WO2018047341A1

WO2018047341A1 - Vehicle

Info

Publication number: WO2018047341A1
Application number: PCT/JP2016/076809
Authority: WO
Inventors: 友樹桑野; 陽介清水; 萩原　敬三
Original assignee: 株式会社東芝
Priority date: 2016-09-12
Filing date: 2016-09-12
Publication date: 2018-03-15

Abstract

Provided is a vehicle which is equipped with an internal combustion engine (2), a motor (4), and a main circuit battery (15) for driving the motor (4), controls the output of the main circuit battery (15), and electrically separates the battery. Thus, a vehicle equipped with: an internal combustion engine (2) for outputting mechanical energy for driving an axle (5); a power generator (9) for converting some of the mechanical energy into electrical energy; a motor (4) which is connected to a DC link and drives the axle (5) using electrical energy; a main circuit battery (15) which is connected in parallel to the DC link (11), and drives the motor (4); and a control unit (7) for controlling in a manner such that the electrical energy generated by the power generator (9) and the consumed electrical energy are substantially identical to one another, and electrically separating the battery from the DC link (11) while the main circuit battery (15) is neither charging nor discharging.

Description

vehicle

Embodiments according to the present invention relate to a vehicle on which an internal combustion engine and a main circuit battery are mounted as a power source.

In general, in addition to an internal combustion engine that serves as a power source for rotating wheels, a hybrid vehicle that is equipped with a battery and that uses a motor as a second power source is known. For example, Patent Document 1 proposes a hybrid vehicle in which a ring gear is provided on a drive shaft that is rotationally driven by an engine, and a motor is attached via a reduction gear or directly. In this hybrid vehicle, a part of the engine power is transmitted to the drive shaft using the power distribution and integration mechanism, and the remaining power is transmitted to the generator to drive the motor, battery and other electronic devices. It is converted into electric power for charging.

In the drive control of this hybrid vehicle, the engine required power to be output according to the accelerator opening is the axle required power for rotating the drive shaft, the battery charge / discharge required power, the drive mechanism and each device (such as an air conditioner). Calculated from the power loss.

JP 2009-96360 A

The drive control of the hybrid vehicle in Patent Document 1 described above is not control that feeds back the battery output. Therefore, the power consumption required for charging / discharging the battery appropriately is affected by the loss fluctuation of the driving equipment and each equipment and the load fluctuation of the auxiliary equipment. The situation that cannot be obtained is assumed.

Also, the converter that converts the current voltage output from the generator is required to have a higher conversion capability as the time rating is increased. High conversion capacity leads to high cost and large size. On the other hand, the burden on the converter is reduced by using the battery as an auxiliary. However, batteries have lower energy density than fossil fuels and cannot be expected as regular assistance.

If the battery cannot be charged immediately even if the SOC (State Of Charge) decreases below the specified value due to discharge for driving, the battery is electrically disconnected after the converter and inverter are gated off. ing. After that, after a certain period of time has elapsed, the converter and the inverter are gated on again to resume operation. If the vehicle is in a hill-climbing state during the separation period, the transmission of auxiliary power is interrupted and the speed decreases, and the vehicle suddenly changes due to a sudden torque change when the operation is resumed. The situation where a speed change and a shock are given arises.

Therefore, there is provided a vehicle that uses an internal combustion engine and a motor as a power source, reduces the burden on the converter of the power split mechanism by a battery for driving the motor, and controls the battery output while maintaining the maximum vehicle output.

The vehicle according to the embodiment includes an internal combustion engine that outputs mechanical energy that drives an axle, a generator that converts part of the mechanical energy into electric energy, and a DC link that transmits the electric energy generated by the generator. And a motor that is electrically connected to the DC link, is supplied with the electrical energy from the generator and applies a driving force of the axle by rotation of a rotating shaft, and is electrically connected in parallel to the DC link. The main circuit battery, the electric energy generated by the generator, and the electric energy that is consumed including the electric energy required for driving the motor are controlled to be substantially the same, and the main circuit is in a state without charge / discharge. A controller that electrically disconnects the battery and the DC link.

