JP2001037247A - Power supply unit, equipment and motor drive provided therewith, and electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit for connecting two DC power supplies of different voltages, such as an electric system for driving and an electric system for a control circuit of an electric vehicle, and for transmitting power between these power supplies. SOLUTION: When there are an inverter for driving a three-phase motor and two DC power supplies connected to the inverter, each of the DC power supplies is divided into two or more parts and a neutral point Q1 of a three- phase motor 30, and a mid point P6 between low voltage batteries 61, 62 which are a second DC power supply are connected. Moreover, the positive pole side and the negative pole side of the low voltage batteries are connected to a division point P5 of another DC power supplies (fuel batteries) 21, 22 through diodes DmU and DmL respectively. By controlling the current of each phase of the three-phase motor through the inverter, the voltage at the neutral point of the three-phase motor 30 can be controlled. The low voltage batteries are charged by this voltage. The three-phase motor 30 can be driven also by the low voltage batteries 61, 62 through diodes DaU and DaL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having two DC power supplies and an apparatus and a vehicle using the power supply device. More specifically, the present invention relates to a multi-phase motor for switching power from one DC power supply by switching a switching element. The present invention relates to a power supply device provided with a power control circuit for supplying power to a vehicle, and a device or a vehicle equipped with the power control device.

[0002]

2. Description of the Related Art Electric energy can be used in a wide range of technical fields such as heat, light, power, and information communication, and is used as an energy source in various industries. Ratings are set for each device using the electric energy, and normal operation is guaranteed under the specified rated voltage and rated power. Therefore, general industrial equipment includes a plurality of equipments having different rated voltage values and a plurality of power supplies having different power supply voltages for these equipments. For example, an electric vehicle includes a high-voltage operated motor used for driving the vehicle, and a low-voltage electric system for a computer, a lamp, and other auxiliary devices for controlling the output torque of the motor.

[0003] Further, with the progress of semiconductor power converters, power converters such as inverters, converters, chopper circuits and the like can be easily configured using semiconductors such as power transistors and thyristors, and these can be controlled with high precision by a computer. Is available. Therefore, industrial equipment in recent years includes charging / discharging means capable of charging / discharging electric energy as the plurality of power supplies, for example, a battery or a power capacitor, and converts unnecessary mechanical energy or the like into electric energy, and converts this into charging / discharging means. Energy saving is achieved by regeneration and charging. Also, an auxiliary power supply is prepared for backup or the like when a failure occurs in the main power supply.

[0004]

However, in an apparatus provided with a plurality of DC power supplies, there are various restrictions when a multi-phase motor is driven by the plurality of DC power supplies or when power is transferred from one power supply to the other. was there. For example, considering a case in which a polyphase motor is driven from both of two DC power supplies, a configuration in which connection is switched using a relay or the like,
A configuration is required in which the windings of the motor are duplicated and each coil is independently connected to a power supply. Further, in the configuration using a plurality of DC power supplies, when conditions such as whether any one of the DC power supplies is a rechargeable secondary battery or which power supply voltage is high change, the power transfer is performed. However, it has been pointed out that a step-down circuit and a step-up circuit must be separately provided, and the circuit configuration becomes complicated.

The present invention has been made to solve the above problems, and has been made to simplify the configuration of a power supply device having a plurality of power supplies for driving a polyphase motor.
Another object is to simplify the device configuration of an electric vehicle or the like incorporating the power supply device.

[0006]

Means for Solving the Problems and Their Functions and Effects The power supply device of the present invention made to solve the above problems is
A first DC power supply, a field coil interposed between the star-connected polyphase motor and the first DC power supply, and switching of a switching element to supply power from the first DC power supply to the multi-phase motor. A power supply device comprising: a power control circuit for supplying a phase motor; and a second DC power supply separate from the first DC power supply, wherein the first DC power supply is divided into at least two or more and serially Connected, providing a terminal for connection to the outside at the division point, connecting one terminal of the second DC power supply to the intersection of the star connection of the polyphase motor, The gist is that the other terminal is connected to the division point of the first DC power supply via a rectifying element in a direction for preventing a current from flowing out from the second DC power supply. This power supply device has a configuration in which first and second DC power supplies are simply connected to a polyphase motor having a star-connected field coil. Such a configuration has a configuration in which the first DC power supply is divided into a plurality of parts and connected in series. However, the second DC power supply may be one, or may be divided into two or more power supply units. . Further, when the first and second DC power supplies are divided into two, dividing the power supply capacities into substantially equal sizes is simple in circuit design. Of course, it is also possible to use it asymmetrically.

In the power supply device having the above-described structure, the field coil of the connected multi-phase motor is connected in a star connection (in the case of a three-phase motor, Y is connected).
Since the potential at the intersection point, which is referred to as a "character connection", is controllable, it is possible to use the two DC power supplies in various modes by using this.

For example, when the second DC power supply is a rechargeable power supply having a lower voltage than the first DC power supply, the on / off of the switching element is controlled to change the potential at the intersection of the star connection of the polyphase motor. Controlling the power of the first power supply to the second
Is charged. According to such a configuration, it is possible to charge the second DC power supply while operating the polyphase motor with a simple configuration.

Further, the second DC power supply is divided into two power supply units and connected in series, and a midpoint of the series connection is connected to an intersection of the star connection of the multiphase motor. And each of the positive and negative sides of the second DC power supply is connected to the split point of the first DC power supply via each rectifying element in a direction that prevents the flow of current from the second DC power supply. Then, the potential at the intersection of the star-shaped connection of the polyphase motor may be alternately controlled to the positive side and the negative side to charge the two power supply units alternately. In this case, charging can be performed alternately, so that it is possible to use one while charging the other.

[0010] In the above configuration, at least a deviation between the charging states of the two power supply units constituting the second DC power supply is detected, and the two power supplies are set so that the detected deviation of the charging state falls within a predetermined range. Switching of charging of the unit may be performed. In this way, the charging states of the two power supply units can be controlled within a predetermined range. The deviation of the state of charge may be directly detected as a deviation, or the state of charge may be individually detected and calculated as the difference.

According to a second power supply device of the present invention, a first DC power supply, a polyphase motor having a field coil connected in a star shape, and the first
A power control circuit interposed between the DC power supply and the power supply circuit for supplying power from the first DC power supply to the multi-phase motor by switching of a switching element; and a second DC power supply separate from the first DC power supply. A power supply device comprising: a first DC power supply divided into at least two parts and connected in series; a terminal for connection to the outside provided at a division point;
One terminal of the DC power supply is connected to the intersection of the star connection of the polyphase motor, and the other terminal of the second DC power supply is connected from the second DC power supply side through the switching element. The gist is that it is connected to the field coil of the multi-phase motor so as to be able to conduct electricity.

[0012] The power supply device can supply electricity to the field coil of the polyphase motor from the second DC power supply via the switching element. Using this configuration, the second
It is also possible to make a so-called unipole operation of the polyphase motor using the DC power supply of the above as a power source. When the voltage of the second DC power supply is different from the voltage of the first DC power supply, a rectifying element such as a diode may be provided on the lower DC power supply side, or a contact may be provided. The first DC power supply and the second DC power supply may be alternatively connected to the switching element.

Further, a third power supply unit according to the present invention includes a first DC power supply, a polyphase motor in which a field coil is connected in a star shape, and a switching element having a field coil interposed between the first DC power supply. A power supply device comprising: a power control circuit that supplies power from the first DC power supply to the multi-phase motor by switching; and a second DC power supply that is separate from the first DC power supply,
The second DC power supply is divided into two power supply units and connected in series, a connection terminal is provided at a midpoint of the series connection, and the connection terminal of the second DC power supply is And connecting at least one of the positive and negative sides of the power supply unit of the second DC power supply from the second DC power supply through the switching element through the switching element. The gist is that the motor is connected to the field coil of the phase motor so as to be able to conduct electricity.

