CN108023526B

CN108023526B - Control device and control method for power drive unit

Info

Publication number: CN108023526B
Application number: CN201711057394.4A
Authority: CN
Inventors: 石川修; 小川泰文; 北川润
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2016-11-04
Filing date: 2017-11-01
Publication date: 2020-12-11
Anticipated expiration: 2037-11-01
Also published as: JP2018074870A; JP6336005B2; DE102017219563A1; CN108023526A; DE102017219563B4

Abstract

The invention provides a control device and a control method for a power drive unit, which can simplify the calculation of a target boosted voltage and reduce the calculation load of a microcomputer. In a step-up determination process for determining whether or not a step-up by a step-up converter is necessary based on an operating point constituted by a motor rotation speed and a command torque, a target step-up voltage is set based on whether or not the operating point is present in a step-up necessary region on a step-up determination map selected in a step-up determination map selection process for selecting a 1 st step-up determination map as a step-up determination map, and the step-up converter is controlled so that the step-up voltage of the step-up converter becomes the set target step-up voltage.

Description

Control device and control method for power drive unit

Technical Field

The present invention relates to a control device and a control method for a power drive unit that controls a power drive unit including a boost converter, a motor inverter, and a generator inverter.

Background

In recent years, hybrid vehicles, electric vehicles, and the like have attracted attention as electric vehicles taking energy saving and environmental concerns into consideration. The hybrid vehicle uses an electric motor as a power source in addition to a conventional engine, and the electric vehicle uses an electric motor as a power source. Both of them convert the direct current stored in the battery into alternating current by an inverter circuit, and supply the alternating current to the electric motor to drive the electric motor for running.

Conventionally, there is known a motor drive control device configured to include: an inverter for driving the motor; a boost converter that boosts a voltage from the battery and supplies the boosted voltage to the inverter; and a control device that calculates a target value of a voltage boosted by the boost converter (hereinafter referred to as a target boosted voltage) based on the rotation speed and the target output torque of the motor, and controls the boost converter based on the calculation result (for example, see patent document 1).

In the conventional technique described in patent document 1, an induced voltage constant is calculated from a target output torque, and a target post-boost voltage appropriate for efficient operation of the motor is calculated from a product of the induced voltage constant and the rotation speed of the motor and a conversion coefficient α of a direct-current voltage and an alternating-current voltage.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3797361

Disclosure of Invention

Technical problem to be solved by the invention

However, when calculating a target post-boost voltage appropriate for efficient operation of the motor from the rotational speed and the target output torque of the motor as in the conventional technique described in patent document 1, the target post-boost voltage is calculated for each calculation processing cycle in a situation where the operating point of the motor changes every moment when the vehicle is traveling. Therefore, the microcomputer has a large computational load, and therefore, it is necessary to use a high-performance and expensive microcomputer with a high computational processing speed, resulting in an increase in cost.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device and a control method for a power drive unit, which can simplify the calculation of a target boosted voltage and reduce the calculation load of a microcomputer.

Technical scheme for solving technical problem

The control device of a power drive unit according to the present invention controls a power drive unit having: a boost converter that boosts a voltage supplied from a battery; a motor inverter that converts the electric power supplied from the step-up converter and supplies the converted electric power to the motor to drive the motor; and a generator inverter that converts electric power from the generator and stores the converted electric power in the battery, the control device including: a storage unit that stores a 1 st step-up determination map, the 1 st step-up determination map being associated with a motor rotation speed and a command torque, and being divided into a step-up required region and a step-up unnecessary region by a torque line indicating a torque obtained by subtracting a certain value from a torque on a torque line indicating a maximum torque that the motor can output when the step-up converter is not stepped up; a command torque generation unit that acquires an accelerator opening degree from an accelerator opening degree sensor that detects the accelerator opening degree and generates a command torque from the acquired accelerator opening degree; a target post-boost voltage setting unit that acquires a motor rotation speed from a motor rotation speed sensor that detects a motor rotation speed, performs a parameter acquisition process that acquires a command torque from a command torque generation unit, performs a boost determination map selection process that selects a 1 st boost determination map stored in a storage unit as a boost determination map, performs a boost determination process that determines whether or not boosting by the boost converter is necessary using the boost determination map selected in the boost determination map selection process, based on an operating point constituted by the motor rotation speed and the command torque acquired in the parameter acquisition process, and sets a target post-boost voltage of the boost converter based on a result of the boost determination process; and a control unit that controls the boost converter so that the boosted voltage of the boost converter becomes the target boosted voltage set by the target boosted voltage setting unit, wherein the target boosted voltage setting unit determines that boosting is necessary if the operating point on the boost determination map selected in the boost determination map selection process is present in the boost-necessary region in the boost determination process, sets the target boosted voltage to a preset voltage setting value, determines that boosting is unnecessary if the operating point on the boost determination map selected in the boost determination map selection process is present in the boost-unnecessary region in the boost determination process, and sets the target boosted voltage to the voltage of the battery.

The control method of a power driving unit in the present invention controls a power driving unit having: a boost converter that boosts a voltage supplied from a battery; a motor inverter that converts the electric power supplied from the step-up converter and supplies the converted electric power to the motor to drive the motor; and a generator inverter that converts electric power from the generator and stores the converted electric power in the battery, the control method including: a command torque generation step of acquiring an accelerator opening degree and generating a command torque from the acquired accelerator opening degree; a target post-boost voltage setting step of acquiring a motor rotation speed, performing a parameter acquisition process of acquiring the command torque generated in the command torque generation step, performing a boost determination map selection process of selecting the 1 st boost determination map as a boost determination map, performing a boost determination process of determining whether or not boosting by the boost converter is necessary, using the boost determination map selected in the boost determination map selection process, based on an operation point constituted by the motor rotation speed and the command torque acquired in the parameter acquisition process, and setting a target post-boost voltage of the boost converter, based on a result of the boost determination process; and a control step of controlling the boost converter so that the boosted voltage of the boost converter becomes the target boosted voltage set in the target boosted voltage setting step, wherein a 1 st boost determination map is associated with the motor rotation speed and the command torque, and is divided into a region requiring boosting and a region not requiring boosting by a torque line indicating a torque obtained by subtracting a certain value from a torque on a torque line indicating a maximum torque that the motor can output when the boost converter is not boosted, and in the target boosted voltage setting step, in the boost determination process, if an operating point on the boost determination map selected in the boost determination map selection process exists in the region requiring boosting, it is determined that boosting is necessary, the target boosted voltage is set to a preset voltage setting value, and in the boost determination process, if an operating point on the boost determination map selected in the boost determination map selection process exists in the region not requiring boosting If it is determined that boosting is not necessary, the target boosted voltage is set to the voltage of the battery.

Effects of the invention

According to the present invention, it is possible to obtain a control device and a control method for a power drive unit, which can simplify the calculation of a target boosted voltage and reduce the calculation load of a microcomputer.

Drawings

Fig. 1 is a schematic configuration diagram of an electric vehicle in embodiment 1 of the present invention.

Fig. 2 is a schematic circuit configuration diagram of a circuit of the power driving unit in embodiment 1 of the present invention.

Fig. 3 is a diagram showing an example of a schematic hardware configuration in the case where the control device according to embodiment 1 of the present invention is configured by a computing means.

