JPH09298840A - Charger of electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety of the charging of the battery of an electric vehicle and simplify its structure, by insulating electrically the battery from a commercial power supply during the charging. SOLUTION: Providing two sets of stator windings 41, 42 in a brushless synchronous motor 40, both the stator windings 41, 42 are insulated electrically from each other but are coupled magnetically to each other. A switch 60 connected with the stator windings 42 is opened in a motor driving mode to be closed in a battery charging mode. In the motor driving mode, converting the DC power of a battery 1 into an AC power by an inverter 3, the AC power is fed to the motor 40 to rotate and driven the motor 40. In the case of charging the battery 1, the AC power of a commercial power supply 8 is fed to the motor 40 via the switch 60. At this time, the windings 42, 41 function as an insulation transformer to insulate electrically the battery 1 from the power supply 8. Also, making the inverter 3 function as a PWM converter, the AC power is converted into an DC power to charge the battery 1 by it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for an electric vehicle, which can ensure safety by electrically insulating between the electric vehicle and a commercial power source during charging and simplifying the structure. It was devised as follows.

[0002]

2. Description of the Related Art An electric vehicle is equipped with a battery, an inverter and an AC electric motor. The DC electric power of the battery is converted into AC electric power by the inverter and the AC electric power is supplied to the AC electric motor to drive the AC electric motor to drive the vehicle. . Generally, three-phase induction motors, brushless synchronous motors, etc. are adopted as AC motors for electric vehicles. Also, as the inverter, a type of inverter that has the function of not only reverse conversion (power running) but also forward conversion (regeneration) is adopted, and the AC power generated in the AC motor is converted to DC power on downhill roads. The DC power is then charged into the battery. Further, when the charging power of the battery decreases, the AC power (50 Hz or 60 Hz) of the commercial power source is converted into DC power and the DC power is charged in the battery.

In order to charge a battery with reduced charging power by using a commercial power source, a charger has been generally used in the past. As the charger, there were a vehicle-mounted type and a ground-mounted type. An electric vehicle equipped with a vehicle-mounted charger has an advantage that it can be charged by a commercial power source such as a general household, but has a drawback that the structure is complicated because the charger is mounted in the electric vehicle. In addition, an electric vehicle that uses a charger installed on the ground has the advantage of simplifying the configuration of the electric vehicle because it is not equipped with a charger, but on the other hand, a special charger that installs a charger is used when charging. There is a drawback that you have to go to a special charging place (charging station).

As described above, when a charger is used, whether it is a vehicle-mounted type or a ground-mounted type, there is a problem. Therefore, a technique for charging without using the charger has been developed. As described below, this technique utilizes a stator winding of an AC motor to perform charging.

Here, an example of a conventional charging device for an electric vehicle, which uses a stator winding of an AC motor for charging,
This will be described with reference to FIG.

As shown in FIG. 9, an electric vehicle is equipped with a battery 1, a DC capacitor 2, an inverter 3, a brushless synchronous motor 4 and the like.

The DC capacitor 2 is composed of a large-capacity electrolytic capacitor or the like, and the DC capacitor 2 has a function of absorbing the ripple component of the DC current and keeping the voltage of the battery 1 constant.

The inverter 3 has switching elements S1,
A U-phase arm composed of feedback diodes D1 and D2 connected in antiparallel to S2 and each switching element, and feedback diodes D3 and D4 connected in antiparallel to switching elements S3 and S4 and each switching element. And a W-phase arm composed of feedback elements D5 and D6 connected in antiparallel to the switching elements S5 and S6 and the respective switching elements.
The inverter 3 performs a switching operation according to a switching signal sent from the control circuit 5 to each of the switching elements S1 to S6 to perform an inverse conversion. Thereby, the DC voltage supplied from the battery 1 is converted into a three-phase AC voltage and sent to the brushless synchronous motor 4.

