JP3577174B2 - Battery charger - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery charging device using a permanent magnet type three-phase AC generator, such as a motorcycle.
[0002]
[Prior art]
2. Description of the Related Art In a conventional battery charging system for a motorcycle, a thyristor-type Reg / Rec using a permanent magnet type three-phase AC generator is mainly used, and its circuit configuration is as shown in FIG.
[0003]
During charging of the battery, the current of the permanent magnet type three-phase alternating current generator (hereinafter referred to as ACG) is rectified by the diodes D1 to D6 and charged to the battery (B).
[0004]
Eventually, when the battery is fully charged, controller C detects the battery voltage, turns on second thyristor groups T4 to T6 provided in antiparallel with diodes D4 to D6, and shorts ACG. To control charging. That is, each phase of the ACG is short-circuited by the route of the U phase-T4-T5-V phase, the V phase-T5-D6-W phase, and the W phase-T6-D4-U phase. As described above, since the charging is controlled by short-circuiting the ACG, there is a problem that heat loss occurs and the efficiency of the system becomes extremely poor.
[0005]
As a charger, there is a three-phase full-wave rectifier charger with a control rectifier as shown in FIG. This is a three-phase thyristor open-type Reg / Rec, which eliminates the above-mentioned disadvantages of the uncontrolled rectifier system.
[0006]
That is, when charging the battery, the thyristors T1 to T3 are phase-controlled to charge the battery B.
[0007]
When the battery B is fully charged, the controller CONT detects the battery voltage and turns off the thyristors T1 to T3 to control the charge amount.
[0008]
In this case, since the thyristors T1 to T3 are turned off, the generator ACG becomes unloaded, and the ACG output voltage increases. Then, as the engine speed increases, the ACG output voltage and the frequency increase, and as a result, the core loss of the generator increases drastically, and the efficiency of the battery charger deteriorates.
[0009]
[Problems to be solved by the invention]
As described above, any of the prior arts has the same drawback in that the efficiency is deteriorated when the ACG output is shorted or opened when the battery is fully charged. However, there is a difference in the magnitude of the ACG loss between the case of short-circuit and the case of open-circuit depending on the engine speed.
[0010]
Therefore, the present invention has been made by paying attention to this point. FIG. 3 is a characteristic diagram showing a relationship between the engine speed and the generator loss. The characteristic curve A is the characteristic when the ACG output is shorted by the circuit as shown in FIG. 1, and the characteristic curve B is the characteristic when the ACG output is open by the circuit as shown in FIG. It is.
[0011]
As can be seen from the curve in FIG. 3, the generator loss is smaller in the open type when the engine speed is lower than Nex and in the short type when the engine speed is higher than Nex. The present invention has been realized by making good use of these two characteristics.
[0012]
[Means for Solving the Problems]
The present invention relates to a battery charger for charging a battery (B) with a DC voltage rectified by a three-phase full-wave rectifier circuit with a control rectifier, using a permanent magnet type three-phase alternating current generator (ACG) as an input. The attached three-phase full-wave rectifier circuit is composed of a first thyristor group (T1, T2, T3) and a diode group (D4, D5, D6), and each of the diodes (D1, D2, D3) of the diode group D4, D5, D6) are connected to the second thyristor group (T4, T5, T6) in anti-parallel, respectively, and before the battery reaches a predetermined voltage, the first thyristor group (T1, T1, T2, T3) are turned on, and the second thyristor group (T4, T5, T6) is turned off to charge the battery. After the generator reaches a predetermined rotation speed and the battery (B) is fully charged, One thyristor group (T1, T2, T3) turns off and the second Thyristors group (T4, T5, T6) is a battery charging device, wherein a turned ON.
[0013]
In this way, if the circuit configuration is such that the ACG output is opened when the engine speed is lower than the predetermined value and the ACG output is shorted when the engine speed is higher than the predetermined value, the generator loss can be kept low. As a result, the efficiency of the battery charger can be increased.
[0014]
Embodiment
FIG. 4 shows a thyristor-shot / open-type Reg / Rec using a permanent magnet type three-phase AC generator in the battery charging system for a motorcycle according to the present invention.
