JPH03235700A - Power supply system - Google Patents

Abstract

PURPOSE:To reduce an electromagnetic noise by providing a short-circuiting winding wound on a core, a change-over means for change-over of short-circuit and open of the short-circuited winding, and a controller for controlling switching of the change-over means in response to the voltage of a battery. CONSTITUTION:If the voltage of a battery 3 is low, a control circuit 13 controls a change-over means 12 to open a short-circuiting winding 10. When the winding 10 is opened, since no current flows to the winding itself, alternating of a magnetic flux generated in a core 7 by the rotation of a permanent magnet 6 is used for generating power in an armature winding 9. If the voltage of the battery 3 is high, the control circuit 13 controls the means 12 to short-circuit the winding 10. When the winding 10 is short-circuited, an armature reaction is generated to reduce an alternating magnetic flux of the core 7 by the rotation of the magnet 6 or to move an electric neutral point, thereby reducing or eliminating power generated in the winding 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a power supply device using a brushless synchronous generator that generates magnetic flux using permanent magnets.

[Prior Art] Conventionally, an output adjustment device for a brushless synchronous generator has used a thyristor to intermittent the output current of the generator to adjust the output power.

[Problems to be Solved by the Invention] In the conventional output adjustment device, the thyristor directly interrupts the large current generated by the generator, and thus electromagnetic noise is generated when the current is interrupted. This electromagnetic noise then rides on an output wire that takes out the output of the generator, and is radiated to the surroundings.

An object of the present invention is to provide a power supply device that generates less noise.

[Means for Solving the Problems] In order to achieve the above object, the power supply device of the present invention employs the following technical means.

The power supply device includes a battery connected to an electric load, a permanent magnet driven to rotate, an iron core that forms a magnetic circuit with the permanent magnet, and an armature winding wound around the iron core, and includes a The present invention includes a brushless synchronous generator that generates an alternating current in the armature winding through rotation, and an output adjustment device that adjusts the output power of the generator.

The output adjustment device controls a short-circuit winding wound around the iron core, a switching means for switching the short-circuit winding between sudden closing and opening, and switching of the switching means according to the voltage of the battery. and a control circuit.

The control circuit basically switches the shorted winding to open when the battery voltage is low, and switches the shorted winding to shorted when the battery voltage is high. The mode is not limited.

An example of a specific aspect is shown. The short circuit and open time are controlled by duty ratio control, and as the battery voltage increases, the short circuit time becomes longer than the open time. It opens when the battery voltage is lower than a predetermined voltage, and shorts when the battery voltage is higher than a predetermined voltage. The battery is opened when the battery voltage is lower than the first predetermined voltage, and the second is opened when the battery voltage is higher than the first predetermined voltage.
One that switches between shorting and opening at high speed when the voltage is lower than a predetermined voltage, and short circuits when the battery voltage is higher than a second predetermined voltage (the type shown in the embodiment).

[Operation] When the voltage of the battery is low, the control circuit controls the switching means to open the shorted winding or increase the opening ratio. When a shorted winding is opened, no current flows through the shorted winding itself. That is, the armature winding is not affected by armature reactions due to shorted windings. Therefore, the alternation of magnetic flux generated in the iron core due to the rotation of the permanent magnet is directly used as power generated by the armature winding.

Conversely, when the battery voltage is high, the control circuit controls the switching means to short-circuit the short-circuited winding or increase the short-circuit ratio. When a shorted winding is shorted, an armature reaction occurs. The armature reaction reduces or eliminates the alternating magnetic flux in the core due to the rotation of the permanent magnet or moves the electrical neutral point, thereby reducing or eliminating the power generated in the armature winding.

[Effects of the Invention] As explained in the above operation, the present invention controls the power generated by the armature winding, that is, the output power of the generator, by controlling the switching means according to the voltage of the battery. Battery is kept at proper voltage.

Further, the present invention can control the output power of the generator without directly interrupting the output current of the generator as in the prior art. Therefore, the present invention can suppress the electromagnetic noise that conventionally occurs when the output current of the generator is directly interrupted.

[Example] Next, a power supply device of the present invention will be described based on an example shown in the drawings.

(Configuration of Example) FIG. 1 is an electrical circuit schematically showing a power supply device.

The power supply device 1 is a vehicle electrical load 2 such as a light,
It consists of a brushless synchronous generator 4 (see Fig. 3) that supplies power to a battery 3 (for example, rated at 12 mm) that is a vehicle power source, and an output adjustment device 5 that controls the output power of this generator 4. There is.

