JPH07177675A - Charging method for battery - Google Patents

Abstract

PURPOSE:To provide a charging method for battery in which the price can be lowered significantly by simplifying the charging circuit. CONSTITUTION:When a battery is charged by a power generating unit comprising a power converter for converting the output from a generator into a desired AC power and taking out an output from the power converter through a smoothing circuit, charging power is fed to a battery through a transformer 30 inserted into the output circuit of the power converter 5 and a rectifying circuit 31 connected with the transformer 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a power converter for converting the output of a generator into desired AC power, and charging the battery from a power generator that takes out the output of the power converter through a filter circuit. Regarding the method.

[0002]

2. Description of the Related Art FIG. 3 shows the structure of a conventional portable engine-type power generator. In the figure, 1
Is a fuel tank, 2 is a fuel supply device (injector), 3
Is a gas turbine engine (hereinafter, simply referred to as engine) E, 4 is a magnet type three-phase synchronous generator (hereinafter, simply referred to as generator) SG, and 5 is a power converter. The AC output of this power converter 5 is the reactor Lo and the capacitor C.
It is output through a filter circuit consisting of o. The power conversion device 5 includes a forward conversion unit 6, a capacitor 7, and an inverse conversion unit 8. The output terminals 9u and 9w are connected to a 100-volt or 200-volt outlet.

The generator 4 has a main winding 4P on the high voltage side and an auxiliary winding 4S on the low voltage side, and the main winding 4P is connected to the power converter 5. The electric power generated by the auxiliary winding 4S is used as electric power for auxiliary equipment such as the fan and the fuel supply device 2. Main winding 4
The generated voltage of P is Vp. Further, the voltage Vs generated by the auxiliary winding S is taken into the rotation speed detector 20 and is used to detect the rotation speed of the generator 4. The detected rotation speed N is compared with the rotation speed command N ^*, and the deviation is detected by the deviation amplifier 21.
Is supplied to the fuel supply device 2 through the control unit and the fuel supply device 2 is controlled so that the above deviation is eliminated.

As shown in FIG. 4, the forward conversion section 6 has six transistors Q _{1 to} Q ₆ which are bridge-connected and diodes D _{1 to} D ₆ which are respectively connected in anti-parallel to each other. . As shown in FIG. 4, the inverse converter 8 has four bridge-connected transistors T _{r1 to} T _r4 and four anti-parallel connected diodes D _{7 to} D ₁₀ , respectively. There is.

Reference numeral 10 is a battery for an engine starter having a nominal voltage of 12 volts or 24 volts, which is connected via a step-down circuit (step-down chopper circuit) 11 between the positive and negative electrodes of the DC circuit of the power converter 5. There is. 10A indicates the internal resistance r of the battery, and 10B indicates the battery voltage V _B. The step-down chopper circuit 11 includes a chopper element 12, a reactor 13, and a diode 14. Reference numeral 15 denotes a charge control circuit, which compares a charging current I _B detected by the current sensor DCCT 16 with a charging current command value I _B ^* and amplifies the deviation, a deviation amplifier 17, and a PWM signal generator 18 for generating a PWM signal. The chopper element 12 is controlled by applying this PWM signal to the base of the chopper element 12 via the switch 19A. This switch 19A is opened except when charging.

In this apparatus, when the engine 3 is started, the switch SW is closed, the battery 10 is connected to the main circuit, and one of the transistors and one of the diodes forming the inverse converter 8 and the reactor L of the filter circuit are connected.
By using o, a booster circuit is formed, the voltage of the battery 10 is boosted, and the forward conversion unit 6 is operated in reverse conversion to drive the generator 4 as a motor.

After the start of the engine 3 is completed, the battery 10 charges the battery 10 by opening the switch SW and operating the step-down circuit (step-down chopper circuit) 11.

[0008]

Since this type of portable engine-type power generator is required to be as inexpensive as possible, the number of parts can be reduced as much as possible and inexpensive parts can be used. However, in the case where the charging power is obtained from the power conversion device 5 as described above, an expensive step-down circuit (step-down chopper circuit) 11 is naturally used, which occupies the cost of the entire circuit device. The proportion of the charging circuit became large, which was a bottleneck for cost reduction.

The present invention has been made to solve this problem, and an object of the present invention is to provide a battery charging method in which the charging circuit can be simplified and the price thereof can be significantly reduced as compared with the conventional case. And

[0010]

In order to achieve the above object, the present invention provides a power converter for converting the output of a generator into desired AC power, and filters the output of the power converter. When charging the battery using the power generator taken out through the circuit as the battery charging power source,
The charging power is supplied to the battery through a transformer inserted in the output circuit of the power converter and a rectifying circuit connected to the transformer.

