JP2013243868A - Charging system of battery vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging system of a battery vehicle which can achieve fast charge even in the case of on-board type, by utilizing a drive system which is mounted or provided for running of a vehicle.SOLUTION: The charging system of a battery vehicle which runs by converting power of a battery 4 into AC power by means of inverters 3A, 3B and rotating two independent AC motors 2A, 2B comprises: a three-phase connector C in which two terminals TU, TV are connected independently with any two coils L11, L12 of one motor 2A, and the remaining terminal TW is connected with any one coil L21 of the other motor 2B; and a three-phase power supply 5 which is connected with the three-phase connector C and supplies power to the inverters 3A, 3B functioning as converters via the coils L11, L12, L21 thus charging a battery 4.

Description

  The present invention relates to a charging system for a battery-powered vehicle, and is particularly useful when applied to rapid charging of an electric vehicle.

  In order to popularize electric vehicles (EVs), expansion of charging facilities is required as social infrastructure. However, conventional quick chargers are designed to complete charging in a short time instead of limiting the size and weight, and of course, the installation cost is increased.

  This is a problem inherent in off-board (stationary) chargers, and it is extremely important to consider effective installation locations and number of installations as social infrastructure.

  On the other hand, there is an on-board type (mounted type) charger, and a normal charging charger corresponds to this. In recent years, it has become a charging system for general homes that is well recognized as a charging system for small electric vehicles including plug-in hybrid electric vehicles (PHEVs). However, the on-board type charger has the minimum required specification due to the reduction in size and weight, and depending on the battery capacity, it may take half a day to fully charge.

  Whether it is an off-board type or an on-board type, the charger mainly has a PFC (Power Factor Correction) circuit for power factor improvement and a DC / DC converter for charge control. In particular, when the capacity of the charger is increased, the weight of the reactor used in the PFC circuit cannot be ignored, and there is a limit to the onboard type including a capacitor and the like.

  For example, Patent Document 1 and Patent Document 2 exist as publicly known documents disclosing rapid charging for electric vehicles.

JP 2000-152408 A JP-A-5-207668

  In view of the above-described prior art, the present invention provides a charging system for a battery-powered vehicle that can realize rapid charging even if it is an on-board type by using a drive system that is mounted or equipped for traveling of the vehicle. The purpose is to do.

The first aspect of the present invention for achieving the above object is as follows:
It is a charging system for a battery-powered vehicle that has two electric motors and travels by rotating the electric motor by converting the electric power of the battery into AC power by an inverter,
A three-phase connector in which two terminals are independently connected to any two coils of one motor and the remaining terminals are connected to any one coil of the other motor;
Charging a battery-powered vehicle, comprising: a three-phase power source that supplies power to the inverter that functions as a converter through each coil by being connected to the three-phase connector to charge the battery. In the system.

The second aspect of the present invention is:
A charging system for a battery-powered vehicle that has at least three electric motors and travels by rotating the electric motor by converting the electric power of the battery into alternating current power by an inverter,
A three-phase connector with each terminal connected to the neutral point of one of the motor coils;
Charging a battery-powered vehicle, comprising: a three-phase power source that supplies power to the inverter that functions as a converter through each coil by being connected to the three-phase connector to charge the battery. In the system.

The third aspect of the present invention is:
In the battery-powered vehicle charging system described in the first or second aspect,
The three-phase power source is a charging system for a battery-powered vehicle, wherein the three-phase power source is a pole transformer.

The fourth aspect of the present invention is:
In the battery-powered vehicle charging system described in the first or second aspect,
A charging system for a battery-powered vehicle, wherein a single-phase power source is used instead of the three-phase power source, and a single-phase AC voltage is applied to two terminals of the three-phase connector. .

  According to the present invention, the inverter that converts the DC power of the battery into AC power for driving the motor can be used as a converter for rectification by using the coil of the in-vehicle motor as a reactor, so that the related art It is possible to realize a predetermined quick charge similar to that performed by using an off-board type quick charger without relying on the off-board type quick charger.