The brushless synchronous motor 4 is provided with three-phase stator windings 4u, 4v, 4w on a stator and a permanent magnet (PM) as a field magnet on a rotor (not shown).

The double-headed switch 6 includes stator windings 4u, 4v, 4
connected to w, and in the motor drive mode, terminals A1,
Connected to A2 and A3, and in charging mode terminals B1 and B
2, B3. The terminals A1, A2 and A3 are connected to each other, and the terminals B1, B2 and B3 are connected to the plug 7.

On the other hand, the general household side has a three-phase commercial power source 8
An outlet 9 connected to is disposed.

In the motor drive mode for traveling as an electric vehicle, the plug 7 is removed from the outlet 9 and the double-headed switch 6 is connected to the terminals A1, A2 and A3. At this time, based on the control of the control circuit 5, the brushless synchronous motor 4 is rotationally driven by the three-phase AC voltage being sent from the inverter 3 to the brushless synchronous motor 4 to run.

In the charging mode in which the voltage of the battery 1 drops and the battery 1 is charged, the double-headed switch 6 has terminals B1, B2, B.
3 and the plug 7 is connected to the outlet 9.
Therefore, the AC power of the commercial power supply 8 is supplied to the inverter 3 via the outlet 9, the plug 7, the double-headed switch 6, the stator windings 4u, 4v, 4w. At this time, the stator windings 4u, 4v, 4w function as a reactor. The inverter 3 performs forward conversion under the control of the control circuit 5, converts AC power into DC power, and charges the battery 1 with the converted DC power.

[0014]

The charging device shown in FIG. 9 has an advantage that a charger is not required and that charging can be performed at ordinary households. But when in charge mode,
That is, the plug 7 is connected to the outlet 9 and the double-headed switch 6
Is connected to the terminals B1, B2, B3, the electric path from the commercial power source 8 to the battery 1 is connected and cut off in the middle of the electric path (electrical cutoff of the path).
It has not been done. In other words, the electric vehicle is not electrically insulated from the commercial power supply 8 during charging. Therefore, during charging, the voltage of the commercial power source 8 may be transmitted to the electric vehicle side as it is, and electric shock may occur on the electric vehicle side. More specifically, the commercial power supply 8
One of the wires is grounded, so in the unlikely event that the voltage of the commercial power supply 8 is being input to the electric vehicle for charging,
If an accident occurs, a ground fault or short circuit may occur. In addition, a current may flow through the human body to the ground and return to the commercial power source, forming a loop, which may cause electric shock.

In view of the above, in the prior art in which the above problems are improved, as shown in FIG. 10, the insulating transformer 10 is provided between the plug 7 and the double-headed switch 6 of the electric vehicle. However, in this case, since the insulating transformer 10 is separately required, the number of parts increases and the structure becomes complicated. That is, at the beginning, the stator winding 4 is aimed at reducing the number of parts by eliminating the need for a charger.
In spite of trying to use u, 4v, 4w, the improved type for preventing electric shock requires a new insulating transformer 10, which is contrary to the original purpose of reducing the number of parts. Will end up.

In view of the above-mentioned prior art, it is an object of the present invention to provide a charging device for an electric vehicle, which can be electrically insulated between the electric vehicle and a commercial power source during charging while simplifying the structure.

[0017]

SUMMARY OF THE INVENTION The structure of the present invention for solving the above-mentioned problems is a battery and the DC power of this battery is converted back to AC power and output, and the AC power input from the AC side is converted to DC power. In an electric vehicle equipped with an inverter that also has a function of performing forward conversion to, a control circuit that controls the forward-reverse conversion operation of this inverter, and an AC electric motor that receives the AC power output from the inverter and is rotationally driven, The stator of the AC motor is provided with first and second stator windings that are electrically insulated and magnetically coupled, and in a motor drive mode in which the AC motor is rotationally driven, In a charging mode in which the second stator winding is opened and the battery is charged, there is provided switching means for connecting the second stator winding to a commercial power source, and the control circuit further comprises the charging circuit. The de, and controlling so as to operate the inverter as a PWM converter.

