JP3419082B2 - Orthogonal transformation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a MOS transistor
The present invention relates to an orthogonal transform device including a bridge circuit used. Book
The orthogonal transformation device of the invention is, for example, an alternator for an automobile.
(AC generator) rectifies the AC power generation voltage to charge the battery.
It is applied to a quadrature transforming device. However, in this specification
Orthogonal conversion device converts DC power to AC power
In addition to cases where AC power is converted to DC power,
No. [0002] 2. Description of the Related Art High-side switches and low-side switches
Switches are connected in series, three phase inverter circuits are connected in parallel.
And a pair of DC terminals connected to both ends of the battery.
And the connection point between the two switches is the armature winding of the AC motor.
Bridge circuits that are individually connected to each phase output
The AC motor is operated by interrupting the switch.
In the conventional orthogonal transform device comprising a control unit
As a high-side switch and low-side switch,
Polar transistor or IGBT and its parallel connection
Using a parallel circuit consisting of a high voltage junction diode
ing. Further, the bipolar transistor or I
Each high-side switch consisting of GBT (NPN format)
The control voltage of the switch is controlled by each transistor (high-side switch).
H), the potential of the main electrode on the armature winding side
It must be precisely controlled as a reference,
The lower end of the electric means (battery), that is, the low-side switch
Control voltage based on the potential of the battery
And the battery voltage is converted to AC
And the lower end of the rectifier that rectifies the secondary voltage
The main electrode (emitter) on the armature winding side of the high-side switch
Data). Further, the output voltage of the rectifier is controlled to
For forming the control voltage for forming the control voltage of the side switch
The reference potential of the control signal applied to the switching means
The main electrode on the armature winding side of each high-side switch (Emi
Must be formed with reference to the potential of
The control unit uses the low end of the battery as the reference potential
Transmission of control signal to switching means for forming control voltage
Is transmitted so that the reference potential can be shifted using a photocoupler.
Had been. [0005] On the other hand, JP-A-4-138030 discloses that
It has the same structure as the bridge circuit,
Bipolar transformer as switch and low side switch
N-channel MOS power instead of transistor or IGBT
-Use a transistor (however,
(Iode not required), alternator (three-phase synchronous generator)
A three-phase full-wave rectifier that rectifies the three-phase AC voltage output from
is suggesting. [0006] [Problems to be solved by the invention]First, thisInvention solved
Explain the problem to be attempted. Conventional AC motor or
The bridge circuit for driving the generator is
High-voltage junction die in parallel with a transistor or IGBT
It is necessary to connect an arm, and a total of 6 high voltage
There is a problem that an iodine is required. Note that these
High voltage junction diode is armature wound due to current phase delay
This is a passage when current is sent from the wire side to the battery side.
The same as the above bipolar transistor or IGBT
Requires a large chip area. On the other hand, similar to the three-phase full-wave rectifier disclosed in the above publication,
Instead of the above-mentioned bipolar transistor or IGBT
Instead, a bridge circuit is configured using MOS transistors
It is conceivable that such an AC motor or
In controlling the generator, the three-phase AC voltage applied to the AC motor
Because the actual AC current is delayed with respect to the phase of
When the side switch is turned on, the power is
Current may flow, in this case the high-side switch
Is the main electrode on the battery side of
Battery like an OS transistor type three-phase full-wave rectifier
Gate electrode potential (control voltage) with reference to the main electrode on the rear side
It is necessary to determine the high-side switch as described above.
Control voltage based on the potential of the main electrode on the armature winding side of the switch.
The method of determining the pressure did not make sense. In addition, the above-mentioned bipolar transistor or
Is a motor control using IGBT and high voltage junction diode
Your bridge circuit has many elements, is complex, large, and expensive
There was a problem that becomes. In addition,
Reference voltage consisting of a power supply, AC power supply for transformer input, and rectifier
Change means and control signal isolation means for each high-side switch
Is complicated, large, and expensive.
There was a defect. [0009]thisThe invention has been made in view of the above problems.
Of an AC motor or generator with a delayed current phase.
