JP4497404B2 - Portable generator - Google Patents

Description

  The present invention relates to a portable generator, and more particularly to a portable generator suitable for charging a battery with a relatively large capacity direct current.

  2. Description of the Related Art A portable generator driven by an engine or the like has been widely used as a power source for electric devices used for outdoor work or leisure activities. Further, in recent years, the use is expanding to uninterruptible power supply devices for computers, so-called UPS backup power sources and the like. When this type of portable generator is configured as a generator for direct current output, there is a tendency for the output to be able to supply a relatively low voltage and large current even though the fuselage is small. In such a generator that requires a large current output, the wire diameter of the output winding becomes thicker, and a higher level of consideration is required for the insulation between the windings depending on the withstand voltage and the material of the insulating material. Become.

Therefore, the present applicant has proposed a portable generator capable of reducing the wire diameter of the output winding and reducing the capacity of the power element (utility model registration No. 2 511843). In the invention related to the registered utility model, a plurality of output windings wound independently on the same iron core and a plurality of thyristor bridge rectifier circuits provided corresponding to the plurality of output windings are mutually independent. These power supply units are formed, the outputs of the power supply units are connected in parallel, and the outputs are combined.
Utility Model Registration Gazette No. 2511843

  When the portable generator disclosed in Patent Document 1 is used for battery charging, that is, when a battery is used as a load, it is necessary to change the charging voltage according to the voltage specification of the battery to be connected. For this purpose, a changeover switch may be provided to change the output of the generator for each battery connected. However, it is cumbersome to check the voltage specifications and operate the switch every time the battery is connected, and if the output is changed accidentally, the battery will be overcharged or not fully charged. There is a risk of

  An object of the present invention is to provide a portable generator capable of solving the above-described problems and preventing the battery from being overcharged and insufficiently charged due to erroneous operation of the changeover switch.

  In order to achieve the above object, the present invention provides a portable generator for converting an alternating current output from an output winding of a generator into a direct current by a rectifier circuit and outputting the direct current to an output terminal. Switching means for selecting the load, load voltage detection means for detecting the voltage of the load connected to the output terminal, for example, a battery to be charged, and the load voltage corresponding to the output voltage setting value selected by the switching means A first feature is that load determining means for enabling the output of the rectifier circuit to start when the load voltage is within the set load voltage range is provided.

  Further, the present invention warns when the load determination means does not determine that the load voltage is within the load voltage range set corresponding to the output voltage set value selected by the switching means. There is a second feature in that a display means is provided.

  In the present invention, a plurality of the output windings are wound independently on the same iron core, and the rectifier circuit is composed of a rectifier element with a control terminal provided corresponding to the plurality of output windings. A third feature is that control means for controlling the output voltage of each of the rectifier circuits to converge to the selected output voltage set value as a target value is provided.

  According to the present invention having the first feature, the connected load voltage, for example, the voltage of the battery connected as the load is in a predetermined range with respect to the output voltage set value selected by the changeover switch. The output can be supplied from the rectifier circuit to the load only when Therefore, output does not start with mismatched output voltage and load voltage.For example, when the load is a battery, the battery is charged with an output voltage that does not match the battery even if the changeover switch is operated incorrectly. It is possible to prevent overcharging and insufficient charging.

  According to the second feature, when the load voltage is not within a predetermined range with respect to the output voltage setting value, a mismatch between the output voltage setting value and the load voltage is easily recognized by a warning light or a warning sound. it can. Therefore, the person who operates the generator can take appropriate measures such as switching the changeover switch or replacing the battery to be connected.

  According to the third feature, in the configuration in which a relatively large current and low voltage output is connected to the load, the output of the generator is appropriately switched according to the load, or an appropriate load is connected to the output of the generator. It can be done.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a main part of a portable generator according to an embodiment of the present invention. In FIG. 1, the stator 1 of the generator body includes four independent output windings L1, L2, L3, and L4 and an auxiliary winding L5 that is independent of these output windings L1 to L4. It is configured by winding around a salient pole of one stator core (not shown). The output windings L1 to L4 have the same number of turns and wire diameter. That is, it is the same specification.

  A rotor (not shown) is provided on the outer periphery of the stator 1. The rotor has a plurality of magnets arranged in an annular shape, and is a so-called outer rotor. This rotor is connected to a drive source (here, an engine is assumed), and is driven to rotate along the outer periphery of the stator 1.

  The output windings L1 to L4 are respectively connected to three-phase rectification bridge circuits 2, 3, 4, and 5 configured by thyristors (rectifier elements with control terminals) and diodes. The symbols in the drawings showing the thyristor and the diode are well known, and are not denoted by reference numerals in order to avoid complication of the drawing. Smoothing capacitors 6, 7, 8, and 9 are provided on the output sides of the three-phase rectifier bridge circuits 2 to 5, respectively. The plus side output lines of the three-phase rectifier bridge circuits 2 to 5 are integrated into one and connected to the plus side output terminal 10, and the minus side output line is integrated into one and connected to the minus side output terminal 11.