The configuration of the present invention also has a battery and a function of inversely converting the DC power of the battery into AC power and outputting the AC power, and also converting the AC power input from the AC side into the DC power. In an electric vehicle that includes an inverter, a control circuit that controls the forward-reverse conversion operation of the inverter, and an AC electric motor that is driven to rotate by receiving the AC power output from the inverter, the stator of the AC electric motor includes an electric motor. Of the first and second magnetically coupled stator windings, the inverter being a first inverter whose AC side is connected to the first stator winding. And the second side in which the AC side is connected to the switching terminal
And a second stator winding in the motor drive mode in which the AC motor is rotationally driven.
In the charging mode for connecting to the switching terminal of the inverter to charge the battery, there is provided switching means for connecting the second stator winding to the commercial power source, and the control circuit further includes an inverter in the charging mode. Is controlled to operate as a PWM converter.

The configuration of the present invention also has a battery and a function of inversely converting the DC power of the battery into AC power and outputting the AC power, and also converting the AC power input from the AC side into the DC power. In an electric vehicle that includes an inverter, a control circuit that controls the forward-reverse conversion operation of the inverter, and an AC electric motor that is driven to rotate by receiving the AC power output from the inverter, the stator of the AC electric motor includes an electric motor. And a magnetically coupled first and second stator windings, the second stator winding is opened in a motor drive mode for rotationally driving the AC motor. , In the charging mode for charging the battery,
A switching means for connecting the second stator winding to a commercial power source is provided, a voltage control circuit for adjusting a DC voltage value is interposed between the inverter and the battery, and the control circuit further comprises: In the charge mode, the operation of the main circuit of the inverter is controlled to be stopped.

The configuration of the present invention also has a battery and a function of inversely converting DC power of the battery into AC power and outputting the AC power, and converting AC power input from the AC side into DC power. In an electric vehicle that includes an inverter, a control circuit that controls the forward-reverse conversion operation of the inverter, and an AC electric motor that is driven to rotate by receiving the AC power output from the inverter, the stator of the AC electric motor includes an electric motor. Of the first and second magnetically coupled stator windings, the inverter being a first inverter whose AC side is connected to the first stator winding. And the second side in which the AC side is connected to the switching terminal
And a second stator winding in the motor drive mode in which the AC motor is rotationally driven.
In a charging mode for connecting to the switching terminal of the inverter and charging the battery, switching means for connecting the second stator winding to a commercial power source is provided, and between the first inverter and the battery. A voltage control circuit for adjusting a DC voltage value is provided, and the control circuit controls to stop the operation of the main circuit of the inverter in the charging mode.

The commercial power supply is a three-phase AC power supply or a single-phase AC power supply.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. It should be noted that parts having the same functions as those of the prior art will be described with the same reference numerals.

FIG. 1 shows a first embodiment of the present invention.
As shown in the figure, an electric vehicle includes a battery 1, a DC capacitor 2, an inverter 3, a brushless synchronous motor 4
0, a control circuit 5, a switch 60, and a plug 7 are provided.

Of these, the brushless synchronous motor 40 is
The stator includes three-phase first stator winding 41 including windings 41u, 41v, and 41w and windings 42u, 42v, and 42.
It comprises a three-phase second stator winding 42 of w. Although the stator windings 41, 42 are electrically insulated, the windings 41u, 42u, the windings 41v, 42v, the winding 4
It is arranged so as to be magnetically coupled between 1w and 42w. The stator winding 42 is connected to the switch 60. A rotor (not shown) of the brushless synchronous motor 40 is provided with a permanent magnet (PM) as a field.

The structure of the other parts is the same as that shown in FIGS.

In the motor drive mode for traveling as an electric vehicle, the plug 7 is removed from the outlet 9 and the switch 60 is opened. At this time, based on the control of the control circuit 5, the inverter 3 is inversely converted,
By sending a three-phase AC voltage from the inverter 3 to the first stator winding 41 of the brushless synchronous motor 40, the brushless synchronous motor 40 is rotationally driven to travel.

