JPH08107672A - Three phase/two phase converter circuit - Google Patents

Abstract

PURPOSE: To lessen the number of expensive insulating transformers or insulating amplifiers to be used in a three phase/two phase converter circuit used for the primary flux operation of the hybrid device of an engine and an induction motor, and to simplify its arithmetic circuit. CONSTITUTION: The potential of the first phase w out of three-phase AC voltages is used as a reference potential. The linear voltage Vvw between the second phase v and the first phase w, and the linear voltage Vwu between the first phase w and the third phase u are inputted to an arithmetic circuit through insulating transformers respectively, and specified calculation is performed by the arithmetic circuit to output two phase AC voltages Vd and Vq meeting at right angles.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a three-phase / two-phase conversion circuit,
In particular, it relates to a three-phase / two-phase conversion circuit that is indispensable for primary magnetic flux calculation of an engine / induction motor hybrid device.

In a hybrid device in which an engine and a three-phase induction motor are combined, a direct torque control type three-phase induction motor is used to transfer energy between the engine and the three-phase induction motor to rotate the same. I'm trying to control. At that time, a three-phase / two-phase conversion circuit is indispensable for the primary magnetic flux calculation of the direct torque control type inverter. The present invention relates to this three-phase / two-phase conversion circuit.

[0003]

2. Description of the Related Art FIG. 11 is a diagram showing a conventional example and shows an example of a conventional three-phase / two-phase conversion circuit.

As shown in the figure, in the conventional three-phase / two-phase conversion circuit, the voltages Vu, Vv, and Vw of each phase are detected, and these are input to the arithmetic circuit via an insulating transformer.
The arithmetic circuit performs a predetermined arithmetic operation and outputs the two-phase voltages Vd and Vq which are orthogonal to each other.

[0005]

In the conventional three-phase / two-phase conversion circuit shown in FIG. 11, the voltages Vu, Vv, and Vw of each phase are detected, and these are input to an arithmetic circuit via an insulating transformer. Therefore, three expensive isolation transformers are required. Therefore, there is a problem that the price of the device incorporating the three-phase / two-phase conversion circuit is increased.

Further, the voltages Vu, Vv, and Vw of each phase
There is also a problem that the arithmetic circuit becomes complicated because the arithmetic is performed using. The present invention solves the above problems,
A three-phase / two-phase conversion circuit that can reduce the number of expensive isolation transformers and simplify the arithmetic circuit, especially the three-phase / two-phase converter used for the primary magnetic flux calculation of the engine / induction motor hybrid device. It is an object to provide a two-phase conversion circuit.

[0007]

In order to achieve the above object, the present invention is configured as follows. (1) A circuit for converting a three-phase AC voltage into a two-phase AC voltage, wherein the potential of the first phase of the three-phase AC voltage is used as a reference potential, and the line voltage between the second phase and the first phase, and Phase 3-First
The line voltage between phases is input to an arithmetic circuit through an insulating transformer or an insulating amplifier, respectively, and a predetermined arithmetic operation is performed by the arithmetic circuit to output two-phase AC voltages orthogonal to each other.

(2) A circuit for converting a three-phase alternating current into a two-phase alternating current, in which the first-phase current and the third-phase current of the three-phase alternating current are respectively isolated by an insulating transformer or an insulating amplifier. It is configured such that it is input to the arithmetic circuit via the arithmetic circuit and a predetermined arithmetic operation is performed by the arithmetic circuit to output two-phase alternating currents orthogonal to each other.

