply devices have been used that control the output voltage to be constant with respect to changes in load capacity.

FIG. 13 is a circuit diagram showing a configuration example of a conventional electric vehicle power supply device of this type.

In FIG. 13, two switching devices (SA, SB) 3 connected in series with each other and a snubber circuit 5 connected in parallel with each switching device 3 constitute a first arm, Two switching devices (SC, S connected in series)
D) 4 and the snubber circuit 5 connected in parallel to each switching device 4 constitute a second arm, and as a whole, a full-bridge connection inverter circuit is constituted.

On the input side of this inverter circuit, a pantograph 1 for collecting current from a train line via an input circuit 2
Are connected.

The primary side winding of the insulation transformer 9 is connected to the output side of the inverter circuit.

Further, to the secondary winding of the insulating transformer 9, a rectifier circuit 10 composed of four diodes connected in a full bridge is connected.

On the other hand, snubber circuits 5 are connected in parallel to the rectifier circuits 10.

A filter reactor 11 is connected in series to the rectifier circuit 10 and the snubber circuit 5.

Further, a filter capacitor 12 is connected in parallel with the filter reactor 11 and the rectifier circuit 10.

On the other hand, the filter capacitor 12 is connected in parallel with a voltage detector 13 for detecting the voltage of the filter capacitor 12.

Further, based on the voltage detection signal 14 from the voltage detector 13 and the voltage detection signal 19 from the input circuit 2, the switching devices 3 and 4 switch at a constant frequency to change the input DC voltage. A control unit 20 is provided for controlling the output voltage to be constant with respect to changes in load capacity.

That is, in the conventional electric vehicle power supply device, the switching devices 3 and 4 and the rectifying circuit 10 are provided.
The snubber circuit 5 is connected to the switching devices 3 and 4 so that the switching devices 3 and 4 are hard-switched (voltage and current are cut off).

[0014]

By the way, in the above-mentioned conventional electric vehicle power supply device, since the switching devices 3 and 4 and the diodes in the rectifier circuit 10 are hard-switched, the voltage and the current are changed. The switching devices 3 and 4 cut off, and due to the characteristics of the diodes in the switching devices 3 and 4 and the rectifier circuit 10, when off, the voltage time product when the voltage rises × the current time product when the current drops, and when on, A loss that is twice the switching frequency of the loss per switching, which is obtained by the voltage time product when the voltage drops × the current time product when the current rises, is generated.

Further, at the time of hard switching, the snubber circuit 5 is necessary, and the snubber circuit 5 also causes a loss.

Further, when the switching frequency is low, the conversion efficiency is not particularly lowered, but when high frequency switching is performed for the purpose of downsizing the insulating transformer 9 and the filter reactor 11, it is proportional to the frequency. As a result, the loss increases, so that the conversion efficiency of the power supply device is reduced, resulting in unnecessary power consumption.

An object of the present invention is to provide an electric vehicle power supply device capable of reducing the switching loss due to the switching device and increasing the conversion efficiency of the device during high frequency switching.

[0018]

In order to achieve the above-mentioned object, in the invention corresponding to claim 1, a switching device is constituted by a DC / DC converter insulation circuit having an electric train line as an input, and the switching device has a constant frequency. In an electric vehicle power supply device that switches and controls an output voltage to a constant value with respect to a change in a DC voltage of an input and a change in a load capacity, two first switching devices connected in series to each other and each of the first switching devices. A first arm composed of a lossless snubber capacitor connected in parallel to each switching device, and two second switching devices connected in series, and each connected in series to each second switching device. Full-bridge connection inverter circuit composed of a second arm composed of an auxiliary reactor and a primary side winding An insulating transformer having a leakage inductance, is connected to the secondary coil of a transformer,
A rectifier circuit consisting of four diodes connected to the full bridge, a filter reactor connected in series with the rectifier circuit, a filter capacitor connected in parallel with the filter reactor and the rectifier circuit, and a voltage that detects the voltage of the filter capacitor. Each of the switching means is configured so that the detection means, the resonance capacitor connected between the inverter circuit and the primary winding of the isolation transformer, and the secondary voltage is controlled to be constant based on the voltage detection signal from the voltage detection means. A control function that controls the conduction ratio of the device and the time of the phase difference between the first arm and the second arm, and outputs an on / off signal to each switching device so that each switching device performs zero current or zero voltage switching. And a control unit having the same.