In the charging mode in which the voltage of the battery 1 drops and the battery is charged, the switch 60 is turned on and
The plug 7 is connected to the outlet 9. Therefore, the three-phase AC power of the commercial power supply 8 is sent to the brushless synchronous motor 40 via the outlet 9, the plug 7, and the switch 60. As described above, the stator windings 41 and 42 of the brushless synchronous motor 40 are electrically insulated but magnetically coupled, so that the stator windings 41 and 42 function as a transformer. . Therefore, the AC power sent to the brushless synchronous motor 40 is sent to the inverter 3 through the brushless synchronous motor 40.

The control circuit 5 sends a switching signal to the inverter main circuit (each switching element S1 to S6) so that the inverter 3 functions as a PWM converter. Therefore, the AC power sent to the inverter 3 is converted into DC power, and the battery 1 is charged with this DC power.

In the embodiment shown in FIG. 1, the stator winding 4
Since the stator winding 1 and the stator winding 42 are electrically insulated, the commercial power source 8 and the battery 1 of the electric vehicle can be electrically insulated at the time of charging, and the safety is improved. That is, even if an accident occurs while the voltage of the commercial power source 8 is being input to the electric vehicle for charging, a ground fault or a short circuit occurs because of electrical insulation. There is no such thing.
In addition, a loop in which electric current flows through the human body to the ground and returns to the commercial power source is not formed, and there is no possibility of electric shock. Further, the brushless synchronous motor 40 has two sets of stator windings 4
Since only 1, 42 are provided, a member having a large installation space is not required, which contributes to a reduction in the number of parts.

Next, a second embodiment of the present invention will be described with reference to FIG. It should be noted that parts having the same functions as those in FIG. 1 are denoted by the same reference numerals, and overlapping description will be omitted.

As shown in FIG. 2, in the second embodiment, in addition to the inverter 3, a second inverter 3a having the same structure as this inverter 3 is provided, and the second of the brushless synchronous motor 40 is provided. The stator winding 42 is connected to the changeover switch 61. The changeover switch 61 is turned on to the terminals C1, C2, C3 side in the motor drive mode,
In the charging mode, the power is supplied to the terminals E1, E2, E3. Terminals C1, C2 and C3 are connected to U of the inverter 3a,
It is connected to each phase arm of V and W, and terminals E1 and E
2, E3 are connected to the plug 7. Further, the control circuit 5a controls the inverters 3 and 3a.

In the motor drive mode for traveling as an electric vehicle, the plug 7 is removed from the outlet 9 and the changeover switch 61 is closed to the terminals C1, C2 and C3. At this time, based on the control of the control circuit 5a,
By sending a three-phase AC voltage from the inverter 3 and the inverter 3a to the first stator winding 41 and the second stator winding 42 of the brushless synchronous motor 40, the brushless synchronous motor 40 rotates and travels. Done. That is,
The brushless synchronous motor 40 is driven by a multiplex (double) inverter.

In the charging mode in which the voltage of the battery 1 drops and the battery 1 is charged, the changeover switch 61 has terminals E1 and E.
The plug 7 is plugged into the outlet 2 and E3, and the outlet 9
Connected to. Therefore, the three-phase AC power of the commercial power supply 8 is sent to the brushless synchronous motor 40 via the outlet 9, the plug 7, and the changeover switch 61. As described above, the stator windings 41, 4 of the brushless synchronous motor 40 are
Since 2 is electrically insulated but magnetically coupled, the stator windings 41 and 42 function as a transformer. Therefore, the AC power sent to the brushless synchronous motor 40 is sent to the inverter 3 through the brushless synchronous motor 40.

The control circuit 5a sends a switching signal to the inverter main circuit (each switching element S1 to S6) so that the inverter 3 functions as a PWM converter. Therefore, the AC power sent to the inverter 3 is converted into DC power, and the battery 1 is charged with this DC power.

Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment is the first embodiment shown in FIG.
The voltage control circuit 11 is added to the above embodiment. The voltage control circuit 11 is composed of a chopper device or the like. The configuration of the other parts is similar to that of the first embodiment shown in FIG.

In the third embodiment, in the voltage charging mode, the inverter 3 is not operated as a PWM converter, and the switching elements S1 to S6 are turned off. The AC voltage sent from the brushless synchronous motor 40 is fed to the feedback diodes D1 to D1 of the inverter 3.
It is rectified by D6 (which functions as a three-phase bridge rectifier circuit) to obtain a DC voltage. Then, the voltage control circuit 11 adjusts the value of the DC voltage and supplies the adjusted DC voltage to the battery 1 for charging. The operation in the motor drive mode is the same as that in the first embodiment.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is the second embodiment shown in FIG.
The voltage control circuit 12 is added to the above embodiment. The voltage control circuit 12 is composed of a chopper device or the like. The configuration of the other parts is similar to that of the second embodiment shown in FIG.

In the fourth embodiment, in the voltage charging mode, the inverter 3 is not operated as a PWM converter and the switching elements S1 to S6 are turned off. The AC voltage sent from the brushless synchronous motor 40 is fed to the feedback diodes D1 to D1 of the inverter 3.
It is rectified by D6 (which functions as a three-phase bridge rectifier circuit) to obtain a DC voltage. Then, the voltage control circuit 12 adjusts the value of the DC voltage and supplies the adjusted DC voltage to the battery 1 for charging. The operation in the motor drive mode is the same as that in the second embodiment.

Next, a fifth embodiment of the present invention will be described with reference to FIG. This form is a modification of the first embodiment shown in FIG. That is, the stator of the brushless synchronous motor 40a is provided with a three-phase stator winding 41 and a single-phase stator winding 43 composed of windings 43u and 43w. Further, the switch 60a, the plug 7a, the outlet 9a, and the commercial power supply 8a are of single-phase type.

Although the stator windings 41 and 43 are electrically insulated, the windings 41w and 43u are wound between the windings 41u and 43u.
It is arranged so as to be magnetically joined between 3w.

In the fifth embodiment, the same operation as in the first embodiment is performed. That is, in the motor drive mode for traveling as an electric vehicle, the plug 7a is removed from the outlet 9a and the switch 60a is opened. At this time, the inverter 3 is inversely converted under the control of the control circuit 5, and the three-phase AC voltage is sent from the inverter 3 to the stator winding 41 of the brushless synchronous motor 40a, whereby the brushless synchronous motor 40a is rotationally driven. Driving is performed.

In the charging mode in which the voltage of the battery 1 drops and the battery 1 is charged, the switch 60a is turned on and the plug 7a is connected to the outlet 9a. Therefore, the single-phase AC power of the commercial power source 8a is the outlet 9a,
It is sent to the brushless synchronous motor 40a via the plug 7a and the switch 60a. As described above, since the stator windings 41 and 43 of the brushless synchronous motor 40a are electrically insulated but magnetically coupled, the stator windings 41 and 43 function as a transformer. . Therefore, the AC power sent to the brushless synchronous motor 40a is sent to the inverter 3 through the brushless synchronous motor 40a.

The control circuit 5 sends a switching signal to the inverter main circuit (each switching element S1 to S6) so that the inverter 3 functions as a PWM converter. Therefore, the single-phase AC power sent to the inverter 3 is converted into DC power, and the battery 1 is charged with this DC power.

Next, a sixth embodiment of the present invention will be described with reference to FIG. This form is a modification of the second embodiment shown in FIG. That is, the changeover switch 61a
Is a three-phase type terminal C1, C2, C3 and a single-phase type terminal E
It can be switched between 1 and E2. Further, the plug 7a, the outlet 9a, and the commercial power source 8a are of single-phase type.