The generator 4 includes a permanent magnet 6 that is rotationally driven by the engine. This permanent magnet 6, as shown in FIG.
It is a cylindrical member fixed around a shaft 6a driven by an engine. An iron core 7 is provided around the permanent magnet 6, as shown in FIG. This iron core 7 is fixed within a housing (not shown) so as not to contact the permanent magnet 6. Further, the iron core 7 constitutes a magnetic circuit using permanent magnets 6, and a slot 8 provided in the iron core 7 includes an armature winding 9 that generates an alternating current by changing the magnetic poles of the magnetic circuit. Note that, in addition to the armature winding 9, a short-circuit winding 10 (described above) of the output adjustment device 5 is wound within the slot 8.

The armature winding 9 of this embodiment has three phases and is Y-connected as shown in FIG. The current generated in the armature winding 9 is supplied to the electric load 2 and battery 3 through a rectifier 11 provided within the housing of the generator 4.

As described above, the output adjustment device 5 includes a short-circuit winding 10 wound together with the armature winding 9 in the slot S, a switching means 12 for switching between short-circuiting and opening of the short-circuiting winding 10, and this switching means. 12 and a control circuit 13 for switching control.

The short-circuit winding 10 has three phases similar to the armature winding 9, and the winding direction, number of turns, cross-section of the wire, etc. are determined so as to cancel out alternating magnetic flux in the iron core 7 when short-circuited. Further, the short-circuited winding 10 of this embodiment is provided in a short-circuited state so as to be Y-connected.

The switching means 12 is a relay consisting of a coil 14 and a normally closed contact 15. When the coil 14 is energized, the short-circuit winding 10 is opened 5, and when the coil 14 is de-energized, the short-circuit winding 10 is opened.
is short-circuited.

The control circuit 13 controls the coil 14 according to the voltage of the battery 3.
The switching means 12 is switched by controlling the energization state of the switch.

An example of the control circuit 13 will be explained based on the electric circuit shown in FIG. The control circuit 13 includes a coil energizing circuit 16, an oscillation circuit 17, and a voltage detection circuit 18.

The coil energizing circuit 16 has terminals 19 and 20 connected to the coil 14, and when the drive transistor 21 is turned on, the coil 1 is turned on.
4 is energized. Note that the terminal 19 is connected to the output of the generator 4,
That is, it is connected to the positive electrode of the battery 3. The coil energizing circuit 16 is an inverting circuit including a control transistor 22. When the control transistor 22 is on, the drive transistor 21 is off, and when the control transistor 22 is off, the drive transistor 21 is on.

The voltage detection circuit 18 controls the energization of the control transistor 22 of the coil energization circuit 16 via the oscillation circuit 17 in accordance with the voltage of the input terminal 23 connected to the battery 3 . The voltage detection circuit 18 includes a comparator 24. When the input voltage from the input terminal 23 is lower than a first predetermined voltage (for example, around 13V), the output of the comparator 24 is low, the control transistor 22 is turned off, and the coil 14 is energized.

When the input voltage from the input terminal 23 is equal to or higher than the first predetermined voltage, the output of the comparator 24 becomes high, and the oscillation circuit 1
Activate 7. The oscillation circuit 17 includes two inverters 2
5.26, it is equipped with a CR circuit 27 that determines a time constant, and when the output of the comparator 24 becomes high, the control transistor 22 is short-circuited at high speed.The number of turns of each short-circuit winding 10 varies depending on the number of turns of each short-circuit winding 10. For example, when it is 3 turns,
The coil 14 is turned on and off at a frequency of approximately 1 kHz), and energization and de-energization of the coil 14 are switched at high speed.

Then, the input voltage from the input terminal 23 is set to a second predetermined voltage (for example,
14 to 15 V), the oscillation stop transistor 29 is turned on and the oscillation of the oscillation circuit 17 is stopped. As a result, the control transistor 22 is turned off by the high output of the comparator 24, and the current supply to the coil 14 is stopped.

(Operation of the embodiment) Next, the operation of the above embodiment will be briefly explained.

b) When the voltage of the battery 3 is lower than the first predetermined voltage.

By the action of the control circuit 13, the coil 14 of the switching means 12
is turned on, and the shorted winding 10 is opened.

When the shorted winding 10 is opened, no current flows through the shorted winding 10 itself, so the armature winding 9 is not affected by the armature reaction. As a result, the alternation of magnetic flux generated in the iron core 7 due to the rotation of the permanent magnet 6 is directly used as power generated by the armature winding 9.

As a result, when the voltage of the battery 3 decreases, the power supply device 1 can supply a large amount of generated power to the battery 3.

Ex) When the voltage of the battery 3 is higher than the first predetermined voltage and lower than the second predetermined voltage.

