JP7206721B2 - motor generator controller - Google Patents

Description

The disclosed technology relates to a motor-generator control device that is suitable for hybrid vehicles, electric vehicles, and the like, and that can be used for both electric motors and generators.

When an electric motor is used as a drive source for an automobile, a wide range of driving force is required in both torque and rotation speed. For example, at low speed such as starting, high torque is required because it is used for starting and starting the engine. On the other hand, when driving at high speed on level ground or downhill, high torque is not required, but high rotation is required. In addition, in the above-described hybrid vehicle and the like, the electric motor is generally used not only as a drive source but also as a generator that recovers kinetic energy as electrical energy during braking in many cases.

In such motor-generator motors (usually permanent magnet synchronous motors), a large number of windings (stator coils) can generate a strong magnetic force, which is advantageous for high torque. However, since the back electromotive force increases, it is disadvantageous for high rotation. On the other hand, if the number of turns is small, the back electromotive force is small, which is advantageous for high rotation, but the torque that can be output is small. Therefore, it is disadvantageous for high torque. In other words, it is difficult to achieve a wide range of driving force required by automobiles with the motor itself.

Therefore, techniques have been proposed to realize a wide range of driving force by switching the connection state of the windings of the motor (for example, Patent Documents 1 and 2).

Patent Literature 1 discloses a winding switching device that electrically switches the connection state of the windings of a three-phase AC motor. The winding switching device is provided with a winding switching unit having an electric circuit composed of semiconductor switches, diodes, capacitors, and the like. The winding switching unit is connected to the other end of each phase winding, one end of which is connected to the inverter, and to the intermediate point of each phase winding.

The winding switching unit switches between a state in which the former is electrically connected (first connection state) and a state in which the latter is electrically connected (second connection state) by turning on and off the semiconductor switch. switch. In the first connection state, all windings of each phase are energized, which is advantageous for low-speed, high-torque operation. In the second connection state, half the windings of each phase are energized, which is advantageous for high-speed, low-torque operation.

Patent Document 2 discloses a winding switching device that mechanically switches the connection state of the windings of a three-phase AC motor. The winding switching device is generally composed of a device main body electrically connected to the inverter and the three-phase AC motor, a movable body slidably accommodated in the device main body, and a driving device for sliding the movable body. It is configured.

Wiring corresponding to each phase is provided inside the movable body. When the movable body is slid by the driving device, the connection state of the windings of each phase is switched between a series state and a parallel state.

JP 2009-225617 A JP 2017-70112 A

As in the winding switching device of Patent Document 1, if short-circuiting is performed at the intermediate point of each phase winding in order to achieve a connection state that is advantageous at high speed, the remaining windings are not used. Consequently, windings are wasted and efficiency is reduced. Therefore, in order to eliminate such a decrease in efficiency and waste of windings, the winding switching device of Patent Document 1 also uses the remaining windings like the winding switching device of Patent Document 2, can be connected in parallel.

However, in order to switch to such a connection state at the winding switching portion, the electric circuit becomes complicated and a large number of electronic parts are required. As a result, the winding switching portion becomes large, and the member cost becomes high.

In this respect, the winding switching device of Patent Document 2, which performs mechanical switching, can relatively inexpensively switch the windings of each phase between the series state and the parallel state.

However, the winding switching device of Patent Document 2 has a complicated structure and requires a certain size because it is necessary to stack the switching wirings for each phase with intervals in the sliding direction. Therefore, installation locations are limited. Further, in the winding switching device of Patent Document 2, when switching windings, it is necessary to slide the movable body with high precision by the driving device and to ensure stable electrical connection of the contacts. Therefore, there is room for improvement in terms of responsiveness and stability as well.

In addition, in the case of mechanically switching the windings, as in the winding switching device of Patent Document 2, due to structural differences, Switching takes time. Therefore, at the time of switching, the torque output by the motor (output torque) becomes discontinuous, and torque shock is likely to occur. Furthermore, when switching between the series state and the parallel state, a torque shock also occurs due to the difference in the output torque in each state.

Therefore, the technology disclosed realizes smooth winding switching with a low cost and simple structure so that the motor generator can stably respond to a wide range of driving power required by automobiles. is the main purpose.

The disclosed technology includes a motor provided with a plurality of different winding groups, an inverter that drives and controls the motor by supplying alternating currents of different phases to each of the winding groups, and the motor and the inverter. The present invention relates to a control device for a motor-generator mounted on a vehicle capable of electric travel, including a switching mechanism unit connected between .

The control device includes a measurement unit that detects the operating state of the motor, and a control unit that controls the inverter and the switching mechanism based on signals input from the measurement unit.

Each of the winding groups is composed of a plurality of winding elements. The switching mechanism section opens and closes between a series winding state in which the winding elements are connected in series and a parallel winding state in which the winding elements are connected in parallel according to the operating state of the motor. It has a plurality of contacts for switching the connection state of each of the winding groups. The switching mechanism includes a relay, and at least one of the plurality of contacts is a mechanical contact of the relay.

According to this control device, each of the winding groups of the motor is composed of a plurality of winding elements, and the switching mechanism section switches between the series windings in which the winding elements are connected in series according to the operating state of the motor. and a parallel winding state in which the winding elements are connected in parallel. Therefore, by switching the winding state while efficiently using the windings provided in the motor, the motor performance can be expanded over a wide range of torque and rotation speed. As a result, the motor-generator can stably respond to a wide range of driving forces required by automobiles.

The switching mechanism section includes a relay, and at least one of the plurality of contacts for switching the winding state by opening and closing is configured by the mechanical contact of the relay. Therefore, a complicated electronic circuit using a large number of electronic parts and a complicated mechanical structure can be avoided, and smooth winding switching can be realized with a low-cost and simple structure.