Fig. 4A is a flowchart showing a series of operations performed by the control device in embodiment 1 of the present invention to set a target boosted voltage.

Fig. 4B is a flowchart showing a series of operations performed by the control device in embodiment 1 of the present invention to set the target boosted voltage.

Fig. 5 is a diagram showing an example of the 2 nd boosting decision map used by the target post-boosting voltage setting unit according to embodiment 1 of the present invention.

Fig. 6 is a diagram showing an example of the 1 st boosted voltage determination map used by the target boosted voltage setting unit according to embodiment 1 of the present invention.

Fig. 7 is a diagram showing an example of a target boosted voltage map used by the target boosted voltage setting unit in embodiment 1 of the present invention.

Fig. 8 is a diagram showing an example of an optimum voltage map obtained by mapping an optimum voltage that minimizes the loss of the generator in embodiment 1 of the present invention.

Fig. 9 is a timing chart for explaining a vehicle operation when the control device temporarily determines whether or not boosting is necessary using the 2 nd boosting determination map as a comparative example in the case of rapid acceleration of the electric vehicle in embodiment 1 of the present invention.

Fig. 10 is a timing chart for explaining vehicle operation when the control device determines whether or not boosting is necessary using the 1 st boosting determination map in the case where the electrically powered vehicle is rapidly accelerated in embodiment 1 of the present invention.

Fig. 11 is a timing chart for explaining the vehicle operation when the control device determines whether or not the voltage increase is necessary using the 2 nd voltage increase determination map when the electrically-powered vehicle in embodiment 1 of the present invention is gradually accelerating.

Detailed Description

Hereinafter, a control device and a control method of a power drive unit according to the present invention will be described in accordance with a preferred embodiment with reference to the drawings. In the description of the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description is omitted. In the following embodiments, the present invention is applied to a power drive unit mounted on an electric vehicle, for example.

Embodiment mode 1

Fig. 1 is a schematic configuration diagram of an electric vehicle in embodiment 1 of the present invention. In fig. 1, the electric vehicle includes an engine 1, a generator 2, a motor 3, tires 4, a power drive unit 5 (hereinafter referred to as PDU5), a battery 6, a control device 7, a vehicle speed sensor 8, an accelerator opening degree sensor 9, a motor rotation speed sensor 10, a generator rotation speed sensor 11, and an engine rotation speed sensor 12.

PDU5 is disposed between battery 6 and generator 2 and motor 3. PDU5 includes a boost converter 53 that boosts the voltage supplied from the battery 6, a motor inverter 51 that converts the electric power supplied from the boost converter 53 and supplies the converted electric power to the motor 3 to drive the motor, and a generator inverter 52 that converts the electric power from the generator 2 and stores the converted electric power in the battery 6.

The boost converter 53 boosts the dc voltage supplied from the battery 6. The motor inverter 51 converts the direct current supplied from the boost converter 53 into alternating current, and supplies the alternating current to the motor 3. Similarly, the generator inverter 52 converts the direct current supplied from the step-up converter 53 into alternating current, and supplies the alternating current to the generator 2. The generator inverter 52 converts the ac power generated by the generator 2 into dc power, and stores the dc power in the battery 6.

Here, when the control device 7 sets the travel mode to the EV travel mode and controls the travel of the vehicle, the engine 1 is stopped and the generator 2 does not generate power. Therefore, the boost converter 53 boosts the dc power stored in the battery 6, and the motor inverter 51 converts the dc power into 3-phase ac power and supplies the ac power to the motor 3. Thereby, the motor 3 is driven, and the tire 4 is further driven, so that the vehicle travels.

When the control device 7 sets the running mode to the power generation running mode and controls the running of the vehicle, the engine 1 is driven and the generator 2 generates power. Thereby, the electric power generated by the generator 2 is charged to the battery 6 via the generator inverter 52 and the boost converter 53. The motor inverter 51 converts the electric power generated by the generator 2 or the direct current stored in the battery 6 into an alternating current, and supplies the alternating current to the motor 3. Thereby, the motor 3 is driven, and the tire 4 is further driven, so that the vehicle travels.

During deceleration of the vehicle or the like, the motor 3 is rotated by the tire 4, the motor 3 regeneratively generates power, and the power generated by the regenerative power generation is charged to the battery 6 via the motor inverter 51. The generator inverter 52 converts the dc power stored in the battery 6 into ac power and supplies the ac power to the generator 2, thereby driving the generator 2 and also starting the engine 1.

In embodiment 1, a series hybrid vehicle shown in fig. 1 is exemplified as a specific example of an electric vehicle to which the present invention can be applied, but the present invention is not limited to this, and for example, the present invention can be applied to a parallel hybrid vehicle. Here, the tandem system is a system in which the engine is used only for power generation and the motor is used only for driving and regeneration of the axle. The parallel type is a system in which a plurality of power sources mounted, that is, an engine and an electric motor, are used to drive wheels. In fig. 1, a tandem structure is shown.

In embodiment 1, the case where the generator 2 and the motor 3 are provided separately is exemplified, but the present invention is not limited to this, and a motor/generator that can drive and generate power may be provided as the generator 2 and the motor 3.

Here, a circuit of PDU5 will be described with reference to fig. 2. Fig. 2 is a schematic circuit configuration diagram of a circuit of PDU5 in embodiment 1 of the present invention. Fig. 2 also illustrates the power generator 2, the motor 3, and the battery 6 in addition to the PDU 5.

In fig. 2, the motor inverter 51 of PDU5 includes a U-phase switch circuit 511, a V-phase switch circuit 512, and a W-phase switch circuit 513.

The U-phase switch circuit 511 includes an upper arm side switch circuit 511H and a lower arm side switch circuit 511L. The V-phase switch circuit 512 includes an upper arm side switch circuit 512H and a lower arm side switch circuit 512L. The W-phase switch circuit 513 includes an upper arm side switch circuit 513H and a lower arm side switch circuit 513L.

The upper arm side switching circuits 511H to 513H are each composed of a switching element such as an IGBT or FET and a flywheel diode, and are controlled by the control device 7. The lower arm side switching circuits 511L to 513L are each composed of a switching element such as an IGBT or FET and a flywheel diode, and are controlled by the control device 7.

The generator inverter 52 of PDU5 includes a U-phase switching circuit 521, a V-phase switching circuit 522, and a W-phase switching circuit 523.

The U-phase switch circuit 521 includes an upper arm side switch circuit 521H and a lower arm side switch circuit 521L. The V-phase switch circuit 522 includes an upper arm side switch circuit 522H and a lower arm side switch circuit 522L. The W-phase switch circuit 523 includes an upper arm side switch circuit 523H and a lower arm side switch circuit 523L.

The upper arm side switching circuits 521H to 523H are configured by switching elements such as IGBTs and FETs and flywheel diodes, and are controlled by the control device 7. The lower arm side switching circuits 521L to 523L are each composed of a switching element such as an IGBT or FET and a flywheel diode, and are controlled by the control device 7.

The boost converter 53 of the PDU5 includes a 1 st switching circuit 531H, a 2 nd switching circuit 531L, a reactor 532, a 1 st smoothing capacitor 533, and a 2 nd smoothing capacitor 534.