Therefore, in the electric vehicle power supply device of the invention corresponding to claim 1, by taking the above-mentioned means, all the four switching devices constituting the inverter circuit are driven by zero current or zero voltage. Since the switching is repeated, the switching can be performed with almost zero switching loss, the loss due to the switching device can be reduced, and the conversion efficiency of the device at the time of high frequency switching can be increased.

Further, according to the invention corresponding to claim 2, in the electric vehicle power source device of the invention according to claim 1,
A first current detecting means for detecting the output current of the inverter circuit is added, and the first current detecting means is provided based on the current detecting signal from the current detecting means.
The function of finely adjusting the phase difference control between the ON time on the arm side and the OFF time on the second arm side is added to the control means.

Therefore, in the electric vehicle power source device of the invention according to claim 2, by taking the above-mentioned means, in addition to exhibiting the same operation as that of the invention according to claim 1, The soft switching operation can be stably performed even with a transient load change, and useless switching loss can be prevented. That is, it is possible to improve the dynamic and static characteristics of the output voltage when the input voltage changes and the load changes.

Further, in the invention according to claim 3, in the electric vehicle power source device of the invention according to claim 2, the current detecting means for detecting the output current of the inverter circuit is the secondary winding of the insulation transformer. It is provided in series with the filter reactor after the line side rectifier circuit.

Therefore, in the electric vehicle power source device of the invention according to claim 3, by taking the above-mentioned means, in addition to exhibiting the same operation as that of the invention according to claim 2, Since the current flowing through the filter reactor is a direct current, there is little change in the magnetic flux of the metal part of the core part that is the current detection part of the current detection means, and the current detection means can be operated without using an expensive core material such as an amorphous iron core. Can be configured. That is, it is not necessary to use a special current detecting means that does not overheat the high frequency alternating current.

On the other hand, in the invention corresponding to claim 4, in the electric vehicle power source device of the invention according to claim 2,
A resonance capacitor is provided between the secondary winding of the insulation transformer and the rectifier circuit.

Therefore, in the electric vehicle power source device of the invention according to claim 4, by taking the above-mentioned means, in addition to exhibiting the same operation as that of the invention according to claim 2, Since the secondary winding side of the isolation transformer generally has a low isolation voltage, it is possible to reduce the withstand voltage of the resonance capacitor used.

In the invention corresponding to claim 5, in the power supply device for an electric vehicle of the invention according to claim 2,
2 auxiliary reactors connected in series to form an integrated type 2
Two second switching devices are connected in series, and two auxiliary reactors are connected in series to one side of the resonance capacitor.

Therefore, in the electric vehicle power source device of the invention according to claim 5, by taking the above-mentioned means, in addition to exhibiting the same operation as that of the invention according to claim 2, The number of parts can be reduced.

Further, in the invention according to claim 6, in the electric vehicle power source device of the invention according to claim 2, an intermediate tap is provided in the secondary winding of the insulation transformer, and the diode in the rectifier circuit is provided. Only two have half-bridge rectification circuits.

Therefore, in the electric vehicle power source device of the invention according to claim 6, by taking the above-mentioned means, in addition to exhibiting the same operation as that of the invention according to claim 2, The number of parts can be reduced.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the concept of the present invention will be described.

According to the present invention, a simple resonance circuit and auxiliary components are added, and the resonance circuit is controlled so that the switching device is turned on or off when the voltage applied to the switching device or the applied current is zero. By so doing, switching loss is prevented from occurring and the conversion efficiency at the time of high frequency switching is improved.

That is, the voltage applied to the switching device and the timing at which the flowing current becomes zero voltage or zero current state are the ON / OFF signal to the switching device, the resonance time of the device for resonance that the circuit has, and the output voltage. Therefore, the switching operation is controlled at the optimum timing.

By switching at zero voltage or zero current, the switching loss can be made almost zero.

Further, with respect to the diode of the rectifier circuit on the secondary winding side of the insulation transformer, the resonance operation is used, so that the soft switching is performed and the switching loss can be reduced.

The soft switching method of each switching device according to this switching method will be described below.

Here, a series-connected switching device in which a capacitor is connected in parallel is referred to as a first arm, and a series-connected switching device in which a capacitor is not connected is referred to as a second arm.

When the switching device (first arm) is turned off, the cutoff current is shunted to the lossless snubber capacitor to perform zero current switching.

When the switching device (first arm) is turned on, it is when the diodes connected in parallel are turned on, and therefore the applied voltage of the switching device is in the zero state, so that the zero voltage is applied. It becomes switching.