In such a configuration, the second DC power supply is divided into two power supply units, and it is possible to operate a multi-phase motor in a so-called unipole operation by using one of the two power supply units as a power source. When the voltage of the second DC power supply is different from the voltage of the first DC power supply, a rectifying element such as a diode may be provided on the lower DC power supply side, or a contact may be provided. The configuration in which the first DC power supply and the second DC power supply are alternatively connected to the switching element may be the same as the above-described configuration.

This power supply device can be used in various ways. One is a configuration in which, when the first DC power supply is a chargeable power supply having a higher voltage than the second DC power supply, the voltage of the second DC power supply is boosted to charge the first DC power supply. . Such step-up charging is performed by controlling turning on / off of a switching element, performing step-up using the field coil of the polyphase motor, and charging the first DC power supply with the power of the second power supply. Is achieved.

In this power supply device, the field coil of the polyphase motor, the switching element of the power control circuit, and the like can be used as boosting components, and the configuration can be simplified.

At least a deviation of the state of charge of each divided power supply of the first DC power supply is detected, and the two power supply units are switched so that the deviation of the detected state of charge falls within a predetermined range. The charging may be performed. By employing such a configuration, the state of charge of the divided first DC power supply can be kept within a predetermined range.

As a specific circuit configuration of such a configuration, a power control circuit is prepared for each field coil of the multi-phase motor by pairing the switching elements.
The switching element pair is connected between the positive and negative power supply lines of the first DC power supply, and each switching element includes:
A flyback diode is connected, an intermediate point where the switching elements are connected to each other is connected to the field coil, and the step-up charging means is connected to the second DC of the paired switching elements. One of the switching elements on the side forming a closed circuit including a power supply and the field coil is turned on, then the switching element is turned off, and the first element is connected via the flyback diode.
Charging means for charging the DC power supply. Since a flyback diode is usually used in a circuit using a switching element, a configuration in which boost charging is performed without new components can be realized.

In the above configuration, the configuration of the first invention, that is, the first DC power supply is divided into a plurality of parts and connected in series,
Is connected to the intersection of the star connection of the polyphase motor, and the other terminal of the second DC power supply is
It is also possible to add a configuration connected to a division point of the first DC power supply via a rectifying element in a direction for preventing the flow of current from the second DC power supply.

Also, as the first and second DC power supplies, a battery or a large-capacity capacitor can be used.
Batteries accumulate electrical energy using chemical changes, and include various secondary batteries that have been used in the past, such as lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lithium-ion batteries, and lithium polymer batteries. Available. A secondary battery can store power for a relatively long time when compared with a capacitor. As the large-capacity capacitor, a capacitor such as an electric double layer capacitor is known. Since a capacitor has a self-discharge characteristic, it is generally charged at the time of use, and an electric system using a power capacitor requires a charging circuit for charging the capacitor. Therefore,
This charging circuit can be substituted by the configuration of the power supply device of the present invention. Further, even in a system having a charging circuit for a large-capacity capacitor separately, it is also possible to use the configuration of the power supply device of the present invention when the charging circuit is malfunctioning or the electric energy is insufficient. Further, as the first and second DC power supplies, it is also possible to use a power supply such as a non-rechargeable battery or a generator, such as a fuel cell. These various types of power supplies may be employed depending on the application used.

The various types of power supply devices described above can be applied to various devices. For example, an apparatus equipped with a motor driven directly by fuel as one of the power sources and provided with the first power supply device of the present invention, wherein the multi-phase motor is rotatable around an output shaft of the motor. A coupled DC motor, wherein the first DC power supply is a power supply for driving the motor, and the second DC power supply is a power supply for a control device that controls the device. When the remaining capacity of the DC power supply 2 is equal to or less than a predetermined value, the on / off ratio of the switching means is controlled to change the potential at the intersection of the star connection, and the first DC power supply It can be used as a device including a charging unit for charging the second DC power supply. In such a device, when the remaining capacity of the second DC power supply is equal to or less than a predetermined value, the second DC power supply can be charged by changing the potential of the star connection of the polyphase motor.

[0022] Further, the present invention is an apparatus equipped with a prime mover directly driven by fuel as one of the power sources, and further provided with the second and third power supply devices of the present invention, wherein the multi-phase motor is provided with the prime mover. An electric motor rotatably coupled to an output shaft, the first DC power supply is a power supply for driving the motor, and the second DC power supply is a power supply for a control device that controls the device. And starting control means for driving the electric motor to start the motor when the motor is started, and when the remaining capacity of the first DC power supply is insufficient for starting the motor at the time of starting. It is also possible to use the apparatus as a device including a start-up charging unit that drives the boosting charging unit and charges the first DC power supply with the second DC power supply. With this configuration, when the remaining capacity of the first DC power supply is insufficient at the time of starting, the prime mover can be started after charging the first DC power supply with the second DC power supply.

As such a device, an electric vehicle that uses an internal combustion engine as a prime mover and runs with power from an internal combustion engine and / or an electric motor can be considered.

The present invention can also be realized as a motor driving device. That is, this motor driving device is a motor driving device provided with the second power supply device of the present invention, and uses the power control circuit to drive the polyphase motor with the first DC power supply. And individually turning on and off the switching elements connected to the power lines of the connected first and second DC power supplies, and using the second DC power supply to unipolarly switch the polyphase coil. And a second motor driving unit that operates.

According to this configuration, the polyphase motor can be driven by the second DC power supply by a so-called unipole operation. It should be noted that the second DC power supply is divided into two parts, and a bipole operation is also possible by using the two parts alternately.

Further, in such a motor drive device, a power control circuit is prepared for each field coil of the multi-phase motor in a pair of the switching elements, and the switching element pair is connected to the first DC power supply. An intermediate point, which is connected between the positive and negative power supply lines and where the switching elements are connected to each other, is connected to the field coil. A second motor driving means is connected to the second DC power supply and the field coil. One of the paired switching elements may be sequentially turned on and off so as to form a closed circuit including a coil, thereby forming a field in the polyphase motor. According to such a configuration, the configuration of the well-known inverter using the switching element can be used as it is, which is simple.

As an apparatus provided with the above-described motor drive device, for example, a vehicle can be considered. That is, a vehicle equipped with a prime mover directly driven by fuel as one of the driving sources, wherein the multi-phase motor is coupled to a drive shaft of the vehicle or a rotation shaft of the prime mover, and the driving state of the vehicle depends on the driving state. Accordingly, as an electric vehicle that drives the drive shaft using the power of the prime mover and / or the polyphase motor,
The present invention can be embodied. In such an electric vehicle, the polyphase motor can be driven using either of the two DC power supplies, and when one DC power supply fails or the remaining capacity decreases, the other DC power supply is used to drive the polyphase motor. It can be used to drive and run a vehicle.

[0028]

Another embodiment of the present invention The power supply device of the present invention is not limited to the above embodiment, but includes the following embodiment. First, the division of the first DC power supply may be three or more. Further, the dividing point of the first DC power supply connected via the rectifying element in the direction for preventing the flow of current from the second DC power supply does not need to be limited to a single point. In the case where the image is divided into two, it is also possible to connect to different division points. Further, in the configuration in which boost charging is performed using the second DC power supply, the number of polyphase motors and boost charging means provided with the field coils need not be single, but may be plural. If the step-up charging means in the power supply device of the present invention is configured by using the field coils and the charging means of each of the plurality of multi-phase motors, the step-up charging means can be configured in multiple layers. In the case where the charging means having n layers and m layers is configured, n output currents whose phases are shifted by 2π / n from each other at the same duty ratio shifted by 2π / m in electrical angle are provided for added charging. .

Further, as a component requirement of the power supply device,
It also includes adding normal electrical elements. For example, when the inductance component of the DC power supply is so large that it cannot be ignored, a low-pass filter or the like may be added in order to prevent deterioration of the switching characteristics of the switching element due to the inductance component. Further, without separately preparing an electric element, a reactance, a capacitor, a resistor, and the like constituting the low-pass filter, a reactance, a capacitor, and a resistor used as a part constituting another electric circuit may be used. .