FIG. 1 is a block diagram showing a conceptual configuration of mode 1 in a hybrid vehicle drive system according to an embodiment. FIG. 2 is a block diagram showing a conceptual configuration of mode 2 in the hybrid vehicle drive system according to the embodiment. FIG. 3A is a block diagram conceptually showing a part of the hybrid controller. FIG. 3B is a partial block diagram showing the remaining part of the hybrid controller of FIG. 3A. FIG. 4 is a flowchart for explaining mode switching of the vehicle drive system. FIG. 5A is a block diagram for explaining generator / motor torque command calculation in mode 1 of the drive system. FIG. 5B is a block diagram showing a detailed configuration of a battery output control unit in the drive system shown in FIG. 5A. FIG. 6 is a block diagram for explaining the generator / motor torque command calculation in mode 2 of the drive system. FIG. 7 is a block diagram for explaining an extension mode sequence of the drive system. FIG. 8 is a diagram conceptually showing operating points of the internal combustion engine of the drive system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a conceptual configuration of mode 1 in a hybrid vehicle drive system according to an embodiment, and FIG. 2 is a block diagram showing a conceptual configuration of mode 2. As shown in FIG.
The vehicle of the present embodiment is a hybrid vehicle that uses a motor driven by an internal combustion engine and a main circuit battery as a power source, and FIGS. 1 and 2 conceptually show a drive system of the hybrid vehicle.

The drive system 1 includes an internal combustion engine 2 as a main power source, a power transmission system 3 that divides and combines mechanical energy generated by the internal combustion engine 2, and an auxiliary power source provided in the power transmission system 3. The motor 4, the wheel 6 connected to the power transmission system 3 via the axle 5, and a hybrid controller [control unit] 7 that controls the components in the drive system 1. Here, the internal combustion engine 2 is a power source that generates mechanical energy by burning fossil fuel inside an engine such as a gasoline engine or a diesel engine, a gas turbine, or the like. In this example, the main power source is the internal combustion engine 2 and the auxiliary power source is a motor. However, the main power source is the motor 4 and the auxiliary power source is the internal combustion engine 2. Is also possible.

The power transmission system 3 includes a power split mechanism 8 that at least bisects mechanical energy, a generator 9 that converts one of the split mechanical energy into AC, for example, three-phase AC electrical energy, and controls the generator 9 for AC. Converter 10 for generating DC current voltage from DC, DC link 11 for transmitting DC current voltage (power), and inverter for generating AC to AC, for example, three-phase AC current voltage from DC and controlling motor 4 12, and a power coupling mechanism 14 that couples auxiliary mechanical energy generated by the motor 4 and the other mechanical energy that is divided into the power split mechanism 8 and transmitted by the transmission member 13. The mechanical energy coupled by the power coupling mechanism 14 rotates the wheel 6 via the axle 5. In the following description, mechanical energy and electrical energy will be referred to as power or power when there is no need for division.

The power split mechanism 8 and the power coupling mechanism 14 in the present embodiment are configured with a planetary gear mechanism. This planetary gear mechanism is known, for example, a sun gear S, a planetary gear P circumscribing the sun gear S, a ring gear R inscribed by the planetary gear P, and a planetary carrier C that rotates along the orbit of the planetary gear. And. In the present embodiment, the planetary carrier C is rotated by mechanical energy generated by the internal combustion engine 2. The rotational power of the sun gear S is transmitted to the generator 9. The rotational power of the ring gear R is transmitted to the power coupling mechanism 14 through the transmission member 13.

The generator 9 converts mechanical energy P supplied through the sun gear S of the power split mechanism 8 into electrical energy. The generator 9 is, for example, a motor that connects the sun gear S and the rotating shaft, and outputs three-phase AC power.
The converter 10 has a control function for controlling the power generation operation by the generator 9 and converts the three-phase AC power output from the generator 9 into DC power.

Further, the inverter 12 converts the DC power supplied from the DC link 11 into AC power and outputs the AC power to the motor 4. Further, the inverter 12 converts AC power supplied from the motor 4 that performs a regenerative operation into DC power and outputs the DC power to the DC link 11.
The motor 4 is driven by AC power supplied from the inverter 12, converts electric energy into mechanical energy, and outputs the mechanical energy to the power coupling mechanism 14.

Furthermore, a main circuit battery (BAT) 15 is connected via a contactor 16 to the DC link 11 connecting the converter 10 and the inverter 12. The contactor 16 is a known electromagnetic contactor and can electrically disconnect the main circuit battery 15 by opening using electromagnetic force.

The DC link 11 is connected to an auxiliary power unit (APU) 17 that supplies electric energy to an auxiliary machine such as an air conditioner. The main circuit battery 15 is a rechargeable battery, and is composed of, for example, an assembled battery including a plurality of secondary battery cells, and can be charged by the generator 9. The main circuit battery 15 provides the hybrid controller 7 with information such as battery temperature, estimated SOC value, and battery output detection value, and the auxiliary machine power unit 17 provides the auxiliary power consumption detection value to the hybrid controller 7.

The hybrid controller 7 includes an information processing device (for example, a computer) having a calculation function and a memory function, and a memory. FIGS. 3A and 3B show block configurations as an example. The hybrid controller 7 includes a system power / vehicle required torque calculation unit 21, an internal combustion engine output calculation unit 22, an internal combustion engine operating point determination unit 23, a mode 1 generator / motor torque command calculation unit (hereinafter referred to as mode 1 calculation). 24), a mode 2 generator / motor torque command calculation unit (hereinafter referred to as mode 2 calculation unit) 25, an extension mode sequence unit 26, and mode changeover switches 27 and 28.

