JPH0711967A - Control device for tcg - Google Patents

Abstract

PURPOSE:To prevent the occurrence of excessive rotation during motor-drive of a TCG arranged to a turbocharger through detection of rotation acceleration. CONSTITUTION:Signals 6 from various on-mount devices and a signal from the rotation sensor 21 of a TCG are guided to a controller 5 to output a command to the power part 3 of a rotating electric machine (TCG) 2 arranged to a turbocharger. By means of a rotation signal from the rotation sensor 21, rotation acceleration is detected. By controlling a feed current to the TCG 2 according to the rotation acceleration, control is effected so that the number of revolutions is prevented from exceeding an upper limit value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TCG controller for electrically driving a rotary electric machine (TCG) mounted on a turbocharger.

[0002]

2. Description of the Related Art A turbocharger is widely used in which a turbine is rotated by exhaust gas of an engine, a compressor is driven by the torque of the turbine, and supercharged air is pressure-fed to the engine by compression of air. A turbocharger generator (TCG) is known in which a rotary electric machine that serves as a motor / generator is attached to a turbocharger of this type, and the turbocharger generator (TCG) is electrically driven or operates in accordance with the operating state of the engine.

Such control of the TCG is controlled by a control device having a microcomputer configuration, and signals from various in-vehicle devices such as an engine rotation signal, a turbine rotation signal, an accelerator opening signal, and a boost pressure signal are controlled. When input to the device, the T
The CG is electrically or electrically operated.

A heavy load is applied to the engine when a vehicle with a large load is climbing, and the engine speed does not increase even when the accelerator pedal is depressed, but the engine speed decreases. At this time, when the TCG is in an electrically operated state, the rotational speed of the turbocharger increases, the supercharging air pressure to the engine increases, and the engine torque increases, but the rotational acceleration of the rotary shaft of the turbocharger causes the supply current to flow. The upper limit of rotation depends on the amount of exhaust gas from the engine and the upper limit of rotation is set by the mechanical strength of the turbine or the like, so control is usually performed so as not to exceed this upper limit.

[0005]

However, when the vehicle starts to climb a steep slope as described above, the driver rapidly and deeply depresses the accelerator pedal. Therefore, the control device detects the depression state of the accelerator pedal and applies a large current as an electric motor operation, but the inertial force is applied to the turbine blades and the like, so that the rotational speed does not increase rapidly. Therefore,
Further, the control device increases the input current, which may eventually cause the turbine or the like to exceed the rotation upper limit value.

The present invention is intended to solve such a conventional problem, and its object is to prevent the rotational speed of the turbine shaft from exceeding the upper limit value even if an excessive power-on command is issued from the control device. It is to provide such a control device for TCG.

[0007]

In order to achieve the above-mentioned object, according to the present invention, a control device for a TCG for controlling an excessive rotational speed during electric drive of a motor-generator arranged on a turbine shaft of a turbocharger. In the above, the acceleration detection means for detecting rotational acceleration by monitoring the rotation speed of the motor-generator, and the power supply to the motor-generator is controlled based on the signal from the acceleration detection means even if the speed limit is not reached. There is provided a TCG control device including a current control means.

[0008]

In the electric drive of the TCG, the electric current supplied to the TCG is limited when the rotational acceleration is large even within the operating range of the turbine speed, so that excessive rotation can be suppressed. Also,
The current limit corresponding to the rotational acceleration lowers the current value when the rotational speed is large, so that sufficient rotational speed control is performed.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system configuration diagram showing an embodiment of a TCG control device according to the present invention, and FIG. 2 is an overall system diagram to which the present embodiment is applied. In these drawings, reference numeral 1 denotes a turbocharger, which is a turbine 11 driven by exhaust gas from an engine (not shown), and a compressor 12 attached to a rotary shaft of the turbine 11 for compressing intake air.
And the compressed air is sent to the engine as supercharged air to increase the torque of the engine.