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment: An embodiment of the present invention will be described below using an example. FIG.
1 is a schematic configuration diagram of an electric system of a fuel cell electric vehicle including a power supply device according to an embodiment of the present invention. FIG. 2 shows a system configuration of the electric vehicle, and FIG.
Details of the electric system from 22 to the motor 30 are shown in FIG. Although the power supply device of the present invention is not limited to an application such as an electric vehicle, the power supply device will be described along with specific use as a vehicle for easy understanding of a use state.

As shown in FIG. 2, this vehicle is provided with a three-phase motor 30 as a drive source.
By disengaging the differential gear 33, the wheels 36, 37
Is transmitted to Electric energy for driving the three-phase motor 30 is generated by the two fuel cells 21 and 22. The fuel cells 21 and 22 are solid polymer membrane fuel cells that generate power using hydrogen and oxygen as fuel gas. Although oxygen in the atmosphere is used for oxygen, hydrogen gas is obtained by reforming methanol stored in a tank 41 by a reformer 43. In this electric vehicle, a fuel cell control unit 48 for controlling a fuel cell system 45 including the reformer 43 and a power system 51 for driving the three-phase motor 30 using generated electricity are controlled. A control unit 50 is provided.

According to FIG. 1, the electric system 5 of the electric vehicle
The outline of No. 1 will be described. The power system 51 includes a three-phase motor 30 using the above-described two fuel cells 21 and 22, two low-voltage (12 volt) batteries 61 and 62, and a DC power supply.
55 and four diodes D for driving the
It is composed of mU, DmL, DaU, DaL and the like.
A torque command value Tc * corresponding to the vehicle driving force and a command value In * for charging the low-voltage batteries 61 and 62 are input to the control unit 50 from the outside. The inverter 55 is controlled on the basis of data from various sensors provided in. FIG. 1 shows only the fuel cell current sensor 58 that detects a current flowing into a connection point between the two fuel cells 21 and 22 as a sensor, but actually a sensor that detects each phase current of the three-phase motor 30 And sensors for detecting the number of revolutions of the three-phase motor 30, and remaining capacity sensors 81 and 82 (see FIG. 1) for detecting the charged amounts of the low-voltage batteries 61 and 62. Note that, for example, there is a motor that can be detected by monitoring another parameter such as a change in each phase current, such as the rotation speed of the three-phase motor 30. In such a case, it may be detected directly by a sensor or may be calculated using another parameter.

Configuration of Power System 51: Details of the electrical connection in the power system 51 will be described with reference to FIG. The two fuel cells 21 and 22 are connected in series, and the positive power line P1 and the negative power line P2 are connected to the inverter 55 as they are. The inverter 55 forms a transistor inverter centered on the transistors Tr1 to Tr6. These transistors Tr
1 to Tr6 are arranged in pairs each of which is on the source side and the sink side with respect to the power supply lines P1 and P2, and each of the three-phase coils (UVW) of the three-phase motor 30 is connected to the connection point. ing. Each transistor Tr1 to Tr6
, Diodes (anti-parallel diodes) D1 to D6 for protection against back electromotive force are interposed. From the control unit 50, the inverter 55
Are output as control signals Su, Sv, Sw for driving the respective transistors Tr1 to Tr6, and their inverted signals (in the following description, both signals are collectively referred to as control signals). When the three-phase motor 30 is operated (power running and regeneration), the control unit 50
The ratio of the on time of 1 to Tr6 is determined by the control signals Su, S
The control is sequentially performed by v and Sw.

In the three-phase motor 30, the three-phase coils U, V, and W for the magnetic field are connected in a star shape (Y-connection), and the three-phase coils are connected to a neutral point Q1, which is an intersection of the coils U, V, and W. Is also a type of motor provided with connection terminals. This three-phase motor 30
The current flowing through each phase coil U, V, W is controlled to a pseudo sine wave by PWM control in the control unit 50, and is controlled to have a waveform shifted from each other by 120 degrees. As a result, when the three-phase motor 30 is running, a rotating magnetic field is formed by the current flowing through the three-phase coils U, V, W, and the rotor with the permanent magnet attached to the outer periphery is , Rotating by interaction with this magnetic field,
The wheels 36 and 37 are driven through 1 to drive the vehicle. The connection of the neutral point Q1 of each phase coil will be described later in detail.

Next, connection of a fuel cell or a low-voltage battery will be described. The fuel cells 21 and 22 according to the present embodiment
However, it can be seen that one fuel cell is divided into two. Therefore, this fuel cell 21,
The 22 connection points are called "division points". The positive electrode side and the negative electrode side of the low-voltage batteries 61 and 62 are connected to the division point P5 via diodes DmU and DmL. The connection direction of the diodes DmU and DmL is a direction in which the flow of the current from the division point P5 to the low-voltage battery side in the charging direction is allowed and the flow in the reverse direction is prevented.

The two low-voltage batteries 61, connected to the fuel cells 21, 22 via the diodes DmU, DmL,
62 corresponds to a second DC power supply. The connection point of the two low-voltage batteries connected in series is hereinafter referred to as a “middle point”. The middle point P6 is connected to the neutral point Q1 of the three-phase motor 30. In this embodiment, the three-phase motor 30 is connected to the neutral point. However, the three-phase motor 30 is always connected to the neutral point (a point where the potential becomes 0 when the three-phase motor is driven by a sine wave shifted by 120 degrees). No need to connect to. Each phase coil U,
The three-phase motor 30 may be provided at the intersection of V and W.
May be at an intersection at which a predetermined potential is obtained when the device is operated.

The positive electrode of the low voltage battery 61 is connected to the positive power line P1 of the inverter 55 via a diode DaU, and the negative electrode of the low voltage battery 62 is connected to the negative power line of the inverter 55 via a diode DaL. Each is connected to the line P2. Diode Da
The connection directions of U and DaL are directions in which the flow of current in the discharge direction from the low-voltage battery side is allowed and the flow in the reverse direction is blocked.

Various controls: FIGS. 1 to 3
, The schematic configuration of the power supply device of this embodiment and the electric vehicle equipped with the power supply device have been described. The control system of the three-phase motor 30 will be further described with reference to a functional block diagram of FIG. In FIG. 4, detailed connections of the power supply system are omitted, and only necessary items are described along the control flow. As shown in the figure, the control unit 50 includes a motor current command unit 52 and a PWM control unit 53 in control.
Is provided. The motor current command unit 52 receives a motor torque command value Tc * from the outside, and outputs current command values Iu *, Iv *, Iw of each phase. * Is output. actually,
Since torque control is performed using the d-axis current and the q-axis current of the motor, two-phase / three-phase conversion is internally performed. The PWM control unit 53 corrects the received current command value with the neutral point current command value In * to obtain correction command values Iu **, Iv **, Iw ** of each phase current. Actual currents Iu, I actually flowing through the coils of each phase
The on time of the transistor of the inverter 55 is controlled by v and Iw. Actual currents Iu, Iv, Iw
Are detected by the current sensors 71, 72, 73.
The three-phase motor 30 is provided with a rotation sensor 75. The sensor 75 detects the angle of the rotor of the three-phase motor 30 and the electric angle θ of the motor required for control. The electrical angle θ is used for two-phase / three-phase conversion in the motor current command unit 52.

In the power supply device of this embodiment described above and the electric vehicle equipped with the power supply device, the following three types of processing are electrically performed using the fuel cells 21 and 22 and the low-voltage batteries 61 and 62. Can be realized. It is needless to say that it is not necessary to perform all of these processes, and it is only necessary to perform only the control necessary for vehicle control. (1) Three-phase motor 30 using fuel cells 21 and 22 as power sources
(2) a process of charging the low-voltage batteries 61 and 62 by the fuel cells 21 and 22 while the vehicle is traveling; and (3) a process of driving the three-phase motor 30 using the low-voltage batteries 61 and 62 as a power source. The processing of (1) among these processing is not different from the conventional processing, and therefore the description is omitted.