Iside switch can be controlled easily with simple device configuration
To provide an orthogonal transform device having a simple bridge circuit
For that purpose.Then thisLet the invention be solved
The following describes other problems. High side switch is N
Three-phase full wave composed of channel MOS transistors
Rectifier or motor or generator drive of the first aspect described above
In the bridge circuit for^- Mold breakdown voltage layer is directly under the gate electrode
Between the P-type substrate region of the battery and the N-type region on the battery side.
The armature winding side like a conventional bridge circuit.
When the potential of the gate electrode is not formed based on the N-type region
In this case, the resistance between the gate electrode and the N-type region on the armature winding side
Anxiety about pressure. [0010]thisThe invention has been made in view of the above problems.
And a MOS transistor as a high side switch
In the above bridge circuit or three-phase full-wave rectifier using
The N-type region (main electrode) on the armature winding side and the gate electrode
To provide an orthogonal transformation device capable of insulating protection between
For that purpose.Then thisLet the invention be solved
The following describes other problems. Brushless drive means for electric vehicles
An AC rotating electric machine such as a DC motor is used.
In such a case, it is convenient to let the motor
It is. However, during the power generation operation, the NPN structure bipolar
The bridge circuit consisting of a transistor or IGBT is
It cannot be operated during the power generation operation.
It is necessary to connect a diode in parallel for each transistor.
As a result, the device configuration was complicated, large, and expensive. [0012]thisThe invention has been made in view of the above problems.
In this case, the power generation operation and the electric operation are switched and executed.
Driving an electric motor with a simple configuration and a small bridge circuit
Its purpose is to provide a controllable orthogonal transform device.
are doing.Then thisOther problems to be solved by the invention
Will be described. The induction rotating electric machine has a simple structure,
The advantage is that frequency control and vector control can be easily performed.
However, there is a large delay in the current phase,
Power is transmitted from the machine to the battery (hereinafter referred to as reverse power transmission).
It often happens that there is a phase period. For this reason,
From NPN structure bipolar transistor or IGBT
Bridge circuit cannot operate during the above reverse power transmission.
The high-voltage junction diodes described above are arranged in parallel for each transistor.
It is necessary to connect in rows, and the device configuration is complicated, large, and high
Value. [0013]thisThe invention has been made in view of the above problems.
And the induction rotating electric machine having the reverse power transmission period
Quadrature transformer that has a configuration and can be driven and controlled by a small bridge circuit.
It is an object of the present invention to provide a conversion device. The present invention
The other purpose is to realize the functions and effects described later.
You. [0014] Means for Solving the Problems The present inventionDirectlyInterchange device
Is a high-speed circuit composed of N-channel MOS transistors.
And a low-side switch connected in series
The required number of phase inverter circuits are connected in parallel.
A flow end is connected to both ends of the power storage means, and a connection between the two switches is made.
Continuation pointAC rotating electric machineOf each armature winding
The bridge circuit to be connected and the gate voltage of each switch
And a control unit for controlling the position and turning on and off the switches.
The P-type substrate immediately below the gate electrode of the high-side switch
The plate region is orthogonal to the N-type region on the armature winding side.
The conversion device includes at least a constant voltage diode.
The gate electrode of the high-side switch and each phase output terminal
Voltage drop means for generating a predetermined voltage drop between
And the control unit,The potential of the storage means and the high
High voltage exceeding the sum of the threshold voltage of
Step-up means for outputting to the gate electrode of the high-side switch
When,A high terminal is connected to the output terminal of the booster,
And a lower terminal is connected to a lower end of the power storage means.
Input of each gate control signal,
Multiple high-side switch controls that intermittently switch
Step andWherein the high-side switch control means comprises:
Controls the electric operation and power generation operation of the AC rotating electric machine,
In controlling the power generation operation, the potential at the connection point
Turn on the high-side switch of the phase higher than the battery potential
The potential of the connection point is lower than the ground potential.
-Turn on the side switchIt is characterized by: [0015] [0016] [0017] [0018] [0019] [Action and effect of the invention]ClearlyAccording to N channel
Each high side of MOS transistor type bridge circuit
The potential of the storage means + high side is connected to the gate electrode of the switch
High voltage higher than the switch threshold voltage and low
Between the high-side switch and the
Swing this AC motor or generator
Irrespective of the current direction of the
AC motors such as induction motors without connecting
A bridge circuit that drives and controls the motive can be configured.