  As a result, a simple and inexpensive rapid charging system can be constructed without requiring a special installation space, which can greatly contribute to the popularization of electric vehicles.

  In particular, pole transformers and the like can be used directly as three-phase power supplies. Therefore, by incorporating power transformers such as pole transformers into the infrastructure of the rapid charging system, Can be improved drastically.

It is explanatory drawing which shows notionally the electric vehicle carrying the charging system of this invention. It is a circuit diagram which shows the charge system of the battery traveling vehicle which concerns on the 1st Embodiment of this invention. It is a wave form diagram which shows the waveform of the three-phase alternating current voltage for charge in the charging system shown in FIG. It is a wave form diagram which shows the waveform of the switching pulse which controls ON / OFF of the switch element of the converter of the charging system of the battery traveling vehicle which concerns on the 1st Embodiment of this invention. It is a circuit diagram which shows the charging system of the battery traveling vehicle which concerns on the 2nd Embodiment of this invention. It is a figure which shows the charge cord for a connection for connecting a single phase power supply or a three phase power supply, and the three-phase connector on a vehicle side, (a) is for single phase charge, (b) is for three phase charge.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram conceptually showing an electric vehicle equipped with the charging system of the present invention. As shown in the figure, the vehicle 1 is equipped with a drive system such as an electric motor 2, an inverter 3, and a battery 4, and direct current power supplied from the battery 4 is converted into alternating current power by the inverter 3. To drive the vehicle 1. On the other hand, when the battery 4 is charged, the coil of the motor 2 is used as a reactor, and the inverter 3 functions as an AC / DC converter, so that the three-phase power source 5 such as a pole transformer is directly connected to the coil of the motor 2. Thus, rapid charging is performed by supplying a large current. Here, in order to use the coil as a reactor without rotating the electric motor 2, at least two electric motors are required. This is because in order to prevent the motor 2 from rotating, it is necessary to inhibit the formation of a rotating magnetic field formed by applying a three-phase alternating current to the three coils.

  As a vehicle 1 having two electric motors 2, there is an electric vehicle driven by a two-wheel motor, and as a vehicle 1 having four electric motors 2, there is an electric vehicle driven by a four-wheel motor. In addition to the electric motors, there are those equipped with a generator for supplying electric power to the drive system of the vehicle 1. In this case, the total number of electric motors and generators, that is, the electric motors and the generators, Think of it as a unit number. This is because the electric motor and the generator have the same basic structure, and each coil can be used as a reactor.

  FIG. 2 is a circuit diagram showing the charging system for the battery-powered vehicle according to the first embodiment of the present invention. This embodiment is a charging system applied to a two-wheel motor drive type electric vehicle.

  As shown in FIG. 2, this embodiment is a charging system for a two-wheel motor drive type electric vehicle having two motors 2A and 2B for driving driving. In addition to the motors 2A and 2B, the vehicle body I of the electric vehicle includes two inverters 3A and 3B that individually drive and control the motors 2A and 2B as a drive system, and a battery 4 that is a DC power source. Yes. The capacitor C0 is an in-vehicle component connected between the battery 4 and the inverters 3A and 3B for smoothing.

  Here, the electric motor 2A has coils L11, L12, and L13 corresponding to the three-phase U phase, V phase, and W phase, respectively. The electric motor 2B has coils L21, L22, and L23 corresponding to the three-phase U phase, V phase, and W phase, respectively. When the electric motors 2A and 2B function as electric motors, that is, when the electric motors 2A and 2B function as driving sources for running the vehicle 1 (see FIG. 1; the same applies hereinafter), the terminals (T11, T12, T13) and (T21, T22, T23) are connected to each other. They are connected together to form the neutral point of the star connection.

