WO2016157386A1

WO2016157386A1 - Starting power generation device and starting power generation method

Info

Publication number: WO2016157386A1
Application number: PCT/JP2015/059997
Authority: WO
Inventors: 達也新井
Original assignee: 新電元工業株式会社
Priority date: 2015-03-30
Filing date: 2015-03-30
Publication date: 2016-10-06

Abstract

A starting power generation device comprising: a starter generator comprising a field section and an armature unit, said field section comprising a permanent magnet and said armature unit having a winding section comprising a multi-phase coil; an orthogonal converter having an AC terminal and converting power in both directions between DC and AC; and a plurality of switching elements interposed between the AC terminal and the winding section and connecting and disconnecting the winding section to/from the AC terminal.

Description

STARTING POWER GENERATION DEVICE AND STARTING POWER GENERATION METHOD

The present invention relates to a starting power generation device and a starting power generation method.

2. Description of the Related Art Conventionally, in a vehicle, particularly a small two-wheeled vehicle, an ACG (alternating current generator) starter motor (starting generator) that functions as a starter motor when the engine starts and also functions as a generator after the engine starts (for example, Patent Document 1). Patent Document 2 and Patent Document 3).

This ACG starter motor includes a permanent magnet that forms a field and is designed so that the winding specifications of the armature satisfy the torque characteristics required when starting the engine (Patent Document 1 and Patent Document 2). ). In such a configuration, the ACG starter motor is used as a generator as it is, and the amount of power generation exceeds the amount of power required for the electrical load, and surplus power is generated. Further, in such an ACG starter motor, a method is used in which the generated power is suppressed by short-circuit control of the semiconductor elements constituting the rectifier circuit. In this system, the current that flows back through the ACG starter motor flows through the armature winding of the ACG starter motor and the power device element that drives the ACG starter motor. As well as worsening engine friction. For this reason, in the configurations described in Patent Document 1 and Patent Document 2, a plurality of armature windings of the ACG starter motor are provided in parallel to be used as an ACG starter motor and as a generator. Control to switch the armature winding is performed.

JP 2003-83209 A Japanese Patent No. 4851844 Japanese Patent No. 4329527

However, the configurations described in Patent Document 1 to Patent Document 3 have the following problems. First, in the configuration described in Patent Document 1, the armature winding is formed by four windings connected in parallel, but one of the three phases is commonly connected in all windings. Yes. That is, the winding used as the ACG starter motor and the winding used as the generator are connected to a common node and are not completely separated. The winding is selected by a relay. For this reason, the use of the relays frequently turned on and off, such as idle stop control, has a problem of reducing contact life. Further, in the configuration in which one phase of each winding is connected in common, the following points become problems when the relay is replaced with a MOSFET (metal oxide field effect transistor). In other words, the relay can cut off the current in both directions by turning off the contact, but even if the MOSFET is turned off, the current flows through the parasitic diode between the drain and source, so that the current can only be cut in one direction. Can not. For this reason, when a MOSFET is used instead of a relay to separate the windings, the windings used as the ACG starter motor are not separated and the generated power is supplied from the windings of the ACG starter motor. The problem is that the power is excessively supplied and the power loss increases.

In the configuration described in Patent Document 2, the neutral point is controlled and can be used only when the armature winding is a star connection, and when the armature winding is a delta connection. There is a problem that it cannot be dealt with. If a combination with a delta-connected armature winding having no neutral point is considered, the number of individual relays increases, resulting in problems of high cost and complicated wiring.

In the configuration described in Patent Document 3, the ACG starter motor is composed of two armature windings. When used as an ACG starter motor, only one armature winding is used and used as a generator. When used, two windings are used. In addition, unlike the configurations described in Patent Document 1 and Patent Document 2, in the configuration described in Patent Document 3, the field is configured using windings. In this configuration, a current is normally applied to the field winding using a brush. Compared with the case where the field is configured using a permanent magnet, the configuration described in Patent Document 3 is difficult to reduce the size of the device, and as shown in Patent Document 2, it can be directly attached to the crankshaft. There is a problem that it is not suitable.

It is an object of the present invention to provide a starting power generation device and a starting power generation method that can solve the above-described problems.