You. This is because MOS transistors are in principle dual.
Armature with directionality, due to current phase delay of AC motor
A mode in which current is sent from the winding to the storage means side (reverse power transmission
Mode), it is possible to control the drive without any problems.
Based on look. Another important point is the high side
When implementing switch PWM control, the conventional bipolar
In a transistor or an IGBT, as described above, the armature
A mode in which current is sent from the winding to the storage means side (reverse power transmission
Mode) is performed through the high breakdown voltage junction diode
Therefore, there is a problem that it is difficult to perform PWM control.
And On the other hand, according to the present invention, in the reverse power transmission mode,
What is the MOS transistor high-side switch?
PWM control can be performed without any trouble. Further according to the present invention, a conventional bipolar
Of high side switch consisting of transistor or IGBT
Control based on the potential of the main electrode on the armature winding side
Since there is no need to determine the electrode potential,
Reference voltage consisting of a power supply, AC power supply for transformer input, and rectifier
Change means and control signal isolation means for each high-side switch
It is not necessary to provide the
There is also the advantage that you can. The present inventionAccording to further, The high side switch
A predetermined voltage is applied between the gate electrode of the switch and the output terminal of each phase.
Characterized by comprising voltage drop means for generating a voltage drop
Therefore, the maximum voltage between these two is
The gate is regulated by applying a high voltage between them.
The insulating film is prevented from being destroyed. The present inventionAccording to, Parasitic diode on the battery side
N-channel MOS transistor with N- type breakdown voltage layer
Gate electrode and armature of high-side switch
A predetermined voltage drop between the winding side main electrode (N-type region)
Since there is a means for generating voltage drop,
The maximum voltage is defined by the voltage drop
As a result, gate insulation is achieved by applying a high voltage between the two.
Destruction of the membrane is prevented. The present invention relates to a bridge for controlling an induction machine.
It can be applied to circuits as well as to three-phase full-wave rectifiers.
The present inventionIs more, Voltage drop means by constant voltage diode
Because of this configuration, the breakdown voltage (gate
(Set below the withstand voltage of the rim)
Gate electrode of the switch and the main electrode on the armature winding side (N-type
Region) is not applied to the gate insulating film between
The gate insulating film can be reliably protected. More specifically, the power of the high-side switch is
The main electrode on the armature winding side is low and the gate electrode is high.
During the period when the high side switch is turned on by applying a bell
Therefore, the potential difference between the two is applied to the gate insulating film,
If the breakdown voltage of the constant voltage diode is set to less than this potential difference,
When current flows through the constant voltage diode,
The rise in the gate electrode potential is suppressed, and damage to the gate insulating film is prevented.
Evaded. The withstand voltage of the constant voltage diode is
Set to a voltage exceeding the threshold voltage of the id switch
It is necessary to increase the gate electrode potential
But the high-side switch is turned on even if it is insufficient as described above
The main electrode on the armature winding side of this high-side switch
The rank can rise. The present inventionAccording to further, Constant voltage diode and
A resistor is connected in series. That is, the constant voltage
Connecting a diode, the armature of the high-side switch
Of the main electrode on the winding side (that is, the phase output end of the armature winding)
When the potential is high and the potential of the gate electrode is low,
When turning the high-side switch from on to off,
The diode becomes forward-biased and the high-side switch
Switch is difficult or slow, or
Of the inverter circuit (amplifier) for controlling the side switch
It becomes necessary to reduce the output impedance. According to this configuration, the resistor is provided.
Therefore, the forward bias current can be suppressed.
Reverse currents higher than the withstand voltage of the voltage diode can be suppressed.
Wear. However, only the voltage drop across the gate insulating film
Since the voltage increases, the withstand voltage and resistance of the
The resistance value should be an appropriate value according to the rating of the high-side switch.
Selected. [0028] The present inventionIs more, Opposite to constant voltage diode
To a constant voltage diode. In this way,
Voltage equal to the withstand voltage of the voltage diode + forward bias voltage drop
Voltage is applied to the gate insulating film.