(3) In an engine / induction motor hybrid device in which an engine and an induction motor are coupled, a rotating magnetic flux (primary interlinkage magnetic flux) is applied to a three-phase winding of a three-phase induction motor by combining switching elements. The inverter unit to generate and the instantaneous input voltage and current of the three-phase induction motor are converted into two-phase voltage and two-phase current which are orthogonal to each other by the three-phase / two-phase conversion circuit, and the primary flux linkage vector And a calculation circuit for calculating the instantaneous torque,
The maximum and minimum values of the predetermined primary interlinkage magnetic flux, the area of the predetermined magnetic flux declination, the types of forward rotation, stop, and reverse rotation of the torque are used as elements, and the switching voltage pattern of the inverter is stored as data. The switching table is accessed based on the switching table being operated, the primary interlinkage magnetic flux vector and the instantaneous torque output from the arithmetic circuit, and the primary interlinkage magnetic flux command and the torque command of the target value, and the inverter is accessed. In the engine / induction motor hybrid device equipped with a switching pattern selection circuit for selecting the switching voltage pattern of the
The three-phase / two-phase conversion circuit described in (1) and (2) above is used for the two-phase conversion circuit.

[0010]

The three-phase / two-phase conversion circuit according to the present invention includes a circuit for converting a three-phase AC voltage into a two-phase AC voltage and a circuit for converting a three-phase AC current into a two-phase AC current.

A circuit for converting a three-phase AC voltage into a two-phase AC voltage uses a potential of the first phase of the three-phase AC voltage as a reference potential, a line voltage between the second phase and the first phase, and a third phase. -First
Detect the line voltage between phases. The detected line voltage between the second phase and the first phase, and the line voltage between the third phase and the first phase are
Each is input to the arithmetic circuit via an insulating transformer or an insulating amplifier, and the arithmetic circuit performs a predetermined arithmetic operation to output two-phase AC voltages orthogonal to each other.

The circuit for converting the three-phase AC current into the two-phase AC current detects the first-phase current and the third-phase current of the three-phase AC current. The detected first-phase current and third-phase current are input to an arithmetic circuit via an insulating transformer or an insulating amplifier, respectively, and a predetermined arithmetic operation is performed by the arithmetic circuit to output mutually orthogonal two-phase alternating currents. .

As described above, in the three-phase / two-phase conversion circuit according to the present invention, a circuit for converting a three-phase AC voltage into a two-phase AC voltage and a circuit for converting a three-phase AC current into a two-phase AC current. , Both require only two isolation transformers or amplifiers. Therefore, it is possible to reduce the number of expensive isolation transformers or isolation amplifiers used.

Further, in the three-phase / two-phase conversion circuit according to the present invention, since there are two input elements to the arithmetic circuit, the structure of the arithmetic circuit can be simplified. The principle of the present invention will be described below.

In the three-phase / two-phase conversion circuit shown in FIG. 11 as a conventional example, the voltages Vu, Vv, and Vw of each phase are detected, and the detected voltages Vu, Vv, and Vw of each phase are respectively isolated by an insulating transformer. The amplified signal is input to an arithmetic circuit and subjected to a predetermined arithmetic operation to obtain two-phase voltages Vd and Vq which are orthogonal to each other.
Was being output.

Similarly for the three-phase current, the two-phase current Id
And Iq were output. The arithmetic circuit performed the following arithmetic operations.

[0017]

[Equation 1]

The following relational expression holds between the phase voltage / line voltage. Vu + Vv + Vw = 0 Vuv + Vvw + Vwu = 0 Vvw = Vv−Vw Vwu = Vw−Vu Substituting these relational expressions into Equations (2) and (3),
When the line voltages Vvw and Vwu are arranged, the following equations (7) and (8) are obtained.

The following relational expression holds between the line currents. Iu + Iv + Iw = 0 By substituting this relational expression into Expressions (4) and (5) to eliminate Iv, the following Expressions (9) and (10) are obtained.

[0020]

[Equation 2]

Equations (7) and (8) are the line voltage Vvw
And Vwu, the two-phase voltages Vd and Vq are obtained. Also, equations (9) and (10) are
It is shown that the two-phase currents Id and Iq are obtained from the line currents Iu and Iw. In the arithmetic circuit of the three-phase / two-phase conversion circuit according to the present invention, equations (7) and (8) and equations (9) and (10) are executed.

[0022]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, showing an example of a three-phase / two-phase conversion circuit according to the present invention, particularly a circuit for converting a three-phase AC voltage into a two-phase AC voltage. It is a figure.

