JP2005117812A - Hybrid energy electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric vehicle that uses a battery as a main power supply and can quickly cope with abrupt changes of powering and a load at braking. <P>SOLUTION: When the charging state of a battery 51 reaches the lower limit of the intermediate state of the capacity of the battery, a command for increasing an output of power is outputted to a generation system 60, and, when the charging state of the battery 51 reaches the upper limit of the intermediate state of the capacity of the battery, a command for decreasing an output of power is outputted to the generation system 60. When the charging state of the battery 51 reaches the lower limit of the intermediate state of the capacity of the battery, an energy accumulation means 70 generates power and feeds the power to the battery 51, and, when the charging state of the battery 51 reaches the upper limit of the intermediate state of the capacity of the battery, the energy accumulation means 70 absorbs power by the power of the battery 51. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric vehicle using a battery as a main power source for driving, and more particularly to a hybrid energy electric vehicle having a function capable of adjusting supply and demand of electric power.

  A typical electric vehicle for construction uses a battery as a power source. This type of electric vehicle is subject to restrictions based on battery capacity for travel distance and operation time. On the other hand, there is an electric vehicle that is equipped with a generator that uses an internal combustion engine as a power source and runs while charging a battery. This type of electric vehicle can be operated for a long time. However, in the case of an electric vehicle running in a space where ventilation is not sufficient, such as a tunnel, it is necessary to suppress exhaust gas as much as possible. Then, the electric vehicle carrying a micro turbine generator is proposed for the purpose of exhaust gas suppression (patent document 1). On the other hand, there has been proposed a hybrid energy locomotive equipped with a generator driven by an engine to output electric power for driving an electric motor, and an electric power accumulating means for coping with excessive or insufficient driving electric power (Patent Document) 2)

JP 2002-262407 A USP 6,591,758

  By the way, the techniques disclosed in Patent Documents 1 and 2 both function as a buffer for when the power is excessive or insufficient, by driving the motor using the power supplied by the generator driven by the engine as the main power source. It is the composition which makes it. That is, the battery is positioned as a secondary power source.

  By the way, when an engine-driven generator is used as the main power source, the supply and demand of the drive power is controlled mainly by controlling the operation of the generator. However, an engine-driven generator may not be able to ignore the time delay for increasing or decreasing the output in response to a power command. For this reason, it is not possible to quickly control the output according to the driving situation of the electric vehicle.

  The present invention provides an electric vehicle with good controllability that can supply power by a generator while using a battery as a main power source, and can quickly respond to sudden fluctuations in load during power running and braking. It is to provide.

The present invention
In an electric vehicle using a battery as a driving power source,
A traveling drive system that is used for traveling and that drives and brakes;
An operation instruction device for receiving operation instructions;
A power generation system driven by a microturbine;
A main power supply including a battery capable of charging and discharging;
An auxiliary power supply device capable of absorbing / releasing power,
The main power supply device has a sensor for detecting the state of charge of the battery, and a management system that performs control for maintaining the state of charge of the battery in an intermediate state of its capacity,
The auxiliary power supply device has means for storing energy, a generator motor for driving the means for storing energy and generating electric power thereby, and a controller for controlling power generation and driving,
When the management system detects that the state of charge of the battery reaches the lower limit of the intermediate state of its capacity based on a signal from the sensor, it outputs a command for increasing the power output to the power generation system When detecting that the state of charge of the battery reaches the upper limit of the intermediate state of its capacity based on the signal from the sensor, a command for reducing the output of power is output to the power generation system,
When the controller of the auxiliary power supply detects that the state of charge of the battery reaches the lower limit of the intermediate state of its capacity based on the signal from the sensor, it generates power by the energy storage means and supplies power to the battery. The hybrid battery is characterized in that when it is detected that the state of charge of the battery reaches an upper limit of an intermediate state of its capacity based on a signal from the sensor, the power is absorbed by the energy storage means by the power of the battery. An energy electric vehicle is provided.

  Here, the energy storage means of the auxiliary power device may be a flywheel.

  Hereinafter, embodiments of the electric vehicle according to the present invention will be described with reference to the drawings. In the following embodiment, an example applied to a construction locomotive will be described. Of course, the present invention can be applied to an electric vehicle having an appropriate shape and structure. Also, the use is not limited to construction. Applicable to electric vehicles for cargo and passenger use. Furthermore, it is not limited to a locomotive. For example, the present invention can be applied to a self-propelled carriage, a self-propelled passenger car, a self-propelled work machine, and the like.