The control device is also configured such that the plurality of contacts comprises three of the mechanical contacts that switch each of the winding groups to one of the series winding state and the parallel winding state, and the relay is configured to: a plurality of terminals consisting of a fixed terminal and a movable terminal that constitute the three mechanical contacts; a movable part that supports the movable terminal; , and the actuation part actuates the movable part to switch the open/closed states of the three mechanical contacts at the same time.

Then, simply by actuating the actuating part, the open/closed states of the three mechanical contacts are switched at the same time. Therefore, the switching mechanism can be realized with a cheaper and simpler structure than electrical contacts using semiconductor switches or the like. can.

Moreover, since each winding group is configured to switch between the series winding state and the parallel winding state in one operation, either the series winding state or the parallel winding state can be reliably selected. You can switch. Therefore, it is also excellent in terms of control stability.

The control device may also control the inverter so that the alternating current flowing through the mechanical contact becomes substantially zero at the timing when the mechanical contact is opened and closed.

When switching a mechanical contact, if the mechanical contact is opened and closed while current is flowing through the contact, there is a risk that the mechanical contact will be damaged due to overcurrent or the like. Further, in the case of a mechanical contact, it takes time to switch, unlike an electrical contact that can be switched instantaneously.

As a result, power is not supplied to the motor during that time, and the torque output by the motor becomes zero (a zero torque period occurs). As a result, the output torque becomes discontinuous, and torque shock may occur.

On the other hand, if the inverter is controlled so that the alternating current flowing through the mechanical contact becomes approximately zero when the mechanical contact opens and closes, the current is approximately zero, so the mechanical contact opens and closes. However, the damage can be avoided. In addition, even if the output torque becomes discontinuous by securing the time to switch the mechanical contact, the influence thereof can be suppressed, so that the torque shock can also be suppressed.

In the control device, the plurality of contacts comprise three contacts for switching each of the winding groups to either one of the series winding state and the parallel winding state, and the switching mechanism section It may further include an electronic changeover switch configured in a circuit, and the three contacts may be configured by mechanical contacts of the relay and electrical contacts of the electronic changeover switch.

In this case also, some of the contacts of the switching mechanism are composed of the mechanical contacts of the relay, so a complicated electronic circuit using many electronic parts and a complicated mechanical structure can be avoided. With a simple structure, smooth winding switching can be achieved.

Moreover, in this case, although the details will be described later, by arranging the mechanical contacts and the electrical contacts in a predetermined arrangement, the winding state can be continuously switched without generating a zero torque period even while the motor is energized. becomes possible. Another advantage is that the motor can be stably driven even if the relay is damaged.

In the control device, the control unit supplies a correction current through the electronic changeover switch at the timing when the mechanical contact is opened and closed, thereby corresponding to the mechanical contact and the electronic changeover switch. The switching mechanism section and the inverter may be controlled so that the alternating current flowing through the winding group is corrected.

The torque constant of the motor changes as the winding state is switched. Therefore, even if continuous switching is possible, torque shock occurs due to the change in torque constant. On the other hand, in this case, since the correction current can be supplied to the winding group through the electronic changeover switch during the transition of switching, the correction current can suppress the fluctuation of the output torque.

According to the disclosed technology, it is possible to achieve smooth winding switching with a low cost and simple structure, so that the motor generator can stably respond to a wide range of driving power required by automobiles. .

1 is a schematic diagram showing a main part of a vehicle to which disclosed technology is applied; FIG. It is a block diagram showing the main composition of a control device. 4 is a schematic diagram showing the configuration of a motor and a switching mechanism; FIG. It is a schematic diagram showing a winding structure of a stator. It is a schematic diagram showing a series winding state. It is a schematic diagram showing a parallel winding state. FIG. 4 is a diagram showing motor characteristics in each of a series winding state and a parallel winding state; 4 is a schematic diagram showing the structure of a switching mechanism; FIG. This is an example of winding state switching control. FIG. 4 is a diagram showing an example of phase currents when switching winding states (switching from series winding state to parallel winding state) during motor energization; It is an example of switching control corresponding to FIG. It is a schematic diagram showing the structure of the switching mechanism unit in the control device of the application. FIG. 10 is a diagram showing an example of phase currents in winding state switching control (switching from series winding state to parallel winding state) during motor energization in the control device of the application example; 12 is an example of switching control corresponding to FIG. 11; FIG. 10 is a diagram showing an example of phase currents in winding state switching control (switching from a parallel winding state to a series winding state) during energization of a motor in a control device of an application example; 14 is an example of switching control corresponding to FIG. 13;

Embodiments of the disclosed technology will be described in detail below with reference to the drawings. However, the following description is essentially merely an example, and does not limit the present invention, its applications, or its uses.

<In-vehicle example>
FIG. 1 shows a vehicle 1 to which the technology disclosed is applied. The illustrated vehicle 1 is a so-called hybrid vehicle. A vehicle 1 is equipped with an engine 2, a motor generator 3, a low-voltage power supply 4, a PCM 5 (an example of a control unit), and the like. The motor generator 3 includes a motor 30, a switching mechanism section 31, an inverter 32, and the like. A control device for controlling the motor-generator 3 includes these devices 30, 31, and 32, the PCM 5, sensors 9a to 9d, which will be described later, and the like.

The engine 2 is a known internal combustion engine that generates power for the vehicle 1 by burning fuel. The engine 2 is provided with a fuel tank, an intake/exhaust system, and the like (not shown since these are known). A crankshaft 2a of the engine 2 is connected in series with a rotary shaft 30a of a motor 30 via a clutch 6. As shown in FIG. A rotating shaft 30a of the motor 30 is connected to the driving wheels 1a of the vehicle 1 via the transmission 7, the differential gear 8, and the like. Transmission 7 also functions as a clutch.