When the switching device (second arm) is turned off, after the switching device (first arm) is turned off, the resonance capacitor, the leakage inductance in the insulating transformer, and the secondary side filter reactor cause series resonance. Do it, and gradually decay.

Since it is judged that the current is zero or that the current has flowed in the opposite direction and the off control is performed, zero current switching is performed.

At this time, the current resonates and is gradually attenuated, and the current flows in the opposite direction.

Therefore, the shared current of the diode that flows in the rectifier circuit on the secondary winding side of the isolation transformer also has the same value as the current that flows in the load side as the amount of current flowing in the bridge changes. When it goes up, all the current flows out to the diode on the off side, and it turns off at the Vf voltage of the diode on one side.

Therefore, the diode which is turned off shifts to the off state due to almost zero voltage, and therefore, zero voltage switching is performed.

When the switching device (second arm) is turned on, the auxiliary inductance connected in series with the switching device delays the rise time of the current as compared with the fall time of the voltage, resulting in zero current switching. Become.

As described above, according to the present invention, each switching device is controlled so as to be turned on or off when the voltage becomes zero voltage or current.

Further, in the present invention, in order to make the output voltage constant, the conduction ratio of each switching device and the first
The time, which is the phase difference between the on / off timings of the arm and the second arm, is controlled simultaneously.

Hereinafter, embodiments of the present invention based on the above concept will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a circuit diagram showing a configuration example of an electric vehicle power supply device according to the present embodiment. The same elements as those in FIG. 13 are designated by the same reference numerals. There is.

In FIG. 1, 2 connected in series with each other.
One switching device (SA, SB) 3 and a lossless snubber capacitor 7 connected in parallel to each switching device (SA, SB) 3 constitute a first arm, and two switching devices (SA, SB) 3 are connected in series. The second arm is composed of two switching devices (SC, SD) 4 and auxiliary reactors 6 connected in series to each of the second switching devices (SC, SD) 4, respectively, and a full bridge connection is provided as a whole. It constitutes an inverter circuit.

On the input side of this inverter circuit, a pantograph 1 for collecting current from a train line via an input circuit 2 is provided.
Are connected.

On the output side of the inverter circuit, the primary winding of the insulating transformer 9 having a leakage inductance in the primary winding is connected.

Further, to the secondary winding of the insulating transformer 9, a rectifier circuit 10 composed of four diodes connected in a full bridge is connected.

On the other hand, the rectifier circuit 10 is connected in series with a filter reactor 11.

A filter capacitor 12 is connected in parallel with the filter reactor 11 and the rectifier circuit 10.

On the other hand, a voltage detector 13 for detecting the voltage of the filter capacitor 12 is connected in parallel to the filter capacitor 12.

A resonance capacitor 8 is connected between the inverter circuit and the primary winding of the insulation transformer 9.

Further, based on the voltage detection signal 14 from the voltage detector 13 and the voltage detection signal 19 from the input circuit 2, the switching devices 3 and 4 switch at a constant frequency to change the input DC voltage. In order to control the output voltage constant with respect to the fluctuation of the load capacitance, and to control the secondary voltage constant based on the voltage detection signal 14 from the voltage detector 13, each switching device 3, 4
The ON / OFF signal to each switching device 3 and 4 is controlled so that each switching device 3 and 4 performs zero current or zero voltage switching by controlling the current flow rate of the device and the phase difference time between the first arm and the second arm. A control unit 20 having a control function of outputting A, B, C, D is provided.

FIG. 2 is a circuit diagram showing a configuration example of the input circuit 2 in FIG.

As shown in FIG. 2, the input circuit 2 includes an electromagnetic contactor 31, a DC reactor 32, and a diode 33.
, A thyristor 34, a resistor 35, a DC capacitor 36, and a voltage detector 37, as shown in the figure.

Reference numeral 38 denotes a voltage detection signal from the voltage detector 37.

FIG. 3 is a circuit diagram showing an equivalent example of the internal leakage inductance of the insulating transformer 9 in FIG.

In FIG. 3, 91 is an insulating transformer winding,
Reference numeral 92 is a leakage inductance included in the primary winding.

Next, the operation of the electric vehicle power source device of the present embodiment configured as described above will be described with reference to FIGS. 4 to 6.

In FIG. 1, the switching device S
The control unit 20 first turns off the switching device SA in response to the signal A from the state where A and SD are on and power is being supplied to the secondary load side.