An embodiment of the present invention will be described with reference to FIG. Of the three-phase AC voltage, the w-phase voltage is used as the reference voltage. Then, the w-phase to v-phase line voltage Vvw and the u-phase to w-phase line voltage Vwu are detected. The detected line voltages Vvw and Vwu are input to the arithmetic circuit via an insulating transformer or an insulating amplifier, respectively.

The arithmetic circuit outputs two-phase voltages Vd and Vq which are orthogonal to each other from the line voltages Vvw and Vwu according to the above equations (7) and (8). Also,
Two-phase currents Id and Iq that are orthogonal to each other are output from the line currents Iu and Iw according to the expressions (9) and (10).

Next, an example in which the three-phase / two-phase conversion circuit according to the present invention is applied to an engine / induction motor hybrid device will be described. FIG. 2 is a diagram showing the entire engine / induction motor hybrid device.

In the figure, 1 is an engine, 2 is a three-phase induction motor, 3 is an inverter section, 4 is a current-voltage sensor, and 5
Is an inverter control circuit, 6 is an arithmetic circuit, 7 is a switching pattern selection circuit, 8 is a switching table, 9 is a system computer, 10 is a tachometer, 11 is a battery, 12 is a braking resistance control circuit, 13 is a switching element, and 14 is a resistor. It is a vessel.

The engine 1 is connected to a three-phase induction motor 2, and energy is transferred between the engine 1 and the three-phase induction motor 2. The three-phase induction motor 2 is a torque direct control induction motor controlled by a switching pattern formed by the switching elements Sa0 to Sc1 in the inverter unit 3.

The inverter unit 3 includes a switching element Sa.
A three-phase AC voltage is supplied to the three-phase induction motor 2 according to a switching pattern formed by 0 to Sc1 to generate a rotating magnetic flux in the three-phase winding of the three-phase induction motor 2. At that time, the instantaneous current and the instantaneous voltage flowing through the three-phase induction motor 2 are detected by the current / voltage sensor 4, and the instantaneous current and the instantaneous voltage are input to the inverter control circuit 5.

The inverter control circuit 5 includes an arithmetic circuit 6, a switching pattern selection circuit 7, and a switching table 8. The arithmetic circuit 6 determines the primary interlinkage flux vector of the three-phase induction motor 2, that is, the magnitude of the primary interlinkage vector and the primary interlinkage flux based on the instantaneous current and the instantaneous voltage detected by the current-voltage sensor 4. Calculate the vector angle (magnetic flux declination angle) and the instantaneous torque respectively.

The switching pattern selection circuit 7 has a magnitude of the primary interlinkage magnetic flux vector obtained by the arithmetic circuit 6, an angle of the primary interlinkage magnetic flux vector, an instantaneous torque, and three phases given from the system computer 9. The switching voltage to be set in the inverter unit 3 by accessing the switching table 8 so that the target value is within a certain error range from the primary interlinkage magnetic flux command and the torque command that are the target values of the induction motor 2. Select a pattern.

The switching table 8 has a predetermined maximum value φmax and minimum value φmi of the primary interlinkage magnetic flux.
The switching voltage pattern of the inverter unit 3 is stored as data with n, a region of a predetermined magnetic flux deviation angle, and types of normal rotation, stop, and reverse rotation of torque as elements.

The system computer 9 has information on the rotating magnetic field, that is, frequency, obtained from the inverter control circuit 5, particularly the arithmetic circuit 6, gear position information from the tachometer 10 attached to the three-phase induction motor 2, engine rotation information, and Is the information when the accelerator or brake is stepped on, the information when the starter switch or retarder switch is turned on, and the respective targets of the primary flux linkage command and torque command corresponding to the state of the engine 1 at that time. The value is output to the inverter control circuit 5.

Further, the system computer 9 is supplied with information about the voltage and current of the battery in order to monitor the state of charge of the battery 11 so that the battery 11 will not be over-discharged or over-charged. , Is protected through the control of the system computer 9.