In addition to the battery temperature, estimated SOC value, detected battery output value, and detected auxiliary machine power consumption value, the hybrid controller 7 is provided with the motor rotation speed from the motor 4, and torque according to the driver's instructions. A request / release command and a power extension mode ON / OFF command are input.

Hereinafter, each command and signal flow in the vehicle of the present embodiment will be described.
In FIG. 3A and FIG. 3B, the system power / vehicle required torque calculation unit 21 rotates the torque of the motor 4 and a torque request / release command issued by the driver from a driving operation according to the driving state of the vehicle (such as climbing or acceleration / deceleration) Based on the numerical information, a system power request indicating how much power is required and a vehicle required torque are output.

Based on this system power request, SOC (StateＳＯOf Charge: charge rate) estimated value that is the remaining capacity of the main circuit battery 15 and battery temperature information, the internal combustion engine output calculation unit 22 calculates the internal combustion engine required output value. . This calculation result is calculated as a corrected internal combustion engine required output value by adding an internal combustion engine output correction value, which will be described later, by the adder 29. Further, the internal combustion engine operating point determination unit 23 outputs a speed command to the internal combustion engine 2 according to the operating point shown in FIG. 8 using the internal combustion engine required output value.

FIG. 8 is a diagram conceptually showing operating points of the internal combustion engine of the drive system.
FIG. 8 shows an optimum operation line of the internal combustion engine based on the internal combustion engine output with respect to the internal combustion engine speed. Here, internal combustion

engine operation points

101a, 101b, and 101c arbitrarily and discretely set on the optimal operation line are shown. In this example, the internal combustion engine operating point 101a is set in a region where the efficiency is high within the range allowed by the battery output performance.

The extension mode sequence unit 26 receives a power extension mode ON / OFF command for commanding the setting / cancellation of the extension mode by the driver's operation and a battery output detection signal value from the main circuit battery 15. The extension mode sequence unit 26 outputs a battery output control ON signal, a battery output control OFF signal, and a torque command value hold signal to the mode 1 calculation unit 24, and performs mode switching (voltage control start) to the switching terminals of the mode changeover switches 27 and 28. ) Signal is output, and a battery open signal is output to the contactor 16. The opening of the main circuit battery means that the main circuit battery 15 is electrically disconnected from the DC link 11, and the battery opening signal is a signal for instructing to electrically disconnect. Further, the power extension mode is a mode set in response to a request for a longer vehicle maximum output.

The mode 1 calculation unit 24 receives the motor rotational speed from the motor 4 and the generator rotational speed from the generator 9. Further, the mode 1 calculation unit 24 receives the vehicle request torque from the system power / vehicle request torque calculation unit 21 and the battery output detection value from the main circuit battery 15. As described above, the battery output control ON signal, the battery output zero control ON signal, and the torque command value hold signal are input to the mode 1 calculation unit 24 from the extension mode sequence unit 26. Further, the mode 1 calculating unit 24 outputs the internal combustion engine output correction value to the adding unit 29, and outputs the generator torque command [mode 1] to the input terminal of the mode switch 27 shown in FIG. 3B. The motor torque command [mode 1] is output to the input terminal of the changeover switch 28.

3B, the motor rotation speed is input from the motor 4, the generator rotation speed is input from the generator 9, and the vehicle request torque is input from the system power / vehicle request torque calculation section 21. Is done. Further, a generator torque command value by voltage control is input from the converter 10 to the mode 2 calculation unit 25, and a motor torque value by voltage control is input from the inverter 12.

The mode 2 calculation unit 25 outputs a generator torque command [mode 2] and a motor torque command [mode 2] to the input terminals of the mode changeover switches 27 and 28, respectively. Further, mode 2 calculation unit 25 outputs a generator voltage control ON command to converter 10 and outputs a motor voltage control ON command to inverter 12.

Next, with reference to FIGS. 5A and 5B, the signal processing of the signals and commands in the mode 1 calculation unit 24 will be described in detail.
First, the dividing unit 31 uses the corrected fuel engine required output value output from the adding unit 29 as the internal combustion engine speed output from the internal combustion engine 2 or the detected value of the generator and motor speed and the ring gear. Is divided by the number of revolutions of the internal combustion engine calculated from the number of gears Gr and the number of gears Gs of the sun gear, and is calculated as an internal combustion engine torque request. The (planetary carrier) rotation speed of the internal combustion engine) = (motor rotation speed × Gr + generator rotation speed × Gs) / (Gr + Gs). Next, the multiplying unit 32 multiplies the internal combustion engine torque request by a ratio of −Gs / (Gr + Gs) to calculate the generator torque command 1.