In the second aspect, the charging current is controlled by controlling the rotation speed of the generator.

According to a third aspect of the present invention, the smoothing circuit is a smoothing circuit for removing harmonics including a reactor, and the transformer has a secondary winding added to the reactor so as to have a transformer function.

According to a fourth aspect of the present invention, the generator is a gas turbine engine as a prime mover, is a generator that is driven by an electric motor when the engine is started, and the battery is a starter battery that serves as a power source at the start.

According to a fifth aspect of the present invention, when the battery is charged, a rotation speed command for charging is given.

[0015]

In the present invention, the transformer inserted in the output circuit of the power converter performs the step-down action, and the conventional step-down chopper circuit and its control circuit are not required.

Further, the transformer can be constructed by utilizing a conventional smoothing circuit reactor for the output circuit of the power converter.

[0017]

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

In FIG. 1, 30 is a transformer,
In this embodiment, the reactor Lo described with reference to FIG. 3 is configured to have the auxiliary winding 30S that is a secondary winding. A half-wave rectifier circuit 31 including diodes 31A and 31B is connected between terminals of the auxiliary winding 30S via a switch SW1, and the rectified output of the half-wave rectifier circuit 31 has a value L.
It is supplied to the battery 10 through the reactor 32.
SW2 is connected between the negative side of the capacitor 7 and the negative side of the battery 10.

The charging current I _B detected by the current sensor DCCT16 is compared with the charging current command value I _B ^* ,
The output of the deviation amplifier 17 for amplifying the deviation is the adder 33.
Is added to the charging speed command value N _B ^* . The deviation amplifier 21 calculates the deviation between the output N of the rotation speed detector 20 and the output of the adder 33. Since other configurations are the same as those of the conventional one, they are denoted by the same reference numerals. Note that the reference symbols P,
N indicates the positive electrode and the negative electrode of the capacitor 7, and the symbol O indicates the connection point between the reactor Lo of the filter circuit and the capacitor Co.

In this apparatus, when starting the engine 3, the switch SW and the switch SW2 are closed,
The switch SW1 is opened, the battery 10 is connected to the main circuit, and a booster circuit is formed by using one of the transistors and one of the diodes that form the inverse conversion unit 8 and the reactor Lo of the filter circuit, and the voltage of the battery 10 is increased. Is boosted and the forward conversion unit 6 is operated to perform reverse conversion, and the generator 4 is operated as an electric motor.

The battery 10 has a switch SW and a switch SW2 after the start of the engine 3 is completed.
Open, and switch SW1 is turned on to charge.

That is, after the start of the engine 3 is completed,
The forward conversion unit 6 of the power conversion device 5 is operated for forward conversion to rectify the output of the generator 4, and the inverse conversion unit 8 is operated as an inverter (P
(By WM control), the voltage v _vu shown in FIG. 2A is extracted from the power conversion device 5. The filter circuit including the reactor Lo and the capacitor Co attenuates the harmonic component contained in the voltage v _vu and outputs the voltage v _C shown in FIG. 2B. At this time, transformer 3
On the primary side of 0, the voltage v _T1 = (v _vu shown in FIG.
-V _C ) is applied, and a voltage v _T2 that insulates this voltage is induced in the auxiliary winding 30S. When the switch SW1 is turned on, this voltage v _T2 is half-wave rectified by the half-wave rectifier circuit 31. If this half-wave rectified voltage is v _dc and the battery voltage is v _B , And, on average, it becomes the following formula.

[0023]

Since the magnitude of the charging current I _B can be controlled by adjusting the magnitude of the half-wave rectified voltage v _dc ,
In this embodiment, the rotation speed command N _B ^* for charging is given, and at the time of charging, the fuel supply device 2 is controlled so that the rotation speed N = N _B ^* of the generator 4 and the rectified voltage of the forward converter 6 is obtained. The magnitude of the half-wave rectified voltage v _dc is adjusted by adjusting v _Dc .

As described above, in this embodiment, the power converter 5
Since the step-down transformer 30 inserted in the output circuit of FIG. 2 performs the step-down action and the conventional step-down chopper circuit and its control circuit are not necessary, a significant cost reduction can be achieved.

Further, as the transformer 30, the output circuit of the power converter 5 is provided with a secondary winding in the reactor of a conventional smoothing circuit so as to have a transforming effect, so that the step-down transformer 30 is newly provided. There is an advantage that it can be eliminated.