By driving the engine 2 with the clutch 6 engaged, the vehicle 1 can run by burning fuel, like a normal vehicle. Further, by driving the motor 30 with the clutch 6 disengaged, the vehicle can be driven electrically. Furthermore, by driving the engine 2 and the motor 30 with the clutch 6 engaged, the vehicle 1 can run on both fuel combustion and electric power.

In addition, when the vehicle 1 is braked, the motor 30 can be rotated by the rotational force of the drive wheels 1a by disengaging the clutch 6, for example. Thereby, the motor 30 can be made to function as a generator, and the kinetic energy can be recovered to the low-voltage power supply 4 as electrical energy. This vehicle 1 is a so-called parallel hybrid vehicle.

The low voltage power supply 4 is a DC power supply. A specific example of the low-voltage power supply 4 is, for example, a secondary battery that can be charged and discharged, and uses a relatively low voltage (rated voltage) of 48V. In addition to the low-voltage power supply 4, the vehicle 1 is also equipped with a battery with a rated voltage of 12 V (not shown) in order to supply electric power to the electrical components installed therein.

The low-voltage power supply 4 is electrically connected (hereinafter also simply referred to as connection) to the motor 30 via the inverter 32 and the switching mechanism section 31 . The inverter 32 is a device that converts DC power into AC power and outputs it (because it is a known device, its details are omitted). Based on a control signal input from the PCM 5, the inverter 32 converts the DC power input from the low-voltage power supply 4 into three-phase AC power with different phases (so-called three phases of U-phase, V-phase, and W-phase). and output to the motor 30. The inverter 32 drives and controls the motor 30 by supplying the three-phase AC power to the motor 30 .

The switching mechanism section 31 is connected so as to be interposed between the motor 30 and the inverter 32 . Functionally, the switching mechanism section 31 may be interposed between the motor 30 and the inverter 32 , but the switching mechanism section 31 in this embodiment is provided integrally with the motor 30 . Integrating the motor 30 and the switching mechanism 31 has the advantage of simplifying the wiring and simplifying the structure of the control device, as will be described later. On the other hand, by arranging the switching mechanism section 31 separately from the motor 30, the influence of the heat generated by the motor 30 can be suppressed, so there is an advantage that the heat resistance required of the switching mechanism section 31 can be reduced.

The PCM 5 (powertrain control module) is a device that comprehensively controls the operation of the vehicle 1, such as controlling the driving of the engine 2 and the motor 30, for example. The PCM 5 is a well-known microcomputer-based controller, and as shown in FIG. and an input/output bus 5c (I/O bus) for inputting/outputting signals.

The PCM 5 is connected with various sensors (an example of a measurement section) for detecting the operating states of the engine 2 and the motor 30 . For example, a water temperature sensor 9a (a sensor attached to the engine 2 that measures the temperature of the cooling water), a crank angle sensor 9b (a sensor that is attached to the engine 2 and measures the rotation angle of the crankshaft 2a), accelerator opening degree sensor 9c (attached to the accelerator pedal mechanism of the vehicle 1 and measuring the accelerator opening corresponding to the operation amount of the accelerator pedal), motor sensor 9d (attached to the motor 30 and measuring the rotation angle of the rotating shaft 30a). measuring sensor), etc. are connected. Detection signals output from these sensors are always input to the PCM 5 during operation of the vehicle 1 . Further, the inverter 32 is provided with an ammeter for measuring the current value flowing through the inverter 32 . A signal output from the ammeter is also constantly input to the PCM 5 (the ammeter is also an example of the measurement unit).

The PCM 5 is also connected to the inverter 32 and the switching mechanism section 31 together with the engine 2 . The PCM 5 outputs control signals to the inverter 32 and the switching mechanism section 31 based on the detection signals input from the sensors 9a to 9d described above and controls them. Thereby, the motor 30 is driven and controlled according to the driving state of the vehicle 1 .

(motor 30)
FIG. 3A schematically shows the motor 30 and the switching mechanism section 31. As shown in FIG. The motor 30 of this embodiment is a so-called permanent magnet synchronous motor. The motor 30 has a stator 30b and a rotor 30c. The rotor 30c is provided integrally with the rotating shaft 30a. A plurality of permanent magnets 30d are arranged at equal intervals along the entire circumference of the rotor 30c. These permanent magnets 30d are arranged such that the N poles and S poles are alternately arranged in the circumferential direction and the radial direction, and constitute the magnetic poles of the rotor 30c.

The stator 30b has a substantially cylindrical shape and is arranged around the rotor 30c such that its inner peripheral surface faces the outer peripheral surface of the rotor 30c with a small gap therebetween. The stator 30b has a stator core 30e made of a magnetic material and a plurality of coils 30f. The stator core 30e has a plurality of slots arranged at regular intervals along its entire circumference. The coil 30f is constructed by winding a covered electric wire in a predetermined order through these slots.

Stator 30b is thereby provided with three different winding groups 50, consisting of a U-phase group, a V-phase group and a W-phase group, as shown in FIG. 3B. These winding groups 50 are connected to each other at a neutral point 51 (so-called Y-connection or star-connection). Each winding group 50 has two winding elements (a first winding element 50a and a second winding element 50b) each having approximately the same number of turns, and these winding elements 50a and 50b are connected in series. configured as follows. Alternating currents in different phases are supplied from the inverter 32 to the winding groups 50 of each phase through respective input terminals.

(Switching mechanism 31)
The switching mechanism unit 31 has a function of switching the connection state of the winding group 50 so that a wide range of driving force suitable for driving the vehicle 1 can be obtained from the output from the motor 30 .