[1] Charging a low-voltage battery with a fuel cell
Electricity control: The fuel cells 21 and 22 during the running of the vehicle (2)
The process for charging the low-voltage batteries 61 and 62 will be described below. In the three-phase motor 30, if the neutral point Q1 is not connected to any external circuit, each phase current Iu,
The sum of Iv and Iw is always 0, but if the neutral point Q1 is connected to an external circuit, it is possible to allow the current to flow from the neutral point Q1. This is because, in the control of the three-phase motor 30, the potential at the neutral point can be controlled. In FIG.
An equivalent circuit for charging one low-voltage battery 62 is shown. At this time, the relationship between the current ΔIB flowing from the neutral point Q1 of the three-phase motor 30 to the low-voltage battery 62 and the neutral point potential Vb is shown in FIG. If the potential of the connection point between the fuel cells 21 and 22 is 0 and the neutral point potential is the voltage Vb0 when the charging current ΔIB of the low-voltage battery 62 is 0, the sum of the phase currents Iu, Iv and Iw is 0. And Iu + Iv + Iw = 0. Further, a current IB (+) flowing from the positive electrode side of the two fuel cells 21 and 22 and a current IB flowing into the negative electrode side thereof
(−) Are equal, and the current ΔIB from the neutral point Q1 of the three-phase motor 30 to the low voltage battery 62 to reach the division point P5 of the fuel cells 21 and 22 becomes zero.

Here, consider the case where the low voltage battery 62 is charged using the fuel cells 21 and 22. Since the division point P5 of the fuel cells 21 and 22 and the negative electrode side of the low-voltage battery 62 are connected via the diode DmL,
Assuming that the division point P5 has a potential of 0, if the potential of the neutral point Q1 of the three-phase motor 30 is high enough to charge the low-voltage battery 62, charging is performed.
Assuming that the voltage of the low-voltage battery 62 itself is Vb, the neutral point potential VN is controlled by controlling the neutral point potential of the three-phase motor 30.
What is necessary is just to make it higher than the voltage Vb0 by the potential difference a. At this time, from the neutral point Q1 to the low voltage battery 6
Assuming that the current flowing for charging of No. 2 is In, the equation of the current balance is as follows: Iu + Iv + Iw + In = 0 (1) ΔIB = IB (+) − IB (−) (2)

FIG. 7 shows a process for performing such current control.
This will be described with reference to the flowchart of FIG. When the electric vehicle of the embodiment runs using the three-phase motor 30, the control unit 50 first performs a process of reading a motor torque command value Tc * (step S100). The motor torque command value Tc * can be obtained as a necessary shaft output from, for example, the accelerator pedal depression amount and the vehicle speed. Next, control unit 50 calculates command values Iu *, Iv *, Iw * of each phase current based on this motor torque command value Tc * (step S110). Each phase current required to obtain the required torque is internally calculated by the current command unit 52 by calculating the d-axis current, and the result is subjected to two-phase / three-phase conversion, The command value of each phase current is obtained.

Next, a process of reading the neutral point current command value In * is performed (step S120). The neutral point current command value In * corresponds to a charge command value for the low-voltage battery 61 or 62. The charge command value is a remaining capacity sensor 81,
The control unit 50 computes based on the remaining capacity of the low-voltage batteries 61 and 62 detected by 82, the operation state of the fuel cells 21 and 22, and the rated charging current of the low-voltage batteries 61 and 62. In the equivalent circuit of FIG. 5, the neutral point current command value In * is
2 corresponds to the charging current ΔIB. The current I to be exchanged between the neutral point Q1 of the three-phase motor 30 and the outside
n * is eventually balanced with each phase current as shown in the above equation (1). Therefore, a current Io * to be added to each phase current is obtained as a magnitude of 1/3 of the neutral point current command value In * (step S130).

The obtained current Io * is added to the current command values Iu *, Iv *, Iw * of each phase, and the current command values of each phase are corrected. Iv *
*, Iw ** (step S140). Thereafter, the correction command value and the current I actually flowing in each phase
Based on u, Iv, and Iw, the on-time of each transistor of the inverter 55 is determined, and so-called PWM control is performed to control the current flowing through each of the field coils U, V, and W of the three-phase motor 30 (step). S150). In this process, the values detected by the current sensors 71 to 73 may be used as the actual currents Iu, Iv, Iw of each phase.

By performing the above-described processing, the current flowing into each phase coil of the three-phase motor 30 eventually becomes Io *
And the potential at the neutral point Q1 increases accordingly. As a result, the potential difference between the neutral point Q1 and the division point P5 of the fuel cells 21 and 22 becomes higher than the output voltage Vb of the low-voltage battery 62 by a predetermined voltage a, and the low-voltage battery 62 It will be charged by ΔIB (= In *). FIG. 8 shows the relationship between each phase current and the charging current in this case, and the state of the neutral point potential VN. At this time, as shown in FIG. 9 which is an equivalent circuit, the current flows out more from the fuel cell 21 side, and the difference IB (+) − IB (−) of this current becomes the charging current of the low-voltage battery 62. Would be equivalent.

By the above-described processing, the fuel cell 21,
The low-voltage battery 62 can be freely charged even during operation of the three-phase motor 30 using the first DC power supply 22 as the first DC power supply. Of course, it is easy to charge the low-voltage battery 61 by controlling the neutral point voltage of the three-phase motor 30 to the negative side. FIG. 10 shows an equivalent circuit in this case. Also,
FIG. 11 shows the relationship between the current and applied voltage of each phase coil when charging the low-voltage battery 61 and the neutral point voltage Vb. The basic operation is not different from the case where the low-voltage battery 62 is charged. It should be noted that which of the low-voltage batteries 61 and 62 is charged may be determined according to the remaining capacity of each battery detected by the remaining capacity sensors 81 and 82. In order to charge both of them substantially equally, the neutral point potential may be alternately controlled to a plus side and a minus side with a predetermined hysteresis.

[2] Three-phase motor using low-voltage battery
Driving control: (3) low-voltage batteries 61 and 6
The process of driving the three-phase motor 30 using the power supply 2 as the power source has been described. This process will be described. When the electric vehicle starts running, the fuel cells 21 and 22 may not be functioning sufficiently yet, and their output voltage may be low. In this state, the three-phase motor 30 is driven using the low-voltage batteries 61 and 62, and the vehicle can travel. As shown in FIG. 12, a relay contact is provided between the fuel cells 21 and 22 and the inverter 55, and while the three-phase motor 30 is driven by the low-voltage batteries 61 and 62, the inverter 5
It is also desirable to cut off the connection between the fuel cell 5 and the fuel cells 21 and 22 in order to ensure control simplicity. In the following description, the contacts 91 and 92 of the relay are used to connect the fuel cells 21 and
2 and the inverter 55 are disconnected. This relay is controlled by the control unit 50.
ON / OFF of the contacts 91 and 92 is controlled.

In the state shown in FIG. 12, the fuel cells 21 and
Instead of 22, the low-voltage batteries 61 and 62 are connected to the inverter 55 via the diodes DaU and DaL. Therefore, if the control unit 50 controls on / off of each of the transistors Tr1 to Tr6 of the inverter 55, the three-phase motor 30 can be driven by using the low-voltage batteries 61 and 62 as voltage sources, and the vehicle can run. . One of these uses is the fuel cell 21,
The vehicle travels during a period when the output of the motor 22 does not sufficiently increase yet, and the other is a limp home that allows the vehicle to travel to a garage or a repair shop by itself when the fuel cell system fails. In the former case, the vehicle runs using the low-voltage batteries 61 and 62 until the reformer and other devices reach normal operation. In this case, the low-voltage batteries 61, 6
2 may have a capacity that allows the vehicle to normally travel for a predetermined time. In the latter case, the driving in an emergency is intended, so that the capacity of the low-voltage batteries 61 and 62 does not need to be very large.

