JPH05328684A - On-vehicle two-source generator - Google Patents

Abstract

PURPOSE:To prevent the increase of generated voltage by having a power inverter circuit, which can supply power from an auxiliary generator to a main power-supply generator and by operating the power inverter circuit, when a detection control circuit for detecting the generated voltage of the auxiliary generator exceeding a specified value operates. CONSTITUTION:A main generator 1 is composed of field coil 3, voltage regulation circuit 4, stator coil 6 and full-wave rectifier diode 8. An auxiliary generator 2 is composed of permanent magnet rotor 17, stator coil 7 and full-wave rectifier diode 9. The auxiliary-power supply line 13 side of the full-wave rectifier diode 9 is a Zener diode. A power inverter circuit 19 is constituted by a transformer 22, field-effect transistor FET, diode D, etc. A signal is given when the voltage of a terminal VB1 exceeds a specified value so that the power inverter circuit 19 is operated. The generated current of the auxiliary generator 2 is increased while the voltage of the terminal VB1 is reduced.

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 driven by an internal combustion engine, which excites the auxiliary power generator, and is an alternating current generator having a rotor having a permanent magnet. The present invention relates to a generator suitable for preventing the generated voltage from increasing.

[0002]

2. Description of the Related Art As a conventional device, it has been disclosed in JP-A-1-157251.

In the above example, there was little consideration for miniaturization.

What can be considered there is to use one permanent magnet for excitation of one of the generators. There is a problem that the generated voltage becomes excessive when the generator current in which the excitation is a permanent magnet becomes small and the rotating speed becomes large, and the rectifying semiconductor or the insulator is destroyed.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent destruction of a rectifying semiconductor or an insulator.

[0006]

Means for Solving the Problems In a case where a main power generator and a sub power generator are provided and the sub power generator is excited by a permanent magnet rotor, electric power capable of supplying power from the sub power generator to the main power generator. A detection control circuit is provided which has a conversion circuit and detects when the voltage generated by the sub-generator exceeds a specified value.

When the detection control circuit operates, the power conversion circuit is operated.

[0008]

In the generator excited by the permanent magnet, the generated voltage changes depending on the rotation speed and the generated current. In particular, when the rotation speed is high and the generated current is small, the generated voltage becomes large.

When the detection control circuit that detects that the generated voltage exceeds a certain specified value operates, a power conversion circuit that can supply power from the sub-generator to the main power generator is operated. Then, the generated current increases and the generated voltage decreases.

In general, the following equation holds in a generator excited by a permanent magnet.

VB = E−I · Z where VB: generated voltage E: induced voltage (proportional to rotation speed) I: generated current Z: internal impedance

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The main generator 1 comprises a field coil 3, a voltage adjusting circuit (A) 4, a stator coil (A) 6, and a full-wave rectifying diode (A) 8. The generated current is a (+) power line 10,
It flows to the battery 14 or the load (A) 15 via the (-) power supply line 11.

The sub-generator 2 comprises a permanent magnet rotor 17, a stator coil (B) 7, and a full-wave rectifying diode (B) 9, and the generated current is a sub-(+) power supply line 12 and a sub-(+) adjustment voltage line 18. , The load (B) 16 and the secondary (−) power supply line 13.

The side of the sub (-) power supply line 13 of the full wave rectifying diode (B) 9 is a Zener diode. This works when all of the overvoltage protection circuits do not work. The secondary (+) power supply line 12 as one of the overvoltage protection circuits
A resistor R0 and a transistor TR0 are connected in series to the (-) power line 13. When the voltage of the sub (+) power supply line 12 becomes large, the transistor TR0 is made conductive to monitor the current and prevent the increase of the excessive voltage.

The power conversion circuit 19 is composed of a transformer 22, a field effect transistor FET, a diode D and the like.

The photocoupler 20 is used with resistors R1, R2 and R3 to insulate the voltage on the main generator 1 side and convert it to the voltage on the sub generator 2 side.

FIG. 2 shows a detailed view of the detection control circuit 21 of FIG. The terminals of the symbols shown in the detection control circuit of FIG. 1 are indicated by double circles.

A constant voltage circuit 23 is connected to the terminal VB1 so that a constant voltage is used as a power source for each electronic circuit element.
Used as the reference voltage for the analog / digital conversion circuit.

The voltages at the terminals VB1, VB2, and REG are divided by resistors and input to the analog / digital converter connection pins of the microcomputer 25.

A signal is sent from the PWM connection pin of the microcomputer 25 to the terminal T1 via the transistor to turn on / off the switching regulator transistor of the voltage adjusting circuit (B) 5 to keep the voltage of the sub (+) adjusting voltage line 18 constant. Keep on. Then, power is supplied to the load (B) 16.