The braking resistance control circuit 12 turns on / off the switching element 13 based on a signal from the system computer 9 when the brake is depressed, for example.
Generate an M signal. At this time, the three-phase induction motor 2 is operated as a generator, and its electromotive force is sent back to the power source side. That is, when viewed from the engine 1 side, the three-phase induction motor 2
Becomes a heavy load, and the electromotive force becomes regenerative braking (resistive braking) consumed by the resistor 14. Therefore, the braking action is supported.

When starting the engine 1, when the starter switch closing information is input to the system computer 9, the target values of the primary interlinkage magnetic flux command and the torque command for starting the engine are output to the inverter control circuit 5. The inverter unit 3 supplies the three-phase AC voltage for generating the rotating magnetic flux to the three-phase induction motor 2 while changing the switching voltage pattern to be set in the inverter unit 3 every moment according to the starting state of the engine 2.

When the engine 1 is started and brought into a constant speed rotation state, the three-phase induction motor 2 is operated as an induction generator, that is, an alternator, and its generated voltage serves as a power source for other electric components and also drives the inverter section 3. Through battery 1
Charge 1

When the brake is stepped on, the brake information is input to the system computer 9, and the primary chain for decelerating the engine 1 from the system computer 9 to the inverter control circuit 5 via the three-phase induction motor 2. The target values of the magnetic flux command and the torque command are output. The three-phase induction motor 2 is calculated based on the target interlinkage magnetic flux command and the torque command, the magnitude and angle of the primary interlinkage magnetic flux vector obtained by the arithmetic circuit 6, and the instantaneous torque.
A switching voltage pattern that coincides with the target value torque command is selectively set in the inverter unit 3 every moment, whereby the three-phase induction motor 2 performs a braking action.

On the contrary, when the accelerator is depressed, the three-phase induction motor 2 is operated so that the torque increases. Therefore, in addition to the acceleration of the engine 1 side itself, the acceleration of the engine 1 is also supported from the three-phase induction motor 2 side.

FIG. 3 is a diagram showing a detailed structure of the engine / induction motor hybrid device. In the figure, 2
Is a three-phase induction motor, 3 is an inverter unit, 4-1 is a voltage sensor, 4-2 is a current sensor, 6 is an arithmetic circuit, 9 is a system computer, 11 is a battery, 16-1 and 16
-2 is a three-phase / two-phase converter, 17-1 and 17-2 are multipliers, 18-1 and 18-2 are subtractors, 19-1 and 19-2 are integrators, and 20 is an absolute value calculator. , 21-1 and 21-2 are multipliers, 22 is a subtractor, 23 is a magnetic flux declination calculator, 24 is a magnetic flux comparator, and 25 is a torque comparator.

The switch Sa of the inverter unit 3 corresponds to the switching elements Sa0 and Sa1 of FIG. 2, and when the switch Sa is on with the contact 0, the switching element Sa0 of FIG. 2 is on and the switch Sa is on. Is ON with the contact 1, the switching element Sa1 of FIG.
Corresponds to the ON state. Other switch S
Similarly to the above, b and Sc correspond to the respective states of the switching elements Sb0 to Sc1 in FIG.

The voltage sensor 4-1 has two instantaneous voltages between phases,
For example, the interphase voltage Vvw between the v phase and the w phase and the interphase voltage Vwu between the w phase and the u phase are detected, and the current sensor 4-2 is detected.
Detects two instantaneous currents Iu and Iw. Then, the corresponding three-phase / two-phase converter 16-1 is provided.
And 16-2 respectively perform three-phase / two-phase conversion.

Three-phase / two-phase converters 16-1 and 16-2
The three-phase / two-phase conversion circuit according to the present invention is used for.
That is, the circuit for converting the three-phase AC voltage according to the present invention into the two-phase AC voltage is used for the three-phase / two-phase converter 16-1, and the three-phase / two-phase converter 16-2 includes the circuit. A circuit for converting a three-phase alternating current according to the invention into a two-phase alternating current is used.

Here, the rotating magnetic flux vector Φ of the three-phase induction motor 2 due to the three-phase sinusoidal voltage is generally as shown in FIG. 4 when the direct-axis and the horizontal-axis magnetic fields are shown in orthogonal coordinates. Vd and Vq are obtained in the three-phase / two-phase conversion of the phase / two-phase converter 16-1, and id and iq are obtained in the three-phase / two-phase conversion of the three-phase / two-phase converter 16-2.