Can be achieved regardless of direction. The present inventionAccording to, Power generation operation and electric operation
For both drive motors, for example, for electric vehicles that require both
Of the bridge circuit that drives the AC generator motor
N channel side switch and low side switch
It is composed of MOS transistors. This way,
Bridge circuit using an bipolar transistor or IGBT
Need to connect high voltage junction diodes in parallel like
And PWM control even during power generation operation such as regenerative braking
Can be achieved. The present inventionAccording to, Current level with respect to applied voltage
Phase is delayed (for example, close to 90 degrees when there is no load)
The high side of the bridge circuit that drives the induction rotating electric machine
Switch and low-side switch are N-channel MOS
It is composed of transistors. By doing this,
A bridge circuit using a transistor or IGBT
There is no need to connect high voltage junction diodes in parallel. The present inventionIs moreThe control unit controls the guidance circuit
PWM control is performed during the phase period when the inverter is in the reverse power transmission mode.
It is characterized by. In this way, this high endurance
Current through the pressure junction diode
Due to the delay, power is transmitted from the armature winding to the battery (reverse
Even if power transmission is performed, PWM control is performed without any trouble.
The excellent effect that it can be performed can be exhibited. [0033] [0034] 【Example】 (Embodiment 1) Hereinafter, the present invention used for a vehicle alternator will be described.
One embodiment of the orthogonal transform device will be described with reference to FIG. 1
Is a three-phase AC (induction) generator that forms the drive motor for electric vehicles
(Three-phase induction motor), the armature windings 11-1 of which
The output terminals (output terminals of each phase) of the three-phase bridge circuit 3
Connected to AC input terminals (connection points to be described later) 41 to 43,
A pair of DC output terminals of the bridge circuit 3 are connected to a battery (the present invention).
(Power storage means) 7 are connected to both ends. Controller 6 supplied with power from battery 7
The microcomputer has a built-in microcomputer.
Terripotential, accelerator pedal and brake pedal depression amount
Control for controlling the bridge circuit 3 based on the
The signals S1 to S6 are converted to a buffer circuit for power amplification (in the present invention).
High-side switch control means 2). Ba
The buffer circuit 2 receives the gate control signals S1 to S6
Are individually amplified, and the six gate control voltages Vg1 to Vg
g6 is connected to a high-side switch (described later) in the bridge circuit 3.
H to 31 to 33 and low side switches 34 to 36
Output to FIG. 2 shows an example of the buffer circuit 2. This
Buffer circuit 2 is a common emitter NPN bipolar
Base current limit for transistors Tr1 to Tr6 respectively
6 pieces connected by resistance rb and collector load resistance rc
Inverter circuits, and transistors Tr1 to Tr3
To be described later through the collector load resistance rc
The high power supply voltage PW output from the booster 4 is applied.
The collectors of the transistors Tr4 to Tr6 are
The battery voltage VB, which will be described later, is printed through the load resistance rc.
And the emitters of the transistors Tr1 to Tr6 are
It is connected to the lower end GND of the battery 7. As a result, the gate control signals S1 to S3
Gate control voltages Vg1 to Vg3 composed of inverted signal voltages
Changes the high-level power supply voltage PW to a high-level output potential.
And the ground potential (battery low end potential) to low level
It is formed with a logic amplitude as an output potential. Similarly, game
Gate control consisting of inverted signal voltages of the control signals S4 to S6
The control voltages Vg4 to Vg6 change the battery voltage VB to a high level.
Output potential, almost ground potential (lower end potential of battery)
At a low level output potential. Next, the bridge circuit 3 will be described.
This three-phase full-wave bridge circuit 3 is made of Si or Si.
NMOS transistor for power using SiC with high breakdown voltage
-Side high-side switches 31-33 and low-side
Switches 34 to 36 are individually connected in series.
Phase inverter circuits 37 to 39 are connected in parallel.
DC output terminals are individually connected to the high and low terminals of the battery 7.