By the action of the control circuit 13, the coil 14 of the switching means 12
is repeatedly turned on and off at high speed, short-circuited winding 1
0 or high speed to switch between open and short circuit. Short circuit! 110
In the open state, as described above, the alternation of magnetic flux generated in the iron core 7 due to the rotation of the permanent magnet 6 is directly applied to the armature winding to generate power. Conversely, when the short-circuited winding 10 is short-circuited, an alternating current flows through the short-terminated winding 10. This alternating current produces an armature reaction flux that subtracts the magnetic flux in the core 7 caused by the permanent magnet 6. That is, when the short-circuited winding 10 is short-circuited, the magnetic flux generated in the iron core 7 due to the rotation of the permanent magnet 6 is canceled out, and generation of electric power in the armature winding 9 is prevented.

In reality, the short-circuited winding 10 switches between open and short-circuited at high speed, so before the magnetic flux generated in the core 7 due to armature reaction is canceled out, the state switches again to a state where there is no armature reaction, and the magnetic flux in the armature core 7 decreases. The state will be as follows.

As a result, the power generated by the armature winding 9 decreases, and the voltage of the battery 3 is prevented from increasing. In addition, since open and short circuits are switched at high speed, uneven rotation of the engine is not caused.

c) When the voltage of the battery 3 is equal to or higher than the second predetermined voltage.

Control time i? 813 turns off the coil 14 of the switching means 12, and the short-circuit winding 10 is short-circuited.

When the shorted winding 10 is shorted, an armature reaction occurs, as described above, which prevents power from being generated in the armature winding 9.

As a result, overcharging of the battery 3 is prevented.

(Effects of Example) In this example, the output power of the generator 4 is controlled by controlling the armature reaction without directly intermittent output current of the generator 4 as in the prior art.

Therefore, it is possible to reduce the electromagnetic noise that has conventionally been generated by directly intermittent output current of the generator 4.

In addition, in the conventional technology, the output current of the generator 4 was directly intermittent, so even when the output current was cut,
A large magnetic flux alternates in the iron core 7.

In other words, in the conventional technology, iron loss increases when the output current is cut, resulting in poor power generation efficiency under light loads or no loads. However, in this embodiment, since the output power of the generator 4 is controlled by controlling the armature reaction, when the short-terminal winding 10 is short-circuited to suppress the output current, the magnetic flux alternating in the iron core 7 is reduced. ing. Therefore, this embodiment can solve the conventional problem of poor power generation efficiency under light load conditions or no load conditions.

(Modification) In the above embodiment, an example was shown in which the short-circuited winding 10 was Y-connected, but it may also be Δ-connected.

Although an example has been shown in which the short-circuit winding 10 is provided in the same slot 8 as the armature winding 9, it may be provided separately from the armature winding 9.

Although the switching means 12 is configured using a mechanical relay, a semiconductor element may also be used.

Listed in Examples (- Numerical values indicate - examples,
The present invention is not limited to the numerical values in the examples. For example, the present invention may be applied to other batteries with a standard voltage of 6V, 24V, etc.

The control circuit 13 that controls the short-circuit winding 10 in three stages: continuous open, high-speed switching between open and short circuit, and continuous short circuit is shown as an example. , other control circuits may be used instead of smoothly controlling the output by controlling the open and short circuits using the tutee ratio control.

[Brief explanation of drawings]

Figure 1 is an electrical circuit diagram showing the outline of the power supply device, Figure 2 is a perspective view of the rotor, Figure 3 is a sectional view of the main parts of the generator, and Figure 4 is a schematic diagram of the power supply device.
The figure is an electrical circuit diagram of the control circuit. Kuninaka 1...Power supply equipment Death...Electric load 3...
・Battery 4...Brushless synchronous generator 5...
Output adjustment device 6...Permanent magnet 7...Iron core 9.
... Armature winding 10 ... Short circuit winding 12 ... Switching means 13 ... Control circuit

Claims (1)

[Claims] 1) (a) a battery connected to an electric load, (b) a permanent magnet driven to rotate, an iron core that forms a magnetic circuit with this permanent magnet, and an armature wound around this iron core. A power supply device comprising: a brushless synchronous generator including a winding, in which alternating current is generated in the armature winding by rotation of the permanent magnet; and (c) an output adjustment device that adjusts the output power of the generator. In the output adjustment device, (c-1) a short-circuit winding wound around the iron core; (c-2) a switching means for switching between short-circuiting and opening of the short-circuit winding; (c-3) A power supply device comprising: a control circuit that controls switching of the switching means according to the voltage of the battery.