JPH0381525A - Control device for turbocharger with rotating electric machine - Google Patents

Abstract

PURPOSE:To control to narrow variation range in the proximity of the allowable rotating speed of a turbine shaft by controlling power supply to an electric rotary machine according to increase/decrease tendency of a turbine rotating speed, when it reaches a prescribed rotating speed in the proximity of the upper limit rotating speed. CONSTITUTION:An electric rotary machine 3 operable as a motor or a generator is fitted on the shaft 2c of a turbocharger 2. A controller 6 institutes a higher side rotating speed and a lower side rotating speed before and after the upper limit rotating speed of a turbine, and the turbine rotating speed is compared with the higher side or the lower side rotating speed, at full stepping-in of an accel pedal. When it is under the lower side rotating speed, power supply to the power inverter 4 is made maximum. When it is between the higher side and the lower side rotating speed, the current value to the inverter is controlled to supply according to increase/decrease tendency of the turbine rotating speed. Hereby, the turbine rotating speed can be settled at a certain rotating speed between the higher side and the lower side rotating speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a turbocharger with a rotating electric machine, in which an electric generator is attached to the rotating shaft of the turbocharger.

(Prior Art) Since the exhaust gas of an internal combustion engine is high temperature and high pressure, various devices have been proposed to recover the exhaust gas energy as driving force or electric power.

As this type of exhaust energy recovery device, various attempts have been made to attach a rotating electrical machine that serves as an electric generator to the rotating shaft of a tJl-turbine, and to drive the rotating electrical machine as an electric motor or generator depending on the operating state of the engine. There is.

Then, means for detecting the engine load and means for detecting the amount of accelerator pedal depression are installed, and based on signals from these means, the supercharging means and fuel supply means using the rotating electric machine are controlled. The proposal was published in JP-A-63-272.
It is disclosed in Japanese Patent No. 909.

(Problems to be Solved by the Invention) In the control device for a turbocharger with a rotating electrical machine disclosed in the above-mentioned publication, when the engine is at low rotational speed and high load, the turbocharger is not supercharged by exhaust energy. In addition, electric power is supplied from the battery to the rotating electric machine to operate it as an electric motor to increase supercharging pressure, and at the same time, the amount of fuel supplied is increased to increase the output of the engine.

However, when such an electric motor is operated, depending on the amount of depression of the accelerator pedal, for example, when the amount of pedal depression is maximum, a large amount of power is supplied to the rotating electric machine, causing the rotation speed to rise rapidly and exceed the maximum allowable rotation speed. In order to prevent this, the power to the rotating electric machine is turned off before the limit is reached. Therefore, when the power is cut off, the turbine rotation speed will decrease.
When the rotation speed decreases to a predetermined speed, the power is turned on again, so as shown in the turbine rotation control curve shown in FIG.
The rotational speed fluctuates like a triangular wave based on the allowable rotational speed of 10,000 revolutions. Therefore, there is a drawback that the engine output also fluctuates, which adversely affects the driving feeling of the vehicle.

The invention was made in view of these conventional problems, and its purpose is to narrowly control the fluctuation range of the rotation speed in the vicinity of the permissible rotation speed of the turbine when electrically driving a rotating electric machine attached to a turbocharger. An object of the present invention is to provide a control device for a turbocharger with a rotating electrical machine.

(Means for Solving the Problems) According to the present invention, in a control device for a turbocharger with a rotating electrical machine that electrically drives a rotating electrical machine attached to a turbine shaft to activate supercharging pressure to the engine, the turbine When the shaft reaches a predetermined rotational speed near the upper limit rotational speed, a control device for the turbocharger of the rotating electric machine controls the power supplied to the rotating electric machine according to the tendency of increasing/decreasing the rotational speed of the turbine shaft. provided.

(Operation) In the present invention, when the rotational speed of the turbine shaft reaches a predetermined rotational speed near the allowable rotational speed, it is detected whether the turbine rotational speed is increasing or decreasing, and if the turbine rotational speed is increasing, the power supplied to the rotating electrical machine is If it tends to decrease, the supplied power is increased to control the rotation speed of the turbine shaft. Therefore, the vertical fluctuation range of the turbine rotational speed is suppressed.

(Example) Next, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing an embodiment of the tree invention.

In FIG. 1, reference numeral 1 denotes an engine that drives a vehicle (not shown) by the combustion energy of air taken in through an intake pipe 1a and fuel supplied from a fuel tank 1g through an injection pump 1f. The exhaust gas after combustion is discharged through the exhaust pipe 1b. 1c is an accelerator sensor serving as means for detecting the amount of depression of the accelerator pedal, and 1e is a rotation sensor that detects the rotational speed of the internal combustion engine, and transmits detected signals to a controller 6, which will be described later.

A turbocharger 2 is connected to an exhaust pipe 1b and an intake pipe 1a, and has a turbine blade 2b driven by exhaust gas and a compressor blade 2a that pressure-feeds intake air to the intake pipe 1a. A rotating electric machine 3 that operates as an electric motor or a generator is attached to the rotating shaft 2c.

The rotating electrical machine 3 has a rotor 3 a and a stator 3 b. When the rotor 3 a is rotationally driven by exhaust energy, alternating current power is generated in the stator 3 b and transmitted to the battery 5 via the power converter 4 .

