JPH09322545A - Voltage controller of permanent magnet generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of large current switching devices, to eliminate a large current control circuit, and to realize the size reduction and the weight reduction, by a method in which an AC converting means is composed of an equi-width PWM control circuit having a voltage regulating function. SOLUTION: Transistors T2-T5 of an inverter circuit 7 are controlled by an equi-width PWM control type inverter circuit 8. If a DC voltage is higher than a target voltage, an output voltage is turned on and off the lower the voltage. The ON-period and the OFF-period are determined by a differential voltage between the DC voltage and the target voltage and are set so as to make a 3-phase AC voltage constant. If the DC voltage is lower than the target voltage, the PWM control is not carried out. With this constitution, the number of large current switching devices can be reduced, so that the size reduction and the weight reduction can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternating current generator, and more particularly to a control device for a generated voltage of a permanent magnet generator driven by an engine of an automobile or the like.

[0002]

2. Description of the Related Art A three-phase AC generator driven by an automobile engine or the like has a very wide engine speed of 500 to several 1000 rpm, and the power generation voltage changes in proportion to the rotation. It requires a voltage controller consisting of step-up and step-down means. The voltage control device is illustrated in FIG. In FIG. 3, 1 is a permanent magnet generator, and 2 is a step-down / rectifier that steps down / rectifies the output voltage of the permanent magnet generator.
In the rectifier circuit, the diodes D1 to D3 and the thyristor S1
.About.S3, the step-down control circuit 4 controls the gates of the thyristors S1 to S3, and the step-down control is performed by decreasing the phase angle of the power generation output.

Reference numeral 3 is a step-up circuit for stepping up the power generation output voltage of the permanent magnet generator 1, which is composed of leakage inductance of windings of the permanent magnet generator, diodes D4 to D6, switching transistors T1, T2 and diode D7. Therefore, boosting control is performed by controlling the switching transistors T1 and T2 by the boosting control circuit 5.

Next, 6 is a smoothing circuit for smoothing the output of the rectifying circuit, which is composed of a capacitor C1 in this example. Reference numeral 7 is an inverter circuit that generates an AC voltage from a DC voltage. In this example, a single-phase inverter that generates a single-phase AC voltage is illustrated. This inverter circuit is a transistor T3
To T6, these transistors T3 to T6 are controlled by the inverter control circuit 8 to generate an AC voltage that matches the electric equipment used.

Next, 9 is a DC voltage conversion circuit, which is an inverter / voltage regulator circuit composed of transistors T7 to T10, an inverter / voltage regulator control circuit 10, a voltage transformer T for transforming a voltage, and an AC to DC voltage. It is composed of rectifying diodes D8 to D10 for rectifying, a choke L for smoothing the rectified output, and a capacitor C2, and converts the rectified generator output into a DC low voltage for automobile auxiliary equipment and electrical components. It is a thing.

[0006]

In the above-mentioned voltage control device for a permanent magnet generator, a high voltage AC voltage is converted into a high voltage DC voltage by a step-down / rectifier circuit, a step-up circuit, and a smoothing circuit, and the high voltage Since a DC voltage is converted into an AC voltage of a desired frequency and voltage by an inverter circuit and converted into a low voltage DC voltage for automobile auxiliary equipment and electrical components by a DC voltage conversion circuit, many elements are required and large Therefore, there is a problem that a more complicated circuit is required, the price is high, and it is disadvantageous in terms of reliability. The present invention has been made in view of such problems, and its purpose is to:
An object of the present invention is to provide a device that can obtain a stable voltage as a generated voltage of a permanent magnet type generator driven by an engine of an automobile at any engine rotation in a small size and at a low cost.

[0007]

In order to solve the above problems, according to the present invention, a permanent magnet generator driven by an automobile engine and a generated output voltage of the permanent magnet generator are converted into direct current and rectified. Rectifying means, boosting means for boosting the output of the rectifying means, AC converting means for converting the output voltage of the boosting means into an AC voltage of an arbitrary frequency or voltage, and the output voltage of the AC converting means of an automobile. In a voltage control device for a permanent magnet generator having a direct current converting means for converting to a low voltage direct current voltage for auxiliary equipment and electrical equipment, the alternating current converting means is constituted by a constant width PWM control circuit having a voltage adjusting function. And a voltage control device for a permanent magnet generator, wherein in the voltage control device for a permanent magnet generator, the DC conversion means converts the output of the AC conversion means into a low voltage DC voltage. Voltage controller for a permanent magnet generator, characterized in that so as to conversion is provided, further,
In the voltage control device for the permanent magnet generator, the voltage control device for the permanent magnet generator is characterized in that the boosting means performs the boosting control only when the generated voltage of the permanent magnet generator is lower than a predetermined value. Further, in the voltage control device for the permanent magnet generator, when the input voltage to the AC conversion means is less than or equal to a predetermined value, the pulse width of the constant-width pulse PWM control circuit is set to the maximum width and the AC conversion means is operated. When the input voltage is equal to or more than a predetermined value, the constant-width pulse PWM control circuit pulse width is controlled according to the voltage value.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a control device for a permanent magnet generator driven by an automobile engine or the like, since the number of large current switching elements can be reduced, the control device is small, lightweight and economically advantageous. Can be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a voltage control circuit for a permanent magnet generator showing an embodiment of the present invention. Reference numeral 1 is a permanent magnet generator, which is a three-phase AC generator having a permanent magnet rotor. Reference numeral 11 is a rectifying circuit for rectifying the generated voltage of the permanent magnet generator 1.
It is composed of a three-phase full-wave rectifier circuit composed of diodes D1 to D6. A step-up circuit 3 is composed of a transistor T1 and a diode D7, and controls on / off of the transistor T1 to perform step-up using energy accumulated in the leakage inductance of the permanent magnet generator 1. Reference numeral 5 denotes a step-up control circuit for controlling the transistor T1, which turns on / off the transistor T1 when the DC-converted voltage does not reach the target voltage. When T1 is turned on, the output of the generator 1 is short-circuited, a short-circuit current flows in the winding of the generator 1, energy is accumulated in the leakage inductance of the winding, and then when T1 is turned off, the accumulated energy is released. Output voltage rises. When the voltage after DC conversion is equal to or higher than the target voltage, the on / off operation of T1 is stopped. In this way, the generator output is boosted or converted as it is into the direct current in the three-phase full-wave rectifier circuit 11, rectified and smoothed in the smoothing circuit 6, and then the inverter circuit 7
And the inverter control circuit 8 are sent to the AC conversion means.