When the switching device SA is turned off,
To the lossless snubber capacitor 7 connected in parallel,
The current flowing in the switching device SA is shunted,
Start charging operation.

At this time, at the same time, the switching device S
Lossless snubber capacitor 7 connected in parallel with B
Becomes a discharge operation.

When the switching device SA is turned off, the current is shunted to the lossless snubber capacitor 7, so that the current is not cut off. Therefore, there is zero current switching, and the switching loss is zero.

When the charging / discharging operation of the lossless snubber capacitor 7 is completely completed, the current continues to flow due to the leakage inductance (92 in FIG. 3) and the filter reactor 11 in the insulating transformer 9 and is connected in parallel with the switching device SB. Begins to flow into the existing diode.

The control section 20 is set to occur at a certain time before the timing at which the switching device SD is turned off next, and judges this state as the setting timing.

The voltage applied to the switching device SB at the set timing is determined to be zero voltage because the diodes connected in parallel are on, and the control unit 20 responds to the signal B to switch the switching device SB. Turn on SB.

Therefore, the switching device SB becomes zero voltage switching, and the switching loss is zero.

Next, the return current flowing through the diode connected in parallel with the switching device SB and the switching device SD is gradually attenuated due to the resonance phenomenon between the resonance capacitor 8 and the filter reactor 11.
After reaching zero current, current begins to flow in the opposite direction.

At this time, the current is the switching device S
B and the diode connected in parallel with the switching device SD begin to flow.

Next, at the timing when the switching device SD is turned off before the dead band time before the timing when the switching device SC is turned on, the return current is flowing in zero or in the opposite direction, so the control unit 20 controls the switching device SD. The switching device SD is turned off by the signal D at the timing when the current flowing through the device becomes zero.

As a result, the switching device SD
Is off switching at zero voltage and zero current,
It can be turned off without providing a normal snubber circuit, resulting in zero switching loss.

Further, the return current gradually decreases, the flow direction reverses, and the current value flowing through the secondary side increases.

Then, when the return current reaches the same value as the current flowing through the secondary side, the two diodes (switching device S) connected diagonally in the diode in the rectifier circuit 10 are connected.
When A and SD are on, the diode that was supplying power to the secondary side is off.

At this time, the voltage applied to the diode to be turned off is the Vf voltage of the two diodes diagonally opposite to each other at which all the currents have started to flow, and therefore the diode is turned to the off state in the same state as the state of zero voltage. .

Therefore, the secondary side rectifying diode also has zero voltage switching, and the switching loss becomes zero.

Further, during conventional normal hard switching, surge voltage is generated from abrupt cutoff of current at diode recovery (timing after switching from ON state to OFF state). Therefore, snubber is used to suppress surge voltage. A surge voltage suppression circuit such as a supersaturated reactor was required in the circuit or series, but in this embodiment, the surge voltage suppression circuit is not necessary because it is zero voltage switching, and there is no loss generated from the surge voltage suppression circuit, and switching is performed. Is possible.

After the switching device SD is turned off, the control section 20 turns on the switching device SC by the signal C.

When the switching device SC is turned on,
The mode is in which power is supplied to the secondary side together with the switching device SB.

When the switching device SC is turned on,
Since the rise time of the load current flowing through the switching device SC is suppressed by the auxiliary reactor 6, the time when the current starts to flow is delayed with respect to the time when the voltage applied to the switching device SC becomes zero voltage. Is suppressed and the state shifts to the ON state.

Therefore, the switching device SC becomes zero current switching.

After that, the operation returns to the first switching mode, and the switching devices SA → SB, SB → SA, S
Switching from C to SD and SD to SC is repeated to output a rectangular wave voltage to the secondary winding side of the insulating transformer 9 to supply electric power.

As described above, all the four switching devices SA, SB, SC, SD repeat switching with zero current or zero voltage, so that switching is performed with almost zero switching loss to improve the conversion efficiency of the device. You can

Next, the control contents for keeping the output voltage constant and the zero voltage / zero current switching control will be described.

Since the charging / discharging operation time of the lossless snubber capacitor 7 when the switching device SA or SB of the lossless snubber capacitor 7 is off is performed by shunting the load current, the time also changes when the power supply amount to the load changes. .

That is, if the amount of power supplied to the load is large,
If the current is large and the charging / discharging time is short, and the amount of power supplied to the load is small, the current is small and the charging / discharging time is long.

After the switching devices SA and SB are turned on, the switching devices SD and S are respectively turned on.
The time until C is turned off depends on the current decay time by the resonance capacitor 8.