When the three-phase motor 30 is driven by using the low-voltage batteries 61 and 62, if both batteries are used, there is no difference from the normal control, but only one of the low-voltage batteries is used. It is also possible to drive the three-phase motor 30. In this case, as shown in FIG. 13, the transistors Tr2, Tr4, Tr6 may be driven to drive the three-phase motor 30 using the low-voltage battery 62, or conversely, the transistors Tr1, Tr3, Tr5 To drive the three-phase motor 3 using the low-voltage battery 61. In the former case, the current flows sequentially from the positive electrode side of the low-voltage battery 62, that is, the middle point P6, through the respective phase coils of the three-phase motor 30, and the transistors Tr2
It passes through Tr4 and Tr6 and returns to the low voltage battery 62 via the diode DaL. The other low-voltage battery 6
When 1 is used, a current flows through each phase coil through the diode DaU and the transistors Tr1, Tr3, and Tr5. Therefore, although the direction of the current flowing through the coil is reversed depending on which battery is used, the three-phase motor 30 can be controlled in any case by controlling the on / off timing of the transistor (order of each phase). Forward and reverse rotation can be controlled freely. Such control using the transistor group on one side of the inverter is usually called a unipole operation.

According to the first embodiment described above, a dedicated DC / DC converter is not required for the charging operation from the first DC power supply to the second DC power supply, and the circuit configuration can be simplified. can do. Further, since the three-phase motor 30 can be driven by any of the fuel cells 21 and 22 as the first DC power supply and the low-voltage batteries 61 and 62 as the second DC power supply, the reliability as a vehicle is improved. Can be improved.

(2) Second Embodiment: Next, a second embodiment of the present invention will be described. FIG. 14 is an explanatory diagram illustrating a schematic configuration of a hybrid vehicle equipped with the power supply device of the second embodiment. A hybrid vehicle is a vehicle equipped with both an engine and a motor. As described below, the hybrid vehicle shown in FIG. 14 has a configuration in which the power of the engine can be directly transmitted to the drive wheels. Such a hybrid vehicle is particularly called a parallel hybrid vehicle.

Basic Structure of Hybrid Vehicle of Second Embodiment: The hybrid vehicle shown in FIG. 14 has an engine 150 driven by using gasoline as fuel, and first and second motors M
A power conversion output device 110 including G1, MG2 and a planetary gear 120 is provided. Engine 150 capable of outputting power, first motor MG1, second motor MG
The two are mechanically connected via a planetary gear 120. The planetary gear 120 is also called a planetary gear and has three rotation shafts connected to respective gears described below. The planetary gear 120 includes a sun gear 121 that rotates at the center, and a planetary pinion gear 12 that revolves while rotating around the sun gear.
Third, a ring gear 122 that rotates on its outer periphery. The planetary pinion gear 123 is supported by a planetary carrier 124.

Engine 150 as a prime mover provided in the power system is a normal gasoline engine, and rotates crankshaft 156. In the hybrid vehicle of this embodiment, the crankshaft 156 of the engine 150 is connected to the planetary carrier shaft 127 via the damper 130. The damper 130 has a crankshaft 156
This is provided to absorb torsional vibrations that occur in. The rotor 132 of the motor MG1 is connected to the sun gear shaft 125. The rotor 142 of the motor MG2 is connected to the ring gear shaft 126. The rotation of the ring gear 122 is controlled by the chain belt 129, the differential gear 1
Axle 112 and wheels 116R, 116L via
Is transmitted to The engine 150 is an EFI ECU 170
Is controlled and operated. EFI ECU 170
Is a one-chip microcomputer having a CPU, a ROM, a RAM, and the like therein. The CPU executes a fuel injection charge and other controls of the engine 150 according to a program recorded in the ROM. Although not shown, various sensors indicating the operating state of the engine 150 are connected to the EFIECU 170 to enable these controls.

Motors MG1, MG provided in power system
Reference numeral 2 denotes a synchronous motor generator, which includes rotors 132 and 142 each having a plurality of permanent magnets on the outer peripheral surface, and stators 133 and 1 on which a three-phase coil forming a rotating magnetic field is wound.
43. The stators 133 and 143 are the case 11
9 is fixed. The three-phase coils wound around the stators 133 and 143 of the motors MG1 and MG2 are connected to the battery 1 via first and second drive circuits 191 and 192, respectively.
94. First and second drive circuits 191,
Reference numeral 192 denotes a transistor inverter including two transistors as switching elements for each phase. The first and second drive circuits 191 and 192 are connected to the control unit 190. When transistors of drive circuits 191 and 192 are switched by a control signal from control unit 190, battery 194 and motor MG
1 and MG2. Motor MG1, MG
The motor 2 can operate as an electric motor that rotates and receives the supply of electric power from the battery 194 (hereinafter, this operation state is referred to as power running), and the motor 3 operates when the rotors 132 and 142 are rotated by external force. The battery 194 can also be charged by functioning as a generator for generating an electromotive force at both ends of the phase coil (hereinafter, this operation state is referred to as regeneration). The hybrid vehicle of the present embodiment can run in various other states based on the action of the planetary gear 120, but a description of a specific running mode is omitted. The control unit 190 includes a rotation speed sensor 13 for detecting an operation state of the power conversion output device 110.
Various sensors such as 4,144 are connected.

Connection of Electric System of Second Embodiment: Next, two power supply systems mounted on this hybrid vehicle will be described. As described above, the high-voltage battery 194 corresponding to the first DC power supply is mounted on the hybrid vehicle, and the battery 194 is connected to the first and second drive circuits 191 and 192, respectively. 2 motors MG1,
It is connected to MG2 so that power can be exchanged between them. The voltage of this power supply system is less than about 300 volts, and is hereinafter referred to as a high-voltage electric system. On the other hand, this hybrid vehicle is also provided with a low-voltage power supply system corresponding to a second DC power supply.
It is connected to U170 and control unit 190. From the low voltage battery 184, a DC voltage of about 12 volts is supplied to each ECU. This power supply system is hereinafter referred to as a low-voltage electric system. As shown in FIG. 15, the high-voltage battery 194 and the low-voltage battery 184 have two batteries 194a and 194b and a battery 184, respectively.
a, 184b and the first drive circuit 191
Connected to each other.

The electrical configuration of the second embodiment shown in FIG. 15 has two fuel cells 21 and 22 as the first DC power supply.
Compared with the circuit diagram of the first embodiment (FIG. 3) using high-voltage batteries 194a and 194b corresponding to the first DC power supply.
Are the same except that they are secondary batteries. Therefore, the description of the detailed connection relation is omitted. Further, as shown in FIG. 14, the high voltage batteries 194a and 194b
Although it is also connected to the second drive circuit 192 for the second motor MG2, the connection with the second drive circuit 192 is omitted in FIG. Further, the high-voltage battery 194
a and 194b to drive the first motor MG1 and a method of controlling the neutral point potential of the first motor MG1 to charge the low-voltage batteries 184a and 184b. The description is omitted because it is the same. In this embodiment, the high-voltage batteries 194a, 194
When the low-voltage batteries 184a and 184b are charged using b, one of the high-voltage batteries 194a or 194b may be discharged or the other may be advanced. Therefore,
Remaining capacity SOCa, S of both batteries 194a, 194b
It is also preferable that the OCb is detected or estimated, and when the difference between the two becomes equal to or more than a certain value, the potential of the neutral point Q1 of the motor MG1 is switched between positive and negative to use both batteries 194a and 194b equally. It is. FIG. 16 shows the state of the switching control.

Next, the charging operation of the high-voltage batteries 194a and 194b using the low-voltage batteries 184a and 184b, which is a control unique to the second embodiment, will be described. It should be noted that the low-voltage battery 184 allows the high-voltage battery 194
Is charged for the following reason. When starting the engine 150 from a state where the hybrid vehicle is stopped and the engine 150 is also stopped, the control unit 190 locks the second motor MG2 and sets the high-voltage battery 194
The first motor MG1 is rotated by the electric power supplied from the first motor MG1. As a result, the planetary carrier shaft 127 of the planetary gear 120 rotates, and the crankshaft 156 is cranked. Therefore, if the high-voltage battery 194 is empty, the engine 150 cannot be cranked and the engine 150 cannot be started. Such a situation is caused by the high voltage battery 194
Is discharged for some reason, for example, when the vehicle is not used for a long time with the high-voltage battery 194 deteriorated due to aging, or when the vehicle is stopped immediately after climbing a long uphill road, the ignition key is turned off. This may occur when, for example, is turned off. This is a case where the remaining capacity of the high-voltage battery 194 is almost zero. In such a case, if power remains in the low-voltage battery 184, if the high-voltage battery 194 can be charged by boosting the power, the start control using the high-voltage battery 194 can be started. Once the engine 150 starts, the first motor MG1 can be used as a generator, so that the power to be transferred from the low-voltage battery 184 to the high-voltage battery 194 is the power required to start the engine 150.