The port P connection pin of the microcomputer 25 is connected to the terminal T0 via a resistor to turn on / off the transistor TR0. This is to turn on the transistor TR0 when the voltage of the terminal VB1 exceeds the specified value (2), increase the current of the sub-generator 1 and reduce the voltage of the terminal VB1.

Timer connection pin TM1, of the microcomputer 25
TM2 is connected to terminals F1 and F2 via resistors.

In this operation, when the voltage of the terminal VB1 exceeds the specified value (1), a signal is issued and the power conversion circuit 19 is operated. Increase the generated current of the sub-generator 2 to increase the terminal VB1.
Reduce the voltage of.

The input / output voltage of the power conversion circuit 19 becomes the input voltage of the auto coupler 20, and a voltage proportional to the output side is applied to the resistor R2.

This voltage is applied to the terminal REG, divided by the input / output circuit 24 of the detection control circuit 21, and the microcomputer 25
Applied to connection pin A3 for the analog-to-digital converter of the.

The generated current differs depending on the on / off time of the field effect transistors FET1 and FET2 of the power conversion circuit 19.

This characteristic is shown in FIG.

This indicates that the input radio wave increases as the conduction ratio of the field effect transistor FET of the power conversion circuit 19 increases.

The increase of the input current means the increase of the generated current, and the generated voltage decreases as shown in the item of action.

The output voltage differs according to the amount of charge of the battery 14 and the current consumption of the load (A) 15 and has a certain width as shown by the dotted line.

When the output voltage exceeds the specified value (3),
Reduce the flow rate.

The specified value (3) of the output voltage is set to be larger than the voltage at which the voltage adjusting circuit (A) 4 operates only in the main generator 1. This increases the current of the sub-generator 2. During this operation, when VB1 exceeds the specified value (2), the transistor TR0 is turned on. So the secondary generator 2
Current is further increased to reduce the VB1 voltage.

When the voltage VB1 further rises, a current is passed through the Zener diode ZD of the diode (B) 9 in full wave so as not to exceed this voltage.

Of the operations described above, a flowchart of software relating to the microcomputer 25 is shown in FIG. The operation contents of the flowchart are described next to the symbols. The judgment symbol Y means (yes) and N means (no).

The reference value (1) described here indicates a generated voltage VB1 which can ensure the minimum allowable voltage to the load (B) 16 by rotating the permanent magnet rotor of the sub-generator 2.

The reference value (2) means the sub (+) adjustment voltage line 1
The voltage in the range of 8 is acceptable.

[0038]

EFFECTS OF THE INVENTION Even when the load current is small and the generated voltage increases at high speeds in the operating state of the generator using a permanent magnet for excitation, the generated voltage is prevented from increasing by supplying electric power to another power source. I was able to.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an excessive voltage generation prevention circuit of a generator using a permanent magnet according to the present invention.

FIG. 2 is a detailed view of the control circuit of FIG.

FIG. 3 is a characteristic diagram of a power conversion circuit.

FIG. 4 is a waveform diagram showing ON / OFF signals of FETs.

FIG. 5 is a flowchart of control circuit software.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main generator, 2 ... Sub generator, 3 ... Field coil, 4 ... Voltage adjusting circuit (A), 5 ... Voltage adjusting circuit (B), 6 ... Stator coil (A), 7 ... Stator coil (B) ), 8 ... Full wave rectifying diode (A), 9 ... Full wave rectifying diode (B), 10 ... (+) power source line, 11 ... (-) power source line, 12
... secondary (+) power supply line, 13 ... secondary (-) power supply line, 14 ... battery, 15 ... load (A), 16 ... load (B), 17 ... permanent magnet rotor, 18 ... secondary (+) adjustment voltage line , 19 ... Power conversion circuit, 20 ... Photocoupler, 21 ... Detection control circuit, 2
2 ... Transformer, 23 ... Constant voltage circuit, 24 ... Input / output circuit,
25 ... Microcomputer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Tahara 4026 Kujimachi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Masakazu Hori 2520 Takaba, Katsuta City, Ibaraki Hitachi Ltd. Mfg. Co., Ltd. Automotive Equipment Division (72) Inventor Yoshiaki Honda 2520 Takaba, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division (72) Inventor Sakae Hikita 2477 Kashima Yatsu, Katsuta, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd.

Claims (1)

[Claims] Claim: What is claimed is: 1. A main power generator and a sub generator, wherein the sub generator is excited by a permanent magnet rotor, and a power conversion circuit capable of supplying power from the sub generator to the main power generator is provided. A dual power supply generator for a vehicle, characterized in that a detection control circuit for detecting that the voltage generated by the sub-generator exceeds a certain specified value and a power conversion circuit is activated when the detection control circuit operates.