Therefore, in order for each element to perform zero voltage and zero current switching, the timing at which the switching devices SA and SB are turned on assumes the resonance time of the resonance circuit, as described above.
Timing when SB turns on and switching device S
The timing at which C and SD are turned off must be determined by determining that the current becomes zero or flows in the opposite direction.

Therefore, according to the control example described below, the control unit 20 sends ON / OFF signals to the respective switching devices SA, SB, SC, SD while satisfying the conditions required for the zero current / zero voltage switching. It is output and the output voltage is controlled to be constant.

FIG. 4 is a block diagram showing a configuration example of the control unit 20 according to this embodiment.

When the change in the load is small or the change in the input voltage is small, the on-timing of the switching devices SA and SB and the off-timing of the switching devices SC and SD are small. Control can also be used.

From the voltage detection signal 19 (input filter capacitor voltage): VD3, the transformation ratio of the insulating transformer 9: P, and the rated output voltage: Vout, the control reference value of the switching device (ON time of the switching device / 1 cycle) Time): Find αr.

[0096]

[Equation 1]

Vrin: Rated input filter capacitor voltage output reference voltage: The difference between Vout and the voltage detector signal 14 from the voltage detector 13: VD1 is obtained, and the correction value obtained by proportional / integral calculation with respect to this difference, The control voltage: α1 is obtained by adding the control reference value.

[0098]

[Equation 2]

This control voltage: α1 is compared with a reference sawtooth waveform in which a sawtooth waveform is missing every other pair of 180 degrees out of phase, and each switching device SD is turned on and then the switching device is turned on. SA off,
The time from when the switching device SC is turned on to when the switching device SB is turned off is calculated as a PWM wave.

When the PWM wave is H, the switching devices SA and SB are on, and when they are inverted to L, they are off.

In parallel with the above control, the ON time of the switching devices SA and SB is controlled so as to increase or decrease in proportion to the time obtained from the PWM wave.

Then, the switching devices SA, SB
Is turned on at the switching device SC,
For the timing when SD turns on, for example, 20 kHz
If the switching frequency is, the timing is set appropriately from the time constant of the resonance circuit so that it is a fixed time of 5 μS or the like.

Also, regarding the on-time of the switching devices SC and SD, the same operation as the phase difference time (or overlapping angle) of the switching devices SA and SB and the switching devices SC and SD obtained above is performed,
The calculation is performed so that the operation with the PWM wave can be performed.

However, the switching devices SC and SD
The reference value of the output voltage when calculating the ON time is set to a value that is approximately 5% higher than the reference value for calculating the phase difference time.

As described above, when the amount of power supplied to the load is small and the charge / discharge time of the lossless snubber capacitor 7 is long, or after the switching devices SA and SB are turned on, the switching devices SD and SC are turned off respectively. Regarding the time, even under the condition that the current decay time by the resonance capacitor 8 is long, the output voltage can be controlled to be constant while performing the zero voltage and zero current switching by changing the switching timing.

FIG. 5 is a diagram showing the time-series state of the voltage / current waveform of each part and the on / off timing of each switching device during the operation of the main circuit.

The switching waveform is a waveform when the load current flows to some extent and the current of the filter reactor 11 is not intermittent.

That is, when the load current is small, the phase difference between the switching devices SA and SB and the switching devices SC and SD becomes large, and when there is no load or the like, the switching devices SA and SB are completely calculated from the above calculation. In the OFF state, only the switching devices SC and SD perform PWM control, that is, control that only changes the ON time.

Since the reference voltage is raised by the phase difference time calculation as described in the example of the calculation method, the output voltage at this time is controlled to a value increased by the increased reference voltage.

FIG. 6 is a diagram showing the time-series state of the voltage / current waveform of each part and the on / off timing of each switching device during operation of the main circuit under no load or light load (when the load current is small). is there.

As described above, in the electric vehicle power supply device according to the present embodiment, each switching device SA, S is provided by the simple addition of the resonance circuit and the auxiliary parts and the resonance circuit.
When the applied voltage to B, SC, SD or the conduction current is zero, that is, each switching device SA, SB, S
Since the switching devices SA, SB, SC, SD are controlled to be turned on or off when C, SD become zero voltage or zero current, the switching devices SA, SB, SC, SD are used. It is possible to reduce the switching loss and increase the conversion efficiency of the device during high frequency switching.