Specifically, as shown in FIGS. 4A and 4B, the switching mechanism unit 31 has three contact points for each winding group 50 of each phase of the U-phase group, the V-phase group, and the W-phase group. It has one switch 61 and a second switch 62 . The first switch 61 is arranged between the first winding element 50a and the second winding element 50b. Each phase winding group 50 has a first bypass wiring 63 that bypasses the first winding element 50 a , and the first switch 61 is also configured to be connectable to the first bypass wiring 63 .

Each phase winding group 50 also includes a portion between the first winding element 50a and the second switch 62 and the neutral point so as to bypass the first switch 61 and the second winding element 50b. 51, a second bypass wiring 64 is provided. The second switch 62 is arranged on this second bypass wiring 64 . The structure of the winding group 50 of each phase is the same. Therefore, in these figures, only the U-phase group shows a specific structure, and the structures of the V-phase group and the W-phase group are omitted (the U-phase group will be explained as an example hereafter).

The switching mechanism unit 31 sets the two switches 61 and 62 in the winding group 50 of each phase to predetermined states, thereby switching the two windings as shown in FIG. Either the state in which the elements 50a and 50b are connected in series (series winding state) or the state in which two winding elements 50a and 50b are connected in parallel (parallel winding state) as shown in FIG. 4B On the other hand, the connection states of the U-phase, V-phase, and W-phase winding groups 50 are switched.

As shown in FIG. 4A, when the connection state of the winding groups 50 of each phase becomes a series winding state, the state is the same as when the number of turns of the coil 30f is substantially increased with respect to the supplied AC power. (increased inductance). As a result, the interlinking magnetic flux with the magnet generated when the winding group 50 is energized increases, so high torque can be obtained.

On the other hand, as the number of turns increases, a strong back electromotive force is generated between the rotating rotor 30c and the permanent magnet 30d due to electromagnetic induction. As a result, as the number of rotations increases, the supply voltage substantially decreases, so the number of rotations that can be driven decreases. Further, the generation of a strong back electromotive force increases the current for weakening the magnetic flux, so even when the engine 2 is driven, high efficiency cannot be obtained as the number of revolutions increases.

On the other hand, as shown in FIG. 4B, when the connection state of the winding groups 50 of each phase becomes a parallel winding state, the state is the same as when the number of turns of the coil 30f is substantially reduced with respect to the supplied AC power. becomes (decrease inductance). As a result, the magnetic flux interlinking with the magnet generated when the winding group 50 is energized is reduced, and the back electromotive force is accordingly suppressed. be possible. However, since the interlinking magnetic flux with the magnet is reduced, high torque cannot be obtained.

FIG. 5 illustrates the operating regions of the motor 30 corresponding to the motor characteristics in each of the series winding state and the parallel winding state. A solid line indicates the operating region corresponding to the motor characteristics in the series winding state. A dashed line indicates the operating region corresponding to the motor characteristics in the parallel winding state.

In FIG. 5, the vertical axis represents the level of the torque due to the motor output, and the horizontal axis represents the level of the rotation speed due to the motor output. The upper side of the horizontal axis is the operating range of the motor 30 as an electric motor, that is, the range during power running, and the lower side of the horizontal axis is the operating range of the motor 30 as the generator, that is, the range during regeneration.

In the series winding state, a relatively high torque T1 (T1') can be output at low rotation speeds, but output is possible only up to a relatively low rotation speed R1. On the other hand, in the parallel winding state, it is possible to output up to a relatively high rotation speed R2, but it is possible to output only up to a relatively low torque T2 (T2') even at a low rotation speed.

On the other hand, the motor-generator 3 is configured so that either one of the series winding state and the parallel winding state can be selected and used. Therefore, both of these motor characteristics can be exhibited, and a wide range of driving force suitable for driving the vehicle 1 can be obtained from the output of the motor 30, from low rotation high torque to high rotation low torque. there is

(Specific structure of switching mechanism 31)
In the control device of the present embodiment, the switching mechanism section 31 includes a relay 70 (so-called relay), and the first switch 61 and the second switch 62 shown in FIG. 4A etc. are configured by one relay 70. . The relay 70 is configured to interpose between and connect the first winding element 50a and the second winding element 50b that are separated from each other. In addition, in the configuration of the winding group 50, for the sake of convenience, the side having the input terminal will be described as the upstream side, and the side having the neutral point 51 will be described as the downstream side.

A specific example of the relay 70 is shown in FIG. The relay 70 includes an electromagnet 71, a swing plate 72, a frame 73, a coil spring 74 (elastic member), a first fixed terminal 75, a second fixed terminal 76, a third fixed terminal 77, a first movable terminal 78, and a second movable terminal. It consists of 79, etc. The electromagnet 71 is an example of an action portion, and the rocking plate 72, frame 73, and coil spring 74 are an example of a movable portion.

The first movable terminal 78 , the first fixed terminal 75 , and the third fixed terminal 77 constitute the first switch 61 , and the second movable terminal 79 and the second fixed terminal 76 constitute the second switch 62 . ing. The first movable terminal 78 is connected to the upstream side of the second winding element 50b. The first fixed terminal 75 is connected via the first bypass wiring 63 to the upstream side of the first winding element 50a.

The third fixed terminal 77 is connected downstream of the first winding element 50a. The second movable terminal 79 is connected to the neutral point 51 via part of the second bypass wiring 64 . The second fixed terminal 76 is connected to the downstream side of the first winding element 50a via part of the second bypass wiring 64. As shown in FIG.

The main body of the rocking plate 72 is made of an insulating member. A magnetic body (not shown) is attached to the lower surface of the rocking plate 72 (on the electromagnet 71 side). One end (base end) of the rocking plate 72 is rotatably supported by the frame 73 . The proximal end of the rocking plate 72 is biased by a coil spring 74 so that the other end (tip) rotates upward in FIG.