Further, in the subtracting unit 33, a generator torque correction value by a battery output control unit described later is subtracted from the generator torque command 1 and output as a generator torque command 2.

The generator torque command 2 is input to the input terminal 34a of the holding unit 34. The other input terminal 34b of the holding unit 34 is feedback-connected to the output terminal 34c, and the output signal is fed back. The holding unit 34 is switched by a torque command value hold signal from the extension mode sequence unit 26, and either the generator torque command 2 or the signal of the generator torque command [mode 1] so far is set as the generator torque command. Output as [Mode 1]. In this example, when the torque command value hold signal is input, the holding unit 34 holds the generator torque command [mode 1] so far.

Further, the generator torque command 2 branches and is multiplied by a ratio of −Gr / Gs by the multiplication unit 35 to be calculated as a ring gear torque. The ring gear torque is subtracted from the vehicle required torque by the subtracting unit 36 and output as a motor torque command.

The motor torque command is input to the input terminal 37a of the holding unit 37. The other input terminal 37b of the holding unit 37 is feedback-connected to the output terminal 37c, and the output signal is fed back. The holding unit 37 is switched by a torque command value hold signal from the extension mode sequence unit 26, and either the motor torque command or the command of the motor torque command [mode 1] so far is sent to the motor torque command [mode 1]. Is output as In this example, when the torque command value hold signal is input, the holding unit 37 holds the motor torque command [mode 1] so far.

Next, the battery output control unit 41 shown in FIG. 5B will be described.
The battery output control unit 41 is a generator torque for controlling to a predetermined battery output target value (hereinafter referred to as a target value) including a battery output zero for battery release (electrical disconnection). Outputs the correction value. Note that the battery output zero here is not limited to complete zero, and if it is close to zero, no practical problem occurs.

First, the switching unit 42 switches and outputs the battery output detection value and the 0 value in response to the battery output control ON signal. Here, the switching unit 42 outputs the battery output detection value in response to the input of the battery output control ON signal.

Further, the switching unit 43 switches the target value and 0 value of the battery output by the battery output control ON signal, and outputs it to the input terminal of the switching unit 44. Here, the switching unit 43 outputs the target value of the battery output in response to the input of the battery output control ON signal. Further, the switching unit 44 switches between the target value and the zero value from the switching unit 43 and outputs them according to the battery output zero control ON signal. Here, the switching unit 44 outputs a zero value in response to the input of the battery output zero control ON signal.

Next, the subtraction unit 45 subtracts the target value or 0 value output from the switching unit 44 from the battery output detection value output from the switching unit 42 and outputs the result to the PI control unit 46. The PI control unit 46 generates a DC link power correction value by PI control for the battery output detection value or a value obtained by subtracting the target value from the battery output detection value. The multiplication unit 47 multiplies the DC link power correction value by the gear number Gs of the sun gear, and outputs the multiplication result to the division unit 48.

In addition, when the multiplication unit 49 multiplies the motor rotation number by the gear number Gr of the ring gear and outputs it to the addition unit 51, the multiplication unit 50 multiplies the generator rotation number by the sun gear number Gs, It outputs to the addition part 51.

The addition unit 51 adds the output values from the

multiplication units

49 and 50, and outputs the addition result to the division unit 48. The division unit 48 divides the multiplication result of the DC link power correction value and the sun gear gear number Gs by the addition result by the addition unit 51 to calculate a generator torque correction value. This generator torque correction value is output to the subtraction unit 33 and the multiplication unit 53. Multiplier 53 multiplies the generator torque correction value by 1 / Gs and outputs the result to multiplier 54. The multiplication unit 54 multiplies the addition result of the addition unit 51 by the multiplication result of the multiplication unit 53 and outputs the result as an internal combustion engine output correction value. Further, the division unit 52 divides the addition result of the addition unit 51 by 1 / (gr + Gs) to generate the internal combustion engine speed, and outputs it to the division unit 31 described above.

In the mode 1 in which the main circuit battery 15 is connected to the DC link in the present embodiment, the conceptual balance of electric energy (power consumption and power generation power) is Pinv_max + Papu_max = Pcnv1 + Pbat. Note that the consumed power is the electric energy necessary for driving the motor 4 and the auxiliary power unit (APU) 17 and the electric energy supplied from the generator 9 and the main circuit battery 15 is the consumed power.