Step-up control: FIG.
9 is a flowchart showing a boosting program when charging the high-voltage battery 194 using the power-up program 84. At the time of starting, the EFIECU 170 and the control unit 190
Electric power is supplied from the high-voltage battery 194 to the motor MG1 via the first drive circuit 191 to try to start the engine 150 by the first motor MG1. However, when it is determined that the normal operation ends abnormally and that the cause is the overdischarge of the high-voltage battery 194, the boosting program in FIG. 17 is started. When the boosting program is started, first, the control unit 190
The transistor Tr2 of the drive circuit 191 is set to 0.5 [sec.
c] A control signal for turning on / off at a predetermined duty ratio γ of the cycle (= on time Ton / (on time Ton + off time Toff)) is output. When the transistor Tr2 is turned on, the first motor MG1 is output from the low-voltage battery 184b.
Middle point, U-phase coil of motor MG1, transistor Tr
2. Low voltage battery 184b through diode DaL
Is intermittently formed (step S21).
0). As a result, the current flowing from the low-voltage battery 184b via the U-phase coil of the first motor MG1 gradually increases, and is stored here as magnetic energy. FIG. 18 shows the current change of each part over approximately one cycle at this time.
As shown in the figure, when the transistor Tr2 is turned on multiple times, the current flowing through the transistor Tr2 gradually increases. The predetermined time during which the transistor Tr2 is turned on is 0.42 [sec] in this embodiment. When the transistor Tr2 is turned off after the elapse of the on-time, the induced voltage generated by the magnetic energy stored in the U-phase coil of the first motor MG1 causes the high voltage batteries 194a and 194b via the diode D1.
Current flows instantaneously into the high-voltage batteries 194a and 1
94b is charged. That is, in the power supply device of the present embodiment, the U-phase coil, which is one of the armature coils of the first motor MG1, serves as the reactance of the booster circuit, and the diode D1 of the first drive circuit 191 as the inverter serves as the reactant of the booster circuit. Acts as a flyback diode.

The first from the signal from the control unit 190
The above operation is repeated by repeatedly turning on and off the transistor Tr2 of the driving circuit 191 of the high voltage battery 191, using the low voltage battery 184b as a power supply.
4a and 194b are gradually charged. The control of the transistor Tr2 by the conduction ratio γ is performed for a predetermined time TT
Is continued until the predetermined time TT has elapsed (step 220).
The energization of r2 ends. This time TT is determined as the time when the amount of charge to the high-voltage batteries 194a and 194b is equivalent to 10 [KJ] as work energy. That is, in this example, managing the time TT corresponds to detecting the charge amounts of the high-voltage batteries 194a and 194b. By repeating the above operation,
The low-voltage battery 194b is connected to the other low-voltage battery 18
4a, the transistor Tr1 is used instead of the transistor Tr2.
The above-described boost control may be performed. In this case, when the transistor Tr1 is turned off, the electric energy of the low-voltage battery 184a is temporarily stored in the form of magnetic energy in the U-phase coil, and then is transferred to the high-voltage battery 184a via the diode D2 functioning as a flyback diode. It flows into 194a and 194b and is charged.

When the charging of the high-voltage batteries 194a and 194b is completed, the program ends and the control returns to the normal control mode. When the necessary power is charged in the high-voltage batteries 194a and 194b, the control unit 190 thereafter sets
Control for starting engine 150 can be performed using first and second motors MG1 and MG2.

Operation and effect of the second embodiment: According to the hybrid vehicle of this embodiment configured as described above, the high-voltage battery 184a or 184b of the low-voltage electric system can be operated at a high voltage without providing a special boost converter. Electrical energy can be distributed to the voltage batteries 194a and 194b. Therefore, the high voltage batteries 194a, 19
Even if the battery 4b is overdischarged and cannot be started, the engine 150 can be started using the low-voltage battery 184a or 184b as a final power source. The booster circuit required at this time is the first motor MG
1 U-phase coil and first drive circuit 19 as an inverter
It is configured using one transistor Tr2 and diode D1, and is realized at a low cost with a small, simple electric circuit. These parts are electric parts originally provided in the hybrid vehicle. Therefore, problems such as an increase in cost and a decrease in reliability due to the adoption of new components are not caused. It goes without saying that the same operation and effect as those of the first embodiment can be obtained. That is, a dedicated DC / DC converter is not required for the charging operation from the first DC power supply to the second DC power supply, and the circuit configuration can be simplified. Further, the first motor MG1 can be driven by any of the high-voltage batteries 194, 194b as the first DC power supply and the low-voltage batteries 184a, 184b as the second DC power supply. Reliability can be improved.

Other Description: In the above description, the U-phase coil of the first motor MG1 is used as a reactance for temporarily storing power as magnetic energy for boosting, but the V-phase coil and the W-phase coil are used in the same manner. can do. That is, when a V-phase coil is used, the transistor Tr4 is turned on and off, and the high-voltage batteries 194a and 194b are charged via the diode D3. When a W-phase coil is used, the transistor Tr6 is turned on.
Off, and the high voltage battery 19 via the diode D5.
4,194b. The current flowing through each phase is
Since no contribution is made to the rotating magnetic field in the first motor MG1, the motor MG1 is
Does not rotate. Of course, similarly, each phase coil of the second motor MG2 can be used as a reactance.

(3) Other Configuration Examples: Next, some modifications of the above embodiment will be described. [1] If the three-phase motor 30 is not driven by the low-voltage batteries 61 and 62 described above, the diodes DaU and DaL
Need not be provided. One low-voltage battery can be used. In this case, the low-voltage battery may be connected to the neutral point Q1 of the three-phase motor and the dividing point P5 of the fuel cell via a diode that blocks the flow of current from the low-voltage battery. . If the low-voltage battery and the power supply line of the inverter 55 are connected via a diode, the three-phase motor 3
It is also possible to drive 0.

[2] One low-voltage battery may be used. The low-voltage batteries 61 and 62 of the first embodiment and the low-voltage batteries 184a and 184b of the second embodiment can form a power system using only one of them. In this case, for example, in the case of the first embodiment, only one of the fuel cells 21 and 22 is used to charge one of the low-voltage batteries, but the amount of fuel gas supplied to the fuel cell is controlled. There is no problem in using only one side for charging.

[3] Since the diodes DaU and DaL are present, in the first embodiment, power cannot be regenerated using the three-phase motor 30. Therefore, diodes DaU and DaL are used instead of the contacts 91 and 92 shown in FIG.
Transfer contacts 93, 9 that simultaneously switch the connection with
4 may be adopted and the diodes DaU and DaL may not be used. With such a configuration, it is possible to enable the regeneration of electric power using the three-phase motor 30. The circuit configuration in this case is shown in FIG. In such a configuration example, when the three-phase motor 30 using the fuel cells 21 and 22 is operated, the contacts 93 and 94 are switched to the fuel cell side. In this state, the charging operation of the low-voltage battery 61 or 62 using the fuel cells 21 and 22 as a power source is possible. Further, when performing a unipole operation by the low-voltage batteries 61 and 62 or performing a power regeneration operation using the three-phase motor 30, the contacts 93 and 94 are switched to the low-voltage batteries 61 and 62. In this case, since the connection to the fuel cells 21 and 22 is cut off, the low voltage batteries 61 and 62 are directly connected to the power line of the inverter 55, and the low voltage batteries 61 and 6 are connected.
Both the powering of the three-phase motor 30 using the motor 2 and the regeneration of the electric power become possible.