(Second Embodiment) FIG. 7 is a circuit diagram showing a configuration example of an electric vehicle power supply device according to the present embodiment. The same parts as those in FIG. Is omitted and only different parts will be described here.

That is, as shown in FIG. 7, the electric vehicle power supply device according to the present embodiment has the current detector 17 for detecting the output current of the inverter circuit in FIG. The function of connecting to the wire on the wire side and finely adjusting the phase difference control between the ON time on the first arm side and the OFF time on the second arm side based on the current detection signal 18 from the current detector 17 is described above. The configuration is added to the control unit 20.

FIG. 8 is a block diagram showing a configuration example of the control unit 20 for realizing the above contents.

Next, the operation of the electric vehicle power source device of the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 1 will be omitted, and only the operation of the different parts will be described here.

In the electric vehicle power supply device of the first embodiment described above, the switching devices SA, S are turned off when the switching devices SC, SD are turned off.
The timing when B is turned on is controlled at a constant time such as 5 μS.

However, the timing control is not sufficient for the transient fluctuation of the load, and in the short time, each switching device SA, SB, SC, SD becomes hard switching instead of soft switching. there is a possibility.

In this respect, in this embodiment, the current detector 1
The load current is detected by 7 and the fixed time (hereinafter, T
switching device S, which was referred to as a sab)
For the on timing of the switching devices SA, SB with respect to the off timing of C, SD, the detected current amount is multiplied by a specified coefficient, and then the constant time Tsab is multiplied.

For example, when the current amount is small, Tsa
b becomes short, and immediately before the switching devices SC and SD turn off, the switching devices SA and S
B turns on, and Tsab becomes longer as the amount of current increases, and the switching devices SC and SD turn on considerably earlier than the timing at which they turn off.

The specified coefficient is a value obtained from the time constant of the resonance circuit.

As described above, in the electric vehicle power supply device according to this embodiment, the current detector 17 is added and the control unit 20 is added.
With the addition of the above logic, the phase difference control between the ON time on the first arm side and the OFF time on the second arm side is finely adjusted based on the load current. Therefore, similar to the above-described first embodiment. In addition to the above effect, the soft switching operation can be stably performed even with a transient load change, and it is possible to prevent wasteful switching loss.

That is, it is possible to improve the dynamic and static characteristics of the output voltage when the input voltage changes and the load changes.

(Third Embodiment) FIG. 9 is a circuit diagram showing a configuration example of an electric vehicle power supply device according to the present embodiment. The same parts as those in FIG. Is omitted and only different parts will be described here.

That is, as shown in FIG. 9, the electric vehicle power supply device according to the present embodiment includes the current detector 17 for detecting the output current of the inverter circuit in FIG. The line side rectifier circuit 10 is provided in series with the filter reactor 11 at the subsequent stage.

Next, the operation of the electric vehicle power supply device of the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 7 is omitted, and only the operation of the different parts will be described here.

In FIG. 9, since the current detector 17 for detecting the load current is provided in series with the filter reactor 11 at the subsequent stage of the rectifier circuit 10 on the secondary winding side of the insulating transformer 9, the filter reactor 11 is provided. Since the current flowing through is a direct current, there is little change in the magnetic flux of the metal part of the core part which is the current detection part of the current detector 17.

Therefore, the current detector 17 can be constructed without using an expensive core material such as an amorphous iron core.

As described above, in the electric vehicle power supply device according to this embodiment, the current detector 17 for detecting the load current is used.
Is provided in series with the filter reactor 11 in the subsequent stage of the rectifier circuit 10 on the secondary winding side of the insulating transformer 9, so that the same effect as that of the second embodiment described above can be obtained. In addition, the current detector 17 can be configured without using an expensive core material such as an amorphous iron core.

That is, it becomes unnecessary to use a special current detector that does not overheat with respect to the high frequency alternating current.

(Fourth Embodiment) FIG. 10 is a circuit diagram showing a configuration example of an electric vehicle power supply device according to the present embodiment. The same parts as those in FIG. Is omitted and only different parts will be described here.

That is, in the electric vehicle power supply device according to the present embodiment, as shown in FIG. 10, the resonance capacitor 8 in FIG. 7 is provided between the secondary winding of the insulating transformer 9 and the rectifying circuit 10. The configuration is provided.

Next, the operation of the electric vehicle power source device of the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 7 will be omitted, and only the operation of the different parts will be described here.