Connected, each switch of each phase inverter circuit 37-39
The connection points 31 to 36, that is, the AC input terminals 41 to 43
Each of the armature windings 11 to 13 of the induction motor 1
It is configured to be connected separately. The low side switches 34 to 36
P-type substrate directly below the gate electrode with the main electrode on the lower terminal side
Region (either a P-type substrate or a P-type well region)
A potential is applied to the substrate area, and the high-side switch is
The P-type substrate region immediately below the gate electrodes of
N on the winding 11-13 side⁺Connect to the mold area and apply potential
I have. Therefore, in this embodiment, the high side
The main electrodes (N⁺Type
Region) and a first parasitic consisting of a junction between the P-type substrate region
Diodes D1 to D3 and low side switch 34
To 36 of the main electrodes (N⁺Type
Region) and a third region comprising a junction between the P-type substrate region
Raw diodes D4 to D6 are parasitically formed as shown in FIG.
Will be done. Here, the first parasitic diodes D1 to D6
Has a withstand voltage exceeding the maximum rated voltage value of the battery 7
You. Specifically, these parasitic diodes D1 to D6 are junctions.
N in part^-Type withstand voltage layer, and the junction depletion layer
Higher withstand voltage is secured. Thus the parasitic diode
As is well known, to increase the breakdown voltage of D1 to D6, a MOS transistor is used.
Each of the transistors 31 to 36 has a DMOS structure or a vertical channel M
OS structures and their N^-Use a mold pressure-resistant layer
No. Each of the high-side switches 31 to 33 is
One-chip configuration and low-side switch 3
4 to 36 in a one-chip configuration requires N⁺Mold substrate potential
Is common with GND or VB. Next
Next, the booster 4 will be described. This boost means is usually
The switching inverter of
Parallel charging of multiple capacitors that are charged and discharged more periodically
Switch between electric and series discharge alternately with a switch
Thus, a DC high voltage is output. In this embodiment, the power supply voltage PW is
Re-voltage VB + threshold of high side switches 31-33
Set to the sum of voltage VT + predetermined voltage ΔV (several volts in this case)
It is. By doing so, the buffer circuit 2 becomes
High-side switches 31-33 are intermittent without any problems
You can control. Next, the bridge circuit 3 is electrically driven.
The control operation during operation will be described. The controller operates the various signals and the rotation speeds described above.
Switches 31 to 36 are turned off based on signals or slip signals.
Control. Basically, one high-side switch,
Low side switch different from this high side switch
Are sequentially selected and turned on. (At the time of electric operation, normal power transmission mode) At this time, the armature winding 1
The direction of the applied voltage to 1 to 13 and the current direction are the same phase
During the period (normal power transmission mode), the high-side switch 31
N on the armature winding side of ~ 33⁺The mold area is the source and
N on the battery side⁺The mold region becomes the drain. Therefore, in this embodiment, the gate control
Voltage Vg1 to Vg3 are equal to battery voltage VB + high side switch.
Threshold voltage VT of switches 31 to 33 + predetermined voltage ΔV (this
Here, it is set to the sum of several V).
Switches 31 to 33 are operated in a non-saturated manner, so that the armature windings 11 to 1
3, a sufficiently high potential can be applied. Where the game
When the gate control voltages Vg1 to Vg3 rise sharply,
Armature winding with high-level PW and source electrodes
N on the wire side⁺The mold region becomes, for example, GND and gate insulation
Since a large voltage is applied to the film, the gate control voltage Vg
To slow down the rising speed of 1 to Vg3 to some extent
Is preferred. By doing so, the gate control voltage Vg1
When Vg6 rises to the final potential PW,
N on the armature winding side⁺The potential of the mold region rises to some extent
Thus, the load on the gate insulating film is reduced. (Reverse power transmission mode during electric operation) To armature windings 11 to 13
Phase period in which the direction of the applied voltage and the current
Power mode, which is essentially a phase period during which power is generated)
Is N on the battery side of the high side switches 31-33.⁺
The mold region becomes the source, and N on the armature winding side⁺The type area is
It becomes rain. Even in this case, in this embodiment, the gate control
Voltage Vg1 to Vg3 are equal to battery voltage VB + high side switch.
Threshold voltage VT of switches 31 to 33 + predetermined voltage ΔV (this
Here, it is set to the sum of several V).