  Shunts 12, 13, 14, and 15 are provided at positions before the integration of the positive output lines into one. The potential difference between both ends of each of the shunts 12 to 15 is input to a microcomputer, that is, a controller (see FIG. 2) 16 as a signal indicating the output currents Id1, Id2, Id3, and Id4 of the three-phase rectifier bridge circuits 2 to 5. The potential difference between both ends of each of the capacitors 6-9 is input to the controller 16 as the output voltages Vd1, Vd2, Vd3, Vd4 of the three-phase rectifier bridge circuits 2-5.

  A fuse 17 is provided at a position integrated with each of the positive output lines. The fuse 17 is provided by selecting one that allows the maximum value of the sum of the output currents of the three-phase rectifier bridge circuits 2 to 5. In addition, the positive output line integrated into one line between at least one of the four output lines on the upstream side of the fuse 17 and the four negative output lines (two examples are shown in FIG. 1). Is provided with a diode 18. For example, when the battery 19 serving as a load is erroneously connected in positive and negative directions by the diode 18, the current from the load side flows between the output lines integrated into one via the diode 18. Therefore, the current from the reversely connected load is prevented from flowing into the three-phase rectifier bridge circuits 2 to 5 having a smaller allowable current than that of the output line.

  A battery 19 and a UPS 20 are connected to the positive and negative output terminals 10 and 11, and an output side of the UPS 20 is connected to an electronic device (not shown) such as a computer system. For example, a commercial AC power source 21 is connected to the UPS 20, and the battery 19 is always charged (float charged) using the commercial AC power source 21. The portable generator of the present embodiment is connected to the USP 20, and the commercial AC power supply 21 supplies power to the USP 20 and the battery 19 at the time of a power failure or the like. The battery 19 is configured so that different rated voltages, for example, 48 volts and 36 volts can be connected.

  FIG. 2 is a connection diagram of the controller and its surroundings. The auxiliary winding L5 is connected to the constant voltage circuit 22. The constant voltage circuit 22 includes positive and negative (plus 5 volts and minus 5 volts) three-terminal regulators 221 and 222, and generates a DC power supply voltage of 5 volts each positive and negative stabilized based on the voltage of the auxiliary winding L5. . This DC power supply voltage is used as a power supply for the controller 16. The output waveform of the auxiliary winding L5 is supplied to the controller 16 as a signal for detecting the rotation of the rotor of the generator body. The controller 16 is connected to an EEP-ROM 23 for storing data used by the controller 16.

  The controller 16 outputs thyristor control signals (gate pulses) 16a, 16b, and 16c for ON / OFF control of the thyristors of the three-phase rectifier bridge circuits 2, 3, 4, and 5. The gate pulses 16a to 16c are supplied to the gate terminal, that is, the control terminal of each thyristor. The three-phase rectifier bridge circuits 2 to 5 include three thyristors corresponding to the U, V, and W phases of the output windings L1 to L4, and the thyristors corresponding to the respective phases are the three-phase rectifier bridge circuits 2 to 2. 5 is controlled by these gate pulses 16a to 16c which are common to the five. Therefore, the three-phase rectifier bridge circuits 2 to 5 are controlled in synchronization with each other by the gate pulses 16a to 16c.

  The controller 16 outputs motor drive signals 16d, 16e, 16f, and 16g to the stepping motor in order to control opening / closing of the throttle valve of the engine that drives the outer rotor by a stepping motor (not shown).

  The output switch 24 is a switch for stopping the power generation output of the portable generator in the present embodiment. When the output switch 24 is continuously pressed for a predetermined time, the gate pulses 16a to 16c are stopped by the ON signal 16h of the switch. The power output is stopped. However, the power generation output is merely stopped, and the engine is not stopped only by operating the output switch 24.

  The voltage changeover switch 25 is a switch for setting an output voltage according to a connected load (battery 19 or the like). For example, when the voltage changeover switch 25 is on (the changeover signal 16i is on), the output voltage is set to 36 volts, and when the voltage changeover switch 25 is off (the changeover signal 16i is off), the output voltage is 48 volts. Is set.

  An output indicator lamp 26, an overload indicator lamp 27, and an oil alert indicator lamp 28 are provided. The oil alert indicator lamp 28 is connected to the controller 16 via an oil alert circuit 29. The output indicator lamp 26 is turned on during the generation power output. The overload indicator lamp 27 is lit when overloaded, that is, overcurrent or overvoltage.