  On the other hand, when functioning as a component of the charging system of the present embodiment, the connection of the coils (L11 to L13) and (L21 to L23) at the terminals (T11 to T13) and (T21 to T23) is released and independent. I am letting. In such a state, either two or one is selected and connected to the U-phase, V-phase, and W-phase of the three-phase power source 5 via the three-phase connector C. In this embodiment, the coil L11 is connected to the U phase, the coil L12 is connected to the V phase, and the coil L21 is connected to the W phase. Thus, the three-phase connector C having terminals TU, TV, and TW connected to the U-phase, V-phase, and W-phase of the three-phase power supply 5 has two terminals TU and TV of one motor 2A. While being connected independently to any two coils L11 and L12, the remaining terminal TW is connected to any one coil L21 of the other motor 2B. Thus, a rotating magnetic field is not formed by the electric motors 2A and 2B, and the coils L11, L12, and L21 can be used only as a reactor. Here, the three-phase connector C is also a vehicle-mounted component, and is disposed facing the vehicle body I to the outside. In the case of this embodiment, the coils L13, L22, L23 are in an electrically unconnected state.

  The inverter 3A has switch elements (SW11, SW41), (SW21, SW51), (SW31, SW61) corresponding to the three phases U, V, and W, respectively. Similarly, the inverter 3B has switch elements (SW12, SW42), (SW22, SW52), and (SW32, SW62) corresponding to the three-phase U phase, V phase, and W phase, respectively. When each of the inverters 3A and 3B appropriately controls ON / OFF of each of the switch elements SW11 to SW61 and each of the switch elements SW12 to SW62, when driving the motors 2A and 2B, that is, when driving the vehicle 1, DC / AC To function as a converter.

  On the other hand, when functioning as a component of the charging system of the present embodiment, the AC power of the three-phase power source 5 is converted to DC and functions as an AC / DC converter that supplies DC power to the battery 4. Specifically, the ON / OFF of the switch elements (SW11 to SW61) and (SW12 to SW62) is controlled as follows in the connection state shown in FIG.

  FIG. 3 is a waveform diagram showing the waveform of the charging three-phase AC voltage output from the three-phase power source 5, and FIG. FIG. As shown in FIG. 3, the voltage of the three-phase power source 5 includes a U-phase voltage indicated by a solid line, a V-phase voltage indicated by a dotted line, and a W-phase voltage indicated by a one-dot chain line. Each of the U phase voltage, the V phase voltage, and the W phase voltage has a phase difference of 120 degrees. Therefore, the switch elements SW11, SW21, SW12, SW41, SW51, and SW42 are turned on / off at the timings shown in FIGS. 4 (a) to 4 (f), and the coils L11, L12, and L21 function as reactors. A U-phase current, a V-phase current, and a W-phase current proportional to the phase voltage can be passed.

  More specifically, the switch elements SW11, SW21, SW12, which are constituent elements of the upper arms of the inverters 3A, 3B, are made to correspond to the U phase, the V phase, and the W phase, respectively. The switch elements SW11, SW21, and SW12 are ON / OFF controlled during the positive period and during the period when the W-phase voltage is positive. In addition, the switch elements SW41, SW51, and SW42, which are constituent elements of the lower arms of the inverters 3A and 3B, are also ON / OFF controlled in correspondence with the U phase, V phase, and W phase, respectively. Here, in each period, the switch elements SW11, SW21, and SW12 repeat ON / OFF operations at a predetermined high frequency so that the U-phase current, the V-phase current, and the W-phase current are proportional to the respective phase voltages. Similarly, the switch elements SW41, SW51, and SW42 are repeatedly turned ON / OFF at a predetermined high frequency. However, when one of the U-phase switch element SW11 and the switch element SW41 is ON, the other is OFF. This complementary relationship is similarly established in the relationship between the V-phase switch element SW21 and the switch element SW51 and the relationship between the W-phase switch element SW12 and the switch element SW42.

  As a result, a direct current can be supplied to the battery 4 via the inverters 3A and 3B functioning as AC / DC converters based on the U, V, and W phase currents, and the battery 4 can be charged. At this time, using the switch elements SW11, SW21, SW12, SW41, SW51, and SW42, the magnitude of the charging current is appropriately controlled by changing the duty ratio during the ON / OFF operation by complementary PWM control.

  FIG. 5 is a circuit diagram showing a charging system for a battery-powered vehicle according to the second embodiment of the present invention. The present embodiment is a charging system applied to a four-wheel motor drive type electric vehicle. In FIG. 5, the same parts as those in FIG.