Reference numeral 2 denotes a rotating electric machine (TCG) which is arranged on the turbine shaft and serves as a motor-generator, which operates as an electric motor or a generator according to the operating state of the engine. At the time of high load due to rotation, electric power from the battery 4 is transmitted through the power unit 3 to the TCG
When it is supplied to the compressor 1, the compressor 1 runs as an electric motor and assists the torque of the turbine 11 due to the exhaust energy to assist the compressor 1
The air pressure operation of No. 2 is urged to increase the supercharging air pressure and increase the engine torque.

Reference numeral 5 is a controller, which is a CPU, ROM, R
It is composed of a microcomputer having an AM, an input / output port, etc., and when the TCG 2 is electrically driven, functions such as a control calculation unit, an acceleration calculation unit, and a maximum current instruction value calculation unit are provided as shown in FIG. A power control unit 3 having a regulator, etc. issues a current instruction control output and a command such as on / off of an inverter. It should be noted that such a controller 5 outputs various sensor signals 6 as an accelerator opening sensor 61, an engine rotation sensor 62, a boost pressure sensor 63, and a vehicle speed sensor 64.
Alternatively, a detection signal from the TCG rotation sensor 21 or the like is guided.

Next, the operation of the present embodiment thus constructed will be described. When the TCG 2 is electrically driven, the rotational speed of the turbocharger 1 is constantly monitored by a signal from the TCG rotation sensor 21, and the acceleration calculator 53 is used. The rate of increase in the number of revolutions per unit time, that is, the acceleration is checked.

When the acceleration increases and exceeds the stored predetermined value, the maximum current instruction value is suppressed within the predetermined current value even if the rotation speed of the TCG 2 is within the limit range.
The rotation speed of 2 is controlled within the limit value.

In this embodiment, as a method of obtaining the acceleration limit value, two coefficients of rotation coefficient → (current rotation speed / 85000 rpm) and acceleration coefficient → (current acceleration / 33.3 rpm) are used. The maximum current instruction value is obtained from this value by the following equation, and the current command value to the inverter of the power unit 3 is limited to the obtained value. Maximum current instruction value = 50−rotation coefficient × acceleration coefficient × 50

FIG. 3 shows the operation of the present embodiment as described above as a processing flow chart, and the processing of the current instruction value is performed as in the flow shown in the drawing. Also, FIG.
FIG. 4A shows a state where the current instruction value is limited by the turbine speed and acceleration. FIG. 4A is a curve diagram of the relationship between the speed coefficient and the turbine rotation, and FIG. 4B is the relationship between the acceleration coefficient and the turbine rotation acceleration. FIG. 5 is a curve diagram showing the relationship between the turbine speed / acceleration and the current instruction value,
As shown in the drawing, as the turbine speed increases, the current instruction value is also reduced so that the upper limit value of the speed is not exceeded.

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

[0017]

As described above, according to the present invention, when the TCG is electrically driven, the rotational acceleration is detected by detecting the rotational speed of the TCG, and the supply current is supplied when the acceleration is large even within the limited rotational speed. Since it is limited, it has the effect of preventing the turbine speed from exceeding the upper limit value.Moreover, when the rotation speed is high, the supply current is controlled to a small value, so that the rotation speed can be sufficiently suppressed. Is obtained.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is an overall system diagram to which this embodiment is applied.

FIG. 3 is a process flow chart showing an example of the operation of the present embodiment.

FIG. 4 is a curve diagram showing a current instruction by a turbine speed and acceleration in the present embodiment.

FIG. 5 is a curve diagram showing a relationship between a turbine speed and a current instruction value.

[Explanation of symbols]

 1 ... Turbocharger 2 ... Rotating electric machine 3 ... Power part 5 ... Controller 21 ... TCG rotation sensor

Claims (2)

[Claims] 1. A TC for controlling an excessive rotational speed during electric drive of a motor-generator arranged on a turbine shaft of a turbocharger.
In the G control device, acceleration detection means for detecting rotational acceleration by monitoring the rotation speed of the motor-generator, and supply to the motor-generator even if the rotational speed limit is not reached based on the signal from the acceleration detection means. A controller for TCG, comprising: a current controller for controlling electric power. 2. The TCG control device according to claim 1, wherein the current control means controls the supplied electric power to be small in accordance with an increase in the number of revolutions from the acceleration detection means.