Next, with reference to FIG. 6, the signal processing of the signal and command in the mode 2 calculation unit 25 will be described in detail. FIG. 6 shows a configuration for a generator / motor torque command calculation in mode 2 of the drive system.
First, the Schmitt trigger unit 78 performs threshold detection using hysteresis characteristics generated between the rotation of the motor and the drive voltage, and outputs a motor voltage control ON signal. Further, the inverter voltage (ON circuit) 79 is used to invert the motor voltage control ON signal to generate the generator voltage control ON signal.

Next, with respect to the generator torque, the multiplier 61 multiplies the vehicle required torque from the system power / vehicle required torque calculation unit 21 and the motor rotational speed to obtain the power (motor power) necessary for driving the vehicle. The result is output to the adder 62. The adder 62 adds the power required for driving the vehicle and the auxiliary machine power consumption obtained by the multiplier 61.

Also, the multiplication unit 65 multiplies the generator rotational speed by −1 to invert the sign and outputs the result to the addition unit 67. In addition, the multiplication unit 66 multiplies the motor rotation number by the ratio of Gr / Gs and outputs the result to the addition unit 67. The adder 67 adds the multiplication results of the multiplier 65 and the multiplier 66, respectively. The division unit 63 outputs the generator torque command FF by dividing the motor power by the addition unit 62 by the rotation speed by the addition unit 67.

Next, the adding unit 71 outputs a motor torque command obtained by adding a motor torque command based on voltage control and a motor torque command FF described later to the multiplying unit 72. The multiplier 72 multiplies the motor torque command by a ratio of Gs / Gr and outputs the command to the input terminal of the switching unit 73. A 0 value is input to the other input terminal of the switching unit 73, and the switching is controlled by a generator voltage control ON signal from the inverting unit 79. When the generator voltage control ON signal is input, the switching unit 73 outputs a zero value.

Furthermore, the output (motor torque command or 0 value) of the switching unit 73 is added by the adding unit 64 to the generator torque command FF from the dividing unit 63 and output as a generator torque command (mode 2).

Also, in the motor torque, the multiplier 68 multiplies the vehicle request torque and the generator rotational speed to calculate the generator power and outputs it to the adder 69. The adder 69 adds auxiliary machine power consumption to the generator power generated by the multiplier 68 and outputs the result to the divider 70. The division unit 70 calculates the motor torque command FF by dividing the generator power by the rotational speed of the addition unit 67.

Further, the adding unit 74 adds the generator torque command FF and the generator torque command by voltage control, and outputs the result to the multiplier 75. The multiplier 75 multiplies the added torque command by a ratio of Gr / Gs and outputs the result to the input terminal of the switching unit 76. A zero value is input to the other input terminal of the switching unit 76, and the switching is controlled by a motor voltage control ON signal from the Schmitt trigger unit 78. When the motor voltage control ON signal is input, the switching unit 76 outputs a 0 value.

Furthermore, the output (generator torque command or 0 value) of the switching unit 76 is added by the adding unit 77 to the motor torque command FF from the dividing unit 70 and output as a motor torque command (mode 2).

In the mode 2 in which the main circuit battery 15 in the present embodiment is disconnected to the DC link, the conceptual balance of electric energy (consumed power and generated power) is expressed as Pinv_max + Papu_max = Pcnv2 (> Pcnv1)

Next, with reference to FIG. 7, signal processing of signals and commands related to mode setting of the extension mode sequence unit 26 will be described in detail. FIG. 7 is a block diagram for explaining an extension mode sequence of the drive system.
The comparison unit 81 compares the SOC estimation signal from the main circuit battery 15 with an arbitrarily set SOC lower limit value (SOC_min) stored in the memory 82, and when SOC estimation signal ≦ SOC lower limit value is satisfied. Outputs one signal to the input terminal of the AND circuit (logical product circuit) 83.

The power extension mode ON signal is transmitted by the operation of a driver who desires mode setting, and is output as an input signal to the input terminal of the AND circuit 83 and a battery output control ON signal.
When the power extension mode ON signal and the output signal (one signal) from the comparison unit 81 are input, the AND circuit 83 outputs a battery output zero control ON signal.

The battery output detection value is input to the input terminal of the coincidence circuit (coincidence logic circuit) 84 and the absolute value circuit (abs circuit) 87, respectively. The zero value is input to the other input terminal of the coincidence circuit 84, and the coincidence circuit 84 outputs one signal to the input terminal of the AND circuit 85 when the battery output detection value is zero. A battery output zero control ON signal is inputted to the other input terminal of the AND circuit 85, and when one signal from the coincidence circuit 84 is inputted simultaneously, it is outputted to the flip-flop circuit 86 as an S (set) signal. The flip-flop circuit 86 receives an R (reset) signal from an OR circuit 90 described later and outputs it as a torque command value hold signal (Q). The torque command value hold signal is input to the on-delay circuit 91 and is output as a battery release signal after a preset time.