The inverter circuit 7 is an inverter circuit that converts DC power of an arbitrary voltage into three-phase AC power of a desired frequency and voltage. Transistor T of the inverter circuit 7
2 to T5 are controlled by the inverter control circuit 8 of the constant-width pulse PWM control system. When the DC voltage is equal to or higher than the target voltage, the output voltage is turned on / off to change the voltage as shown in FIG. Works to lower. Here, the on-time and the off-time are determined by the difference voltage between the DC voltage and the target voltage, and are set so that the three-phase AC voltage is constant.
When the DC voltage is below the target voltage, P as shown in FIG.
No WM control is performed. Here, an inverter control circuit 8 for controlling the transistors T2 to T5 of the inverter circuit 7
By setting the basic frequency to 50 or 60 Hz and the carrier frequency (chopping frequency) to several kHz, commercial single-phase AC power can be output, and a device that uses commercial single-phase AC power as a power source Can operate.

Next, reference numeral 12 is a transformer T and diodes D8 to D with the AC output of the inverter circuit 7 as an input.
The DC conversion means is composed of a transformer and a rectifier circuit composed of a choke coil L and a capacitor C2, and generates low-voltage DC power for auxiliary machinery / electrical components of a vehicle. In this DC converting means, the inverter circuit 7
Since the output voltage of is a constant voltage, the constant voltage circuit is omitted.

[0012]

According to the present invention, since the inverter circuit is provided with the constant-width pulse PWM control method, the inverter circuit is provided with the function of stepping down the output voltage and the constant voltage, so that the stepping down of the output voltage of the permanent magnet generator is performed. Since it is possible to reduce the number of circuit elements and control circuits, and further to omit the constant voltage circuit of the circuit that generates low-voltage DC power for auxiliary machinery and electrical components of automobiles,
A compact, lightweight, and economically advantageous control device can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a voltage controller according to an embodiment of the present invention.

FIG. 2 is a diagram showing output waveforms according to an embodiment of the present invention.

FIG. 3 is a diagram showing a conventional voltage control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet generator, 3 ... Booster circuit, 5 ... Booster control circuit, 6 ... Smoothing circuit, 7 ... Inverter circuit, 8 ... Inverter control circuit 11 ... Rectifier circuit, 12 ... DC conversion means

Claims (4)

[Claims] 1. A permanent magnet generator driven by an engine of an automobile, a rectifying means for converting a generated output voltage of the permanent magnet generator into a direct current and rectifying it, and a boosting means for boosting the output of the rectifying means. An alternating current converting means for converting the output voltage of the boosting means into an alternating current voltage having an arbitrary frequency or voltage, and a direct current converting means for converting the alternating current output voltage into a low voltage direct current voltage for automobile auxiliary equipment / electrical equipment. A voltage control device for a permanent magnet generator, wherein the AC conversion means is composed of a constant width PWM control circuit having a voltage adjusting function. 2. The voltage control device for a permanent magnet generator according to claim 1, wherein the direct current conversion means converts the output of the alternating current conversion means into a low voltage direct current voltage. Voltage control device for permanent magnet generator. 3. The voltage control device for the permanent magnet generator, wherein the boosting means performs the boosting control only when the voltage generated by the permanent magnet generator is lower than a predetermined value. Item 2. The voltage control device for a permanent magnet generator according to Item 2. 4. In the voltage control device for the permanent magnet generator, when the input voltage to the AC converting means is less than or equal to a predetermined value, the pulse width of the constant-width pulse PWM control circuit is maximized, and the AC converting means. 4. The constant width pulse PWM control circuit pulse width is controlled according to the voltage value when the input voltage to the input voltage is equal to or higher than a predetermined value, according to claim 1 or claim 2 or claim 3. Voltage control device for permanent magnet generator.