The 1 st switching circuit 531H and the 2 nd switching circuit 531L are constituted by switching elements such as IGBTs and FETs and flywheel diodes, and are controlled by the control device 7. The control device 7 controls the 1 st switching circuit 531H and the 2 nd switching circuit 531L, so that the boost converter 53 boosts the voltage of the battery 6 (hereinafter, referred to as a battery voltage) to a target boosted voltage to be described later, and supplies the boosted voltage to the motor inverter 51 and the generator inverter 52.

Returning to the description of fig. 1, the control device 7 is also generally referred to as an Electronic Control Unit (ECU) and performs overall control of the vehicle. The control device 7 is realized by, for example, a microcomputer that executes arithmetic processing, a ROM (Read Only Memory) that stores data such as program data and fixed value data, and a RAM (Random Access Memory) that updates and sequentially rewrites the stored data.

The control device 7 receives detection signals indicating detection values from a vehicle speed sensor 8 for detecting a vehicle speed, an accelerator opening sensor 9 for detecting an accelerator opening, a motor rotation speed sensor 10 for detecting a rotation speed of the motor 3 (hereinafter, referred to as a motor rotation speed), a generator rotation speed sensor 11 for detecting a rotation speed of the generator 2 (hereinafter, referred to as a generator rotation speed), an engine rotation speed sensor 12 for detecting a rotation speed of the engine 1, and other sensors not shown in the drawings, which are necessary for various controls.

The control device 7 controls the motor inverter 51, the generator inverter 52, the boost converter 53, the engine 1, the motor 3, and the generator 2, respectively, based on detection values input from the sensors.

The control device 7 includes a command torque generation unit 71, a target post-boost voltage setting unit 72, a travel mode setting unit 73, a command torque change rate calculation unit 74, a control unit 75, and a storage unit 76.

The command torque generation unit 71 acquires the accelerator opening degree from the accelerator opening degree sensor 9, and generates a command torque based on the acquired accelerator opening degree. Specifically, the accelerator opening degree acquired from the accelerator opening degree sensor 9 is converted into a command torque based on a map that is set in advance by associating the accelerator opening degree with the command torque, and the command torque is generated.

The target post-boost voltage setting unit 72 determines whether or not boost is necessary using a boost determination map described later, based on the command torque acquired from the command torque generation unit 71, the motor rotation speed acquired from the motor rotation speed sensor 10, and the generator rotation speed acquired from the generator rotation speed sensor 11. Further, the target post-boost voltage setting unit 72 sets the target post-boost voltage of the boost converter 53 based on the determination result.

Travel mode setting unit 73 switches the travel mode to the EV travel mode and the power generation travel mode based on the command torque acquired from command torque generation unit 71, and sets the switched travel mode.

The command torque change rate calculation unit 74 calculates a command torque change rate that is a change rate of the command torque acquired from the command torque generation unit 71.

The control unit 75 controls the vehicle in accordance with the traveling mode set by the traveling mode setting unit 73.

Here, an example of the hardware configuration of the control device 7 is explained with reference to fig. 3. Fig. 3 is a diagram showing an example of a schematic hardware configuration in the case where the control device 7 in embodiment 1 of the present invention is configured by a computing means.

The input and output of signals are performed via the interface 77. The memory 79 stores in advance programs of various functions shown as functional blocks of the control device 7 in fig. 1, data including a 1 st boosting decision map, a 2 nd boosting decision map, and the like, which will be described later, necessary for processing, tables, maps, and the like. The storage unit 76 of the control device 7 in fig. 1 corresponds to a memory 79.

The CPU78 performs arithmetic processing on signals input via the interface 77 in accordance with various programs, data, tables, maps, and the like stored in the memory 79, and outputs the processing results via the interface 77.

Next, a series of operations performed by the control device 7 to set the target boosted voltage will be described with reference to fig. 4A and 4B. Fig. 4A and 4B are flowcharts showing a series of steps of the operation of setting the target boosted voltage by the control device 7 in embodiment 1 of the present invention. Fig. 4A and 4B show a flowchart divided into two diagrams. The processing in the flowchart is repeatedly executed at a predetermined set cycle.

Here, as described above, the control unit 75 controls the vehicle in accordance with the traveling mode set by the traveling mode setting unit 73.

First, a series of processing performed when the travel mode set by travel mode setting unit 73 is the EV travel mode will be described.

In step S101, as the parameter acquisition process, the command torque Trmtag is acquired from the command torque generation unit 71, the motor rotation speed Nem is acquired from the motor rotation speed sensor 10, and the process proceeds to step S102.

In step S102, the running mode setting portion 73 determines whether the currently set running mode is the EV running mode or the power generation running mode based on the command torque Trmtag acquired in step S101. If it is determined that the running mode is the EV running mode, the process proceeds to step S103, and if it is determined that the running mode is the power generation running mode, the process proceeds to step S112. Here, as described above, since it is assumed that the running mode is the EV running mode, the process proceeds to step S103.

In step S103, the command torque change rate calculation unit 74 calculates the amount of change of the command torque Trmtag acquired in step S101 every predetermined set time as the command torque change rate Δ Trmtag. The target post-boost voltage setting unit 72 determines whether or not the command torque change rate Δ Trmtag calculated by the command torque change rate calculation unit 74 is equal to or greater than a preset command torque change rate set value.

When the command torque change rate Δ Trmtag is equal to or greater than the command torque change rate set value, the target post-boost voltage setting unit 72 determines that the torque requested by the driver is large, that is, the vehicle is rapidly accelerated, and the process proceeds to step S104. On the other hand, when the command torque change rate Δ Trmtag is smaller than the command torque change rate set value, the target post-boost voltage setting unit 72 determines that the torque requested by the driver is small, that is, the vehicle is slowly accelerating, and the process proceeds to step S105.

In step S104, as the step-up determination map selection process, the target post-step-up voltage setting unit 72 selects the 1 st step-up determination map as the step-up determination map, and the process proceeds to step S106. The 1 st boost determination map is used to determine whether or not boost by the boost converter 53 is necessary when it is determined in step S103 that the vehicle is accelerating rapidly.

In step S105, as the step-up determination map selection process, the target post-step-up voltage setting unit 72 selects the 2 nd step-up determination map as the step-up determination map, and the process proceeds to step S106. The 2 nd boost determination map is used to determine whether or not boost by the boost converter 53 is necessary when it is determined in step S103 that the vehicle is slowly accelerating.

Thus, in the boost determination map selection process, the target post-boost voltage setting unit 72 selects the 1 st boost determination map as the boost determination map when the command torque change rate calculated by the command torque change rate calculation unit 74 is equal to or greater than the command torque change rate set value. Further, the target post-boost voltage setting unit 72 selects the 2 nd boost determination map as the boost determination map when the command torque change rate calculated by the command torque change rate calculation unit 74 is smaller than the command torque change rate set value.

Here, the 2 nd boosting decision map will be described with reference to fig. 5. Fig. 5 is a diagram showing an example of the 2 nd boosting decision map used by the target post-boosting voltage setting unit 72 in embodiment 1 of the present invention.

As shown in fig. 5, the 2 nd boost determination map is associated with the motor rotation speed and the command torque, and is divided into a boost-required region and a boost-unnecessary region by a torque line indicating the maximum torque that the motor 3 can output when the boost converter 53 is not boosted.