The absolute value circuit 87 outputs the absolute value of the battery output detection value to the input terminal of the comparison circuit 88. The comparison circuit 88 receives a preset torque command hold release threshold value from the memory 89 at the other input terminal, and compares battery output detection value ≧ torque command hold release threshold value. When the battery output detection value ≧ the torque command hold release threshold value, one signal is output to the input terminal of the OR circuit 90. A voltage control start signal, which will be described later, is input to the other input terminal of the OR circuit 90. When this start signal or one signal from the comparison circuit 88 is input, the R signal is output to the flip-flop circuit 86.

Also, the DC link voltage detection value is input to the differentiation circuit (d / dt) 94, and further input from the differentiation circuit 94 to the absolute value circuit (abs) 95. The detected DC link voltage value subjected to the absolute value processing by the absolute value circuit 95 is compared with a voltage change rate maximum value preset from the memory 97 by the comparison circuit 96. If this comparison is DC link voltage detection value ≧ voltage change rate maximum value, one signal is output to the input terminal of the AND circuit 98. As a result of this comparison, when the absolute value of the rate of change calculated from the detected value of the DC link voltage becomes equal to or greater than the maximum voltage change rate, the battery open signal starts DC link voltage control without waiting for the set period.

The battery open signal from the on-delay circuit 91 is input to the other input terminal of the AND circuit 98, and when it is input simultaneously with one signal from the comparison circuit 96, it is output to the input terminal of the OR circuit 93.

The battery open signal from the on-delay circuit 91 is further delayed by a set time by the on-delay circuit 92 and input to the other input terminal of the OR circuit 93. The OR circuit 93 outputs a voltage control start signal when the battery open signal or one signal from the AND circuit 98 is input.

In the vehicle drive system configured as described above, when the main circuit battery 15 is electrically disconnected from the DC link 11, it is necessary to perform it when the main circuit battery 15 is not used. Conventionally, the current flowing through the DC link 11 is cut off and disconnected, but in this embodiment, the load side including electric energy generated by the generator (generated power power) and consumed electric energy such as a motor is used. By controlling so that the consumed electric energy (power consumption power) is the same or substantially the same, and taking balance, the main circuit battery 15 is brought into a non-output state (or a state without charge / discharge), Disconnecting from the DC link 11 is performed. For example, the generator torque command and the motor torque command in mode 1 and the mode 2 command so that the vehicle speed, that is, the vehicle required torque is kept constant and the battery output zero control without load fluctuation caused by the auxiliary machine or the like is performed. This is to match the generator and motor torque commands by DC link voltage control when the main circuit battery 15 is disconnected.

By such a method, the main circuit battery 15 can be seamlessly disconnected from the DC link 11. Therefore, the main circuit battery 15 reduces the burden on the converter of the power split mechanism and controls the battery output while maintaining the maximum vehicle output. By realizing such disconnection, auxiliary power transmission by the motor is continued without interruption during the period of disconnection of the main circuit battery 15, and the speed is reduced even when the vehicle is in a climbing situation. Without occurrence, torque change when operation is resumed is prevented.

Specifically, as shown in FIG. 3A, first, a system power request and a vehicle required torque are calculated from a torque request / release command by the driver and the motor rotation speed. Next, the internal combustion engine required output is calculated from the system power request, the estimated battery SOC value, and the battery temperature. The internal combustion engine 2 outputs power at a point where the efficiency of the internal combustion engine 2 is as high as possible, as shown in FIG. 8, under the constraint condition of the maximum battery output determined by the battery SOC and the battery temperature. That is, basically, the battery output is not explicitly controlled. After determining the required output of the internal combustion engine, an operating point at which efficiency is increased is determined, and an internal combustion engine speed command is determined.

When the main circuit battery 15 is electrically connected (mode 1), torque commands for the generator 9 and the motor 4 are determined as shown in FIGS. 5A and 5B. The internal combustion engine required output is divided by the internal combustion engine speed to calculate the internal combustion engine torque request, and this internal combustion engine torque request is multiplied by -Gs / (Gr + Gs) (Gs: number of sun gear teeth, Gr: ring gear teeth) Number) A generator torque command 1 that balances the internal combustion engine torque request is calculated. A generator torque command 2 is calculated by subtracting a generator torque correction value by battery output control from the generator torque command 1. Next, the ring gear torque transmitted from the internal combustion engine is calculated by multiplying the generator torque command 2 by -Gr / Gs. The ring gear torque is subtracted from the vehicle request torque to calculate a motor torque command.

Next, battery output control when the main circuit battery 15 is electrically connected will be described.
The balance between the power generated by the generator in the DC link 11 and the power consumed on the load side of the motor or the like is expressed by equation (1).

