JP2504086B2 - Voltage control device for rotary electric machine for turbocharger - Google Patents

Description

TECHNICAL FIELD The present invention relates to a voltage control device for a rotary electric machine for a turbocharger, in which a motor-generator is attached to a rotary shaft of the turbocharger.

(Prior Art) Various proposals have been made in which a turbocharger is attached to an exhaust pipe of an engine, and a motor-generator is directly connected to a rotating shaft of the turbocharger to recover exhaust energy.

As such a proposal, a turbocharger for an internal combustion engine, in which a rotating electric machine serving as a motor-generator is attached to a turbocharger and is operated as an electric motor or a generator according to the operating state of the internal combustion engine, is disclosed in Japanese Patent Laid-Open No. 60-195329. Has been done.

Then, in the low-speed heavy-load operating region of the engine, electric power is supplied from the battery to the rotating electric machine to operate the electric motor, which assists the supercharging operation of the turbocharger to increase the boost pressure to increase the engine output.

(Problems to be Solved by the Invention) In the above-mentioned proposal of the turbocharger for the internal combustion engine, when the rotational speed of the turbocharger is low, the counter electromotive voltage of the electric motor-operated rotating electric machine does not rise, and therefore the electric power from the battery is reduced. However, when the turbocharger rotates at a high speed, the back electromotive voltage of the rotating electric machine also increases, which makes it difficult to supply sufficient electric power.

The present invention has been made in view of such a problem, and an object thereof is to supply sufficient electric power from a battery to a rotating electric machine to assist a supercharging operation even when the rotational speed of a turbocharger is high. It is to provide a voltage control device for a rotary electric machine for a turbocharger.

(Means for Solving Problems) According to the present invention, in the voltage control device for a rotary electric machine for a turbocharger, the rotary electric machine mounted on the turbocharger is supplied with electric power from a battery to assist the supercharging operation. Rotation detection means for detecting the rotation speed of the electric machine,
There is provided a voltage control device for a rotary electric machine for a turbocharger, comprising a control means for controlling an AC output voltage of an inverter applied to the rotary electric machine in response to a rotation signal from the rotation detection means. .

(Operation) In the present invention, the rotation speed of the rotating electric machine is detected by the rotation detection means, and the AC voltage of the supply power supplied from the battery and converted by the inverter is controlled in response to the rotation signal from the rotation detection means. Even if the rotational speed of the rotating electric machine becomes high and the counter electromotive voltage thereof rises, the voltage control means has the effect of raising the AC voltage of the supplied power to a high voltage.

(Example) Next, the Example of this invention is described in detail using drawing.

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, and FIG. 2 is a configuration block diagram of a turbocharger with a rotating electric machine to which the present invention is applied.

In FIG. 2, reference numeral 1 denotes a vehicle for driving a vehicle by rotating wheels 3 by combustion energy of air sucked through an intake pipe 1a of an engine and fuel supplied from a fuel tank 2a through an injector 2. Exhaust gas after combustion is discharged through the exhaust pipe 1b. The engine 1 has a clutch 4 for connecting and disconnecting the engine torque, and a transmission 4a for shifting the engine torque. Further, 1c is an engine rotation sensor, 2b is an accelerator pedal sensor attached to an accelerator pedal 2c, and sends an engine rotation signal and an engine load signal corresponding to the accelerator depression amount to the electronic control unit 5, respectively. .

Reference numeral 6 denotes a turbocharger connected to the exhaust pipe 1b and the intake pipe 1a, which has a turbine 6b driven by exhaust gas energy and a compressor 6a for supercharging intake air,
A rotary electric machine 7 that operates as an electric motor or a generator is attached to a rotary shaft 6c that connects both of them. When the turbine 6b is rotationally driven by the exhaust energy, the rotating electric machine 7 is in a generator mode, the generated power is transmitted to the power converter 7a, and the vehicle-mounted battery 5a is charged by the operation of the power converter 7a. . In addition, power converter
7a is a rectifying / smoothing circuit that converts AC power into DC power, a converter circuit that freely converts the voltage of DC power, an inverter circuit that converts DC power into AC power whose frequency can be adjusted, and a booster circuit that boosts voltage using a transformer. Various high voltage control circuits such as a duty control circuit for controlling voltage and current using semiconductor control elements are provided, and various high voltage control circuits are controlled by a control command from the electronic control unit 5.

FIG. 1 is a circuit block diagram showing details of a part of the power converter 7a, in which an inverter circuit or a booster circuit converts DC power from a battery into AC power and boosts it to a desired voltage.