A first movable terminal 78 and a second movable terminal 79 are attached to the distal end of the rocking plate 72 at separate positions. A first fixed terminal 75 and a second fixed terminal 76 are arranged on the frame 73 so as to come into contact with the first movable terminal 78 and the second movable terminal 79 to prevent the rocking plate 72 from rotating upward. ing. A first contact 81 is provided at a contact portion where the first fixed terminal 75 and the first movable terminal 78 contact each other.

A second contact 82 is provided at a contact portion where the second fixed terminal 76 and the second movable terminal 79 contact each other. A third fixed terminal 77 is arranged below the first fixed terminal 75 so as to face the first fixed terminal 75 .

The electromagnet 71 is arranged below the rocking plate 72 so as to face the magnetic body. The electromagnet 71 is connected with the PCM5. When the electromagnet 71 is energized under the control of the PCM 5 , magnetic force is generated in the electromagnet 71 . Thereby, the swing plate 72 swings downward against the biasing force of the coil spring 74 . As a result, the first movable terminal 78 and the second movable terminal 79 are separated from the first fixed terminal 75 and the second fixed terminal 76 , and the first movable terminal 78 contacts the third fixed terminal 77 . A third contact 83 is provided at a contact portion where the first movable terminal 78 and the third fixed terminal 77 contact each other.

That is, when the electromagnet 71 is energized, the opening/closing states of the first to third mechanical contacts 81, 82, 83 are switched at the same time. As a result, the parallel winding state shown in FIG. 4B is switched to the series winding state shown in FIG. 4A. The switching mechanism 31 is designed to be in a parallel winding state in a non-energized state (so-called normal state). When the energization of the electromagnet 71 is stopped, the series winding state is switched to the parallel winding state.

In this way, by using the relay 70 dedicated to switching, in which the open/closed states of the three mechanical contacts 81, 82, and 83 are switched at the same time depending on whether or not one electromagnet 71 is energized, an electrical switch using a semiconductor switch or the like can be achieved. The switching mechanism section 31 can be realized with a cheaper and simpler structure than a contact.

Moreover, since each winding group 50 is configured to be switched between the series winding state and the parallel winding state, it is possible to reliably switch to either the series winding state or the parallel winding state. , and is also excellent in terms of control stability.

Further, as shown in FIG. 3A, between the switching mechanism section 31 and the motor 30, one wire for supplying alternating current from the inverter 32 and first and second switches 62 are provided for each winding group 50. A total of 6 wires are provided, including 2 wires for control. On the other hand, in this control device, the switching mechanism section 31 is provided integrally with the motor 30 as described above. Therefore, the wiring is simplified and the structure of the control device is simplified.

(Example of winding state switching control)
FIG. 7 shows an example of switching control of the winding state of the motor 30 by the PCM 5. In FIG. The illustrated switching control indicates a case where the vehicle 1 starts traveling from a stopped state, such as when the engine 2 is started.

In the vehicle 1 of this embodiment, the motor 30 is mainly driven when the engine 2 is started, when the vehicle 1 starts moving, and when the vehicle 1 moves backward. When the vehicle 1 starts or moves backward, the motor 30 is driven while assisting the driving by the engine 2 . The vehicle 1 may be started and reversed by the motor 30 alone without using the engine 2 .

While the vehicle 1 is running, the engine 2 is normally driven. That is, the vehicle 1 runs mainly using the engine 2 as a drive source. While the vehicle 1 is running, the motor 30 assists the driving of the engine 2 as necessary, or is used as a generator during braking.

As described above, the mechanical contacts 81, 82, 83 of the switching mechanism section 31 are designed to be in a parallel winding state in a non-energized state. In the parallel winding state, the motor 30 characteristics advantageous for high speed can be exhibited. Therefore, even if the power supply to the motor 30 is cut off due to some trouble, the vehicle 1 can be driven smoothly by the driving of the engine 2 .

When the operation of the vehicle 1 is started and the power is turned on, the PCM 5 constantly receives detection signals from the sensors 9a to 9d. When the vehicle 1 starts running from a stopped state, the PCM 5 receives information from predetermined sensors such as the crank angle sensor 9b and the accelerator opening sensor 9c in order to control switching of the winding state of the motor 30. is read (step S1).

The PCM 5 determines whether or not the temperature of the engine cooling water is lower than a predetermined reference temperature T based on the detection signal input from the water temperature sensor 9a (step S2). That is, it is determined whether or not the engine 2 is sufficiently warmed up (warmed up). The reference temperature T is an arbitrary set value and is set in advance in the memory 5b.

If the temperature of the engine cooling water is equal to or higher than the predetermined reference temperature T (No in step S2), the PCM 5 maintains the parallel winding state and returns. That is, the PCM 5 keeps the winding groups 50 in the parallel winding state, drives the motor 30 , starts the engine 2 , starts the vehicle 1 , and reverses the vehicle 1 . Since the engine 2 is warmed up, the engine 2 can be smoothly started by the motor 30 even in a parallel winding state in which high torque cannot be obtained.

As long as the temperature of the engine cooling water does not fall below the predetermined reference temperature T, the parallel winding state is maintained, so the frequency of switching control can be suppressed and efficient control can be performed.

On the other hand, if the temperature of the engine cooling water is lower than the predetermined reference temperature T (Yes in step S2), the PCM 5 determines whether the engine 2 is running based on the detection signal of the crank angle sensor 9b. (Step S3). If the engine 2 is running (No in step S3), the parallel winding state is maintained and the process returns. Even if high torque cannot be obtained, the vehicle 1 can be smoothly started or reversed in cooperation with the engine 2. - 特許庁

If the engine 2 is not running (Yes in step S3), each winding group 50 is switched to a series winding state (step S4). Since the motor 30 is not rotating, it can be switched without any trouble.

The PCM 5 then engages the clutch 6 and starts the engine 2 with the motor 30 (step S5). Since the motor 30 is in a series winding state capable of generating high torque, the engine 2 can be stably started even when the engine 2 is cold.