  FIG. 1 is a side view of an electric vehicle 10 according to an embodiment of the present invention, and FIG. 2 is a plan view of a state where a part of the cover is removed. FIG. 3 shows a power system and a control system of the electric vehicle according to this embodiment.

  The electric vehicle 10 includes a main body 11, a cab 12 disposed at the center of the main body 11, wheels 13 that support the main body 11, a coupler 14, and a travel drive system 30 that drives the wheels 13. The electric vehicle 10 has a structure exhibiting a convex shape when viewed from the side. A driver's cab 12 is formed at the center. An operation controller 40 that functions as an operation instruction receiving device is installed in the cab 12. The electric vehicle main body 11 is equipped with a main power supply system 50 including a battery 51, a generator system 60 including a microturbine generator, and a flywheel system 70 that absorbs / releases power as an auxiliary power supply. ing.

  The operation controller 40 is provided with a display panel 41, an operation panel 42 provided with various operation members 43, and a control device (not shown). The display panel 41 is provided with an indicator lamp, a display and the like for displaying information necessary for driving operation. On the display, for example, the terminal voltage of the battery, the output voltage of the power generation system 60, the output current of the power generation system 60, the number of rotations of the flywheel of the flywheel system 70, and the like are displayed. A control device (not shown) receives an instruction from the operation panel 42 and outputs a command for control of the travel drive system 30 described later. In addition, as the operation member 43, switches, levers, sticks, and the like necessary for operation are installed.

  A battery 51 included in the main power supply system 50 is mounted on one side of the upper portion of the electric vehicle main body 11 with the cab 12 interposed therebetween. On the other side, the generator system 60 and the power supply control device 10 are mounted.

  The travel drive system 30 includes a drive motor 32 that drives the wheels 13 and a driver 31 that controls the drive of the drive motor 32. The drive motor 32 is a rotating machine that functions as an electric motor and a generator. Specifically, the drive motor 32 drives and brakes the axle to which the wheels 13 are attached. In this embodiment, a DC servo motor is used. The driver 31 drives the drive motor 32 in response to an operation command from the operation controller 40. Specifically, a drive pulse corresponding to the speed is generated and supplied to the drive motor 32 in accordance with instructions such as start, stop, acceleration, and deceleration. Further, during braking, a regenerative current is sent to the main power supply system 50.

  The main power supply system 50 includes a battery 51 that outputs a drive current and absorbs a regenerative current, a battery management system 52 that manages the state of charge of the battery 51, a terminal voltage of the battery 51, and the battery 51. And an input / output current sensor 53. The battery management system 52 manages the state of charge of the battery 51 so as to maintain an intermediate state of the capacity (amount of charge at full charge), for example, within a range of 80% to 50%. Specifically, when the state of charge reaches the lower limit of the intermediate state (for example, 50% of the capacity), a power command for increasing the output power is output to the power generation system 60. On the other hand, when the state of charge reaches the upper limit of the intermediate state (for example, 80% of the capacity), a power command for reducing the output power is output to the power generation system 60. These power commands are sent to the microturbine power controller 62 of the power generation system 60.

  The battery management system 52 includes a computer system that includes a central processing unit (CPU) 521, a memory 522, and an interface 523. The memory 522 stores its own operation program and management data. Data for management includes data relating to setting of the upper limit and lower limit of the intermediate state of the battery, data indicating the state of charge of the battery, and the like. The data indicating the state of charge of the battery includes, for example, information from the sensor 53, a calculation result based on the information, and the like. Examples of the information from the sensor 53 include the terminal voltage and input / output current value of the battery 51. The operation program includes a calculation program for determining a charging state, a program for generating a power command for maintaining an intermediate state according to the charging state, a program for determining its output timing, and the like.

  The power generation system 60 includes a micro turbine generator 61 and a micro turbine power controller 62. The micro turbine generator 61 includes a micro turbine 611 and a generator 612 that is driven by the micro turbine 611 to generate power. The micro turbine obtains a rotational force by guiding the fuel stored in the fuel tank 613 and the compressed air stored in the air tank 614 to the combustor for combustion, and rotating the turbine at a high speed. The generator 612 is driven by this rotational force to generate power. Exhaust gas from the micro turbine 611 is discharged to the outside through the air filter 615.