The present invention is a starter generator, and includes a starter generator having an armature part having a winding part made of a multiphase coil and a field part made of a permanent magnet, an AC terminal, and a direct current and an alternating current A plurality of switch elements that are inserted between the AC terminal and the winding part, and connect and disconnect the winding part with respect to the AC terminal. It is characterized by providing.

The present invention is also a starting power generation method, a starting generator having an armature portion having a winding portion made of a multiphase coil, and a field portion made of a permanent magnet, an AC terminal, and a direct current And a plurality of orthogonal transform units that convert electric power bidirectionally between the AC and the AC terminal and the winding unit, and a plurality of connecting and separating the winding unit with respect to the AC terminal A starter generator including a switch element includes a step of controlling the plurality of switch elements to be turned on or off.

According to the present invention, it is possible to easily improve the control characteristics of the starter generator such as reduction of power loss.

It is the block diagram which showed the example of a structure of one Embodiment of this invention. It is the figure which showed typically the example of a structure of the starter generator 1 shown in FIG. FIG. 2 is a circuit diagram illustrating a power conversion unit 6 and a winding unit 11 illustrated in FIG. 1. It is the figure which showed an example of the electricity supply mode of the power converter part shown in FIG. It is the figure which showed an example of the flow of the electric current in the circuit diagram shown in FIG. It is the figure which showed an example of the electricity supply mode of the power converter part shown in FIG. FIG. 7 is a timing chart showing a change over time in the energization mode shown in FIG. 6. FIG. 4 is a timing diagram illustrating an example of operation waveforms in the circuit diagram illustrated in FIG. 3. It is a characteristic view for demonstrating the operation example of the starting electric power generation control system 100 shown in FIG. It is the figure which showed an example of the electricity supply mode of the power converter part shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a starting power generation control system (starting power generation apparatus) 100 according to an embodiment of the present invention. A starting power generation control system 100 shown in FIG. 1 includes a starting generator (ACG starter motor) 1, an engine 2, a crankshaft 3, a rotation angle sensor 4, an engine water temperature gauge 5, a power converter 6, A control unit 7, a starter switch 8, and a battery 9 are included.

The starter generator 1 is directly connected to the crankshaft 3 and rotates in synchronization with the rotation of the engine 2. The starter generator 1 operates as a starter motor or operates as an ACG under the control of the power conversion unit 6. The starter generator 1 includes a winding part 11 and a field part 15 shown in FIG. The winding portion 11 includes

coils

11u, 11v, and 11w that constitute a star-connected three-phase coil (multi-phase coil). The neutral point 11 n is a neutral point of star connection constituting the winding portion 11. The coils 11u to 11w are armature windings wound around an armature core (not shown). The winding portion 11 and an armature core (not shown) constitute an armature portion. In addition, the coil | winding part 11 may be comprised not only by star connection but by delta connection.

FIG. 2 is a diagram schematically showing a configuration example of the winding portion 11 and the field portion 15 of the starter generator 1 as viewed from the axial direction. However, in FIG. 2, only the coil 11u for one phase of the three phases is shown. In the configuration example shown in FIG. 2, the starter generator 1 is an outer rotor type brushless motor in which the field unit 15 includes a plurality of sets of N-pole permanent magnets 15 </ b> N and S-pole permanent magnets 15 </ b> S. The coil 11u is composed of three windings arranged at intervals of 120 degrees with respect to an armature core (not shown). One end of each of the three windings of the coil 11u is commonly connected to the neutral point 11n, and the other end is commonly connected to the terminal 11u2.

On the other hand, in FIG. 1, the engine 2 is a motor mounted on, for example, a small motorcycle. The crankshaft 3 is a component part of the engine 2 and is an axis that converts a reciprocating motion of a piston (not shown) included in the engine 2 into a rotational motion. The rotation angle sensor 4 is a sensor that detects the rotation angle (crank angle) of the crankshaft 3. The engine water temperature gauge 5 is a sensor that detects the temperature of the cooling water of the engine 2.

As shown in FIG. 3, the power conversion unit 6 includes an orthogonal conversion unit 61 and a switch unit 62. The orthogonal transform unit 61 includes six n-channel MOSFETs (hereinafter referred to as MOSFETs) (Q1) to (Q6), and constitutes a three-phase bridge orthogonal transform circuit. The orthogonal transform unit 61 connects the DC terminal 614 on the positive side (high side) of the DC input / output line to the positive electrode of the battery 9 and the DC terminal 615 on the negative side (low side) to the negative electrode of the battery 9. The orthogonal transform unit 61 is connected to the battery 9 and is also connected to the winding unit 11 via the switch unit 62, and performs bidirectional power conversion between AC and DC. The

AC terminals

611, 612, and 613 of the orthogonal transform unit 61 are connected to the ends of the

coils

11 u, 11 v, and 11 w of the winding unit 11 via the switch unit 62.