[0015]
A three-phase full-wave rectifier circuit with a control rectifier is constituted by a first thyristor group T1 to T3 and diode groups D4 to D6 with a permanent magnet type three-phase AC generator ACG as an input, and diode groups D4 to D6. Are connected in reverse parallel to the second thyristor groups T4 to T6, respectively. Then, the output of the three-phase full-wave rectifier circuit with the control rectifier is connected to the battery B.
[0016]
The controller CONT is configured to detect the output voltage and the rotation speed of the permanent magnet type three-phase AC generator ACG, and to supply a gate signal to each thyristor or stop the thyristor.
[0017]
Further, the temperature of the components constituting the battery charger, for example, the permanent magnet type three-phase AC generator ACG or the battery B, or the temperature of the diode or thyristor constituting the rectifier circuit is detected, and the second thyristor group is detected. It is configured to transmit a gate signal.
[0018]
In such a circuit configuration, when the battery is charged, a gate signal is supplied to the thyristors T1 to T3, and when the engine speed is lower than Nex after the battery B is fully charged, for example, when the engine speed is 4000 to 5000 rpm or less. Then, the gate signals of the first thyristor groups T1 to T3 are stopped to open the ACG output. When the voltage is 80 to 100 V or less, the gate signals of the first thyristor groups T1 to T3 are stopped and the ACG output is opened.
[0019]
When the output voltage of the ACG is high at full charge, for example, when the output voltage is 80 to 100 V or more, a gate signal is supplied to the B2 th thyristors T4 to T6 to short the ACG output.
[0020]
By doing so, the generator loss can be kept relatively low from when the engine speed is low to when it is high, and the battery charger can always be operated with high efficiency.
[0021]
Further, when the temperature of the ACG, the battery B, the diode, the thyristor, etc. is detected at the time of full charge, and when at least one of these components rises in temperature , a gate signal is sent to the second thyristor group T4 to T6 , The ACG output may be short-circuited.
[0022]
Similarly, when the output voltage of the ACG is high after the battery B is fully charged, for example, when the output voltage is 80 to 100 V or more, a gate signal is supplied to the B2 thyristor group T4 to T6, and the ACG output May be short-circuited.
[0023]
Further, when the rotational acceleration of the ACG becomes a positive value and becomes a certain value or more, a gate signal may be sent to the second thyristor groups T4 to T6 to short-circuit the ACG output. By doing so, the iron loss of the ACG can be reduced, and an abnormal increase in the output voltage of the ACG can be suppressed.
[0024]
【The invention's effect】
By doing so, the present invention can keep the generator loss relatively low from low to high engine speeds, and can always operate the battery charger with high efficiency. It is possible to realize a battery charger for a motorcycle.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an example of a conventional battery charger for a motorcycle (ACG short system).
FIG. 2 is a circuit diagram of another conventional battery charger for a motorcycle (ACG open system).
FIG. 3 is a characteristic curve of ACG engine speed and generator loss.
FIG. 4 is a circuit diagram of an embodiment of a battery charger for a motorcycle according to the present invention (ACG short / open system).
[Explanation of symbols]
ACG Permanent magnet type three-phase AC generator D1 to D6 Diodes T1 to T3 First thyristor group T4 to T6 Second thyristor group CONT Controller B Battery

Claims (1)

In a battery charging apparatus which receives a permanent magnet type three-phase alternating current generator (ACG) as input and charges a battery (B) with a DC voltage rectified by a three-phase full-wave rectifier circuit with a control rectifier, The wave rectifier circuit includes a first thyristor group (T1, T2, T3) and a diode group (D4, D5, D6), and each diode (D4, D5, D5, D6), the second thyristor group (T4, T5, T6) is connected in anti-parallel, respectively, and before the battery reaches a predetermined voltage, the first thyristor group (T1, T2, T3). Is turned on, the second thyristor group (T4, T5, T6) is turned off to charge the battery (B), and after the generator reaches a predetermined rotation speed and the battery (B) is fully charged, the first Thyristors (T1, T2, T3) are turned off and the second Lister group (T4, T5, T6) battery charging apparatus, wherein a turned ON.

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