  The micro turbine 611 has high combustion efficiency. Therefore, the nitrogen oxide NOx contained in the exhaust gas is about 14 PPm, which is an extremely small amount of 1/25 of the standard specified value. Further, during operation, almost no suspended particulate matter is found in the exhaust gas.

  In this embodiment, an AC generator is used as the generator 612. Of course, a DC generator may be used. The electric power generated by the generator 612 is sent to the micro turbine power controller 62.

  The micro turbine power controller 62 includes a power converter 621 that converts AC power into DC power, and a turbine controller 622 that controls the operation of the micro turbine 611. The power converter 621 may have a function of converting DC power into AC. Thus, the micro turbine 611 may be started by using the power of the battery 51 and the generator 612 as a motor. The turbine controller 622 monitors the rotational speed of the micro turbine, the generator output, and the like via sensors not shown. The turbine controller 622 controls the rotation of the micro turbine in accordance with the power command from the battery management system 52 described above. At this time, as described above, the operation of the micro turbine is monitored, and feedback control is performed so that the generator 612 has a target output.

  The flywheel system 70 includes a flywheel 71, a generator motor 72 that drives or is driven by the flywheel 71, and a flywheel controller 73 that controls the accumulation and release of energy in the flyhole. Have

  As the flywheel 71, for example, one made of a carbon composition or the like is used. In the present embodiment, the flywheel 71 and the generator motor 72 have a structure having a common rotating shaft.

  The flyhole controller 73 includes a power converter that performs power conversion between the generator motor 72 and the battery 51, and drives the generator motor 72 as a generator or as a motor according to the output signal of the sensor 53. The battery 51 is driven to supply or supply electric power to the battery 51. The control part of the flywheel controller 73 can be configured by a computer, for example. It can also be configured by a programmable logic array or the like.

  For example, the flywheel controller 73 determines whether the state of charge of the battery 51 has reached the lower limit or the upper limit of the intermediate state described above. When it is determined that the state of charge of the battery 51 has reached the lower limit of the intermediate state, the flywheel controller 73 causes the generator motor 72 to function as a generator and causes the generator motor 72 to generate power using the rotational torque of the flywheel 71. . On the other hand, if it is determined that the state of charge of the battery 51 has reached the upper limit of the intermediate state, the flywheel controller 73 causes the generator motor 72 to function as an electric motor and increases the rotational speed of the flywheel 71 to absorb power. Let

  The flywheel system 70 can have various specifications according to the purpose. Here, an example of the specification is shown.

Maximum sustained power ... 120kW
Maximum power supply duration ... 20 seconds Available energy storage ... 0.67 kWh (2400 kWs)
Maximum recharge rate ... 120W
Typical idle power consumption: 120W
As shown in the above-mentioned specification, the flywheel system 70 can release or absorb a large amount of power for a short period of time, and has a steep rise and fall during emission and absorption. In the present embodiment, this property is used to quickly release or absorb power. Even if a response delay occurs in the power generation system 60, this can be supplemented. Therefore, the flywheel controller 73 controls the operation of the generator motor 72 so as to absorb power when reaching the upper limit of the intermediate state of the battery 51 and release power when reaching the lower limit. Further, while the battery 51 is maintained in the intermediate state, it is in an idling state, and the generator motor 72 is driven with low power consumption to maintain the rotation of the flywheel 71. The upper limit and the lower limit of the intermediate state of the battery 51 are set in advance in the flywheel controller 73. Note that the upper and lower limits may not be the same as the upper and lower limits set in the battery management system. In this embodiment, the same value is set.

  Next, the operation of the electric vehicle according to this embodiment will be described. Here, first, the operating characteristics of the power generation system 60 will be described with reference to FIGS. 4 and 5. The vertical axis in FIGS. 4 and 5 is an arbitrary scale.