The switch unit 62 includes three MOSFETs (Q7), (Q8), and (Q9). The

coils

11u, 11v, and 11w of the winding unit 11 are connected to the

AC terminals

611, 612, and 613 of the orthogonal transform unit 61, respectively. Connect to or disconnect from. In this case, the three MOSFETs (Q7), (Q8), and (Q9) are connected to the

AC terminals

611, 612, and 613 of the orthogonal transformation unit 61 and the ends of the

coils

11u, 11v, and 11w of the winding unit 11, respectively. It is inserted between the parts. The three MOSFETs (Q7), (Q8), and (Q9) are connected to the

AC terminals

611, 612, and 613 by turning on the end portions of the

coils

11u, 11v, and 11w of the winding portion 11, respectively. The

AC terminals

611, 612, and 613 are separated from each other by being connected to each other or turned off.

Further, in each MOSFET (Q7), (Q8) and (Q9), parasitic diodes D7, D8 and D9 are formed between the drain and source. In this case, the directions of the parasitic diodes D7, D8, and D9 are the same with respect to the

AC terminals

611, 612, and 613, and the anode is connected to the

AC terminals

611, 612, and 613. The cathode is connected to each end of each

coil

11u, 11v and 11w of the winding part 11. By aligning the directions of the parasitic diodes D7, D8, and D9 in this manner, when the MOSFETs (Q7), (Q8), and (Q9) are turned off, the winding unit 11 via the orthogonal transformation unit 61 in the power generation operation is used. From the current to the battery 9 can be cut off. The directions of the parasitic diodes D7, D8, and D9 (that is, the directions of the drains and sources of the MOSFETs (Q7), (Q8), and (Q9)) may be opposite to those illustrated.

The power conversion unit 6 includes a drive circuit (not shown) for on / off control of the MOSFETs (Q1) to (Q9). This drive circuit performs on / off control of the MOSFETs (Q1) to (Q9) in accordance with a predetermined energization mode instructed by the control unit 7. The power converter 6 includes a sensor for detecting the current flowing through each MOSFET. For example, when the MOSFETs (Q7) to (Q9) are switched from on to off, the current flowing through the MOSFET is zero (or almost zero). ) Can be done.

The control unit 7 shown in FIG. 1 is a device that performs ignition control and the like of the engine 2. In this case, the output signal of the rotation angle sensor 4, the output signal of the engine water temperature gauge 5, and the output signal of the starter switch 8 Enter. Further, the control unit 7 instructs a drive circuit (not shown) included in the power conversion unit 6 about the energization mode, that is, the operation state of the MOSFETs (Q1) to (Q9). For example, when the starter generator 1 is used as a starter motor that starts the engine, the control unit 7 turns on all of the MOSFETs (Q7), (Q8), and (Q9), while the starter generator 1 generates power. When used as a device, the duty ratios of the MOSFETs (Q7), (Q8), and (Q9) are changed according to the DC output voltage of the orthogonal transform unit 61. In addition, when the starter / generator 1 is used as a starter motor that starts the engine, the control unit 7 turns on the MOSFETs (Q7), (Q8), and (Q9), while the starter / generator 1 generates power. When used as a machine, each of the MOSFETs (Q7), (Q8), and (Q9) is on / off controlled based on the engine speed so as to perform either retarded angle power generation or conduction angle rectification. The retarded angle power generation and conduction angle rectification will be described later.

On the other hand, the starter switch 8 is a switch operated when the user starts the engine 2. The battery 9 is a secondary battery.

Next, with reference to FIGS. 4 to 8, an example of the operation of the starter generator 1 and the power converter 6 shown in FIG. 3 will be described. FIG. 4 is a diagram showing an example of an energization mode of the power conversion unit 6 shown in FIG. 3 when the starter generator 1 is used as a starter motor. Hereinafter, the control when the starter generator 1 is used as a starter motor is referred to as motor control. Here, each energization mode shown in FIG. 4 is a case of 180 degree energization control. FIG. 4 shows a combination of ON (ON) or OFF (OFF) operations of the MOSFETs (Q1) to (Q9) in the power converter 6. FIG. 5 is a diagram illustrating a current path in the circuit diagram illustrated in FIG. 3 in the energization mode M1 illustrated in FIG.