Specifically, fig. 5 shows a region where the values of the Y-axis command torque and the X-axis motor rotation speed are both positive, that is, quadrant 1. The broken line is a line (hereinafter referred to as "torque line 1") indicating the maximum torque that the motor 3 can output when the boost converter 53 boosts the voltage.

The solid line indicates a maximum torque that can be output by the motor 3 when the voltage of the boost converter 53 is not boosted, that is, when the voltage supplied to the motor inverter 51 is a battery voltage (for example, 300V) (hereinafter, referred to as "2 nd torque line"). The 2 nd torque line is a boundary line for determining whether or not boosting is necessary.

Therefore, when the operating point constituted by the motor rotation speed and the command torque acquired in step S101 is present in the region inside the 2 nd torque line when the 2 nd torque line is defined as the boundary in the 2 nd pressure increase determination map, that is, in the pressure increase unnecessary region, it is determined that pressure increase is unnecessary. On the other hand, when the operating point exists in a region including the 2 nd torque line on the 2 nd torque line when the 2 nd pressure rise determination map is bounded by the 2 nd torque line, that is, when the operating point exists in a region requiring pressure rise, it is determined that pressure rise is necessary.

Thus, if the operating point on the 2 nd boosting determination map selected as the boosting determination map in step S105 is present in the boosting required region, it is determined that boosting is required, and if the operating point on the 2 nd boosting determination map is present in the boosting unnecessary region, it is determined that boosting is not required.

For example, when the command torque increases from 25Nm in a state where the motor rotation speed is fixed at 5000rpm, it is determined that the voltage increase is necessary at a voltage increase determination point a where the command torque becomes 100 Nm.

Thus, in the 2 nd boost determination map, a boundary line for determining whether or not the boost converter 53 needs to perform the boost is set so as to match the 2 nd torque line. Therefore, the non-boosted state of the voltage-up converter 53 can be maintained as long as possible for each motor rotation speed until a command torque equal to or greater than the maximum torque that the motor 3 can output when the voltage-up converter 53 is not boosted is output.

Next, the 1 st boosting decision map will be described with reference to fig. 6. Fig. 6 is a diagram showing an example of the 1 st boosted voltage determination map used by the target boosted voltage setting unit 72 in embodiment 1 of the present invention.

As shown in fig. 6, the 1 st boost determination map is associated with the motor rotation speed and the command torque, and is divided into a boost required region and a boost unnecessary region by a torque line indicating a torque obtained by subtracting a certain value from a torque on the torque line indicating the maximum torque that the motor 3 can output when the boost converter 53 is not boosted.

Specifically, fig. 6 shows a region in which the values of the Y-axis command torque and the X-axis motor rotation speed are both positive, that is, quadrant 1. The broken line is the 1 st torque line, and the solid line is the 2 nd torque line.

The chain line indicates a torque obtained by subtracting a fixed value from the torque on the 2 nd torque line (hereinafter referred to as the 3 rd torque line), and the 3 rd torque line is a boundary line for determining whether or not the pressure increase is necessary.

Therefore, when the operating point constituted by the motor rotation speed and the command torque acquired in step S101 is present in the region inside the 3 rd torque line, that is, in the non-pressure-increase-required region, with the 3 rd torque line as a boundary in the 1 st pressure increase determination map, it is determined that pressure increase is not required. On the other hand, when the operating point exists in a region including the 3 rd torque line on the 3 rd torque line when the 1 st pressure increase determination map is bounded by the 3 rd torque line, that is, when the operating point exists in a region requiring pressure increase, it is determined that pressure increase is necessary.

Thus, if the operating point on the 1 st pressure increase determination map selected as the pressure increase determination map in step S104 is present in the pressure increase required region, it is determined that pressure increase is required, and if the operating point on the 1 st pressure increase determination map is present in the pressure increase unnecessary region, it is determined that pressure increase is not required.

For example, when the command torque increases from 25Nm in a state where the motor rotation speed is fixed at 5000rpm, it is determined that the boost pressure is necessary at a boost pressure determination point B where the command torque becomes 50 Nm.

Thus, in the 1 st boost determination map, a boundary line for determining whether or not boosting by the boost converter 53 is necessary is set so as to coincide with the 3 rd torque line. That is, in the 1 st boost pressure determination map, the boundary line is set on the side where both the command torque and the motor rotation speed are lower than in the 2 nd boost pressure determination map. Therefore, in the 1 st boost determination map, the operating point changes and the time point until the boost converter 53 changes from the non-boost state to the boost state becomes earlier.

Returning to the explanation of fig. 4A and 4B, in step S106, the target post-boost voltage setting unit 72 determines whether or not boosting by the boost converter 53 is necessary, using the boost determination map selected in the boost determination map selection process, from the operating point constituted by the motor rotation speed and the command torque acquired in the parameter acquisition process. Specifically, the target post-boost voltage setting unit 72 performs the boost determination based on the operating point constituted by the command torque Trmtag and the motor rotation speed Nem acquired in step S101, using the 1 st boost determination map selected in step S104 or the 2 nd boost determination map selected in step S105.

When it is determined as a result of the boosting determination that boosting is necessary, the target post-boosting voltage setting unit 72 sets the boosting flag to "1" and the process proceeds to step S107.

In step S107, the target post-boost voltage setting unit 72 determines whether or not the boost flag is "1". When the boosting flag is "1", it is determined that boosting is necessary, and therefore the process proceeds to step S108. On the other hand, if the boost flag is not "1", it is determined that boost is not necessary, and therefore the process proceeds to step S109.

In step S108, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagm to a preset voltage setting value, stores the target post-boost voltage V2tagm in the storage unit 76, and the process proceeds to step S110. The voltage set value can be set as appropriate according to the characteristics of the motor 3, the maximum output, and the like, and in embodiment 1, the voltage set value is set to 600V as an example.

In step S109, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagm to the battery voltage (for example, 300V), and stores the target post-boost voltage V2tagm in the storage unit 76, and the process proceeds to step S110.

Thus, in the step-up determination process, if the operating point on the step-up determination map selected in the step-up determination map selection process is present in the step-up required region, the target post-step-up voltage setting unit 72 determines that step-up is required, and sets the target post-step-up voltage to the voltage set value. In the boosting determination process, if the operating point on the boosting determination map selected in the boosting determination map selection process is in the non-boosting region, the target post-boosting voltage setting unit 72 determines that boosting is not required, and sets the target post-boosting voltage as the battery voltage.

In step S110, control unit 75 determines whether or not the power generation running mode flag is "0". If it is determined that the power generation running mode flag is "0", the process proceeds to step S111. On the other hand, if it is determined that the power generation running mode flag is not "0", the process proceeds to step S115. Here, as described above, since it is assumed that the running mode is the EV running mode, the process proceeds to step S111.

In step S111, the control unit 75 controls the boost converter 53 so that the boosted voltage supplied from the boost converter 53 to the motor inverter 51 becomes the target boosted voltage V2tagm stored in the storage unit 76.

In particular, when the target post-boost voltage V2tagm is the battery voltage, the control unit 75 turns on the 1 st switching circuit 531H of the boost converter at all times and turns off the 2 nd switching circuit 531L at all times, thereby bringing the battery 6 and the motor inverter 51 into a direct connection state.