Based on the detection signal from the motor sensor 9d, the PCM 5 determines whether or not the rotation speed of the motor 30 is within a predetermined low rotation range (step S6). This low rotation region may be a region on the low rotation side when the operable rotation region of the motor 30 is divided into two halves. Further, the low rotation region may be the region on the lowest rotation side when the operable rotation region of the motor 30 is divided into three equal parts.

Then, when the rotation speed of the motor 30 reaches a predetermined low rotation region (Yes in step S6), the PCM 5 switches each winding group 50 to a parallel winding state (step S7). That is, when the engine 2 starts and reaches a certain number of revolutions, it immediately switches to the parallel winding state.

As for the winding state of the motor 30, the parallel winding state is mainly used, and the series winding state is mainly used in a limited state such as starting the engine 2. FIG. Also, when the motor 30 is used as a generator, the parallel winding state is used regardless of whether the number of revolutions is high or low. This suppresses the frequency of switching the winding state.

By performing such infrequent switching of the winding state in the low rotation region, as described below, when the winding state is switched while current is flowing through the motor 30, The influence of the zero torque period can be suppressed.

(switching of the winding state while the motor is energized)
When switching a mechanical contact, if the mechanical contact is opened and closed while current is flowing through the contact, there is a risk that the mechanical contact will be damaged due to overcurrent or the like. Further, in the case of a mechanical contact, it takes time to switch, unlike an electrical contact that can be switched instantaneously.

As a result, power is not supplied to the motor 30 during this period, and the torque output by the motor 30 becomes zero. That is, a zero torque period occurs. As a result, the output torque becomes discontinuous, and a torque shock that makes the vehicle 1 run uncomfortable may occur.

Therefore, in this control device, the control for switching the winding state while the motor 30 is being energized is devised so as to suppress such a problem. Specifically, the PCM 5 controls the inverter 32 so that the alternating current flowing through the mechanical contacts 81, 82, 83 becomes substantially zero when the mechanical contacts 81, 82, 83 are opened and closed. That is, the mechanical contacts 81, 82, 83 of the winding group 50 are switched at the timing when the phase current flowing through the winding group 50 of each phase becomes zero cross.

FIG. 8 shows an example of the phase current when switching the winding state (switching from the series winding state to the parallel winding state) while the motor is energized. Also, FIG. 9 shows an example of the switching control. Since the phase current is an alternating current, the timing of zero crossing where the current flowing through the winding group 50 becomes zero occurs periodically. Note that switching from the series winding state to the parallel winding state is exemplified here, but switching from the parallel winding state to the series winding state, which is the reverse, can also be performed in a similar manner. can.

When the number of rotations of the motor 30 reaches a predetermined low rotation region and there is a request to switch the winding state (Yes in step S10), the PCM 5 detects a detection signal input from the ammeter of the inverter 32. Then, the timing at which the phase current flowing through the winding group 50 to be switched reaches zero cross is determined (step S11).

Then, the PCM 5 controls the inverter 32 at a timing at or near zero cross when the phase current flowing through the winding group 50 to be switched becomes substantially zero, and the current is changed for a predetermined period (for example, several ms). It is maintained at zero (step S12). By doing so, the period t0 (non-energization period) shown in FIG. 8 is ensured.

The PCM 5 controls the switching mechanism 31 to open and close the mechanical contacts 81, 82, 83 during the non-energized period, thereby switching the winding state (step S13). Since the current flowing through the winding group 50 is substantially zero at the timing of the zero cross or its vicinity, the current can be smoothly reduced to zero. Since the current is substantially zero, it is possible to secure time for switching the mechanical contacts 81, 82, 83, and to suppress the influence even if the output torque becomes discontinuous.

Furthermore, the torque constant is different between the series winding state and the parallel winding state. Therefore, as shown by the phantom line in FIG. 8, when switching to the parallel winding state with the same current value as in the series winding state, a difference occurs in the output torque. That is, torque shock may occur.

Therefore, the PCM 5 controls the inverter 32 according to the difference in torque constant during the non-energization period, and adjusts the magnitude of the phase current as indicated by the solid line in FIG. 8 (step S14). As a result, the output torque becomes substantially constant before and after switching, and torque shock caused by the difference in torque constant can be suppressed.

When the number of revolutions is high, the zero torque period becomes relatively large, so it is susceptible to torque shock. On the other hand, in this control device, as described above, switching is performed while the rotational speed is low, so the influence of torque shock can be suppressed.

(Application example)
In the above-described embodiment, the control device in which the contacts 81, 82, and 83 of the switching mechanism section 31 are all mechanical contacts by using the switching-only relay 70 is exemplified. In this application example, an electronic changeover switch 100 configured by an electric circuit is used together with a relay 70, and a control device is illustrated in which the contacts of the switching mechanism section 31 are combined with mechanical contacts and electric contacts. It should be noted that this application example will also be described as being applied to the same vehicle 1 as in the above-described embodiment. Therefore, descriptions of the same configurations and members will be omitted, and different contents will be specifically described.

FIG. 10 shows a specific example of the switching mechanism section 31 of this control device corresponding to FIG. As described above, the switching mechanism section 31 has the first switch 61 and the second switch 62 for each phase winding group 50 of the U-phase group, the V-phase group, and the W-phase group. In this switching mechanism section 31 , the first switch 61 is composed of a relay 70 ′, and the second switch 62 is composed of an electronic changeover switch 100 .

The electronic changeover switch 100 is composed of an electric circuit in which diode bridges, semiconductor switches, diodes, and the like are arranged. Since the electronic switch 100 has a known structure, a detailed description thereof will be omitted.