In the figure, C ₁ and C ₂ are chopper elements that turn on / off the current, Cn is a controller that sends a variable frequency signal to drive and control the chopper element according to a command from the electronic control unit 5, S ₁ , S ₂ is a change-over switch which is switched according to a command from the electronic control unit 5, T ₁ and T ₂ are transformers each having a predetermined transformation ratio, Ca is a capacitor, and D is a rectifier. Then, the changeover switches S ₁ , S ₂
Is operated to the II position, the pulsating electric power from the battery 5a, which is turned on / off by the operation of the chopper element C ₁ under the control of the controller Cn, is boosted by the voltage device T ₂ and applied to the rotating electric machine 7. , The rotating electric machine 7 is driven by an electric motor to assist the supercharging operation of the turbocharger 7, and when the changeover switches S ₁ and S ₂ are operated to the I position, the pulsating flow power from the chopper element C ₁ is transformed. After the voltage is boosted by the transformer T ₁ , it is rectified by the rectifier D ₁ and the capacitor Ca, then becomes a pulsating current by the chopper element C ₂ , and is further boosted by the transformer T ₂ to a high voltage. It is configured to be supplied with electric power.

Incidentally, 6d in FIG. 2 is a turbine sensor which is attached to the rotary shaft 6c and serves as a rotation detecting means.
For detecting the rotation speed of the rotating electric machine 7, that is, the rotation speed of the rotating electric machine 7,
7b is a voltage sensor for detecting the terminal voltage of the rotating electric machine 7, and the detected signals are sent to the electronic control unit 5.

The electronic control unit 5 comprises a microcomputer, a central processing unit for inputting signals from the above-mentioned various sensors and performing arithmetic processing and comparison of counts, various memory devices for storing control programs and various data, various types. It has an input / output device and the like for receiving the signal of or for issuing the control command.

FIG. 3 is a process flow chart showing an example of the operation of the present embodiment. Next, the operation of the present embodiment will be described with reference to FIG.

First, in step 1, when the rotary electric machine 7 is in the engine acceleration mode or the electric motor operating mode, the turbine rotation speed, that is, the rotation speed of the rotary electric machine 7 is detected in step 2 by the signal of the turbine sensor 6d. In step 3, the detected rotation speed N is compared with a predetermined rotation speed Nu. If N> Nu, the counter electromotive voltage of the rotating electric machine 7 is high because of high rotation, so the process proceeds to step 4 and the changeover switches S ₁ , S ₂ will be switched to the I position and the booster circuit of transformer T ₁ and transformer T ₂ will be used. If the detected number of revolutions N does not reach Nu, the process proceeds to step 5, where the selector switches S ₁ and S ₂ are switched to the II position, and only the booster circuit of the transformer T ₂ is used to rotate the rotary electric machine 7. It corresponds to the rotation speed.

Next, in step 6, the voltage rise is set, and in step 7, the on / off cycle, that is, the AC frequency is set by the controller Cn, and the inverter is operated to supply the desired high voltage AC power corresponding to the rotation speed. Then, the rotating electric machine 7 that operates the electric motor is energized.

The present invention has been described above with reference to the above-described embodiment. For example, as shown in FIG. 4, a tap is provided on the secondary winding of the transformer T ₀ input from the chopper element C ₀ , and the tap is connected to the changeover switch S. Various modifications and applications are possible within the scope of the gist of the present invention so as to switch according to the rotation speed by ₀ , and these are not excluded from the scope of the present invention.

(Effect of the Invention) According to the present invention, the rotation speed of the rotating electric machine is detected by the rotation detecting means, and the alternating voltage of the electric power supplied to the rotating electric machine is switched and controlled according to this rotation signal. Even when the counter electromotive voltage becomes a high voltage during high-speed rotation, the effect of increasing the supply voltage to energize the rotary electric machine and assist the supercharge operation of the turbocharger can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, and FIG.
FIG. 4 is a block diagram showing the configuration of a turbocharger with a rotating electric machine to which the present invention is applied, FIG. 3 is a process flow chart showing an example of the operation of this embodiment, and FIG. 4 is a circuit block diagram showing another embodiment. 1 ... Engine, 1c ... Engine rotation sensor, 5 ... Electronic control device, 5a ... Battery, 6 ... Turbocharger, 6d ... Turbine sensor, 7 ... Rotating electric machine, 7a ... Power converter.

Claims (1)

(57) [Claims] 1. A voltage control device for a rotary electric machine for a turbocharger, which supplies electric power from a battery to a rotary electric machine attached to a turbocharger to assist supercharging operation, and a rotation detecting means for detecting a rotational speed of the rotary electric machine. A voltage control device for a rotary electric machine for a turbocharger, comprising control means for controlling an AC output voltage of an inverter applied to the rotary electric machine in response to a rotation signal from the rotation detecting means.