Thus, the control unit 75 controls the boost converter 53 so that the boosted voltage of the boost converter 53 becomes the target boosted voltage V2tagm set by the target boosted voltage setting unit 72.

Next, a series of processing performed when the running mode set by the running mode setting unit 73 is the power generation running mode will be described. Here, the description of step S101, and steps S103 to S109 described above on the assumption that the running mode is the EV running mode is omitted.

In step S102, the running mode setting portion 73 determines whether the currently set running mode is the EV running mode or the power generation running mode based on the command torque Trmtag acquired in step S101. Here, as described above, since it is assumed that the running mode is the power generation running mode, the process proceeds to step S112.

In step S112, the travel mode setting unit 73 sets the power generation travel mode flag to 1, and the process proceeds to step S113.

In step S113, the generator rotation speed Neg is acquired from the generator rotation speed sensor 11, and the process proceeds to step S114.

In step S114, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagg of the generator 2 in accordance with the target post-boost voltage map using the generator rotation speed Neg acquired in step S113.

Here, the target post-boost voltage map will be described with reference to fig. 7. Fig. 7 is a diagram showing an example of a target boosted voltage map used by target boosted voltage setting unit 72 in embodiment 1 of the present invention.

The target boosted voltage map shown in fig. 7 is stored in the storage unit 76 in association with the generator speed and the target boosted voltage. In the target post-boost voltage map, the X axis is the generator rotation speed, and the Y axis is the target post-boost voltage. The target post-boost voltage setting unit 72 may derive the target post-boost voltage V2tagg corresponding to the generator rotation speed Neg acquired in step S113, from the target post-boost voltage map.

Specifically, the target post-boost voltage map is set to: the target boosted voltage is the battery voltage (for example, 300V) until the generator rotation speed reaches 4000rpm, and the target boosted voltage is increased as the generator rotation speed increases from 4000rpm to 10000rpm, and the target boosted voltage is 600V when the generator rotation speed reaches 10000 rpm.

Thus, when the running mode is the power generation running mode, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagg corresponding to the generator rotation speed Neg acquired from the generator rotation speed sensor 11 for the generator 2 in accordance with the target post-boost voltage map, and stores the target post-boost voltage V2tagg in the storage unit 76.

When the running mode is the power generation running mode, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagm by performing the series of processing of the above-described steps S103 to S109 on the motor 3 after performing step S114, and stores the target post-boost voltage V2tagm in the storage unit 76.

Next, the reason why the target post-boost voltage V2tagg is set in accordance with the target post-boost voltage map using the generator rotation speed Neg acquired in step S113 in step S114 and the effect obtained by the configuration will be described with reference to fig. 8. Fig. 8 is a diagram showing an example of an optimum voltage map obtained by mapping an optimum voltage that minimizes the loss of the generator 2 in embodiment 1 of the present invention.

The optimum voltage map shown in fig. 8 is a map obtained by mapping an optimum voltage that minimizes the loss of the generator 2 at each operating point formed by the rotation speed and the torque, assuming that the rotation speed is on the X axis and the torque is on the Y axis in the generator 2. In fig. 8, the solid line indicates the optimum voltage line, and the 1 st voltage line, the 2 nd voltage line, the 3 rd voltage line, the 4 th voltage line, and the 5 th voltage line are illustrated in order from the lower side of the rotation speed.

The region from the 1 st voltage line to the 2 nd voltage line is a 200V region where the optimum voltage is 200V, and the region from the 2 nd voltage line to the 3 rd voltage line is a 300V region where the optimum voltage is 300V. The region from the 3 rd voltage line to the 4 th voltage line is a 400V region where the optimum voltage becomes 400V, and the region from the 4 th voltage line to the 5 th voltage line is a 500V region where the optimum voltage becomes 500V. The optimum voltage on the 5 th voltage line is 600V, which represents the maximum voltage.

For example, the optimum voltage for operating point A at a command torque of-75 Nm and a speed of 5000rpm is 300V. When the rotation speed is kept constant from the operating point A and the command torque is increased to-100 Nm, the optimum voltage is kept at 300V. When the rotation speed was raised to 7000rpm while keeping the torque constant from the operating point a, the optimum voltage was raised to 400V.

Thus, the optimum voltage in the generator 2 has a characteristic of varying depending on the rotation speed without depending on the torque. Therefore, by applying the optimum voltage map to the target boosted voltage map in step S114, it is possible to set a target boosted voltage that satisfies the command torque and minimizes the loss of the generator 2 according to the rotation speed.

Returning to the description of fig. 4A and 4B, since the power generation running mode flag is set to 1 in step S112, the control unit 75 determines that the power generation running mode flag is not "0" in step S110, and the process proceeds to step S115.

In step S115, the control unit 75 compares the magnitude relationship between the target post-boost voltage V2tagm set for the motor 3 and the target post-boost voltage V2tagg set for the generator 2, which are stored in the storage unit 76.

If the control unit 75 determines that the target post-boost voltage V2tagm is greater than the target post-boost voltage V2tagg, the process proceeds to step S111. In step S111, the control unit 75 controls the boost converter 53 so that the boosted voltage supplied from the boost converter 53 to the motor inverter 51 becomes the target boosted voltage V2tagm stored in the storage unit 76.

On the other hand, when the target post-boost voltage V2tagg is greater than the target post-boost voltage V2tagm, the control unit 75 advances the process to step S116. In step S116, the control unit 75 controls the boost converter 53 so that the boosted voltage supplied from the boost converter 53 to the motor inverter 51 becomes the target boosted voltage V2tagg stored in the storage unit 76.

Thus, when the running mode set by the running mode setting unit 73 is the power generation running mode, the control unit 75 controls the boost converter 53 so that the boosted voltage becomes the larger target boosted voltage of the target boosted voltage V2tagm set for the motor 3 and the target boosted voltage V2tagg set for the generator 2.

As described above, as is apparent from fig. 4A and 4B, when the set travel mode is the EV travel mode, target post-boost voltage setting unit 72 and control unit 75 each execute the following processing.

That is, the target post-boost voltage setting unit 72 performs the boost determination map selection process, and sets the target post-boost voltage V2tagm based on the result of the boost determination process using the boost determination map selected in the boost determination map selection process. The control unit 75 controls the boost converter 53 so that the boosted voltage becomes the set target boosted voltage V2 tagm.

Specifically, when it is determined that boosting is necessary as a result of the boosting determination process, the target boosted voltage setting unit 72 sets the target boosted voltage to a preset voltage setting value, and the control unit 75 controls the boost converter 53 so that the boosted voltage supplied from the boost converter 53 to the motor inverter 51 becomes the voltage setting value.

When it is determined as a result of the step-up determination process that step-up is not necessary, the target step-up voltage setting unit 72 sets the target step-up voltage to the battery voltage (for example, 300V), and the control unit 75 controls the step-up converter 53 so that the step-up voltage supplied from the step-up converter 53 to the motor inverter 51 becomes the battery voltage. Specifically, the control unit 75 turns on the 1 st switching circuit 531H of the boost converter 53 and turns off the 2 nd switching circuit 531L all the time, thereby bringing the battery 6 and the motor inverter 51 into a direct connection state.