This relay 70' has the same basic structure as the relay 70 of the embodiment described above, but differs from the relay 70 of the embodiment described above in that the second movable terminal 79 and the second fixed terminal 76 are not provided. That is, in this control device, the first contact 81 and the third contact 83 are mechanical contacts, and the second contact 82 is an electrical contact.

According to the switching mechanism 31, it can be configured with the mechanical relay 70' having a simple structure and the conventional electronic changeover switch 100. Therefore, even if the electronic changeover switch 100 is used, the complexity of the structure can be avoided. And it can be realized inexpensively and compactly.

Furthermore, according to the switching mechanism section 31 having such a structure, it is possible to continuously switch the winding state even while the motor 30 is energized without generating a zero torque period. This control device is devised so as to suppress a torque shock at the time of switching the winding state.

Specifically, the PCM 5 supplies the correction current through the electronic switch 100 at the timing when the mechanical contacts are opened and closed. By doing so, the switching mechanism unit 31 and the inverter 32 are controlled so that the alternating current flowing through the winding group 50 to be switched is corrected.

When switching from the series winding state to the parallel winding state, the PCM 5 switches the winding state while continuously outputting torque at any timing, not limited to the zero-crossing timing. When switching from the parallel winding state to the series winding state, the PCM 5 switches the winding state while continuously outputting torque at the timing of zero crossing.

(switching from series winding state to parallel winding state)
FIG. 11 shows an example of the phase current in the winding state switching control (switching from the series winding state to the parallel winding state) while the motor is energized. Also, FIG. 12 shows an example of the switching control.

When the rotation speed of the motor 30 reaches a predetermined low rotation region and there is a request to switch the winding state (Yes in step S20), the PCM 5 controls the switching mechanism unit 31, and the electronic switch 100 is switched. The switch is turned on (step S21). This timing is any timing other than the zero-crossing timing. In FIG. 11, the electronic switch 100 is switched on at point P1.

As a result, the second switch 62 changes from the open state to the closed state, and the second winding element 50b is connected in parallel with the second bypass wiring 64, as shown in the schematic diagram on the left side indicated by the dashed line in FIG. becomes. Since the torque constant changes accordingly, the PCM 5 controls the inverter 32 so that the phase current is switched to the current value of the parallel winding state with a correction current added to correct that amount.

At this time, since the winding group 50 to be switched is connected to the neutral point 51 via the electronic changeover switch 100, the phase current and the correction current can be supplied to the winding group 50 to be switched. Even if the switching is performed while outputting torque, fluctuations in the output torque can be suppressed by the phase current and the correction current.

The PCM 5 controls the switching mechanism 31 to start switching the mechanical contacts 81 and 83 of the relay 70' at the same time or slightly after turning on the electronic switch 100 (step S23). Since the amount of current flowing through the second winding element 50b is small, the occurrence of overcurrent can be avoided, and switching can be performed while suppressing damage to the mechanical contacts 81 and 83.

Then, after a predetermined switching period t1 during which the mechanical contacts 81 and 83 are switched over, the first contact 81 is switched to the third contact 83 as shown in the schematic diagram on the right side indicated by the dashed line in FIG. Switching between 81 and 83 is completed. In FIG. 11, the third contact 83 is closed at point P2.

When the switching of the mechanical contacts 81 and 83 is completed (Yes in step S24), the PCM 5 controls the inverter 32 at the same timing to stop supplying the correction current (step S25). Thereby, the motor 30 transitions from the series winding state to the parallel winding state at a higher speed than with mechanical contacts alone while continuously outputting torque.

(Switching from parallel winding state to series winding state)
FIG. 13 shows an example of the phase current in the winding state switching control (switching from the parallel winding state to the series winding state) while the motor is energized. Also, FIG. 14 shows an example of the switching control.

When the number of rotations of the motor 30 reaches a predetermined low rotation region and there is a request to switch the winding state (Yes in step S30), the PCM 5 operates based on the signal input from the ammeter of the inverter 32. , the timing at which the phase current flowing through the winding group 50 to be switched reaches zero cross (step S31).

Then, the PCM 5 controls the switching mechanism section 31 to switch the mechanical contacts 81 and 83 at the timing of the zero cross or its vicinity when the phase current flowing through the winding group 50 to be switched becomes substantially zero. start (step S32). In FIG. 13, switching of the mechanical contacts 81 and 83 is started at point P3.

As a result, the first contact 81 is opened and the first winding element 50a is connected in series with the second bypass wiring 64, as shown in the schematic diagram on the left side indicated by the dashed line in FIG. Accordingly, the torque constant changes, so the PCM 5 adds a correction current for correcting that amount, and controls the inverter 32 so as to suppress fluctuations in the output torque (step S33).

Then, after a predetermined switching period t2 during which the mechanical contacts 81 and 83 are switched, as shown in the schematic diagram on the right side indicated by the dashed line in FIG. 83 is closed (timing of point P4 in FIG. 13). That is, the second winding element 50b is connected in parallel with the second bypass wiring 64. As shown in FIG.

When the switching of the mechanical contacts 81 and 83 is completed (Yes in step S34), the PCM 5 controls the switching mechanism section 31 at the same timing to change the state of the schematic diagram on the right side indicated by the dashed line in FIG. 2 switch 62 is turned off (step S35). Since the second switch 62 is the electronic changeover switch 100, it can be turned off instantaneously.

At the same time, the inverter 32 is controlled to change the value of the phase current to the series winding state (step S36). Thereby, the motor 30 transitions from the parallel winding state to the series winding state winding state at a higher speed than with mechanical contacts alone, while continuously outputting torque.

In the case of the control device of this application example, there is also the advantage that stable running of the vehicle 1 can be maintained even if the relay 70' is damaged. For example, when the third contact 83 is stuck, by turning on and off the electronic changeover switch 100, it is possible to easily switch between a series winding state and a winding state (subtraction winding state) advantageous for high rotation. can be done. However, in the subtrahend winding state, the second winding element 50b is short-circuited by the second bypass wiring 64, so only the first winding element 50a is used.