[4] The neutral point Q1 of the three-phase motor 30 and the first
It is also possible to adopt a configuration in which another load is connected between the DC power supply and the division point P5. In this embodiment, since the neutral point voltage is controlled, for example, a heater for a catalyst unit or the like may be connected to the neutral point voltage so that power can be supplied to these loads. Such a high-load circuit is conventionally provided with a dedicated DC / DC power supply to supply power from a high-voltage DC power supply.
Although a converter is provided, a neutral point Q1 of the three-phase motor 30 and a split point P of the first DC power supply are provided.
5 to control the neutral point voltage, these load circuits can be energized without using a special DC / DC converter or the like.

[5] Others: As the first and second DC power supplies, large-capacity capacitors such as electric double-layer capacitors can be used. For other applications, a primary battery may be used as any of the DC power supplies. Further, as the first DC power supply, a DC power supply created from commercial AC can be used.

In the second embodiment, a mechanical distribution type parallel hybrid vehicle using a planetary gear 120 has been described as an example. However, the power supply device of the present invention is a so-called electric distribution system in which power is distributed by a clutch motor having two rotors. The present invention is also applicable to a hybrid vehicle of the type or a so-called series hybrid vehicle. Of course,
As described in the first embodiment, the present invention can be applied to a so-called electric vehicle which does not include a heat engine such as a gasoline engine. Note that a series hybrid vehicle is a vehicle in which power output from an engine is temporarily converted into electric energy, and all power for driving drive wheels is output by a motor.

As described above, the power supply device of the present invention can connect a plurality of DC power supplies having different voltages to a three-phase motor with a simple configuration, and does not cause an increase in the size of the device configuration. Having. Such a configuration can be variously used as a charging circuit from the first DC power supply to the second DC power supply, or as a charging circuit from the second DC power supply to the first DC power supply. Therefore, such a configuration is very useful in various industrial devices in that electric energy can be transferred to electric systems having different potentials without requiring a separate booster circuit or step-down circuit. Also, if this configuration is used as a drive circuit for performing a unipole operation of the three-phase motor using the second DC power supply, it is possible to easily realize motor drive by the second power supply in various industrial devices. The application example of the power supply device of the present invention is not limited to a vehicle and the like, but can be applied to general industrial equipment such as a machine tool and a home appliance.

Although several embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be made without departing from the gist of the present invention. For example, a configuration used for a motor having four or more phases, a configuration in which the second DC power supply has a higher voltage, a configuration in which the second DC power supply is from a plurality of power supply units, and a configuration in which the first DC power supply is a single power supply It can be implemented in various forms such as a configuration.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of an electric vehicle equipped with a power supply device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of an electric vehicle.

FIG. 3 is a circuit diagram showing an electric system of the first embodiment.

FIG. 4 is an explanatory diagram showing an outline of control of the three-phase motor 30.

FIG. 5 is an explanatory diagram showing an equivalent circuit of a circuit for driving the three-phase motor 30 of the first embodiment.

FIG. 6 is a graph showing current-potential characteristics of a low-voltage battery 62.

FIG. 7 is a flowchart illustrating an outline of a control routine executed by a control unit 50 of the first embodiment.

FIG. 8 is a graph showing a relationship between each phase current and a charging current when charging the low-voltage battery 62, and a neutral point voltage.

FIG. 9 is an explanatory diagram showing an equivalent circuit when charging the low-voltage battery 62.

FIG. 10 is an explanatory diagram showing an equivalent circuit when charging a low-voltage battery 61.

FIG. 11 is a graph showing a relationship between each phase current and a charging current when charging the low-voltage battery 61.

FIG. 12 shows a low voltage battery 61, 6 in the first embodiment.
FIG. 3 is a circuit diagram showing a configuration example in the case where powering control is performed on a three-phase motor 30 using the second motor 2;

FIG. 13 is a timing chart illustrating the operation of each transistor in a unipole operation.

FIG. 14 is a schematic configuration diagram of a hybrid vehicle equipped with the power supply device of the second embodiment.

FIG. 15 is a circuit diagram showing the same electrical system.

FIG. 16 is an explanatory diagram showing a state of switching when a low-voltage battery is alternately charged by a high-voltage battery.

FIG. 17 is a flowchart of a boosting program executed by the control unit 190.

FIG. 18 is an explanatory diagram of a current waveform at each part accompanying the execution of the boosting program.

FIG. 19 is a circuit diagram showing a configuration example in which regeneration can be performed on low-voltage batteries 61 and 62.

[Explanation of symbols]

 21, 22 ... fuel cell 30 ... three-phase motor 31 ... drive shaft 33 ... differential gear 36, 37 ... wheels 41 ... tank 43 ... reformer 45 ... fuel cell system 48 ... fuel cell control unit 50 ... control unit 51 ... electric power System 52: Motor current command unit 52: Current command unit 53: PWM control unit 55: Inverter 58: Fuel cell current sensor 61, 62: Low voltage battery 71, 72, 73: Current sensor 75: Rotation sensor 81, 82: Remaining Capacitance sensors 91, 92 ... Contacts 93,94 ... Transfer contacts 112 ... Axles 116R, 116L ... Wheels 119 ... Cases 120 ... Planetary gears 121 ... Sun gears 122 ... Ring gears 123 ... Planetary pinion gears 124 ... Planetary carriers 125 ... Sun gear shafts 126 ... Ring gear shafts 127 ... Planetariki Rear shaft 129 Chain belt 130 Damper 132, 142 Rotor 132 Rotor 133, 143 Stator 150 Engine 156 Crankshaft 170 EFI ECU 180 Converter 184a, 184b Low-voltage battery 190 Control unit 191 First Drive circuit 192 ... second drive circuit 194a, 194b ... high voltage battery 197 ... charge detection sensor 384 ... fuel cell D1 to D6 ... diode DaL ... diode DaU ... diode DmL ... diode DmU ... diode MG1 ... first motor MG2: second motor Tr1 to Tr6: transistor

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[Procedure amendment]

[Submission date] January 13, 2000 (2000.1.1)
3)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 9

[Correction method] Change

[Correction contents]

FIG. 9

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 10

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification Symbol FI Theme Court ゛ (Reference) H02M 7/5387 H02M 7/5387 Z H02P 7/63 302 H02P 7/63 302C (72) Inventor Yukio Inakuma Aichi 41, Chuo-Cho, Yokomichi, Nagakute-cho, Aichi-gun, Japan Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Kazunari Moriya 41-Cho, Ochi-Cho, Nagakute-cho, Aichi-gun, Aichi F1 Toyota Central Research Laboratory, Inc. Terms (reference) 5G003 AA05 BA02 DA07 DA18 FA06 FA08 GB06 GC05 5H007 BB06 CA01 CB05 CC01 DA05 DB01 DC02 EA02 5H115 PG04 PI14 PI16 PI18 PU08 PV09 PV23 QN09 TO12 5H576 BB02 CC02 CC09 DD02 DD04 EE11 GG04 HA02 HB01LL

Claims (28)

