JPH0496697A - Exciting voltage controller for vehicle generator - Google Patents

Abstract

PURPOSE:To realize highly efficient power generation and to considerably contribute to high performance high output power generation by a constitution wherein a stator coil for exciting a field coil, a rectifier and a regulator are provided and a divided exciting output voltage is applied on the field coil. CONSTITUTION:As the rotational speed of engine increases from a standard rotational speed, voltage generated from a stator coil 1 increases gradually thus increasing the voltage at point B. Consequently, the voltage divided by voltage detecting resistors 8h, 8i and applied on the base of a comparing/ amplifying transistor 8f increases and the potential difference from the reference voltage of a Zener diode 8g enlarges thus increasing the base current of the comparing/amplifying transistor 8f correspondingly. As a result, inner resistance decreases and the collector current increases and thereby the voltage drop across resistors 8a, 8b increases thus lowering the potential at point A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an excitation voltage control device for a vehicle generator mounted on a vehicle such as a passenger car.

[Prior art and problems to be solved by the invention] Generally,
Generators for this type of vehicle are configured so that when a key switch is turned on, battery current flows as an excitation current to a field coil (rotor coil), causing the rotor to become an electromagnet.When the rotor rotates when the engine starts, the stator coil An alternating current is generated, and this generated current is rectified by a rectifier and output. By the way, in such a generator, the output voltage output by power generation varies greatly depending on the rotational speed of the engine, so it is not preferable to leave it as it is, so the voltage application to the field coil is controlled intermittently, and the rectification described above is A regulator (constant voltage device) is further provided to perform constant voltage control so that the output voltage becomes a preset value.

By the way, in recent years, vehicles have been equipped with a large number of electrical components, and it is expected that the number of such devices will continue to increase.When considering the power consumption of these electrical components, it is important to consider the need for high-performance, high-power generators. There will be a strong demand for To deal with this, it is possible to increase power generation efficiency by applying the most preferable excitation voltage to the field coil, but the output voltage from the regulator is used to charge the battery and as a power source for various electrical components. Therefore, it is unreasonable to set this as it is as the field coil excitation voltage.

Therefore, in order to correspond to a preferable excitation voltage, a stator coil exclusively for excitation is provided with a different number of turns than the stator coil for power generation, and the alternating current generated from the stator coil for excitation is rectified. It is proposed to use this as the field coil excitation voltage to increase power generation efficiency.

However, if this is used as is, the change in excitation output voltage in response to changes in engine speed will be too large, resulting in the problem of excessive output at high speeds and insufficient output at low speeds. There is a need to solve this problem.

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing an excitation voltage control device for a vehicle generator that can eliminate these drawbacks. a field coil excited by an applied voltage;
A power generation stator coil that generates alternating current by the inductive action from the excited field coil, a power generation rectifier that rectifies the generated alternating current, and a power generation output that converts the rectified voltage into a constant voltage. In a vehicle generator equipped with a power generation regulator that outputs voltage, a stator coil, a rectifier, and a regulator are provided for excitation of a field knowledge coil, which are set separately from the stator coil, rectifier, and regulator for power generation. The present invention is characterized in that a constant excitation output voltage outputted from the excitation regulator is applied to a field coil to perform excitation.

With this configuration, the present invention applies an excitation-only output voltage that is different from the output voltage for power generation to the field coil, but also makes the excitation output voltage a constant voltage, so that it can be used in the engine. It is designed to be unaffected by changes in the rotational speed.

[Example] Next, an example of the present invention will be described based on the drawings. In the drawing, 1 is a Y-connected three-phase stator coil, and the stator coil 1 is pulled out from the middle of the coil winding and connected to a rectifier 2 for power generation, and the end of the winding is connected to a rectifier 2 for power generation. It is connected to a rectifier 3 for excitation, and thereby a stator coil for power generation and a stator coil for excitation are respectively set, but each of these stator coils may be configured with separate windings. Needless to say, these choices are free.