In FIG. 10, since the resonance capacitor 8 is provided between the secondary winding of the insulating transformer 9 and the rectifying circuit 10, the secondary winding of the insulating transformer 9 is
Since the voltage to ground is generally low, the withstand voltage of the resonance capacitor 8 used can be lowered.

As described above, in the electric vehicle power supply device according to this embodiment, the resonance capacitor 8 is provided between the secondary winding of the insulating transformer 9 and the rectifier circuit 10. In addition to obtaining the same effect as in the second embodiment described above, it becomes possible to lower the withstand voltage of the resonance capacitor 8 used.

(Fifth Embodiment) FIG. 11 is a circuit diagram showing a configuration example of an electric vehicle power supply device according to the present embodiment. The same parts as those in FIG. Is omitted and only different parts will be described here.

That is, as shown in FIG. 11, the power supply device for an electric vehicle according to the present embodiment has two auxiliary reactors 6 in FIG. 7 connected in series to form one auxiliary reactor 6 as two switching devices. SC, SD
And the series connection point of the two auxiliary reactors 6 (the midpoint of the integrated auxiliary reactor 6) is connected to one side of the resonance capacitor 8.

Next, the operation of the electric vehicle power source device of the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 7 will be omitted, and only the operation of the different parts will be described here.

In FIG. 11, two auxiliary reactors 6 are provided.
Is a single-body type auxiliary reactor 6 and is inserted in series between the two switching devices SC and SD of the second arm, so that the number of parts can be reduced.

As described above, in the electric vehicle power supply device according to the present embodiment, the two auxiliary reactors 6 are made into a one-piece auxiliary reactor 6 and are connected in series between the two switching devices SC and SD of the second arm. Since it is inserted, the same effect as that of the second embodiment described above can be obtained, and the number of parts can be reduced.

(Sixth Embodiment) FIG. 12 is a circuit diagram showing a configuration example of an electric vehicle power source device according to the present embodiment. The same parts as those in FIG. Is omitted and only different parts will be described here.

That is, as shown in FIG. 12, the electric vehicle power supply device according to the present embodiment is provided with an intermediate tap in the secondary winding of the insulating transformer 9 in FIG. Only two are configured as a half-bridge rectifier circuit.

Next, the operation of the electric vehicle power supply device of the present embodiment configured as described above will be described.

Description of the operation of the same parts as in FIG. 7 will be omitted, and only the operation of the different parts will be described here.

In FIG. 12, by providing an intermediate tap on the secondary winding of the insulation transformer 9 and forming a half bridge rectification circuit with only two diodes in the rectification circuit 10, the number of parts can be reduced.

As described above, in the electric vehicle power supply device according to the present embodiment, the intermediate side tap is provided in the secondary winding of the insulating transformer 9, and the rectifier circuit 10 has only two diodes and the half bridge rectifier circuit. Therefore, the same effect as that of the second embodiment described above can be obtained, and the number of parts can be reduced.

(Other Embodiments) The present invention is not limited to the above-mentioned embodiments, and can be variously modified and carried out at the stage of carrying out the invention without departing from the spirit thereof. Is. In addition, the respective embodiments may be implemented in combination as appropriate as possible, and in that case, combined operation effects can be obtained. Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent features. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem (at least one) described in the section of the problem to be solved by the invention can be solved, and When the effect (at least one) described in the section can be obtained, a structure in which this constituent element is deleted can be extracted as an invention.

[0151]

As described above, according to the electric vehicle power supply device of the present invention, each switching device is controlled so as to be turned on or off when the voltage becomes zero voltage or zero current. As a result, it is possible to reduce the switching loss due to the switching device and improve the conversion efficiency of the device during high frequency switching.

Further, according to the electric vehicle power source device of the present invention, the conduction ratio of each switching device and the time which is the phase difference between the ON / OFF timings of the first arm and the second arm are controlled simultaneously. Therefore, soft switching operation can be stably performed even with a transient load fluctuation, and it is possible to prevent wasteful switching loss, that is, force voltage fluctuation and load fluctuation. It is possible to improve the dynamic and static characteristics of the output voltage over time.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of an electric vehicle power supply device according to the present invention.

FIG. 2 is a circuit diagram showing a configuration example of an input circuit 2 in the electric vehicle power supply device of the first embodiment.

FIG. 3 is a circuit diagram showing an equivalent example of the internal leakage inductance of the insulating transformer 9 in the electric vehicle power supply device of the first embodiment.

FIG. 4 is a block diagram showing a configuration example of a control unit 20 in the electric vehicle power supply device of the first embodiment.