In the case of motor control, the control unit 7 selects one of the energization modes M1 to M6 shown in FIG. 4 and instructs the power conversion unit 6 about the selected energization mode. That is, the control unit 7 repeatedly selects one of the energization modes M1 to M6 shown in FIG. 4 according to the angle of the field unit 15 based on the output of the rotation angle sensor 4, and selects the selected energization mode each time. The power converter 6 is instructed. In this case, the MOSFETs (Q1) to (Q6) are controlled to be switched ON or OFF according to the combination of ON and OFF corresponding to the energization mode. Further, the MOSFETs (Q7) to (Q9) are all controlled to be ON.

FIG. 5 shows a current path in the energization mode M1 shown in FIG. In this case, the MOSFET (Q1) is ON, (Q2) is OFF, (Q3) is OFF, (Q4) is OFF, (Q5) is ON, and (Q6) is ON. Further, MOSFETs (Q7) to (Q9) are all ON.

Next, the energization mode of the power conversion unit 6 shown in FIG. 3 when the starter generator 1 is used as a generator will be described with reference to FIGS. Hereinafter, the control when the starter generator 1 is used as a generator is referred to as power generation control. FIG. 6 is a diagram illustrating an example of an energization mode of the power conversion unit 6 illustrated in FIG. 3 in the case of power generation control. Here, the energization mode shown in FIG. 6 includes 12 stages of stage numbers S1 to S12. 6 is associated with the control states of the MOSFETs (Q1) to (Q9) in the power conversion unit 6 and the output states of the ends of the

coils

11u, 11v, and 11w of the winding unit 11. It shows.

In the chart of FIG. 6, the output state of the winding part 11 is indicated by the magnitude relationship between the terminal voltage of each end of each

coil

11u, 11v and 11w, that is, the terminal voltage of the

AC terminals

611, 612 and 613, and the polarity. ing. Here, the terminal voltages at the ends of the

coils

11u, 11v, and 11w are indicated by Uv, Vv, and Wv, respectively. The polarity is indicated by “+” for positive and “−” for negative. For example, the U-phase voltage relationship “Uv> Wv, Vv” of the stage S2 means that the terminal voltage of the coil 11u is larger than the terminal voltages of the

coils

11v and 11w.

Also, the control state indicates a combination of on (ON) or off (OFF) or duty control (DUTY) operations of the MOSFETs (Q1) to (Q9) in the power converter 6. ON or OFF means that the MOSFET is controlled to be turned on or off during the stage. DUTY means that, for example, in the four consecutive stages, control is performed such that the ratio of the time during which it is turned on (= duty ratio) becomes a value in the range from 0% to 100%. Here, 100% means that all four stages are on. Also, 0% means that all four stages are off.

In this embodiment, the control unit 7 changes the duty ratio in the duty control of the MOSFETs (Q7) to (Q9) according to the DC output voltage of the orthogonal transform unit 61. In this case, the control unit 7 changes the duty ratio according to the comparison result between the reference value corresponding to the charging voltage of the battery 9 and the DC output voltage of the orthogonal transform unit 61 (voltage between the DC terminals 614 and 615). . The control unit 7 increases the duty ratio when the DC output voltage of the orthogonal transform unit 61 is lower than the reference value, and decreases the duty ratio when the DC output voltage is higher than the reference value. At that time, for example, the control unit 7 adjusts the time continuity state of the duty ratio so that each phase of the three-phase alternating current is not biased, or adds hysteresis to the reference value so that the output voltage is not hunted. Can be set. Further, the comparison target with the reference value may be, for example, the terminal voltage of the battery 9 instead of the voltage between the

DC terminals

614 and 615.

In the case of power generation control, the control unit 7 selects one of the stage numbers S1 to S12 shown in FIG. 6 and instructs the power conversion unit 6 of the selected stage number. That is, the control unit 7 repeatedly selects any one of the stage numbers S1 to S12 shown in FIG. 6 according to the angle of the field unit 15 based on the output of the rotation angle sensor 4, and selects the selected stage number each time. The power converter 6 is instructed. In this case, the MOSFETs (Q1) to (Q6) are controlled by switching them on or off. Further, the MOSFETs (Q7) to (Q9) are controlled by being switched ON or OFF, or are duty controlled according to the DC output voltage of the orthogonal transform unit 61.