  As shown in FIG. 5, this embodiment is a charging system for a four-wheel motor drive type electric vehicle having two electric motors 2C and 2D in addition to the electric motors 2A and 2B for driving driving. In the vehicle body II of the electric vehicle, in addition to the motors 2A to 2D, four inverters 3A to 3D and a battery 4 that is a DC power source are mounted as a drive system.

  Here, each of the electric motors 2A to 2D includes coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) corresponding to the three-phase U phase, V phase, and W phase, respectively. (L41, L42, L43) and terminals NU, NV, NW, N are connected to neutral points of the coils (L11, L12, L13) to (L41, L42, L43).

  In this embodiment, inverters 3C and 3D are provided in addition to the inverters 3A and 3B provided corresponding to the electric motors 2A and 2B. The inverter 3C has switch elements (SW13, SW43), (SW23, SW53), (SW33, SW63) corresponding to the three phases U phase, V phase, and W phase, respectively. Similarly, the inverter 3D has switch elements (SW14, SW44), (SW24, SW54), and (SW34, SW64) corresponding to the three-phase U phase, V phase, and W phase, respectively. Similarly to the inverters 3A and 3B, the inverters 3C and 3D drive the motors 2C and 2D together with the motors 2A and 2B by appropriately controlling ON / OFF of the switch elements SW13 to SW63 and the switch elements SW14 to SW64. When the vehicle 1 travels, it functions as a DC / AC converter.

  On the other hand, when functioning as a component of the charging system of the present embodiment, the AC power of the three-phase power source 5 is converted to DC and functions as an AC / DC converter that supplies DC power to the battery 4.

  More specifically, in the charging system according to this embodiment, the coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) of the electric motors 2A, 2B, 2C are connected to the terminals NU, NV, The terminals are connected to terminals TU, TV, TW of the three-phase connector C via NW. As a result, the U, V, and W phase voltages of the three-phase power source 5 are supplied to the coils (L11, L12, L13), (L21, L22, L23) via the terminals TU, TV, TW and the terminals NU, NV, NW. , (L31, L32, L33). The coils (L41, L42, L43) of the electric motor 2D are kept in an electrically unconnected state.

  In such a state, switch elements (SW11 to SW31), (SW12 to SW32), (SW13 to SW33), which are constituent elements of the upper arms of the inverters 3A to 3C, and switch elements (SW41 to SW61) which are constituent elements of the lower arm, The ON / OFF of (SW42 to SW62) and (SW43 to SW63) is controlled as follows. In this embodiment, the coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) of the electric motors 2A, 2B, 2C are used as reactors for the U phase, V phase, and W phase. Therefore, three switch elements (SW11 to SW31), (SW12 to SW32), (SW13 to SW33) and switch elements (SW41 to SW61), (SW42 to SW62), and (SW43 to SW63) are integrally turned on. / OFF controlled. Specifically, the switch elements (SW11 to SW31) are integrally turned ON / OFF by the switching pulse shown in FIG. 4A, and the switch elements (SW12 to SW32) are similarly shown in FIG. 4B. The switching elements (SW13 to SW33) are the switching pulses shown in FIG. 4C, the switching elements (SW41 to SW61) are the switching pulses shown in FIG. 4D, and the switching elements (SW42 to SW62). Is the switching pulse shown in FIG. 4 (e), and the switch elements (SW43 to SW63) are integrally turned on / off by the switching pulse shown in FIG. 4 (f).

  In this embodiment, the coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) of the electric motors 2A to 2C are used as they are, that is, in the first embodiment shown in FIG. Unlike the neutral point, it can be used in the charging mode without dividing the neutral point, so the neutral point split state for use in the charging mode is distinguished from the neutral point effective state for use in the driving mode. Is no longer necessary.

  Further, since the coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) are collectively connected in parallel, the reactance decreases, but the allowable current, that is, the allowable The charging current is three times that of the first embodiment shown in FIG. 2, and a larger charging current can be flowed accordingly, so that the charging time can be further shortened.