By configuring the control device 7 as described above, it is not necessary to calculate a target post-boost voltage appropriate for efficient operation of the motor from the rotation speed and the command torque, as in the conventional technique described in patent document 1, when calculating the target post-boost voltage. As a result, the load of the microcomputer in the arithmetic processing can be significantly reduced.

On the other hand, when the set running mode is the power generation running mode, each of the target post-boost voltage setting unit 72 and the control unit 75 executes the following processing.

That is, the target post-boost voltage setting unit 72 performs the boost determination map selection process on the motor 3, and sets the target post-boost voltage V2tagm based on the result of the boost determination process using the boost determination map selected in the boost determination map selection process. Further, the target post-boost voltage setting unit 72 sets the target post-boost voltage V2tagg for the generator 2, which minimizes the loss of the generator, in accordance with the target post-boost voltage map.

The control unit 75 controls the boost converter 53 so that the boosted voltage supplied from the boost converter 53 to the motor inverter 51 reaches the larger target boosted voltage of the target boosted voltage V2tagg set for the motor 3 and the target boosted voltage V2tagg set for the generator 2.

By configuring the control device 7 as described above, when calculating the target post-boost voltage, it is not necessary to calculate the target post-boost voltage appropriate for the efficient operation of the motor from the rotation speed and the command torque for the motor and the generator as in the conventional technique described in patent document 1. As a result, the load of the microcomputer on the arithmetic processing can be reduced, and the loss in the generator can be reduced within a range in which the maximum torque can be output.

Next, the reason why the 1 st pressure increase determination map is selected when the command torque change rate is equal to or greater than the command torque change rate set value, that is, when the vehicle is accelerating rapidly, and the 2 nd pressure increase determination map is selected when the command torque change rate is smaller than the command torque change rate set value, that is, when the vehicle is accelerating slowly, and the effects obtained by the above-described configuration will be described with reference to fig. 9 and 10.

Fig. 9 is a timing chart for explaining a vehicle operation when the control device 7 temporarily determines whether or not boosting is necessary using the 2 nd boosting determination map as a comparative example in the case of rapid acceleration of the electric vehicle in embodiment 1 of the present invention. Fig. 10 is a timing chart for explaining vehicle operation when the control device 7 determines whether or not boosting is necessary using the 1 st boosting determination map in the case where the electrically powered vehicle is rapidly accelerated in embodiment 1 of the present invention.

Here, since the boost converter 53 needs to have a limitation on the boost ratio due to restrictions on the electrical characteristics of components such as a reactor and a switching circuit (e.g., IGBT), the tracking of the actual boosted voltage of the boost converter 53, that is, the change of the actual voltage with respect to the target boosted voltage becomes slow.

First, the vehicle operation when the control device 7 determines whether or not the boost pressure is necessary using the 2 nd boost pressure determination map when the command torque change rate is equal to or greater than the command torque change rate set value will be described. Fig. 9 shows a comparative example of fig. 10, which shows the behavior of the actual torque with respect to the command torque and the behavior of the actual voltage with respect to the target boosted voltage when the control device 7 temporarily determines whether or not boosting is necessary using the 2 nd boosting determination map when the command torque change rate is equal to or greater than the command torque change rate set value.

In the timing chart 201, the solid line indicates the command torque Trmtag, and the broken line indicates the actual torque Tr. In the timing chart 202, the solid line indicates the target post-boosting voltage V2tagm, and the broken line indicates the actual voltage V2. The actual voltage V2 is a voltage supplied from the boost converter 53 to the motor inverter 51. In the timing chart of fig. 9, it is assumed that the motor rotation speed is fixed at 5000 rpm.

Next, the timing chart of fig. 9 is explained. At time t1, when the driver depresses the accelerator pedal due to rapid acceleration while the boost converter 53 is in the non-boost state, the command torque rises rapidly, and the actual torque starts to track the command torque.

According to fig. 5, when the motor rotation speed is 5000rpm when the step-up converter 53 is not stepped up, the maximum possible output torque corresponding to the motor rotation speed is 100 Nm. Therefore, at time t2 when the command torque is 100Nm, it is determined that the voltage needs to be boosted by the boost converter 53, and the target boosted voltage V2tagm is changed from the battery voltage (e.g., 300V) to the voltage set value (e.g., 600V).

At time t2, the command torque increases to 100Nm, but this is a torque that can be output even when the boost converter 53 is not boosting, and therefore, the actual torque tracks the command torque from time t1 to time t 2.

From time t2 to time t3, the command torque further increases beyond 100Nm, and at time t3, the command torque reaches 200 Nm. However, since the tracking delay of the actual voltage V2 is caused by the limitation of the boosting rate, the actual voltage V2 does not track the target post-boosting voltage V2tagm, and the actual torque becomes lower with respect to the command torque (═ 200 Nm).

At time t4, the actual voltage V2 tracks the target post-boost voltage V2tagm, and the actual torque matches the command torque (200 Nm).

As is clear from the above, from the time t2 to the time t4, the actual torque follows the command torque with a delay, and during this period, the electric motor 3 cannot output the torque requested by the driver, that is, the command torque, and drivability deteriorates.

Next, the vehicle operation when the control device 7 determines whether or not the boost pressure is necessary using the 1 st boost pressure determination map when the command torque change rate is equal to or greater than the command torque change rate set value will be described. Here, as shown in fig. 10, if the control device 7 determines whether or not boosting is necessary using the 1 st boosting determination map, the delay in tracking the torque can be reduced. The reason for this will be mainly explained below.

Fig. 10 shows a behavior of the actual torque with respect to the command torque when the command torque change rate is equal to or greater than the command torque change rate set value, and a behavior of the actual voltage with respect to the target boosted voltage when the control device 7 determines whether or not boosting is necessary using the 1 st boosted voltage determination map.

In the timing chart 301, the solid line indicates the command torque Trmtag, and the broken line indicates the actual torque Tr. In the timing chart 302, the solid line indicates the target post-boosting voltage V2tagm, and the broken line indicates the actual voltage V2. The actual voltage V2 is a voltage supplied from the boost converter 53 to the motor inverter 51. In the timing chart of fig. 10, it is assumed that the motor rotation speed is fixed at 5000 rpm.

Next, the timing chart of fig. 10 is explained. At time t 1', when the boost converter 53 is in the non-boost state, if the driver depresses the accelerator due to rapid acceleration, the command torque rises rapidly, and the actual torque starts to track the command torque.

As shown in fig. 6, when the motor rotation speed is 5000rpm when the step-up converter 53 is not boosting the voltage, it is determined that the command torque when boosting by the step-up converter 53 is 50 Nm. Therefore, at time t 2' when the command torque is 50Nm, it is determined that the voltage needs to be boosted by the boost converter 53, and the target boosted voltage V2tagm is changed from the battery voltage (e.g., 300V) to the voltage set value (e.g., 600V).

At time t3 ', the command torque rises to 100Nm, but this is a torque that can be output even when the boost converter 53 is not boosting, and therefore, the actual torque tracks the command torque from time t2 ' to time t3 '.