Next, with reference to FIG. 7, the time change of each stage S1-S12 in the energization mode shown in FIG. 6 will be described. FIG. 7 is a timing chart showing a time change of the energization mode shown in FIG. FIG. 7 shows the temporal change of the terminal voltages Uv, Vv and Wv at the respective ends of the

coils

11u, 11v and 11w and the control states of the MOSFETs (Q1) to (Q9). In the control states of the MOSFETs (Q1) to (Q9), ON or OFF control is indicated by a level change (H level or L level), and a duty control period is indicated by an arrow. For example, in stage S1, MOSFETs (Q1), (Q2), (Q4), (Q6) and (Q7) are OFF, MOSFETs (Q3), (Q5) and (Q8) are ON, and MOSFET (Q9) Is the duty control state.

Next, an example of operation waveforms in the circuit diagram shown in FIG. 3 will be described with reference to FIG. FIG. 8 shows the waveform of the next part when the rotation speed (rotational speed) of the starter generator 1 is increased from 0 with the duty ratio kept constant at about 60%. That is, FIG. 8 shows the DC output voltage Vout of the orthogonal transform unit 61, the drain currents of the MOSFETs (Q1) to (Q3), the gate voltages of the MOSFETs (Q1) to (Q9), and the terminal voltages Uv, Vv and Each waveform of Wv is shown. For example, a section T1 delimited by a broken line where the current of the MOSFET (Q1) first rises corresponds to the stages S2 to S5 in FIG.

As described above, in the present embodiment, the power conversion unit 6 is interposed between the AC terminals 611 to 613 of the orthogonal conversion unit 61 and the winding unit 11, and is connected to the AC terminals 611 to 613. A plurality of MOSFETs (Q7) to (Q9) (switch elements) for connecting and separating the winding part 11 are provided. According to this configuration, when the generated power becomes excessive, the winding portion 11 can be disconnected, so that no reflux current can be generated. Therefore, generation of power loss due to heat generation can be prevented. Therefore, it is possible to easily improve the control characteristics of the starter generator such as reduction of power loss.

Further, according to the present embodiment, the switching diode for disconnecting and connecting the winding portion 11 is made by making the direction of the parasitic diodes of the MOSFETs (Q7) to (Q9) the same with respect to the AC terminals 611 to 613. Can be composed of a MOSFET having a parasitic diode.

As described above, in the present embodiment, in the case of power generation control, the orthogonal transform unit 61 is controlled based on the engine speed so as to be either retarded angle power generation or conduction angle rectification, and the MOSFET (Q7), Each of (Q8) and (Q9) can be on / off controlled. Here, the retarded angle power generation is power generation control that turns on the MOSFETs (Q1) to (Q6) constituting the orthogonal transform unit 61 by an electrical angle of 180 degrees as shown in FIG. On the other hand, conduction angle rectification is also called conduction angle rectification, and as shown in FIGS. 6 and 7, the MOSFETs (Q1) to (Q6) constituting the orthogonal transformation unit 61 are turned on by an electrical angle of 120 degrees. It is power generation control. At this time, the ON period for each phase corresponds to the period in which the voltage of each phase is the highest voltage. In retarded power generation, two of the three high-side MOSFETs (Q1) to (Q3) and one low-side or three low-side MOSFETs (Q4) to (Q4) to (Q3) to ( Two of Q6) and one of the high side connected to the low-side non-conduction phase are simultaneously turned on. On the other hand, in conduction angle rectification, a total of two MOSFETs, one of the three high-side MOSFETs (Q1) to (Q3) and one of the three low-side MOSFETs (Q4) to (Q6). Only turns on. Therefore, in the conduction angle rectification, the circuit of the circulating current is not formed. Therefore, when the amount of power generation becomes excessive, there is a possibility that an overvoltage is applied to the battery by a rectifier circuit composed of MOSFET parasitic diodes, but in this embodiment, MOSFETs (Q7) to (Q9) are cut off. Thus, the occurrence of overvoltage can be prevented. Further, the output of the starter generator 1 is controlled to an appropriate magnitude by duty-controlling the MOSFETs (Q7) to (Q9) according to the DC output voltage of the orthogonal transform unit 61 (that is, the charging voltage of the battery 9). Can do.