Id and iq thus obtained
Is multiplied by the primary constant R1 in multipliers 17-1 and 17-2, respectively, and Vd-R1.id and Vq-R1.iq are calculated in subtractors 18-1 and 18-2, respectively. Furthermore, the integrator 19-1 provided correspondingly
And 19-2, respectively, to obtain Φd and Φq.

Based on Φd and Φq thus obtained, the absolute value calculator 20 calculates the absolute value of the magnitude of the primary interlinkage magnetic flux to obtain √ (Φd ² + Φq ² ). In addition, in the corresponding multipliers 21-1 and 21-2, id and iq obtained from the three-phase / two-phase converters 16-1 and 16-2
To obtain Φ · id and Φ · iq, and then the subtractor 22 calculates the calculated torque T, that is, Φ ·
Obtain an instantaneous torque of iq-Φ · id.

Further, in the magnetic flux declination calculator 23, the integrator 19
Φd and Φq obtained from −1 and 19-2, and
Absolute value of primary interlinkage magnetic flux obtained from logarithmic value calculator 20
(Φd ²+ Φq²) And the magnetic flux deviation angle is obtained.

In this way, 1 obtained by the arithmetic circuit 6 is obtained.
From the next interlinkage magnetic flux vector and the instantaneous torque, and the target interlinkage magnetic flux command Φ * and the torque command T *, which are the target values of the three-phase induction motor 2 given from the system computer 9, via the switching pattern selection circuit 7. A process of reading the data stored in the switching table 8 is performed.

That is, the magnetic flux comparator 24 compares the target value of the primary interlinkage magnetic flux command Φ * with the absolute value √ (Φd ² + Φg ² ) of the primary interlinkage magnetic flux obtained from the absolute value calculator 20. Then, the magnetic flux deviation | Φ | is obtained, and the torque comparator 25 compares the target value of the torque command T * with the calculated torque T obtained from the absolute value calculator 20, that is, Φ · iq−Φ · id. The torque deviation is obtained.

Based on the magnetic flux deviation | Φ |, the torque deviation, and the magnetic flux deviation angle calculated by the magnetic flux deviation angle calculation circuit 23 of the arithmetic circuit 6, the switching table 8 is accessed to set the switching voltage to the inverter unit 3. Read the pattern.

FIG. 5 is an explanatory view of an embodiment of ROM address generation, FIG. 6 is a storage diagram of an embodiment of ROM address / data,
FIG. 7 is a storage diagram of an embodiment of ROM data, FIG. 8 is an explanatory diagram of rotation magnetic flux vector generation, FIG. 9 is an explanatory diagram of application of a switching voltage pattern, and FIG. 10 is an explanatory diagram of a relationship between a switching voltage vector and a switching voltage pattern.

In the switching voltage pattern application diagram shown in FIG. 9, a voltage is applied from the battery 11 to the three-phase induction motor 2 in the form of a switching voltage pattern vi (Sa, Sb, Sc). Sa, Sb, and Sc indicate the states of the switches, for example, the switches Sa, S
When each contact of b and Sc is connected to the 0 side, 0 side, and 1 side, respectively, the switching voltage pattern is v ₁ (0,
It is expressed as 0, 1). At this time, the switching voltage pattern v ₁ (0, 0, 0) is applied to the three-phase winding of the three-phase induction motor 2.
The voltage corresponding to 1) is applied from the battery 11, and the magnetic flux of the switching voltage vector V1 is generated. this is,
This corresponds to the switching voltage vector V1 in the direction shown in the center of FIG.

The other switching voltage vectors V2 to V6 shown in FIG. 10 have the same meaning, and the switching voltage patterns vi (Sa, Sb, Sc) have three switching states Sa, Sb, Sc. Accordingly, switching voltage vectors V2 to V6 in the directions shown in the central portion of FIG.
Each magnetic flux is generated. Switching voltage pattern v
₀ (0,0,0) and v switching voltage vectors V0 and V7 when the ₇ (1,1,1) is a zero vector, does not generate magnetic flux.