  A circuit unit (tramag circuit) 30 of the transistor type magnet ignition device is provided. A well-known thing can be used for the principal part of a transistor type magnet ignition device. The ground wire of the tramag circuit 30 is connected to that of the oil alert circuit 29 and is connected to the terminal G of the controller 16. The other wire of the tramag circuit 30 is connected to the coil portion 31 of the ignition device. A spark plug 32 is connected to the secondary side of the coil portion 31. The other terminal of the oil alert circuit 29 is connected to the terminal LS of the controller 16. The terminal G and the terminal LS of the controller 16 are configured to be short-circuited inside the controller 16 in order to stop ignition.

  The operation of the generator body will be described. The start is performed using a recoil starter connected to an engine which is a drive source of the generator body. When the recoil starter is pulled, the crankshaft of the engine is rotated, and the auxiliary coil L5 generates a voltage. The constant voltage circuit 22 forms a predetermined voltage by this voltage. The controller 16 can start control when this voltage is applied.

  When the engine is rotated by the recoil starter, the ignition device ignites the engine and starts the generator. Windings L1 to L4 and L5 of the generator main body start power generation, and the generated power is integrated and output as output power from output terminals 10 and 11. This electric power is supplied to the battery 19 and the UPS 20.

  When the generated power is being output, the output indicator lamp 26 is energized. Further, the overload indicator lamp 27 is energized in the case of overcurrent or overvoltage. Further, when it is determined by a well-known method that the engine oil has decreased below the reference value, the oil alert circuit 29 is activated and the oil alert indicator lamp 28 is energized. For example, the oil alert circuit 29 is a switching circuit configured such that a current flows through the oil alert indicator lamp 28 in response to a signal from the terminal LS. Furthermore, when oil decreases or when a power generation system described later is abnormal, the controller 16 short-circuits the terminal LS and the terminal G inside the controller 16 to stop ignition.

  In the present embodiment, the outputs of the four power generation units (power supply units) including the windings and the rectifier circuit are thus integrated, that is, superimposed to obtain a final output. The following control means is provided so that it is convenient to charge the battery 19 having different voltage specifications by this output.

  FIG. 3 is a block diagram illustrating the function of the controller 16 for supplying an output that conforms to the battery voltage specification. Since the three-phase rectifier bridge circuits 2 to 5 are controlled simultaneously, the three-phase rectifier bridge circuit 2 will be described below as a representative. In the voltage setting unit 33, a target value Vref of the output voltage Vd1 of the three-phase rectification bridge circuit 2 is set in advance. The target value Vref is switched according to the switching of the voltage switch 25. Here, an example is given in which either 36 volts or 48 volts can be selected, but the present invention is not limited to this two-stage setting. The output control device 34 outputs a gate pulse for controlling the thyristor of the three-phase rectifier bridge circuit 2 so that the output voltage Vd1 of the three-phase rectifier bridge circuit 2 matches the target value Vref supplied from the voltage setting unit 33.

  The load discriminating unit 35 compares the voltage (load voltage) VL of the battery 19 as a load charged by the three-phase rectifier bridge circuit 2 with the target value Vref of the voltage set in the voltage setting unit 33, and the load voltage It is determined whether VL is within a predetermined range (described later) with reference to the target value Vref. Although the voltages Vd1 and VL are the same voltage, the voltage after the three-phase rectifier bridge circuit 2 starts output is represented as voltage Vd1, and the battery 19 is connected and the three-phase rectifier bridge circuit 2 outputs the voltage. The voltage when not started is represented as voltage VL. The load determination unit 35 permits the output control device 34 to output when the key switch (main switch) 36 is switched to the output start position and the load voltage VL is within a predetermined range with respect to the voltage target value Vref. Supply.

  As a result of the load determination unit 35 determining the load voltage VL, when the load voltage VL is within a predetermined range with respect to the target value Vref, the three-phase rectifier bridge circuit 2 permits the start of output, and is within the predetermined range. If not, output is prohibited, but a device is also provided that allows the operator to easily recognize the determination result.

  FIG. 4 is a diagram illustrating an example of display based on the determination result of the load determination unit 35. In the figure, the abnormal indicator lamp may be dedicated for displaying the load determination result, but in order not to increase the number of indicator lamps, for example, the overload indicator lamp 27 can be used. Is preferred. Hereinafter, the abnormality indicator lamp will be described as the overload indicator lamp 27.

  When the target value Vref is 36 volts, that is, when the changeover switch 25 is switched to the 36 volts side, the operation is as follows. When the load voltage VL is 20 volts or less, the output is prohibited and both the output indicator lamp 26 and the overload indicator lamp 27 are turned off. Further, when the load voltage VL is in the range of 27 volts to less than 42, the output of the three-phase rectifier bridge circuit 2 is permitted. In this case, the output indicator lamp 26 is turned on and the overload indicator lamp 27 remains off. Further, when the load voltage VL is in the range of 42 volts to 55 volts, the output of the three-phase rectifier bridge circuit 2 is prohibited. In this case, the output indicator lamp 26 is turned off and the overload indicator lamp 27 is blinked for warning.