Furthermore, when the rotor 3a is driven by the power from the battery 5 via the power converter 4, the compressor blades 2
The intake air is compressed by the operation of step a, and is supplied iM to the internal combustion engine 1 via the intake pipe 1a. In addition, 1
A boost sensor h detects the supercharging pressure caused by the operation of the compressor blade 2a and transmits it to the controller 6.

The power converter 4 converts AC power from the stator 3b when the generator is operated into, for example, charging power for the battery 5, or converts DC power from the battery 5 into a predetermined AC power to drive the rotating electric machine 3 as a motor. It converts it into electricity. Therefore, in addition to a rectifier circuit and a smoothing circuit that convert AC to DC, it is equipped with an inverter, a booster circuit, etc. that convert DC to AC, and the AC frequency to be converted, its voltage, and power are controlled by commands from the controller 6. It is.

The controller 6 is composed of a microcomputer, and includes a central processing unit that calculates the supplied fuel, required power, boost pressure, etc. based on the operating state of the internal combustion engine 1 and signals from various sensors, a memory for the results of these calculations, and the internal combustion engine. , various memory devices that store control programs for the rotating electrical machine, and human/output devices that receive various types of human power and issue control instructions to related parts. The rotation speed of the turbine shaft is manually controlled by the controller 6 based on the frequency of the back electromotive force induced in the stator 3b when the rotating electrical machine 3 is in rotation.

FIG. 2 is a processing flow diagram showing an example of the operation of this embodiment, and the operation will be explained with reference to the same figure.

In step 1, it is determined from the signal of the accelerator sensor IC whether or not the amount of depression is at the maximum. If the amount of depression is the maximum, the process proceeds to step 2; if the maximum depression is acceptable, the process proceeds to step 5.

If you proceed to step 5, the target boost pressure value (Pt
) and the actual boost pressure value (PB) is larger than the acceleration judgment boost differential pressure (KB) (acceleration state), the process advances to step 9, and the current value I lnv flowing to the inverter of the power converter 4 is determined. Calculate. Further, if Pt-PB in step 5 is small, the process proceeds to step 10, where mote determination is performed.

When the accelerator pedal is depressed to the maximum and the process advances from step 1 to step 2, the turbine rotation speed is determined from the frequency of the back electromotive force from the stator 3b of the rotating electric machine 3, and the turbine rotation speed is determined to be on the lower side of the predetermined rotation speed. When the rotation speed is less than Lr□, proceed to step 3, and the current value I Inv to the inverter
is set to the maximum value Imax, and in step 4, the inverter is turned on to perform electric drive. In addition, when the turbine rotation speed is equal to or higher than the low side rotation speed L rpm in step 2, the process proceeds to step 6, where the turbine rotation speed is compared with the high side rotation speed Hrp of the predetermined rotation speed, and the high side rotation speed is Rotation speed Hrp
If it is less than m, the process goes to step 7, and if it is more than m, the process goes to step 11, where the inverter is turned off and the energization is stopped.

If the process advances to step 7 when the rotational speed is below the high side rotation speed Hrpm, it is determined from the frequency of the electromotive force whether the turbine rotation is increasing or decreasing. If the frequency is increasing and the rotational speed is increasing, Following step 8, the current value I Inv to the inverter is decreased by a predetermined value i, and the process proceeds to step 4, where the inverter is activated.

Further, if it is determined in step 7 that the current value is decreasing, the current value is left as it was at the previous time in step 12, and the inverter is turned on in step 4.

Therefore, by performing the process shown in Fig. 2, the rotation speed of the turbine increases. If the rotation speed is below □, the current applied to the inverter is maximized to increase the rotation speed, and if the turbine rotation speed is L rpm or higher, the rotation speed is increased. In this case, the current to the inverter is controlled in accordance with the tendency of the turbine rotation speed to increase or decrease, thereby suppressing fluctuations in the turbine rotation speed.

Although the present invention has been described above with reference to the above embodiments, various changes can be made within the scope of the invention, and these changes are not excluded from the scope of the invention.

(Effects of the Invention) According to the present invention, the high side rotational speed Hrpm and the low side rotational speed L r before and after the upper limit value of the turbine rotational speed of the turbocharger.
pm, and when the accelerator pedal is fully depressed, the turbine rotation speed is compared with the high side rotation speed or the low side rotation speed, and if it is below the low side rotation speed, the current to the inverter is maximized and the high speed is set. When the rotation speed is between the high side and the low side, the current value is controlled and supplied to the inverter according to the tendency of the turbine rotation speed to increase or decrease. On the other hand, when the turbine speed decreases, the engine speed increases and the exhaust energy increases, so the turbine speed may start to rise.
The effect is that the turbine rotational speed converges to a constant rotational speed between the high side and low side rotational speeds.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is a process flow diagram showing an example of the operation of this embodiment, FIG. 3 is a curve diagram of turbine rotation control in this embodiment, and FIG. 4 is a curve diagram of turbine rotation control in conventional turbocharger control. 1...Engine, 2...Turbocharger, 3...
・Rotating electric machine, 4...power converter, 5...battery,
6... Controller, 2b... Turbine blade,
2c...Rotation axis.

Claims (1)

[Claims] In a control device for a turbocharger with a rotating electrical machine that electrically drives a rotating electrical machine attached to a turbine shaft to apply supercharging pressure to the engine, when the turbine shaft reaches a predetermined rotational speed near its upper limit rotational speed, A control device for a turbocharger with a rotating electrical machine, characterized in that the power supplied to the rotating electrical machine is controlled according to a tendency of increase/decrease in the turbine shaft rotational speed.