FIG. 5 is a diagram showing a time-series state of voltage / current waveforms of respective parts and on / off timings of respective switching devices during main circuit operation in the electric vehicle power supply device of the first embodiment.

FIG. 6 is a diagram showing a case of no load or light load (when the load current is small) in the electric vehicle power supply device of the first embodiment;
The figure which shows the time series state of the voltage / current waveform of each part at the time of main circuit operation, and the on / off timing of each switching device.

FIG. 7 is a circuit diagram showing a second embodiment of the electric vehicle power supply device according to the present invention.

FIG. 8 is a block diagram showing a configuration example of a control unit 20 in the electric vehicle power supply device according to the second embodiment.

FIG. 9 is a circuit diagram showing a third embodiment of an electric vehicle power supply device according to the present invention.

FIG. 10 is a circuit diagram showing a fourth embodiment of an electric vehicle power supply device according to the present invention.

FIG. 11 is a circuit diagram showing a fifth embodiment of an electric vehicle power supply device according to the present invention.

FIG. 12 is a circuit diagram showing a sixth embodiment of an electric vehicle power supply device according to the present invention.

FIG. 13 is a circuit diagram showing a configuration example of a conventional electric vehicle power supply device.

[Explanation of symbols]

1 ... Pantograph (current collector) 2 ... Input circuit 3 ... Switching device (first arm) 4 ... Switching device (second arm) 6 ... Auxiliary reactor 7 ... Lossless snubber capacitor 8 ... Resonant capacitor 9 ... Isolation transformer 10 ... Rectifier circuit 11 ... Filter reactor 12 ... Filter capacitor 13 ... Voltage detector 14 ... Voltage detection signal 17 ... Current detector 18 ... Current detection signal 19 ... Voltage detection signal 20 ... Control unit 91 ... Insulation transformer winding 92 ... Leakage inductance.

Claims (6)

[Claims] 1. A DC / DC converter insulating circuit having a train line as an input, wherein a switching device switches at a constant frequency to make an output voltage constant with respect to a fluctuation of an input DC voltage and a fluctuation of a load capacitance. In an electric vehicle power supply device to be controlled, a first arm including two first switching devices connected in series with each other, and a lossless snubber capacitor connected in parallel with each of the first switching devices, and each other. Two second connected in series
Switching device and a full-bridge connection inverter circuit composed of a second arm consisting of an auxiliary reactor connected in series with each second switching device, and an insulation having leakage inductance in the primary winding A transformer, a rectifier circuit connected to the secondary winding of the isolation transformer and connected to a full bridge, a filter reactor connected in series to the rectifier circuit, the filter reactor and the rectifier A filter capacitor connected in parallel with the circuit; a voltage detection means for detecting the voltage of the filter capacitor; a resonant capacitor connected between the inverter circuit and the primary winding of the isolation transformer; The secondary voltage is controlled to be constant based on the voltage detection signal from the detection means. Thus, by controlling the conduction ratio of each of the switching devices and the time of the phase difference between the first arm and the second arm, each switching device is turned on / off so that each switching device performs zero current or zero voltage switching. A power supply device for an electric vehicle, comprising: a control unit having a control function of outputting an off signal. 2. The electric vehicle power supply device according to claim 1, further comprising a current detection unit that detects an output current of the inverter circuit, the first current detection unit based on a current detection signal from the current detection unit. A power supply device for an electric vehicle, wherein a function for finely adjusting a phase difference control between an on time on the arm side and an off time on the second arm side is added to the control means. 3. The electric vehicle power supply device according to claim 2, wherein the current detection means for detecting the output current of the inverter circuit is a filter at a stage subsequent to the rectification circuit on the secondary winding side of the insulation transformer. An electric vehicle power supply device characterized by being provided in series with a reactor. 4. The electric vehicle power supply device according to claim 2, wherein the resonant capacitor is provided between the secondary winding of the insulation transformer and the rectifier circuit. Power supply. 5. The electric vehicle power supply device according to claim 2, wherein the two auxiliary reactors are connected in series to form an integral type, and are connected to a series connection point of the two second switching devices, and A power supply device for an electric vehicle, wherein a series connection point of the two auxiliary reactors is connected to one side of the resonance capacitor. 6. The electric vehicle power supply device according to claim 2, wherein an intermediate tap is provided on the secondary side winding of the insulation transformer, and a half bridge rectification circuit is provided with only two diodes in the rectification circuit. An electric vehicle power supply device characterized by the above.