[Claims] 1. A first DC power source, a field coil interposed between a star-connected polyphase motor and the first DC power source, and switching of a switching element from the first DC power source. A power control circuit that supplies power of the multi-phase motor to the multi-phase motor, and a second DC power supply that is separate from the first DC power supply, wherein the first DC power supply is at least two or more. Dividing and connecting in series, providing a terminal for connection to the outside at a dividing point, connecting one terminal of the second DC power supply to an intersection of the star connection of the polyphase motor, A power supply device, wherein the other terminal of the second DC power supply is connected to the division point of the first DC power supply via a rectifying element in a direction for preventing a current from flowing from the second DC power supply. 2. The power supply device according to claim 1, wherein the second DC power supply is divided into two power supply units and connected in series, and a midpoint of the series connection and the power supply of the multi-phase motor. The cross point of the star connection is connected, and the positive and negative sides of the second DC power supply are
A power supply device connected to the division point of the first DC power supply via each rectifier in a direction for preventing a flow of current from the second DC power supply. 3. The power supply device according to claim 1, wherein the first DC power supply is divided into two power supply units having substantially equal capacities. 4. The power supply device according to claim 1, wherein the second DC power supply is a chargeable power supply having a lower voltage than the first DC power supply, and the switching element. To control the potential at the intersection of the star-shaped connections of the polyphase motor,
And a step-down charging unit that charges the second DC power supply with the power of the power supply. 5. The power supply device according to claim 4, wherein the second DC power supply is divided into two power supply units and connected in series, and a midpoint of the series connection and the power supply of the multi-phase motor. The cross point of the star connection is connected, and the positive and negative sides of the second DC power supply are
The step-down charging means is connected to the dividing point of the first DC power supply via each rectifying element in a direction for preventing a flow of current from the second DC power supply, A power supply device which is a means for alternately controlling the potential at the intersection of the star connection to the positive side and the negative side to charge the two power supply units alternately. 6. The power supply device according to claim 5, further comprising: a charge state deviation detecting unit configured to detect at least a deviation between states of charge of the two power supply units constituting the second DC power supply; A power supply apparatus comprising: a charging switch that switches charging of the two power supply units so that a deviation of the detected state of charge falls within a predetermined range. 7. A first DC power supply, a field coil is interposed between the star-connected polyphase motor and the first DC power supply, and a switching element is used to switch the first DC power supply from the first DC power supply. A power control circuit that supplies power of the multi-phase motor to the multi-phase motor, and a second DC power supply that is separate from the first DC power supply, wherein the first DC power supply is at least two or more. Dividing and connecting in series, providing a terminal for connection to the outside at a dividing point, connecting one terminal of the second DC power supply to an intersection of the star connection of the polyphase motor, A power supply device, wherein the other terminal of the DC power supply is electrically connected to the field coil of the multiphase motor from the second DC power supply via the switching element. 8. A first DC power supply, a field coil is interposed between the star-connected polyphase motor and the first DC power supply, and switching of a switching element switches the first DC power supply from the first DC power supply. A power control circuit for supplying the power to the multi-phase motor, and a second DC power supply separate from the first DC power supply, wherein the second DC power supply comprises two power supply units. And a connection terminal is provided at a midpoint of the series connection, and the connection terminal of the second DC power supply is connected to an intersection of the star connection of the polyphase motor. And, at least one of the positive side and the negative side of the power supply unit of the second DC power supply can be energized from the second DC power supply side to the field coil of the polyphase motor via the switching element. Power supply connected. 9. The power supply device according to claim 8, wherein the first DC power supply is a chargeable power supply higher in voltage than the second DC power supply, and controls turning on and off of the switching element. A power supply device that performs boosting using the field coil of the multiphase motor and includes boosting charging means for charging the first DC power supply with the power of the second power supply. 10. The power supply device according to claim 9, wherein the step-up charging unit uses the power of the two power supply units of the second DC power supply alternately to generate the divided first power supply unit. A power supply device as a means for charging each of the DC power supplies alternately. 11. The power supply device according to claim 10, further comprising a charge state deviation detecting means for detecting at least a deviation in a charge state of each divided power supply of said first DC power supply, and said step-up charging means. Is a power supply device provided with charge switching means for switching between the two power supply units to perform the charging so that the deviation of the detected state of charge falls within a predetermined range. 12. The power supply device according to claim 9, wherein the power control circuit prepares the switching elements in pairs for each field coil of the multi-phase motor, and sets the switching element pairs to: A first DC power supply is connected between positive and negative power supply lines, a flyback diode is connected to each switching element, and an intermediate point where the switching elements are connected to each other is connected to the field coil. The boosting charging means includes: a second one of the paired switching elements.
One of the switching elements on the side forming a closed circuit including the DC power supply and the field coil is turned on, and then
A power supply device that is a means for turning off the switching element and charging the first DC power supply via the flyback diode. 13. The power supply device according to claim 8, wherein at least one of a positive electrode side and a negative electrode side of the second DC power supply corresponds to a power supply line of the power control circuit via a forward diode. Power supply connected to the 14. The multi-phase motor according to claim 8, wherein each of a positive electrode side and a negative electrode side of the second DC power supply is connected to the second DC power supply via the switching element. A power supply device connected to the field coil so as to be able to conduct electricity. 15. A switching means for disconnecting a connection between the first DC power supply and the power control circuit.
The power supply as described. 16. The power supply device according to claim 7, wherein the first DC power supply is divided into at least two or more and connected in series, and a division point is used for connection to the outside. A terminal is provided, and a terminal of one power supply unit of the divided second DC power supply is connected to the first DC power supply through a rectifying element in a direction for preventing a flow of current from the second DC power supply. A power supply connected to the split point of the power supply. 17. The power supply device according to claim 16, wherein each of the positive electrode side and the negative electrode side of the power supply unit of the second DC power supply prevents a current from flowing from the second DC power supply. A power supply device connected to the split point of the first DC power supply via each rectifier element in each direction. 18. The power supply device according to claim 16, wherein the first DC power supply is divided into two power supply units having substantially equal capacities. 19. The power supply according to claim 16, wherein the second DC power supply is a chargeable power supply having a lower voltage than the first DC power supply, and controls turning on and off of the switching element. A power supply device comprising: a step-down charging unit that controls a potential of the intersection of the polyphase motor and charges the second DC power supply with power of the first power supply. 20. The power supply device according to claim 16, wherein the first DC power supply is a chargeable power supply having a higher voltage than the second DC power supply, and controlling turning on / off of the switching element. A power supply device that performs boosting using a field coil of the polyphase motor and includes boosting charging means for charging the first DC power supply with the power of the second power supply. 21. The first DC power source is a fuel cell or a primary battery.
20. The power supply device according to claim 19. 22. The method according to claim 9, wherein the first DC power supply is a secondary battery or a large-capacity capacitor.
21. The power supply device according to claim 20. 23. An apparatus provided with a power supply device according to claim 1, wherein a motor driven directly by fuel is mounted as one of power sources, wherein the polyphase motor rotates on an output shaft of the motor. A first DC power supply is a power supply for driving the motor, the second DC power supply is a power supply for a control device that controls the device, When the remaining capacity of the second DC power supply is equal to or less than a predetermined value,
Controlling the on / off ratio of the switching means,
A device comprising: charging means for changing the potential at the intersection of the star connection and charging the second DC power supply with the first DC power supply. 24. An apparatus provided with a power supply device according to any one of claims 9 to 12 or 20, wherein a motor driven directly by fuel is mounted as one of power sources. The phase motor is a motor rotatably coupled to an output shaft of the prime mover, the first DC power supply is a power supply for driving the motor, and the second DC power supply controls the device. A power supply for a control device to be performed, further comprising: start control means for driving the electric motor to start the prime mover when the prime mover is started; and when the start is performed, the remaining capacity of the first DC power supply is: A start-up charging unit for driving the boosting charging unit when the start of the electric motor is insufficient, and charging the first DC power source with the second DC power source; 25. The electric vehicle according to claim 24, wherein the prime mover is an internal combustion engine, and the device is a vehicle running by power from the internal combustion engine and / or the electric motor. 26. A motor driving device comprising the power supply device according to claim 7, wherein the multi-phase motor is driven by the first DC power supply using the power control circuit. First switching means connected to a power supply line of the first and second DC power supplies that are individually turned on and off, and the second DC power supply performs the multi-phase operation. A second motor driving means for operating the coil in a unipole operation. 27. The motor drive device according to claim 26, wherein the power control circuit prepares the switching elements in pairs for each field coil of the multi-phase motor, and the switching element pairs are: The first DC power supply is connected between the positive and negative power supply lines, and an intermediate point where the switching elements are connected to each other is connected to the field coil. Means for sequentially turning on and off one of the paired switching elements so as to form a closed circuit including the DC power supply and the field coil, thereby forming a field in the polyphase motor. Motor drive. 28. An engine driven directly by fuel as one of the driving sources, and wherein the motor is mounted as one of the driving sources.
A vehicle equipped with the motor drive device according to claim 1, wherein the multi-phase motor is coupled to a drive shaft of the vehicle or a rotation shaft of the prime mover, and the prime mover and / or the multi-phase motor is driven according to a driving state of the vehicle. An electric vehicle that drives the drive shaft using the power of a phase motor.