[0027]

As described above, according to the present invention, since the step-down chopper circuit and its control circuit can be omitted from the charging circuit, the number of parts can be reduced and the cost can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the above embodiment.

FIG. 3 is a configuration diagram of a conventional engine-type power generator.

FIG. 4 is a circuit diagram of a forward conversion unit and an inverse conversion unit in the above conventional engine-type power generator.

[Explanation of symbols]

 1 Fuel Tank 2 Refueling Device 3 Gas Turbine Engine 5 Power Converter 6 Forward Converter 7 Capacitor 8 Inverse Converter 10 Battery 15 Charging Control Circuit 17 Deviation Amplifier 30 Transformer 31 Half-wave Rectifier 32 Reactor 33 Adder SW, SW1 Switch

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[Procedure amendment]

[Submission date] March 6, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art FIG. 3 shows a configuration of a conventional portable engine-type power generator. In the figure,
1 is a fuel tank, 2 is a fuel supply device (injector),
Reference numeral 3 is a gas turbine engine (hereinafter, simply referred to as an engine) E, 4 is a magnet type three-phase synchronous generator (hereinafter, simply referred to as a generator) SG, and 5 is a power converter. The AC output of this power converter 5 is the reactor Lo and the capacitor C.
It is output through a filter circuit consisting of o. The power conversion device 5 includes a forward conversion unit 6, a capacitor 7, and an inverse conversion unit 8. 9u and 9 v is an output terminal which is connected to a 100 volt or 200 volt outlet.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

The generator 4 has a main winding 4P on the high voltage side and an auxiliary winding 4S on the low voltage side, and the main winding 4P is connected to the power conversion device 5. The electric power generated by the auxiliary winding 4S is used as electric power for auxiliary equipment such as the fan and the fuel supply device 2. The generated voltage of the main winding 4P is Vp. Further, the voltage Vs generated by the auxiliary winding S is taken into the rotation speed detector 20 and is used to detect the rotation speed of the generator 4. Detected rotation speed N
Is compared with the rotation speed command N *, and the deviation is detected by the deviation amplifier 2
1 to the fuel supply device 2 and controls the fuel supply device 2 so that the above deviation is eliminated.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

The charging current IB detected by the current sensor DCCT 16 is compared with the charging current command value IB *, and the output of the deviation amplifier 17 that amplifies the deviation is added to the rotation speed command value N * by the adder 33. . Deviation amplifier 21
Calculates the deviation between the output N of the rotation speed detector 20 and the output of the adder 33. Since other configurations are the same as those of the conventional one, they are denoted by the same reference numerals. The symbols P and N indicate the positive and negative electrodes of the capacitor 7, and the symbol O indicates the connection point between the reactor Lo of the filter circuit and the capacitor Co.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

That is, after the start of the engine 3 is completed, the forward conversion unit 6 of the power conversion device 5 is forward-converted to rectify the output of the generator 4, and the inverse conversion unit 8 is operated as an inverter (by PWM control). Then, the voltage vv-u shown in FIG. 2A is extracted from the power conversion device 5.
The filter circuit including the reactor Lo and the capacitor Co attenuates the harmonic component contained in the voltage vv-u and outputs the voltage vC shown in FIG. 2B. At this time, the voltage vT1 shown in FIG.
= (Vv-u-vC) is applied, and the voltage vT2 that insulates this voltage is induced in the auxiliary winding 30S. When the switch SW1 is turned on, this voltage vT2 is half-wave rectified by the half-wave rectifier circuit 31. If this half-wave rectified voltage is vdc and the battery voltage is vB, then vdc = L · d / dt · IB + rB · IB + vB (1) become that way.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (5)

[Claims] 1. When a battery is charged by using a power generator for converting the output of the generator into a desired AC power and using the power generator for extracting the output of the power converter through a filter circuit as a battery charging power source, A method of charging a battery, wherein charging power is supplied to a battery through a transformer inserted in an output circuit of the power converter and a rectifier circuit connected to the transformer. 2. The method for charging a battery according to claim 1, wherein the charging current is controlled by controlling the rotation speed of the generator. 3. The smoothing circuit is a smoothing circuit for removing higher harmonics, which includes a reactor, wherein the transformer has a transformer function by adding a secondary winding to the reactor. The method for charging a battery according to claim 1 or 2. 4. The generator is a gas turbine engine as a prime mover, is a generator driven by an electric motor when the engine is started, and the battery is a starter battery that serves as a power source at the start. ~ 3 charging method of the battery. 5. The method of charging a battery according to claim 1, wherein a charging speed command is given when charging the battery.