  In this embodiment, since the three-phase current supplied for each of the coils (L11, L12, L13), (L21, L22, L23), (L31, L32, L33) in the charging mode is in phase, each motor 2A The rotating magnetic field is not formed at ˜2C, and therefore the electric motors 2A to 2C are not rotated.

  In the above embodiment, a two-wheel motor drive type electric vehicle having two electric motors and a four wheel motor drive type electric vehicle having four electric motors have been described as examples. However, the present invention is not limited thereto. It is not a thing. The two electric motors include, for example, a combination of one electric motor and one electric generator, and the at least three electric motors include, for example, a combination of two electric motors and one electric generator. In short, in the former case, it is only necessary to use a total of three coils, one coil of one motor or generator and one coil of another generator or motor, as the reactor. In the latter case, Any three-phase coils of any three electric motors or generators may be used as a reactor including a neutral point.

  Furthermore, although the said embodiment is a case where the three-phase power supply 5 is used as a charging power supply, a household single-phase alternating current power supply can also be used. In this case, a charging cord 6 and a single-phase charging adapter 7 as shown in FIG. The single-phase charging adapter 7 is a single-phase connector attached to the vehicle bodies I and II, and has a structure in which a single-phase normal charging connector 8 can be inserted and connected. Here, the two connection lines drawn out from the single-phase charging adapter 7 are connected to any two terminals (terminals TU and TV in the figure) of the three-phase connector C. The remaining one of the three-phase connectors C (terminal TW in the figure) is not connected.

  On the other hand, a single-phase plug 9 having contact pieces 9A and 9B, which are two conductive portions, is connected to the other end portion of the charging cord 6 in which the normal charging connector 8 is connected to one end portion. The single-phase plug 9 is connected to a single-phase power supply by inserting the contact pieces 9A and 9B into a single-phase power outlet (not shown). Thus, by connecting the single-phase power supply outlet and the single-phase charging adapter 7 with the charging cord 6, the single-phase power is supplied to the vehicle body I, II side via the terminals TU, TV, and the single-phase normal Charging can be performed.

  In the three-phase rapid charging according to the above embodiment, as shown in FIG. 6B, the three-phase charging connector 11 connected to one end of the charging cord 10 is inserted into the connector C and each terminal TU is inserted. , TV, TW and the three-phase power supply 5 are connected.

  INDUSTRIAL APPLICABILITY The present invention can be used in an industrial field where electric power is supplied as well as an industrial field where electric vehicles are manufactured and sold.

I, II Body 1 Vehicle
2A, 2B, 2C, 2D Electric motor 3A, 3B, 3C, 3D Inverter 4 Battery
5 Three-phase power supply L11 to L43 Coil C Three-phase connector TU, TV, TW terminal

Claims (4)

It is a charging system for a battery-powered vehicle that has two electric motors and travels by rotating the electric motor by converting the electric power of the battery into AC power by an inverter,
A three-phase connector in which two terminals are independently connected to any two coils of one motor and the remaining terminals are connected to any one coil of the other motor;
Charging a battery-powered vehicle, comprising: a three-phase power source that supplies power to the inverter that functions as a converter through each coil by being connected to the three-phase connector to charge the battery. system. A charging system for a battery-powered vehicle that has at least three electric motors and travels by rotating the electric motor by converting the electric power of the battery into alternating current power by an inverter,
A three-phase connector with each terminal connected to the neutral point of one of the motor coils;
Charging a battery-powered vehicle, comprising: a three-phase power source that supplies power to the inverter that functions as a converter through each coil by being connected to the three-phase connector to charge the battery. system. In the charging system for the battery-powered vehicle according to claim 1 or 2,
The charging system for a battery-powered vehicle, wherein the three-phase power source is a pole transformer. In the charging system for the battery-powered vehicle according to claim 1 or 2,
A charging system for a battery-powered vehicle, wherein a single-phase power supply is used instead of the three-phase power supply, and a single-phase AC voltage is applied to two terminals of the three-phase connector.

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