4 is a regulator for power generation, 5 is a field coil, 6
is a battery, and 7 is a key switch. When the key switch 7 is turned on with the engine stopped, battery voltage is applied from the battery 6 to the excitation regulator (constant voltage circuit) 8, and the voltage detection resistors 8h and 81 A current flows through the
A voltage divided by the voltage detection resistors 8h and 8i is applied to the base of the comparison and amplification transistor 8f, and a base current flows according to the potential difference between this voltage and the reference voltage of the Zener diode 8g.

When the engine is started in this state and power generation begins, a collector current flows through the comparison amplification transistor 8f via the resistors 8a and 8b. A voltage drop occurs in the resistors 8a and 8b in accordance with this collector current, and the potential at point A in the constant voltage circuit 8 is determined in accordance with the collector current of the comparison and amplification transistor 8f, and the potential at this point A. determines the base current of control transistor 8C18d. The collector current of the transistor 8d corresponding to the determined base current is then supplied to the field coil 5 as an excitation output voltage.

As the engine speed increases from such a standard state, the voltage generated by the stator coil 1 also gradually increases, and the voltage at point B also increases accordingly. Then, the base voltage of the comparison and amplification transistor 8f divided by the voltage detection resistors 8h and 8i also increases, the potential difference with the reference voltage of the Zener diode 8g increases, and the base current of the comparison and amplification transistor 8f increases accordingly. To increase. As the base current of the comparison and amplification transistor 8f increases, the internal resistance of the comparison and amplification transistor 8f decreases, and the collector current also increases. When the collector current of the comparison and amplification transistor 8f increases in this way, The voltage drop due to resistors 8a and 8b also increases, causing A.
The potential at the point decreases. For this reason, the base voltage of the control transistors 8c and 8d becomes low, the internal resistance increases, and a voltage drop occurs in the control transistor 8d, so that the output voltage for excitation to the field coil 5,
In other words, the voltage at point B will decrease.

On the other hand, when the voltage at point B decreases, the operation is opposite to the above. In other words, the base voltage of the comparison and amplification transistor 8f decreases, and the collector current decreases. As a result, the voltage drop across the resistors 8a and 8b also decreases, and the base voltage of the control transistor 8C18d increases, causing the transistor 8
The internal resistance of d decreases and acts to increase the output voltage to the field coil 5.

In the embodiment of the present invention configured as described above, the field coil 5 is supplied not with the output voltage from the power generation regulator 4 but with the excitation-only regulator 8.
An excitation output voltage is applied from.

Moreover, the output voltage for excitation is the same as that of the power generation regulator 4.
As shown in Fig. 2, a constant voltage is applied by the excitation-only regulator 8 regardless of the control of the output voltage in can be set to a desired voltage value, and therefore, efficient power generation can be achieved, greatly contributing to high performance and high output.

[Operations and Effects] In summary, since the present invention is configured as described above, the field coil is rectified by the power generated by the excitation-only stator coil, not by the power generation stator coil. However, this rectified excitation-only voltage is also made into a constant voltage by a regulator provided exclusively for excitation, and therefore, it is applied to the field coil regardless of changes in engine speed. This means that the most desirable substantially constant voltage value can be constantly applied without being affected by fluctuations in the generated voltage due to the power generation, which enables efficient power generation and greatly contributes to high performance and high output.

[Brief explanation of the drawing]

The drawings show an embodiment of the excitation voltage control device for a vehicle generator according to the present invention. FIG. 1 is a circuit diagram of the vehicle generator, and FIG. FIG. 2 is an excitation voltage characteristic diagram. In the figure, 1 is a stator coil, 2 is a power generation rectifier, 3 is an excitation rectifier, 4 is a power generation regulator, 5 is a field coil, 6 is a battery, and 8 is an excitation regulator.

Claims (1)

[Claims] a field coil that is excited by an applied voltage; a power generation stator coil that generates an alternating current by an inductive action from the excited field coil; a power generation rectifier that rectifies the generated alternating current; In a vehicle generator equipped with a power generation regulator that converts a rectified voltage into a constant voltage and outputs it as an output voltage for power generation, a field coil for excitation that is set separately from the stator coil, rectifier, and regulator for power generation. A generator for a vehicle, comprising: a stator coil, a rectifier, and a regulator; and a regulated excitation output voltage output from the excitation regulator is applied to a field coil for excitation. Excitation voltage control device.