In the sixth embodiment, the same operation as in the second embodiment is performed. That is, at the time of driving the motor, the changeover switch 61a is turned on to the terminals C1, C2, C3 side, and the brushless synchronous motor 40 is driven by the multiplex (duplex) inverter. In the charging mode, the changeover switch 61a is turned on to the terminals E1 and E2 and the plug 7
a is connected to the outlet 9a. Then, the brushless synchronous motor 40 functions as a transformer, the inverter 3 operates as a PWM converter, and the battery 1 is charged.

Next, a seventh embodiment of the present invention will be described with reference to FIG. This form is a modification of the third embodiment shown in FIG. That is, in the brushless synchronous motor 40a, in addition to the three-phase stator winding 41, the winding 43
A single-phase stator winding 43 composed of u and 43w is provided.
Further, the switch 60a, the plug 7a, the outlet 9a,
The commercial power source 8a is of a single-phase type.

In the seventh embodiment, the same operation as in the third embodiment is performed. That is, when the motor is driven, the switch 60a is opened and the brushless synchronous motor 40a is driven by the inverter. Further, in the charging mode, the switch 60a is turned on, the brushless synchronous motor 40a functions as a transformer, the inverter 3 functions as a rectifier, and the battery 1 is charged by the DC voltage adjusted by the voltage control circuit 11. To be done.

Next, an eighth embodiment of the present invention will be described with reference to FIG. This form is a modification of the fourth embodiment shown in FIG. That is, the changeover switch 61a
Is a three-phase type terminal C1, C2, C3 and a single-phase type terminal E
It can be switched between 1 and E2. Further, the plug 7a, the outlet 9a, and the commercial power source 8a are of single-phase type.

In the eighth embodiment, the same operation as in the fourth embodiment is performed. That is, at the time of driving the motor, the changeover switch 61a is turned on to the terminals C1, C2, C3 side, and the brushless synchronous motor 40 is driven by the multiplex (duplex) inverter. In the charging mode, the changeover switch 61a is turned on to the terminals E1 and E2 and the plug 7
a is connected to the outlet 9a. Then, the brushless synchronous motor 40 functions as a transformer, the inverter 3 functions as a rectifier, and the battery 1 is charged by the DC voltage whose voltage is adjusted by the voltage control circuit 12.

In each of the above embodiments, the brushless synchronous motor is used as the AC motor, but other types of AC motors such as a three-phase induction motor can be used.

[0051]

As described above in detail with the embodiments, according to the present invention, two sets of electrically insulated but magnetically coupled stators of an AC motor are provided. 2 with a stator winding when charging the battery
Safety is improved because the pair of stator windings are used as insulation transformers to avoid direct electrical connection between the commercial power supply and the battery of the electric vehicle for insulation. In other words, even if an accident should occur while the voltage of the commercial power supply is being input to the electric vehicle for charging, a ground fault or short circuit may occur due to the electrical insulation. There is no. In addition, a loop in which electric current flows through the human body to the ground and returns to the commercial power source is not formed, and there is no possibility of electric shock. Further, unlike the prior art, a separate insulating transformer is not required, so that the structure can be simplified.

Further, by utilizing the inverter main circuit as a PWM converter, charging can be performed efficiently.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram showing a fifth embodiment of the present invention.

FIG. 6 is a circuit diagram showing a sixth embodiment of the present invention.

FIG. 7 is a circuit diagram showing a seventh embodiment of the present invention.

FIG. 8 is a circuit diagram showing an eighth embodiment of the present invention.

FIG. 9 is a circuit diagram showing a conventional technique.

FIG. 10 is a circuit diagram showing a conventional technique.