  As shown in FIG. 4B, when pulsed power commands p 1 and p 2 are sent from the battery management system 52 to the turbine controller 622, the turbine controller 622 increases the amount of fuel supplied to the micro turbine 611. Instruct. Accordingly, as shown in FIG. 4A, the rotational speed of the micro turbine 611 changes as r1 and r2. Correspondingly, the micro turbine outlet exhaust gas temperature t changes. As the rotational speed of the micro turbine 611 increases or decreases, as shown in FIG. 4B, the output of the generator 612 changes as g1 and g2.

  Here, as shown in FIG. 4B, the generator outputs g1 and g2 have a response delay compared to the power command pulses p1 and p2. This occurs as the micro turbine 611 obtains torque from the combustion of fuel. On the other hand, in the flywheel system 70, the rotational movement of the flywheel 71 and the conversion of electric power can be quickly performed by the generator motor 72. Therefore, in accordance with the situation where the power command described above must be sent, that is, when the battery 51 reaches the upper limit or the lower limit of the intermediate state, the flywheel controller 73 changes the operation of the generator motor 72 to either power generation or electric drive. By setting the mode, it is possible to respond quickly.

  Further, when the electric vehicle is stopped, as shown in FIG. 5A, the turbine controller 622 controls the fuel supply amount to the micro turbine 611 to be reduced and maintained at a low output. Along with this, the turbine outlet exhaust gas temperature t decreases, and thereafter a substantially constant temperature is maintained. On the other hand, the temperature turbine rotational speed r is maintained in a state where the rotational speed r is slightly increased because the load on the generator 612 decreases. Here, as shown in FIG. 5B, the generator output decreases and is held at a constant value. At this time, the battery 51 is charged. Thereafter, the micro turbine 611 is switched to the cold air operation, and the operation is finished.

  Next, the operation of the electric vehicle will be described. First, when an electric vehicle start instruction is received from the operation controller 40, the turbine controller 622 executes a start operation of the micro turbine 611. Thereafter, when the vehicle is ready for operation, a display to that effect is displayed on the display panel 41 of the operation controller.

  In this state, when a travel instruction is input from the operation controller 40, the driver 31 receives this and generates a drive pulse using the power of the battery 51 and supplies it to the drive motor 32. The drive motor 32 generates torque based on the drive pulse and drives the wheels 13. At this time, the sensor 53 detects the terminal voltage of the battery 51. Based on the output signal of the sensor 53, the battery management system 52 determines whether the state of charge of the battery is in the intermediate state, that is, whether it is within the upper limit and the lower limit of the intermediate state. While in the intermediate state, the operation continues. At this time, the flywheel system 70 is supplied with power for idling for maintaining the rotation of the flyhole 71 from the battery 51.

  Based on the signal from the sensor 53, the battery management system 52 monitors whether the state of charge of the battery 51 is in an intermediate state. As described above, this monitoring can be performed by integrating the terminal voltage of the battery 51, the input / output current, and the like. Here, for the sake of simplicity, monitoring is performed using the terminal voltage. If it is determined that the terminal voltage of the battery 51 detected by the sensor 53 has reached a value corresponding to the lower limit of the intermediate state, the battery management system 52 generates a power command and sends it to the turbine controller 622 of the power generation system 60. The turbine controller 622 outputs a command for increasing the rotational speed to the micro turbine generator 61. For example, control such as increasing the amount of fuel supplied to the micro turbine 611 is performed. However, as described above, the power generation by the micro turbine 611 causes a slight delay in the rise.

  On the other hand, when the flywheel controller 73 determines that the terminal voltage of the battery has reached a value corresponding to the lower limit of the intermediate state based on the signal from the sensor 53, the flywheel 71 drives the generator motor 72 to generate power. I do. The output of the generator motor 72 is fed to the battery 51 as a direct current via the flywheel controller 73. Thereby, the delay of the start-up of the electric power generation system 60 mentioned above can be compensated. As described above, the flywheel system 70 is limited to a short time during which it can be output. However, if it can be held for a short time, then power will be supplied from the power generation system described above, which is sufficient.

  Here, when the output voltage reaches the terminal voltage of the battery 51, the flywheel system 70 stops the output and returns to the idling state.

  On the other hand, when the battery management system 52 determines that the terminal voltage of the battery detected by the sensor 53 has reached a value corresponding to the upper limit of the intermediate state, the battery management system 52 reduces the output power of the power generation system 60 to the turbine controller 622. A power command for instructing to be output is output. As a result, the output from the microturbine generator 61 decreases, the power supplied to the battery 51 decreases, and the increase in the terminal voltage of the battery 51 is suppressed. At this point, the flywheel system is in an idling state, consuming a small amount of power, and the generator motor 72 maintains the rotation of the flywheel.