The switches 31 to 33 can be sufficiently turned on.
In this case, the slackening is unnecessary. (Normal power transmission mode during power generation operation) Reverse power transmission mode during motorized operation
This is the same as in the case of the mode. However, during this power generation operation,
The potential at points 41 to 43 is detected, and the
Phase inverter circuit having a connection point higher in potential than potential VB
Turn on the high-side switch of
Low side of phase inverter circuit with lower connection point
Turn on the switch. (Normal power transmission mode during power generation operation) Normal power transmission during motorized operation
During the period when the generator is being excited,
is there. However, during this power generation operation,
Similarly, the potentials at the connection points 41 to 43 are detected, and the potentials at the connection points are detected.
Has a connection point at a potential higher than the battery potential VB.
Turn on the high-side switch of the inverter circuit and
Phase inverter circuit having a connection point whose potential is lower than the ground potential
Turn on the low side switch. As explained above
In addition, the bridge circuit 3 of the present embodiment is an AC rotating electric machine (here,
In the drive control of induction rotating electric machine), N channel
Adopting a bridge circuit 3 using MOS transistors,
Also, the high-side switches 31 to 31 of the bridge circuit 3
33 is a simple buffer circuit (high side switch).
Switch control means) 2 and the boosting means.
Blocks using conventional bipolar transistors or IGBTs
Like a ridge circuit, parallel connection of high-voltage junction diodes
And forming the gate control voltages Vg1 to Vg3.
A complicated circuit configuration can be omitted. In addition,
In this embodiment, the buffer circuit 2 includes a resistor and an emitter.
Bipolar inverter circuit consisting of grounded transistor
, But various single-stage and multi-stage such as MOS inverter
Naturally, a circuit can be adopted. That is, the common emitter transistor of the buffer circuit 2
Transistor bipolar transistor (T_r1) And resistance
(R_b, R_c) Is configured as shown in FIG.
It is possible to reduce the size. That is, in the configuration of FIG.
Bipolar T_r1Current and T to be supplied to_r1Turns on
Resistance due to collector current_cPower loss
The output current capacity of the boosting means 4 to be supplied is required, and the size is easily increased.
No. In the configuration of FIG. 8, each high side of the bridge
The voltage applied to the gate of the switch is
Side switch (T_r7), Power loss is very high
And the boosting means 4 uses a small capacitor
It can be composed of a charge pump circuit, etc.
Becomes Also, T_r8Is each high side T of the bridge configuration_rTo
When turning off (T_r7Off) and switch on
It is provided to improve speed.
You may. FIG. 8 shows r_B, R_C, T_r1To MOS
In the example described above, T_r2, T_r3The same applies to
You. (Embodiment 2) Another embodiment will be described with reference to FIGS.
You. These drawings show N-channel MOS transistors.
High-side switches 31 to 33 (FIG. 3)
7 shows only the high-side switch 31).
Electrode and armature windings 11-13 N⁺Type area
(The connection point in the present embodiment) 41,
With voltage drop means for limiting the potential difference
It is. In addition, the parasitic diode D1 is similar to the first embodiment.
N^-It has a high breakdown voltage including the mold breakdown voltage layer. In FIG. 3, the voltage drop means is a constant voltage
It is composed of Iode ZD1 and its cathode is used as the gate electrode.
Connected. By doing so, the high-side switch 3
When turning on 1, the inverter of the buffer circuit 2
Even when a high-level potential (PW) is output, the gate
The potential of the pole is the potential of the connection point 41 + the constant voltage diode ZD1
Without rising above a potential equal to the breakdown voltage of the gate.
The insulating film is not damaged. In FIG. 4, the voltage drop means are opposite to each other.
A pair of constant voltage diodes ZD1 connected in series in the direction,
Consists of ZD2. In this way, the high-side switch
When the switch 31 is turned on, the inverter of the buffer circuit 2
Output high-level potential (PW) from the
The potential of the gate electrode is the potential of the connection point 41 + the constant voltage diode Z
Withstand voltage of D1 + forward bias voltage of constant voltage diode ZD2
This potential does not rise above the potential equal to the
Voltage of gate insulating film in
If it is less than this, the gate insulating film will not be damaged.