[Explanation of symbols]

1 Battery 2 DC Capacitor 3,3a Inverter 4 Brushless Synchronous Motor 5,5a Control Circuit 6 Double-headed Switch 7,7a Plug 8,8a Commercial Power Supply 9,9a Outlet 10 Insulation Transformer 11,12 Voltage Control Circuit 40,40a Brushless Synchronous Motor 41, 42, 43 Stator winding 41u, 41v, 41w, 42u, 42v, 42w, 4
3u, 43w Winding 60, 60a Switch 61, 61a Changeover switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H02M 7/219 8726-5H H02M 7/219 7/797 9181-5H 7/797

Claims (6)

[Claims] 1. A battery, an inverter having a function of inversely converting DC power of the battery into AC power and outputting the AC power, and also having a function of converting AC power input from the AC side into DC power. In an electric vehicle that includes a control circuit that controls the forward-reverse conversion operation of the inverter and an AC electric motor that receives the AC power output from the inverter and is rotationally driven, the stator of the AC electric motor is electrically insulated. And a magnetically coupled first and second stator windings, in a motor drive mode for rotationally driving the AC motor,
In a charging mode in which the second stator winding is opened and the battery is charged, switching means is provided for connecting the second stator winding to a commercial power source, and the control circuit is further arranged in the charging mode. , A charging device for an electric vehicle, which controls an inverter to operate as a PWM converter. 2. A battery, an inverter having a function of inversely converting DC power of the battery into AC power and outputting the AC power, and also having a function of converting AC power input from the AC side into DC power. In an electric vehicle that includes a control circuit that controls the forward-reverse conversion operation of the inverter and an AC electric motor that receives the AC power output from the inverter and is rotationally driven, the stator of the AC electric motor is electrically insulated. And a magnetically coupled first and second stator windings, and the inverter includes a first inverter whose AC side is connected to the first stator winding and an AC side which is switched. A second inverter connected to the terminal, and in a motor drive mode for rotationally driving the AC motor,
In the charging mode in which the second stator winding is connected to the switching terminal of the second inverter and the battery is charged, there is provided switching means for connecting the second stator winding to a commercial power source, and further, In the charging mode, the control circuit controls the inverter to operate as a PWM converter. 3. A battery, an inverter having a function of inversely converting DC power of the battery into AC power and outputting the AC power, and also having a function of converting AC power input from the AC side into DC power. In an electric vehicle that includes a control circuit that controls the forward-reverse conversion operation of the inverter and an AC electric motor that receives the AC power output from the inverter and is rotationally driven, the stator of the AC electric motor is electrically insulated. And a magnetically coupled first and second stator windings, in a motor drive mode for rotationally driving the AC motor,
In a charging mode in which the second stator winding is opened and the battery is charged, there is provided switching means for connecting the second stator winding to a commercial power source, and between the inverter and the battery, A charging device for an electric vehicle, comprising a voltage control circuit for adjusting a DC voltage value, which further controls the main circuit of the inverter to stop operating in the charging mode. 4. A battery, an inverter having a function of reversely converting DC power of the battery into AC power and outputting the AC power, and also having a function of converting AC power input from the AC side into DC power. In an electric vehicle that includes a control circuit that controls the forward-reverse conversion operation of the inverter and an AC electric motor that receives the AC power output from the inverter and is rotationally driven, the stator of the AC electric motor is electrically insulated. And a magnetically coupled first and second stator windings, and the inverter includes a first inverter whose AC side is connected to the first stator winding and an AC side which is switched. A second inverter connected to the terminal, and in a motor drive mode for rotationally driving the AC motor,
In a charging mode in which the second stator winding is connected to the switching terminal of the second inverter and the battery is charged, there is provided switching means for connecting the second stator winding to a commercial power source. Between the inverter and the battery, a voltage control circuit for adjusting a DC voltage value is provided, and the control circuit controls to stop the operation of the main circuit of the inverter in the charging mode. Charging device for electric vehicles characterized by: 5. The charging device for an electric vehicle according to claim 1, 2, 3 or 4, wherein the commercial power source is a three-phase alternating current power source. 6. The charging device for an electric vehicle according to claim 1, wherein the commercial power source is a single-phase AC power source.