In addition, when the first contact 81 is stuck or when it is in a state where neither the first contact 81 nor the third contact 83 is brought into contact, the electronic changeover switch 100 is kept in the ON state. A parallel winding state can be maintained. The parallel winding state can exhibit advantageous motor characteristics at high speed. Therefore, by driving the engine 2, the vehicle 1 can be driven smoothly.

Note that the technology disclosed is not limited to the above-described embodiments, and includes various other configurations. For example, the technology disclosed is not limited to HEVs. The technology disclosed is also suitable for electric vehicles equipped with only a motor as a drive source. The structure of the motor is also an example.

1 vehicle 2 engine 3 motor generator 4 low voltage power supply 5 PCM (an example of a control unit)
30 motor 31 switching mechanism 32 inverter 50 winding group 70 relay 81 first contact 82 second contact 83 third contact

Claims (5)

a motor provided with a plurality of different winding groups; an inverter for driving and controlling the motor by supplying alternating currents of different phases to each of the winding groups; and a motor connected between the motor and the inverter. A control device for a motor generator mounted in a vehicle capable of electric travel, comprising a switching mechanism unit with
a measurement unit that detects the operating state of the motor ;
a control unit that controls the inverter and the switching mechanism based on a signal input from the measurement unit;
with
Each of the winding groups is composed of a plurality of winding elements,
The switching mechanism section opens and closes between a series winding state in which the winding elements are connected in series and a parallel winding state in which the winding elements are connected in parallel according to the operating state of the motor. having a plurality of contacts for switching the connection state of each of the winding groups by
The switching mechanism includes a relay, and at least one of the plurality of contacts is configured by a mechanical contact of the relay,
When switching the winding state while the motor is energized, the control unit ensures a predetermined non-energization period in which the phase current flowing through the mechanical contact is substantially zero at the timing when the mechanical contact is opened and closed. and adjusting the magnitude of the phase current according to the difference in the torque constant of the winding state during the non-energization period . In the motor-generator control device according to claim 1,
The plurality of contacts are composed of three mechanical contacts that switch each of the winding groups to either the series winding state or the parallel winding state,
the relay
a plurality of terminals consisting of fixed terminals and movable terminals that constitute the three mechanical contacts;
a movable portion that supports the movable terminal;
one action part that operates the movable part under the control of the control part;
has
A control device for a motor-generator, wherein the open/closed states of the three mechanical contacts are simultaneously switched by the operating portion operating the movable portion. In the motor generator control device according to claim 1 or 2,
Each of the winding groups includes:
a first winding element and a second winding element;
a first bypass wiring and a second bypass wiring;
has
connected to each other at a neutral point,
The switching mechanism unit has a series winding state in which the first winding element and the second winding element are connected in series, a series winding state in which the first winding element and the second winding element are connected in series, and a parallel winding state in which line elements are connected in parallel, and a first switch and a second switch forming a plurality of contacts for switching the winding state of each of the winding groups by opening and closing,
The first switch is arranged between the first winding element and the second winding element and is configured to be connectable to the first bypass wiring bypassing the first winding element,
The motor-generator control device , wherein the second switch is arranged on the second bypass wiring that bypasses the first switch and the second winding element and is connected to the neutral point . a motor provided with a plurality of different winding groups; an inverter for driving and controlling the motor by supplying alternating currents of different phases to each of the winding groups; and a motor connected between the motor and the inverter. A control device for a motor generator mounted in a vehicle capable of electric travel, comprising a switching mechanism unit with
a measurement unit that detects the operating state of the motor;
a control unit that controls the inverter and the switching mechanism based on a signal input from the measurement unit;
with
Each of the winding groups is composed of a plurality of winding elements connected to each other at a neutral point,
The switching mechanism section opens and closes between a series winding state in which the winding elements are connected in series and a parallel winding state in which the winding elements are connected in parallel according to the operating state of the motor. having a plurality of contacts for switching the connection state of each of the winding groups by
The plurality of contacts are composed of three contacts that switch each of the winding groups to either one of the series winding state and the parallel winding state,
The switching mechanism unit further includes an electronic changeover switch configured by an electric circuit including a semiconductor switch ,
The three contacts are composed of a mechanical contact of the relay and an electrical contact of the semiconductor switch ,
When switching the winding state while the motor is energized, the control unit supplies a correction current through the electronic changeover switch and the neutral point at the timing when the mechanical contact is opened and closed, so that the mechanical controlling the switching mechanism and the inverter so that the phase current flowing through the winding group corresponding to the switching contact and the electronic changeover switch is corrected according to the change in the torque constant of the winding state; Generator controller. In the motor generator control device according to claim 4,
Each of the winding groups
a first winding element and a second winding element;
a first bypass wiring and a second bypass wiring;
has
The switching mechanism unit has a series winding state in which the first winding element and the second winding element are connected in series, a series winding state in which the first winding element and the second winding element are connected in series, and a parallel winding state in which line elements are connected in parallel, and a first switch and a second switch forming a plurality of contacts for switching the winding state of each of the winding groups by opening and closing,
The first switch is arranged between the first winding element and the second winding element and is configured to be connectable to the first bypass wiring bypassing the first winding element,
The second switch is arranged in the second bypass wiring connected to the neutral point while bypassing the first switch and the second winding element, and the electronic changeover switch is arranged in the arranged in the second bypass wiring,
The control unit supplies a correction current through the second bypass wiring at the timing when the mechanical contact is opened and closed, thereby flowing through the winding group corresponding to the mechanical contact and the electronic changeover switch. A motor-generator control device that controls the switching mechanism and the inverter so that the phase current is corrected according to the change in the torque constant of the winding state .

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