Where Tgref: Generator torque command (Nm), ωg: Generator angular velocity (rad / s), Tmref: Motor torque command (Nm), ωm: Motor angular velocity (rad / s), Pbat: Battery Output (+ charge, -discharge) (kW), Papu: Auxiliary machine power consumption (kW), Ploss: Generator, motor, inverter, converter loss (kW).
Further, the relational expression of torque is expressed by Expression (2).

Here, Tref: vehicle required torque (N · m).

If Tmref is deleted from Equation (1) and Equation (2), Tgref1 is expressed by Equation (3).

Here, considering the case where the battery charging power is increased by ΔPbat, it can be expressed by equation (4). The generator torque correction value ΔTGref is expressed by equation (5).

The relationship between the generator torque correction value and the internal combustion engine torque correction value ΔT is expressed by equation (6).

Next, with reference to a flowchart shown in FIG. 4, drive control for mode switching (battery disconnection) of the vehicle drive system configured as described above will be described.

In the normal control mode, a torque request / release command for changing the vehicle speed is input from the driver to the hybrid controller 7, and the speed command to the internal combustion engine 2, the torque command to the generator 9, and the motor 4 A torque command is issued (step S1).

Next, as shown in FIG. 7, a battery output control ON signal is output in response to an input of a long-time vehicle maximum output request (power extension mode ON signal) from the driver (step S2). Next, in the battery output control unit 41 shown in FIG. 5B, a preset battery output control target value is read out by the input of the battery output control ON signal, and is subjected to arithmetic processing using the battery detection value. A torque correction value is output.

As the battery output control mode, the motor 4 is driven by the main circuit battery 15 in addition to the power of the internal combustion engine 2 in accordance with the generator torque command 2 corrected by the generator torque correction value, and travels for a certain period (step S3). ). Thereafter, when the estimated battery SOC value detected from the main circuit battery 15 falls below the SOC lower limit value in the extension mode sequence unit 26, a battery output zero control ON signal is output (step S4).

Next, in the battery output control unit 41 shown in FIG. 5B, the generator torque command is corrected so that the output of the main circuit battery 15 becomes zero by the input of the battery output zero control ON signal (step S5). In this battery output zero mode, the output zero becomes the target value, but in reality, it is not completely zero due to a measurement error or the like. Since the main circuit battery 15 is electrically disconnected in a low SOC state, that is, in a state where the charging capacity is low at a predetermined value (for example, the minimum value), the DC link voltage is low and there is room for the high voltage. For this reason, it is desirable that the target value of the battery output be in a charging direction (a direction in which the energy of the DC link 11 is so low that the DC link voltage rises) slightly smaller than zero. By slightly increasing the DC link voltage, the voltage is slightly increased to give a margin with respect to the preset protection voltage of the DC link voltage. Can have. Therefore, the generator 9 generates slightly more power than the power consumed by the motor 4.

If the battery output detection value becomes zero in the battery output zero mode (step S6), a torque command value hold signal is output from the flip-flop circuit 86, and the holding units 34 and 37 shown in FIG. The machine torque command value and the motor torque command value are held, and the vehicle request torque is also held (step S7). However, if a load fluctuation caused by an auxiliary machine occurs during this hold and a battery output detection value greater than a predetermined threshold value is detected from the main circuit battery 15, the hold of each torque command value is once released. Then, the battery output zero control may be performed again. The generator torque command value and the motor torque command value are held, and after a predetermined time has elapsed, a battery open signal (disconnect signal) is sent to the contactor 16 to electrically disconnect the main circuit battery 15 from the DC link 11 ( Step S8). By this separation, the mode 1 is shifted to the mode 2.

Next, after disconnecting the main circuit battery 15, the DC link voltage control in the mode 2 is started after a certain period of time (step S9). If an auxiliary load fluctuation occurs before the voltage control is started and the change rate of the DC voltage is equal to or greater than a predetermined threshold, the DC link voltage control may be started without waiting for a certain period.

As described above, the generator torque command, the motor torque command, and the main circuit battery 15 in the battery output zero control are determined under the condition where the vehicle required torque is constant and the load fluctuation due to the auxiliary machine or the like does not occur. The generator torque command and the motor torque command by voltage control in the disconnected state are substantially the same. As a result, the main circuit battery 15 can be seamlessly disconnected from the DC link 11 while keeping the vehicle output constant.