The switching voltage vector V1
The magnetic flux declination to which V6 belongs is divided into six regions in advance as shown in FIG. 8, and the region θ of the switching voltage vector V1 is 5, the region θ of the switching voltage vector V2 is 3, and the region θ of the switching voltage vector V3. 4, the area θ of the switching voltage vector V4 is defined as 1, the area θ of the switching voltage vector V5 is 6, and the area θ of the switching voltage vector V6 is defined as 2.

In the rotational flux vector generation diagram of FIG. 8, the maximum value φmax and the minimum value φmi of the primary interlinkage magnetic flux are shown.
n is preset. For example, now the primary flux linkage Φ
Has a magnetic flux deviation angle in the region θ = 6, and is in the forward rotation, that is, in the clockwise direction, and the switching voltage vector V6
When rotating under the control of the setting of the switching voltage pattern of the inverter unit 3 in which the magnetic flux is generated, the tip thereof rotates along the switching voltage vector V6.

The primary interlinkage magnetic flux Φ has a region θ =
Maximum value φmax of the primary interlinkage magnetic flux determined in advance by A of 1
Trying to be above. At this time, by switching the switching voltage pattern of FIG. 9 to v ₂ (0,1,0), a magnetic flux due to the switching voltage vector V2 is generated in the three-phase winding of the three-phase induction motor 2, and the primary interlinkage magnetic flux is generated. The tip of Φ rotates along the switching voltage vector V2.

The primary interlinkage magnetic flux Φ has a region θ =
The minimum value φmin of the primary interlinkage magnetic flux determined in advance by B of 1
When it is about to become below, the magnitude of the primary interlinkage magnetic flux becomes a predetermined maximum value φmax of the primary interlinkage magnetic flux by appropriately switching the switching voltage pattern vi (Sa, Sb, Sc) in FIG. It can be set within the minimum value φmin, and the magnitude of the primary interlinkage magnetic flux can generate a rotating magnetic flux vector forming a substantially constant circle.

When the calculation torque T of the calculation circuit 6 exceeds the target value of the torque command T *, the switching voltage vectors V0 and V7, that is, the zero vectors V0 and V7 are selected. That is, the switching voltage pattern v ₀ (0,
0,0), v ₇ (1,1,1).

As described above, the maximum value φmax and the minimum value φmi of the primary interlinkage magnetic flux whose magnitudes are predetermined are set.
The switching table 8 stores data for switching the switching voltage pattern so that it falls within n.

The switching table 8 is R shown in FIG.
The OM address / data storage diagram of one embodiment and the ROM data storage storage diagram of FIG. 7 are provided, and the ROM address / data storage storage diagram of FIG. An example of ROM address generation shown in FIG. 5 is accessed by generation of the addresses shown in the explanatory diagram.

In the ROM address explanatory view shown in FIG. 5, the ROM address is represented by two hexadecimal digits, and the upper digit is four.
Two bits of A5 and A4 among the bits give torque T, that is, "00" for forward rotation, "01" for stop, and "11" for reverse rotation. The lower digit is A3 or A out of 4 bits
The area θ of the primary interlinkage magnetic flux in 3 bits of 2, A1 and 1 of A0
A predetermined maximum value φmax of the primary flux linkage in bits
The above and the minimum value φmin or less are given. That is, A
3, A2 and A1 are "011" and the area θ is 1, "010"
Area θ = 2, “000” area θ = 3, “001” area θ = 4, “101” area θ = 5, “111” area θ = 6, and 1-bit A0 is When the primary interlinkage magnetic flux is 0 or less and is less than or equal to the predetermined minimum value of the primary interlinkage magnetic flux φmin, the primary interlinkage magnetic flux is A0 is “1” and the primary interlinkage flux is the predetermined primary interlinkage flux. Each of the cases represents a case where the maximum value φmax of the above is about to be exceeded.