From time t3 ' to time t4 ', the command torque rises further beyond 100Nm, reaching 200Nm at time t4 '. However, due to the tracking delay of the actual voltage V2 caused by the limitation of the boosting rate, the actual voltage V2 does not track the target post-boosting voltage V2tagm, and the actual torque becomes lower than the command torque (═ 200 Nm).

At time t 5', the actual voltage V2 tracks the target post-boost voltage V2tagm, and the actual torque matches the command torque (200 Nm).

As can be seen from the above, the actual torque is tracked with delay with respect to the command torque from the time t3 'to the time t 5', but the tracking delay period is significantly shortened as compared with the torque tracking delay from the time t2 to the time t4 in the above comparative example.

That is, when the command torque change rate is equal to or greater than the command torque change rate set value, the time point until the control device 7 determines that boosting is necessary is changed from the non-boosted state of the boost converter 53 to the operating point in the case where the 1 st boost determination map is used, compared with the case where the 2 nd boost determination map is used. Therefore, the time point when the boost is started after the increase of the command torque becomes earlier, and as a result, the delay in tracking the actual torque with respect to the command torque is reduced, and the deterioration of drivability at the time of rapid acceleration can be reduced.

Next, the reason why the delay in tracking the torque hardly occurs even when the 2 nd boost pressure determination map is selected when the command torque change rate is smaller than the command torque change rate set value, that is, when the vehicle is accelerated slowly, will be described with reference to fig. 11.

Fig. 11 is a timing chart for explaining the vehicle operation when the control device 7 determines whether or not the voltage increase is necessary using the 2 nd voltage increase determination map when the electrically powered vehicle in embodiment 1 of the present invention is gradually accelerating.

Fig. 11 shows a behavior of the actual torque with respect to the command torque and a behavior of the actual voltage with respect to the target boosted voltage when the control device 7 determines whether or not boosting is necessary using the 2 nd boosting determination map when the command torque change rate is smaller than the command torque change rate set value.

In the timing chart 401, the solid line indicates the command torque Trmtag, and the broken line indicates the actual torque Tr. In the timing chart 402, the solid line indicates the target post-boost voltage V2tagm, and the broken line indicates the actual voltage V2. The actual voltage V2 is a voltage supplied from the boost converter 53 to the motor inverter 51. In the timing chart of fig. 11, it is assumed that the motor rotation speed is fixed at 5000 rpm.

Next, the timing chart of fig. 11 is explained. At time t1 ", when the driver slightly depresses the accelerator due to gradual acceleration in the case where the boost converter 53 is in the non-boost state, the command torque gradually increases, and the actual torque starts to track the command torque.

As shown in fig. 5, when the motor rotation speed is 5000rpm when the step-up converter 53 is not boosting the voltage, it is determined that the command torque when boosting by the step-up converter 53 is 100 Nm. Therefore, at time t2 ″ when the command torque is 100Nm, it is determined that the voltage needs to be boosted by the boost converter 53, and the target boosted voltage V2tagm is changed from the battery voltage (e.g., 300V) to the voltage set value (e.g., 600V).

At time t2 ", the command torque rises to 100Nm, but this is a torque that can be output even when the boost converter 53 is not boosting, and therefore, the actual torque tracks the command torque from time t 1" to time t2 ".

From time t2 ' to time t3 ', the command torque rises further beyond 100Nm, reaching 200Nm at time t4 '.

At time t3 ″, the actual voltage V2 tracks the target post-boost voltage V2tagm, and at time t4 ″, the actual torque matches the command torque (200 Nm).

From time t2 "to time t 3", the actual voltage V2 does not follow the target post-boost voltage V2tagm due to the tracking delay of the actual voltage V2 caused by the limitation of the boost ratio, but the command torque rises slowly, so that the command torque can be basically output even if there is a tracking delay of the actual voltage V2.

That is, even when the 2 nd boost map is used during a gradual acceleration in which the rising rate of the command torque is gradually increased, the delay in tracking the actual voltage V2 due to the limitation of the boost rate does not substantially affect the tracking ability of the actual torque with respect to the command torque.

As described above, according to embodiment 1, as the configuration 1, in the step-up determination process for determining whether or not the step-up by the step-up converter is necessary, based on the operating point configured by the motor rotation speed and the command torque, the step-up converter is configured to set the target step-up voltage and control the step-up converter so that the step-up voltage of the step-up converter becomes the set target step-up voltage, based on the step-up determination map selected in the step-up determination map selection process for selecting the 1 st step-up determination map as the step-up determination map, whether or not the operating point is present in the step-up necessary region.

With the above configuration 1, it is not necessary to calculate the target boosted voltage every control processing cycle, and therefore, the maximum torque can be output and the load of the microcomputer in the calculation processing can be reduced.

As a configuration 2, in comparison with the configuration 1, in the step-up determination map selection process, the configuration is such that the step-up determination map 1 is selected as the step-up determination map when the command torque change rate is equal to or greater than the command torque change rate set value, that is, when the vehicle is accelerating rapidly, and the step-up determination map 2 is selected as the step-up determination map when the command torque change rate is smaller than the command torque change rate set value, that is, when the vehicle is accelerating slowly.

Here, in the 1 st boost pressure determination map, a boundary line for determining whether or not boost pressure is necessary is set on the side where both the command torque and the motor rotation speed are low, as compared with the 2 nd boost pressure determination map. Therefore, if the configuration is such that the 1 st boost determination map is selected as the boost determination map when the vehicle is accelerating rapidly as in the above-described configuration 2, the time point from the non-boost state of the boost converter to the time point when the operating point changes and the boundary line is crossed to determine that boost is necessary becomes earlier. Therefore, when the vehicle is accelerated rapidly, the delay in tracking the actual voltage with respect to the target boosted voltage due to the boost limitation of the boost converter can be reduced. As a result, the tracking delay of the actual torque with respect to the command torque can be reduced.

In the 2 nd boost determination map, a boundary line is set so as to match a torque line indicating the maximum torque that the motor can output when the boost converter is not boosted. Therefore, if the 2 nd boost determination map is selected as the boost determination map when the vehicle is slowly accelerating as in the above-described configuration 2, the non-boosted state of the boost converter can be maintained until the command torque equal to or greater than the maximum torque is commanded in each motor rotation speed. Therefore, the non-boosted state of the boost converter can be maintained as long as possible while the vehicle is slowly accelerating. As a result, in the non-boost state of the boost converter, the switch in the boost converter is not necessary, and therefore, the switching loss of the boost converter can be reduced to the maximum.

As a configuration 3, in contrast to the configuration 2, the control device is configured to set a target post-boost voltage for the motor based on a result of the boost determination process using the boost determination map selected in the boost determination map selection process, and to set a target post-boost voltage for the generator based on the target post-boost voltage map, and to control the boost converter such that the post-boost voltage of the boost converter reaches the target post-boost voltage that is the larger of the target post-boost voltage set for the motor and the target post-boost voltage set for the generator, when the set running mode is the power generation running mode.

With the above configuration 3, the load of the microcomputer on the calculation load processing can be reduced, the delay in tracking the actual torque with respect to the command torque can be reduced, and the loss in the generator can be reduced in the range in which the maximum torque can be output.