No. Similarly, when turning off the high-side switch 31,
And the low-level potential from the inverter of the buffer circuit 2
(Approximately GND potential) even when the gate electrode
Is the potential of the connection point 41-the withstand voltage of the constant voltage diode ZD1.
-Equal to the forward bias voltage drop of the constant voltage diode ZD2
The potential at this potential does not drop
The voltage applied to the gate insulating film should be lower than the withstand voltage of the gate insulating film.
Thus, the gate insulating film is not damaged. In FIG. 5, the voltage drop means is a resistor.
Even in this case, the potential difference between the two is limited, and the
Destruction of the gate insulating film is suppressed. FIG. 6 is a cross-sectional view of FIGS.
FIG. 7 is a synthesis of FIGS. 2 and 5,
Achieve further improvement of gate insulating film breakdown suppression effect
be able to. Note that the gate control signals S1 to S6 and the gate
To use the PWM control signals Vg1 to Vg6 as PWM signals.
Therefore, during the electric operation, the normal transmission potential phase period or the reverse
PWM control can be performed in both of the transmission potential phase periods.
Is understood. Further, the bridge circuit of this embodiment has a high breakdown voltage contact.
Without connecting a diode in parallel with the transistor
It will also be understood that the drive of the generator motor can be controlled.
U.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing an embodiment of an orthogonal transformation device for an AC motor according to the present invention. FIG. 2 is a circuit diagram showing an example of a buffer circuit 2 of FIG. FIG. 3 is a partial circuit diagram illustrating an example of a voltage drop unit according to a second embodiment. FIG. 4 is a partial circuit diagram illustrating an example of a voltage drop unit according to a second embodiment. FIG. 5 is a partial circuit diagram illustrating an example of a voltage drop unit according to a second embodiment. FIG. 6 is a partial circuit diagram illustrating an example of a voltage drop unit according to a second embodiment. FIG. 7 is a partial circuit diagram illustrating an example of a voltage drop unit according to a second embodiment. FIG. 8 is a circuit diagram showing another example of the buffer circuit 2 of FIG. 1; [Description of Signs] 1 is a three-phase AC motor (induction motor), 2 is a buffer circuit (high-side switch control means), 3 is a bridge circuit,
4 is a booster, 6 is a controller, 7 is a battery, 11
Reference numerals 13 to 13 denote armature windings, 31 to 33 denote high side switches composed of MOS transistors, 34 to 36 denote low side switches composed of MOS transistors, 37 to 39 denote phase inverter circuits, and 41 to 43 denote phase inverter circuits 37 to 43.
39 connection points (AC input terminals of the bridge circuit 3).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 7/219 H02J 7/14 H02P 9/30

Claims (1)

(57) [Claims] 1. An N-channel MOS transistor
High side switch and low side switch connected in series
Required number of phase inverter circuits connected in parallel,
A pair of DC terminals are connected to both ends of the power storage means,
Switch connection pointAC rotating electric machineOutput terminal of each phase of armature winding
And a bridge circuit individually connected to each of the switches.
A control unit for controlling the gate potential to turn on and off the switches
And a portion immediately below the gate electrode of the high-side switch.
The P-type substrate region is connected to the N-type region on the armature winding side.
In the orthogonal transformation device, The high side switch including at least a constant voltage diode
A predetermined voltage is applied between the gate electrode of the switch and the output terminal of each phase.
A voltage drop means for generating a voltage drop, The control unit is, Potential of the power storage means and threshold of the high side switch
The high-side switch outputs a high voltage exceeding the sum of the
Means for outputting to the gate electrode of, A higher terminal is connected to the output terminal of the booster, and a lower terminal
A terminal is connected to the lower end of the power storage means.
The high side switch is activated by the input of the gate control signal.
A plurality of individually controlled high-side switch control means;, With The high-side switch control means includes: It controls the electric operation and the power generation operation of the AC rotating electric machine.
In controlling the power generation operation, the potential of the connection point
The high side switch of the phase higher than the battery potential
ON before the phase where the potential of the connection point is lower than the ground potential.
Turn on the low side switch Orthogonality characterized by
Conversion device.