In the ROM address / data explanatory diagram shown in FIG. 6, the upper side of the diagonal line of each frame surrounded by the thick frame is shown in FIG.
Represents the hexadecimal two-digit address generated below, and the lower part of the diagonal line represents the hexadecimal two-digit address for accessing the ROM data of FIG. 7 described next.

In the ROM data explanatory view shown in FIG. 7,
The ROM data is the switching voltage pattern vi (Sa, Sb, Sc) using the 2-digit hexadecimal data obtained from the ROM address / data as an address, as described in the ROM address / data explanatory diagram of FIG. Read out. That is, among the 8 bits of D7 to D0, the upper 2 to 4 bit bits D6, D5, D4 represent the switching voltage pattern vi (Sa, Sb, Sc), the D6 bit is the contact state of the switch Sa, and the D5 bit is Switch Sb
, And the D4 bit represents the contact state of the switch Sc.

For example, the primary flux linkage Φ is now in the region θ = 6 as shown in the rotational flux vector generation explanatory diagram shown in FIG. 8, and the inverter is controlled so that the magnetic flux of the switching voltage vector V6 is generated. It is assumed that the switching voltage pattern of the unit 3 is set.

The magnitude of the primary interlinkage magnetic flux Φ, that is, the tip of the primary interlinkage magnetic flux Φ is the switching voltage vector V6.
Rotate along. Then, the tip of the primary interlinkage magnetic flux Φ tends to become larger than a predetermined maximum value φmax of the primary interlinkage magnetic flux Φ. At this time, in the switching table 8, as described with reference to FIG. 5, the torque T is forwardly rotated, the region θ is 1, and the tip of the primary interlinkage magnetic flux Φ is equal to or larger than the predetermined maximum value φmax of the primary interlinkage magnetic flux. The bit of A5, A4 is "00", A3, A
2, A1 bit is "011", A0 bit is "1",
That is, the address "07" is generated by the hexadecimal two digits "000111".

The ROM address / data shown in FIG. 6 is accessed by the address "07", and the data "20" is read out. Then, the ROM data of FIG. 7 is accessed by using this data "20" as an address, and the data "0"
"0100000" is read. Top 2 of this data
4 bits represent the switching voltage pattern v ₂ , and the switching voltage pattern v ₂ is set in the inverter unit 3. As a result, the magnetic flux of the switching voltage vector V2 is generated in the three-phase winding of the three-phase induction motor 2,
The magnitude of the primary interlinkage magnetic flux Φ, that is, the tip of the primary interlinkage magnetic flux Φ rotates positively along the switching voltage vector V2.

Then, the tip of the primary interlinkage magnetic flux Φ tends to become smaller than a predetermined minimum value φmin of the primary interlinkage magnetic flux. At this time, in the switching table 8, as described with reference to FIG.
From the state in which the tip of the primary interlinkage magnetic flux is going to become smaller than the predetermined minimum value φmin of the primary interlinkage magnetic flux,
A5, A4 bits are "00", A3, A2, A1 bits are "011", A0 bits are "0", that is, "0001".
An address of "06" is generated by the hexadecimal two digits of "10".

The ROM address / data shown in FIG. 6 is accessed by the address "06", and the data "60" is read out. Then, the ROM data of FIG. 7 is accessed by using this data "60" as an address, and the data "01100000" is read. The upper 2 to 4 bits of this data represent the switching voltage pattern v ₆ , and the switching voltage pattern v ₆ is set in the inverter unit 3. As a result, a magnetic flux of the switching voltage vector V6 is generated in the three-phase winding of the three-phase induction motor 2, and the magnitude of the primary interlinkage magnetic flux Φ, that is, the primary interlinkage magnetic flux Φ.
The tip of the positive rotation rotates in the normal direction along the vector V6.

By performing the switching control of the switching voltage pattern of the inverter unit 3 as described above, the magnitude of the primary interlinkage magnetic flux Φ has a predetermined maximum value φmax and minimum value of the primary interlinkage magnetic flux. It becomes possible to generate a substantially circular rotating magnetic flux, that is, a primary interlinkage magnetic flux vector, which is contained between φmin and φmin, in the three-phase winding of the three-phase induction motor 2.