  On the other hand, when the target value Vref is 48 volts, that is, when the changeover switch 25 is switched to the 48 volt side, the following takes place. When the load voltage VL is 20 volts or less, the output is prohibited and both the output indicator lamp 26 and the overload indicator lamp 27 are turned off. The output of the three-phase rectifier bridge circuit 2 is also prohibited when the load voltage VL is in the range of 27 volts to less than 42 volts. Then, the output indicator lamp 26 is turned off, and the overload indicator lamp 27 is blinked for warning. Further, when the load voltage VL is in the range of 42 volts to 55 volts, the output of the three-phase rectifier bridge circuit 2 is permitted. Then, the output indicator lamp 26 is turned on, and the overload indicator lamp 27 is turned off.

  When the load voltage VL does not fall within any of the above ranges regardless of the position of the changeover switch 25, the output indicator lamp 26 remains off and the overload indicator lamp 27 flashes for warning. Let

  The voltage range described above is set in view of the following points. First, the battery 19 obtains a desired voltage by a plurality of batteries. For example, a unit of 48 volts uses four unit batteries and a unit of 36 volts uses three unit batteries in series. In consideration of the lifetime, each unit battery is preferably used so as not to be discharged to 10.5 volts or less. Therefore, the lowest voltage of the usable 48-volt battery 19 is 42 volts (= 10.5 volts × 4). When this minimum voltage of 42 volts is applied to a 36-volt battery 19 composed of three unit batteries, the voltage of the unit battery per battery is 14 volts (= 42 volts / 3). That is, in the case of the battery 19 of 36 volts, if the maximum voltage is 42 volts, the voltage of the unit battery is 14 volts, which does not greatly exceed the float charging voltage range (13.6 volts) according to USP20. Therefore, the load voltage VL of the 36-volt battery 19 and the 48-volt battery 19 is determined with the 42 volts as a boundary.

  The minimum voltage (27 volts) in the voltage range of the 36 volt battery 19 and the maximum voltage (55 volts) of the 48 volt battery 19 are set so as not to be undercharged and overcharged, respectively.

  The voltage range is preferably based on the above-mentioned criteria, but is not limited to this specific value. In short, when the output voltage can be set by the changeover switch, it is only necessary to provide a reference so that the set voltage matches the voltage of the connected load. Further, the warning when the two voltages do not match is not limited to that by an indicator lamp, but may be guidance by a buzzer or electronic synthesized sound.

  In the present embodiment, the present invention has been described by taking as an example a portable generator provided with a plurality of power supply units including a plurality of independent windings and a plurality of rectifier circuits corresponding thereto. However, the present invention is not limited to the number of power supply units. Further, the plurality of rectifier circuits are controlled in synchronization with a single thyristor control signal. However, the present invention is not limited to this, and the rectifier circuit may be controlled with individual thyristor control signals.

It is principal part connection drawing (the 1) of the portable generator which concerns on one Embodiment of this invention. It is a principal part connection diagram (the 2) of the portable generator which concerns on one Embodiment of this invention. It is a block diagram which shows the principal part function of the control part of the portable generator which concerns on one Embodiment of this invention. It is a figure which shows an example of the generator output by the relationship between a load voltage and an output voltage setting value, and a display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Generator main body, 2-5 ... Three-phase rectification bridge circuit, 19 ... Load (battery), 25 ... Changeover switch, 33 ... Voltage setting part, 34 ... Output control device, 35 ... Load discrimination | determination part, 36 ... Key switch

Claims (2)

In the portable generator that converts the alternating current output from the output winding of the generator into direct current with a rectifier circuit and outputs it to the output terminal,
A plurality of the output windings are wound independently of each other on the same iron core;
The rectifier circuit includes rectifier elements with control terminals provided corresponding to the plurality of output windings, respectively .
Switching means for selecting an output voltage set value of the rectifier circuit;
Control means for controlling the output voltage of each of the rectifier circuits to converge to the selected output voltage set value as a target value;
Load voltage detecting means for detecting a voltage of a battery to be charged, which is a load connected to the output terminal;
Load discriminating means for enabling the output of the rectifier circuit to start when the voltage of the battery is within a load voltage range set corresponding to the output voltage set value selected by the switching means. A portable generator featuring the characteristics.   Display means for giving a warning when the load determination means does not determine that the load voltage is within the load voltage range set corresponding to the output voltage set value selected by the switching means. The portable generator according to claim 1, wherein

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