In addition, when the output voltage of the orthogonal transformation unit 61 does not exceed the voltage of the battery 9, the retarded angle power generation can increase the output of the starter generator 1 rather than the conduction angle rectification. Therefore, in the present embodiment, as shown in FIG. 9, for example, when the engine 2 is at a low speed and the starter generator 1 has an insufficient power generation amount, retarded power generation is performed. Then, power generation control by the conduction angle rectification method is performed.

FIG. 9 is a characteristic diagram in which the horizontal axis represents the number of revolutions of the engine 2 and the vertical axis represents the electric load and the power generation amount of the starting generator 1. The power generation amount indicated by the chain line indicates the power generation amount when the duty control by the MOSFETs (Q7) to (Q9) is not performed, and the power generation amount indicated by the solid line is when the duty control by the MOSFETs (Q7) to (Q9) is performed. Indicates the amount of power generation. By performing the duty control according to the present embodiment, the amount of power generation can be controlled to an appropriate size corresponding to the electric load.

FIG. 10 shows an energization mode in power generation control by retarded angle power generation. FIG. 10 shows a combination of ON (ON) or OFF (OFF) operations of the MOSFETs (Q1) to (Q9) in the power converter 6.

As described above, in this embodiment, the starter generator 1 (including the armature portion in which the winding portion 11 which is a three-phase coil (multi-phase coil) is disposed and the field portion made of a permanent magnet is provided. ACG starter motor), an orthogonal transform unit 61 that performs power conversion between AC and DC, and each end of the winding unit 11 and each

AC terminal

611, 612, and 613 of the orthogonal transform unit 61. A plurality of MOSFETs (switch elements) (Q7) to (Q9) for connecting and separating each end portion of the winding portion 11 with respect to each

AC terminal

611, 612, and 613 are provided. According to this configuration, it is possible to easily improve the control characteristics of the starter generator 1 (ACG starter motor) such as reduction of power loss.

Also, the heat generation of the armature winding and the power device can be reduced by reducing the circulating current.

It should be noted that the embodiments of the present invention are not limited to the above-described ones, and include designs and the like within a range not departing from the gist of the invention.

100 Start-up power generation control system 1 Start-up generator 6 Power conversion unit 7 Control units D7 to D9 Parasitic diodes Q1 to Q9 MOSFET
11

Winding part

11u, 11v, 11w Coil (winding)
15 Field part 61 Orthogonal transformation part 62 Switch part 611,612,613 AC terminal

Claims

A starting generator having an armature portion having a winding portion made of a multiphase coil and a field portion made of a permanent magnet;
An orthogonal transformation unit that has an AC terminal and converts power bidirectionally between DC and AC;
A starting power generator comprising: a plurality of switch elements that are interposed between the AC terminal and the winding portion and connect and disconnect the winding portion with respect to the AC terminal.
The starting power generator according to claim 1, wherein the plurality of switch elements are MOSFETs, and the directions of parasitic diodes of the plurality of MOSFETs are the same with respect to the AC terminal.
A controller that controls the orthogonal transform unit and the plurality of switch elements is further provided;
When the starter generator is used as a starter motor for starting the engine, the control unit turns on all the switch elements, while when the starter generator is used as a generator, The starting power generator according to claim 1 or 2, wherein a duty ratio of the plurality of switch elements is changed in accordance with a DC output voltage.
When the starter generator is used as a starter motor for starting the engine, the control unit turns on all the switch elements, whereas when the starter generator is used as a generator, based on the engine speed. 4. The control unit according to claim 1, wherein the orthogonal transformation unit is controlled so as to be either retarded angle power generation or conduction angle rectification, and each of the switch elements is controlled to be turned on / off. 5. Starting power generator.
A starting generator having an armature portion having a winding portion made of a multiphase coil and a field portion made of a permanent magnet;
An orthogonal transformation unit that has an AC terminal and converts power bidirectionally between DC and AC;
In the starting power generator comprising a plurality of switch elements that are inserted between the AC terminal and the winding portion and connect and disconnect the winding portion with respect to the AC terminal,
A starting power generation method comprising the step of controlling the plurality of switch elements to be turned on or off.