[0069]

According to the present invention, in a three-phase / two-phase conversion circuit, the number of expensive insulating transformers or insulating amplifiers used can be reduced and the arithmetic circuit can be simplified.

Further, by applying the three-phase / two-phase conversion circuit according to the present invention to the primary magnetic flux calculating circuit of the engine / induction motor hybrid device, the cost of the device is further reduced. Produce an effect.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an entire engine / induction motor hybrid device.

FIG. 3 is a diagram showing a detailed configuration of an engine / induction motor hybrid device.

FIG. 4 is an explanatory diagram of a rotating magnetic flux vector.

FIG. 5 is an explanatory diagram of an embodiment of ROM address generation.

FIG. 6 is a storage diagram of an embodiment of ROM address / data.

FIG. 7 is a storage diagram of an example of ROM data.

FIG. 8 is a diagram illustrating the generation of a rotating magnetic flux vector.

FIG. 9 is an explanatory diagram of application of a switching voltage pattern.

FIG. 10 is an explanatory diagram of a relationship between a switching voltage vector and a switching voltage pattern.

FIG. 11 is a diagram showing a conventional example.

[Explanation of reference signs] 1 engine 2 three-phase induction motor 3 inverter unit 4 current voltage sensor 4-1 voltage sensor 4-2 current sensor 5 inverter control circuit 6 arithmetic circuit 7 switching pattern selection circuit 8 switching table 9 system computer 10 tachometer 11 Battery 12 Braking resistance control circuit 13 Switching element 14 Resistor 16-1 Three-phase / two-phase converter 16-2 Three-phase / two-phase converter 17-1 Multiplier 17-2 Multiplier 18-1 Subtractor 18-2 Subtractor 19-1 Integrator 19-2 Integrator 20 Absolute value calculator 21-1 Multiplier 21-2 Multiplier 22 Subtractor 23 Flux declination calculator 24 Flux comparator 25 Torque comparator

Claims (3)

[Claims] 1. A circuit for converting a three-phase AC voltage into a two-phase AC voltage, wherein a potential of the first phase of the three-phase AC voltage is used as a reference potential, and a line voltage between the second phase and the first phase, And the line voltage between the third phase and the first phase are input to an arithmetic circuit via an insulating transformer or an insulating amplifier, respectively, and predetermined arithmetic operations are performed by the arithmetic circuit to output two-phase AC voltages orthogonal to each other. A characteristic three-phase / two-phase conversion circuit. 2. A circuit for converting a three-phase alternating current into a two-phase alternating current, wherein a first-phase current and a third-phase alternating current of the three-phase alternating current are used.
Phase currents are input to an arithmetic circuit via an isolation transformer or an isolation amplifier, respectively, and predetermined arithmetic operations are performed by the arithmetic circuit to output two-phase alternating currents that are orthogonal to each other. Conversion circuit. 3. An engine / induction motor hybrid device in which an engine and an induction motor are coupled to each other, wherein a rotating magnetic flux (primary interlinkage magnetic flux) is generated in a three-phase winding of a three-phase induction motor by combining switching elements. The inverter unit and the instantaneous input voltage and current of the three-phase induction motor are converted by the three-phase / two-phase conversion circuit into two-phase voltages and two-phase currents that are orthogonal to each other, and the primary interlinkage magnetic flux vector and An inverter that calculates the instantaneous torque, the maximum and minimum values of the predetermined primary interlinkage magnetic flux, the region of the predetermined magnetic flux declination angle, the types of normal rotation, stop, and reverse rotation of the torque. A switching table that stores the switching voltage pattern of the part as data, the primary interlinkage magnetic flux vector and the instantaneous torque output by the arithmetic circuit, In an engine / induction motor hybrid device including a switching pattern selection circuit that accesses the switching table and selects a switching voltage pattern of the inverter unit based on a standard primary interlinkage magnetic flux command and a torque command, An engine / induction motor hybrid device, wherein the three-phase / two-phase conversion circuit uses the three-phase / two-phase conversion circuit according to claim 1 or 2.