Description of the reference symbols

1 engine, 2 generator, 3 motor, 4 tires, 5 power drive unit, 6 battery, 7 control device, 8 vehicle speed sensor, 9 accelerator opening sensor, 10 motor rotation speed sensor, 11 generator rotation speed sensor, 12 engine rotation speed sensor, 51 motor inverter, 52 generator inverter, 53 boost converter, 71 command torque generating unit, 72 target post-boost voltage setting unit, 73 running mode setting unit, 74 command torque change rate calculating unit, 75 control unit, 76 storage unit, 77 interface, 78CPU, 79 memory, 511U-phase switch circuit, 512V-phase switch circuit, 513W-phase switch circuit, 511H to 513H upper arm side switch circuit, 511L to 513L lower arm side switch circuit, 521U-phase switch circuit, 522V-phase switch circuit, 523W-phase switch circuit, 521H to 523H upper arm side switch circuit, 511H to 513H upper arm side switch circuit, and the like, 521L to 523L lower arm side switching circuits, 531H 1 st switching circuit, 531L 2 nd switching circuit, 532 reactor, 533 st smoothing capacitor, and 534 nd smoothing capacitor.

Claims

1. A control device of a power driving unit, the control device controlling the power driving unit, the power driving unit having:

a boost converter that boosts a voltage supplied from a battery;

a motor inverter that converts the electric power supplied from the step-up converter and supplies the converted electric power to a motor to drive the motor; and

a generator inverter that converts electric power from a generator and stores the converted electric power in the battery, wherein the control device includes:

a storage unit that stores a 1 st step-up determination map, the 1 st step-up determination map being associated with a motor rotation speed and a command torque and being divided into a step-up required region and a step-up unnecessary region by a torque line indicating a torque obtained by subtracting a certain value from a torque on a torque line indicating a maximum torque that the motor can output when the step-up converter is not stepped up, and further stores a 2 nd step-up determination map, the 2 nd step-up determination map being associated with the motor rotation speed and the command torque and being divided into a step-up required region and a step-up unnecessary region by a torque line indicating a maximum torque that the motor can output when the step-up converter is not stepped up;

a command torque generation unit that acquires an accelerator opening degree from an accelerator opening degree sensor that detects the accelerator opening degree, and generates the command torque from the acquired accelerator opening degree;

a command torque change rate calculation unit that calculates a command torque change rate that is a change rate of the command torque acquired from the command torque generation unit;

a target post-boost voltage setting unit that acquires the motor rotation speed from a motor rotation speed sensor that detects the motor rotation speed, performs a parameter acquisition process that acquires the command torque from the command torque generation unit, performs a boost determination map selection process that selects one of the 1 st boost determination map and the 2 nd boost determination map stored in the storage unit as a boost determination map, and performs a boost determination process that determines whether or not boosting by the boost converter is necessary using the boost determination map selected in the boost determination map selection process and an operating point formed by the motor rotation speed and the command torque acquired in the parameter acquisition process, setting a target boosted voltage of the boost converter according to a result of the boosting determination process; and

a control unit that controls the boost converter such that the boosted voltage of the boost converter becomes the target boosted voltage set by the target boosted voltage setting unit,

the target post-boost voltage setting unit

In the step-up determination map selection process, the step-up determination map 1 stored in the storage unit is selected as the step-up determination map when the command torque change rate calculated by the command torque change rate calculation unit is equal to or greater than a preset command torque change rate set value, and the step-up determination map 2 stored in the storage unit is selected as the step-up determination map when the command torque change rate calculated by the command torque change rate calculation unit is smaller than the command torque change rate set value,

in the step-up determination process, if the operating point exists in the step-up required region on the step-up determination map selected in the step-up determination map selection process, it is determined that the step-up is required, and the target post-step-up voltage is set to a preset voltage set value,

in the step-up determination process, if the operating point exists in the step-up unnecessary region on the step-up determination map selected in the step-up determination map selection process, it is determined that the step-up is unnecessary, and the target step-up voltage is set as the voltage of the battery.

2. The control device of a power drive unit according to claim 1,

further comprising a running mode setting unit that switches a running mode to an EV running mode and a power generation running mode and sets the running mode after the switching, based on the command torque acquired from the command torque generation unit,

the storage section further stores a target boosted voltage map associated with the generator speed and the target boosted voltage,

the target post-boost voltage setting unit, when the running mode set by the running mode setting unit is the EV running mode,

performing the step-up determination map selection processing, setting the target step-up voltage based on a result of the step-up determination processing using the step-up determination map selected in the step-up determination map selection processing,

the control unit, when the travel mode set by the travel mode setting unit is the EV travel mode,

controlling the boost converter so that the boosted voltage becomes the set target boosted voltage,

the target post-boost voltage setting unit, when the running mode set by the running mode setting unit is the power generation running mode,

the motor is subjected to the step-up determination map selection processing, the target post-step-up voltage is set based on a result of the step-up determination processing using the step-up determination map selected in the step-up determination map selection processing,

setting the target boosted voltage corresponding to the generator rotational speed acquired from a generator rotational speed sensor that detects the generator rotational speed for the generator based on the target boosted voltage map stored in the storage unit,

the control unit, when the running mode set by the running mode setting unit is the power generation running mode,

the step-up converter is controlled so that the step-up voltage becomes a target step-up voltage that is a larger one of the target step-up voltage set for the motor and the target step-up voltage set for the generator.

3. A control method of a power driving unit, the control method controlling the power driving unit, the power driving unit having:

a boost converter that boosts a voltage supplied from a battery;

a generator inverter that converts electric power from a generator and stores the converted electric power in the battery, wherein the control method includes:

a command torque generation step of acquiring an accelerator opening degree and generating a command torque from the acquired accelerator opening degree;

a command torque change rate calculation step of calculating a command torque change rate that is a change rate of the command torque generated by the command torque generation step;

a target post-boost voltage setting step of acquiring a motor rotation speed, performing a parameter acquisition process of acquiring the command torque generated in the command torque generation step, performing a boost determination map selection process of selecting one of a 1 st boost determination map and a 2 nd boost determination map as a boost determination map, performing a boost determination process of determining whether or not boosting by the boost converter is necessary, using the boost determination map selected in the boost determination map selection process, on the basis of an operating point formed by the motor rotation speed and the command torque acquired in the parameter acquisition process, and setting a target post-boost voltage of the boost converter, on the basis of a result of the boost determination process; and

a control step of controlling the boost converter so that the boosted voltage of the boost converter becomes the target boosted voltage set in the target boosted voltage setting step,

the 1 st step-up determination map is divided into a step-up required region and a step-up unnecessary region by a torque line indicating a torque obtained by subtracting a predetermined value from a torque on a torque line indicating a maximum torque that the motor can output when the step-up converter is not stepped up, in association with the motor rotation speed and the command torque,

the 2 nd step-up determination map is associated with the motor rotation speed and the command torque, and is divided into a step-up required region and a step-up unnecessary region by a torque line indicating a maximum torque that the motor can output when the step-up converter is not stepped up,

in the target post-boost voltage setting step,

in the step-up determination map selection process, the 1 st step-up determination map is selected as the step-up determination map when the command torque change rate calculated by the command torque change rate calculation step is equal to or greater than a preset command torque change rate set value, and the 2 nd step-up determination map is selected as the step-up determination map when the command torque change rate calculated by the command torque change rate calculation step is smaller than the command torque change rate set value,