DESCRIPTION OF SYMBOLS 1 ... Drive system, 2 ... Internal combustion engine, 3 ... Power transmission system, 4 ... Motor, 5 ... Axle, 6 ... Wheel, 7 ... Hybrid controller, 8 ... Power split mechanism, 9 ... Generator, 10 ... Converter, 11 ... DC link, 12 ... inverter, 13 ... transmission member, 14 ... power coupling mechanism, 15 ... main circuit battery, 16 ... contactor, 17 ... auxiliary power unit, 21 ... system power / vehicle required torque calculation unit, 22 ... internal combustion engine output Calculation unit, 23 ... operating point determination unit for internal combustion engine, 24 ... generator / motor torque command calculation unit, 25 ... generator / motor torque command calculation unit, 26 ... extension mode sequence unit, 27, 28 ... mode changeover switch, 29 ... Adding unit, 31 ... Division unit, 32 ... Multiplication unit, 33 ... Subtraction unit, 34, 37 ... Holding unit, 34a, 34b ... Input terminal, 34c Output terminal, 41 ... battery output control unit. 46 ... PI control unit, 78 ... Schmitt trigger unit, 79 ... reversing unit, 81 ... comparing unit, 82 ... memory.

Claims

An internal combustion engine that outputs mechanical energy to drive the axle;
A generator that converts part of the mechanical energy into electrical energy;
A DC link for transmitting the electrical energy generated by the generator;
A motor that is electrically connected to the DC link, is supplied with the electrical energy from the generator, and applies a driving force of the axle by rotation of a rotating shaft;
A main circuit battery electrically connected in parallel to the DC link;
The main circuit battery and the direct current link are controlled in a state where there is no charge / discharge by performing a control to substantially match the electric energy generated by the generator with the electric energy consumed and consumed including the electric energy required for driving the motor. A control unit for electrically disconnecting and
A vehicle comprising:
The vehicle further includes:
A power split mechanism comprising a gear mechanism including a sun gear and a ring gear, and splitting the mechanical energy;
A converter interposed between the generator and the DC link to control the operation of the generator;
An inverter connected to the converter via the DC link and supplying electrical energy to the motor;
A contactor capable of electrically disconnecting the DC link and the main circuit battery by control from the control unit;
An auxiliary machine connected to the DC link and performing a predetermined operation excluding driving of the axle;
A power coupling mechanism that couples the mechanical energy generated by the motor and the mechanical energy divided and transmitted from the power split mechanism, and drives the axle;
Comprising
The controller is
Further, a DC link energy correction value is calculated from a target value of the output of the main circuit battery and a detection value output from the main circuit battery,
A generator torque correction value is calculated from the DC link energy correction value, the number of gears of the sun gear and the number of gears of the ring gear, the number of rotations of the motor and the number of rotations of the generator,
The internal combustion engine output is corrected by the generator torque correction value, the number of gears of the sun gear and the ring gear, and the rotational speed of the motor and the generator,
The vehicle according to claim 1, wherein an output of the main circuit battery is controlled to a target value while satisfying a vehicle required torque.
The controller is
With no charge / discharge of the main circuit battery,
After the elapse of a predetermined period in a state where the torque command of the motor and the vehicle request torque are held, the contactor is opened to electrically disconnect the main circuit battery from the DC link,
After the contactor is opened and a predetermined period elapses, voltage control of the DC link is started, and the hold of the vehicle required torque is released, so that the main circuit can be seamlessly satisfied while satisfying the vehicle required torque. The vehicle according to claim 2, wherein a battery is disconnected from the DC link.
The controller is
In response to a request for a longer vehicle maximum output, a battery output control signal is output,
When the motor is discharged from the main circuit battery at a target value, and after the charging rate reaches a predetermined value, the electric energy generated by the generator and the electric energy consumed are substantially matched, The vehicle according to claim 2, wherein the motor torque command and vehicle required torque are held.
The control unit, when disconnecting the main circuit battery from the DC link, performs control to substantially match the electric energy generated by the generator and the consumed electric energy,
The target value of the output of the main circuit battery is set in the charging direction within a range including a detection error, and after disconnecting the main circuit battery, the DC link voltage applied to the DC link is set to the protection voltage of the DC link voltage. The vehicle according to claim 3, wherein the vehicle is slightly raised.
The controller is
When electrically disconnecting the main circuit battery from the DC link, after holding the torque command of the generator and the motor, and the vehicle required torque,
When an auxiliary machine load fluctuation occurs due to the auxiliary machine, and the absolute value of the main circuit battery output detection value exceeds a preset torque command hold release threshold value, the hold is released, and the main circuit battery is released again. The vehicle according to claim 4, wherein control is performed so that the output of the vehicle becomes zero.
The controller is
When disconnecting the main circuit battery from the DC link, after waiting for a predetermined set period after outputting a battery open signal to open the contactor,
When the absolute value of the rate of change is calculated from the detected value of the DC link voltage applied to the DC link, and the calculation result is equal to or greater than the voltage change rate maximum value,
5. The vehicle according to claim 4, wherein the DC link voltage control is started without waiting for the end of a predetermined setting period after the battery open signal is output.