  Next, when a braking instruction is issued from the operation controller 40, the driver 21 causes the drive motor 32 to function as a generator and drives the drive motor 32 by the movement of the wheels to generate power. The electric power generated here is fed to the battery 51 via the driver 31. At this time, when the battery management system 52 determines that the terminal voltage of the battery 51 has reached a voltage corresponding to the upper limit of the intermediate state based on the signal from the sensor 53, the battery management system 52 instructs the power generation system to the turbine controller 622. A power command for commanding the output power of 60 to be further reduced is output. In the flywheel system 70, the flywheel controller 73 causes the generator motor 72 to function as an electric motor, and further rotates the flywheel with the power of the battery 51. As a result, electric power generated by regenerative braking of the drive motor 32 flowing into the battery 51 is absorbed as rotational energy of the flywheel 71. As a result, since the regenerative current of the drive motor 32 can be absorbed, a braking effect can be ensured.

  As described above, according to the present embodiment, by controlling the drive and braking of the drive motor using the battery as the main power supply, the electric vehicle is controlled using the battery as the main power supply while supplying power by the microturbine generator. It can be performed. Furthermore, it is possible to respond quickly to sudden fluctuations in load during power running and braking, and to realize an electric vehicle with good controllability.

  The embodiment described above is an example of an electric vehicle traveling on a track, but the present invention is not limited to this. For example, the present invention can be applied to an electric vehicle having no track such as a bus and a truck.

FIG. 1 is a side view of an electric vehicle according to an embodiment of the present invention. FIG. 2 is a plan view of a state in which a part of the cover is removed. FIG. 3 is a block diagram showing a power system and a control system of the electric vehicle according to the present embodiment. FIG. 4A is a graph showing the relationship between the rotational speed of the micro turbine and the exhaust gas temperature, and FIG. 4B is a graph showing the relationship between the generator output and the power command pulse. FIG. 5A is a graph showing the relationship between the rotational speed of the micro turbine and the exhaust gas temperature, and FIG. 5B is a graph showing the relationship between the generator output and the battery charging timing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electric vehicle, 30 ... Travel drive system, 31 ... Driver, 32 ... Drive motor, 40 ... Operation controller, 50 ... Main power supply system, 51 ... Battery, 52 ... Battery management system, 60 ... Power generation system, 61 ... Micro Turbine Generator 62 ... Micro Turbine Power Control System 70 ... Fly Wheel System 71 ... Fly Wheel 72 ... Generator Motor 73 ... Fly Wheel Controller

Claims (2)

In an electric vehicle using a battery as a driving power source,
A traveling drive system that is used for traveling and that drives and brakes;
An operation instruction device for receiving operation instructions;
A power generation system driven by a microturbine;
A main power supply including a battery capable of charging and discharging;
An auxiliary power supply device capable of absorbing / releasing power,
The main power supply device has a sensor for detecting the state of charge of the battery, and a management system that performs control for maintaining the state of charge of the battery in an intermediate state of its capacity,
The auxiliary power supply device has means for storing energy, a generator motor for driving the means for storing energy and generating electric power thereby, and a controller for controlling power generation and driving,
When the management system detects that the state of charge of the battery reaches the lower limit of the intermediate state of its capacity based on a signal from the sensor, it outputs a command for increasing the power output to the power generation system When detecting that the state of charge of the battery reaches the upper limit of the intermediate state of its capacity based on the signal from the sensor, a command for reducing the output of power is output to the power generation system,
When the controller of the auxiliary power supply detects that the state of charge of the battery reaches the lower limit of the intermediate state of its capacity based on the signal from the sensor, it generates power by the energy storage means and supplies power to the battery. , When it is detected that the state of charge of the battery reaches an upper limit of an intermediate state of its capacity based on a signal from the sensor, energy is stored in the energy storage means by the power of the battery,
A hybrid energy electric vehicle characterized by The electric vehicle according to claim 1,
A hybrid energy electric vehicle characterized in that the energy storage means of the auxiliary power supply is a flywheel.

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