JP2014087212A - Multi-voltage generator - Google Patents

Abstract

An object of the present invention is to be able to freely supply various kinds of electric power of arbitrary voltage required for a vehicle.
A motor generator is connected to an engine. A storage battery is connected to the motor generator via an inverter and a switch. When a DC voltage is required, the switch 17 between the storage battery 18 and the inverter is disconnected and the necessary voltage is supplied from the engine 11 by phase control. When a DC voltage is necessary, the necessary voltage is supplied from the storage battery 18 or the engine 11 by phase control. In this way, a wide variable voltage can be output to the outside whether it is direct current or alternating current.
[Selection] Figure 1

Description

  The present invention relates to a multi-voltage generator used for general-purpose machines such as agricultural machines and mowers.

  In recent years, the movement of regulating exhaust gas has become a social trend from the viewpoint of regulating exhaust gas including greenhouse gases. In response to this movement, development of hybrid cars and electric cars is underway. On the other hand, a conventional mower and agricultural machine uses a diesel engine as a power source, and a radiator, a muffler, etc. are arranged around the engine, and a transmission is provided to transmit the power to a necessary part. However, the conventional agricultural machine using an engine as a power source has a drawback that many parts such as an engine and a muffler are required, resulting in an increase in manufacturing cost.

  In order to solve this problem, Patent Document 1 proposes an agricultural machine with electric power. As a power source for supplying to the load of the agricultural machine, for example, one that outputs a three-phase AC voltage at 200V is known.

JP 2003-9607 A

  However, the specifications of voltage and the like required for each machine are not constant. For this reason, there has been a problem that it is difficult to supply a necessary voltage to various types of impules when operating various types of impules used in agricultural machinery or the like using a general-purpose power source.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a multi-voltage generator that can be used as a power source for general-purpose machines such as agricultural machines and mowers.

  In order to solve this problem, a multi-voltage generator according to the present invention includes an engine, a three-phase motor generator connected to the engine, and the motor generator, which converts three-phase AC and DC to each other. An inverter, a storage battery connected to a DC terminal of the inverter via a switch, an operation unit for inputting a type of power supply and a necessary voltage value, an output from the engine or from the storage battery according to a voltage level And a controller for controlling the number of revolutions of the inverter and the type of voltage to be output for any one of the outputs.

  Here, when the controller outputs a DC voltage different from the voltage of the storage battery, the motor generator is driven by the engine, and the inverter is phase-controlled to generate a necessary DC voltage and output it to the outside. In the AC voltage output, the motor generator may be driven based on the output from the storage battery or by the engine, and the inverter may be phase-controlled to output the AC voltage to a necessary output.

According to the present invention having such a feature, the multi-voltage generator according to the present invention can be used as a power source having different types of DC and AC, and the problem with the power source can be solved. Accordingly, it is possible to electrify the impul that becomes a load of the agricultural machine or the like. Further, according to the present invention, since one inverter is used, there is an effect that the price can be reduced.

FIG. 1 is a block diagram showing the overall configuration of a multi-voltage generator according to an embodiment of the present invention. FIG. 2 is a block diagram showing an inverter and its peripheral circuit according to the embodiment of the present invention.

  FIG. 1 is a block diagram showing the overall configuration of a multi-voltage generator according to an embodiment of the present invention. As shown in the figure, this multi-voltage generator has an engine 11. The power of the engine 11 drives the motor generator (MG) 12 to rotate. The crankshaft of the engine 11 may be directly connected to the motor generator 12 or may be connected via a connecting means such as a belt.

  The motor generator 12 is a three-phase AC motor and generator, and supplies a three-phase AC corresponding to the number of rotations to the inverter 13 and outputs it from the connector 14 to the outside. In addition, the output of two of the three phases can be output from the connector 15 to the outside as a single-phase alternating current. The inverter 13 performs three-phase AC phase control, and a storage battery 18 is connected to a DC side terminal via a switch 17. The storage battery 18 is a secondary battery of 100 to 500 V, for example, and is used as a secondary battery of a generator system. The inverter 13 is connected to a controller 19 for defining its output. An operation unit 20 is connected to the controller 19. The operation unit 20 is for inputting the type of a DC, single-phase AC or three-phase AC power source and a necessary voltage. The inverter 13 performs phase control when a three-phase alternating current is input, rectifies and smoothes it to obtain a desired DC voltage, and performs phase control when a direct-current voltage is applied from the storage battery 18 to obtain a desired voltage. Outputs three-phase AC voltage.

  Next, details of the inverter 13 will be described. As shown in FIG. 2, in the inverter 13, a smoothing capacitor 32 is connected between input terminals 31a and 31b of a DC power source, and switching elements 33U and 34U, 33V and 34V and 33W, such as power MOSFETs, are connected to both ends thereof. 34W are connected in parallel as shown. A diode for preventing a backflow is connected to both ends of each switching element, and the midpoints of the switching elements 33U and 34U, the midpoints of 33V and 34V, and the midpoints of 33W and 34W are each of the motor generator 12 described above. Connected to the phases as shown in the figure.

  On the other hand, the controller 19 controls the switching timing of the six MOSFETs of the inverter connected between the stator coils to perform phase control, and controls the start of the engine 11 by rotating the motor generator 12.

Next, the operation of this embodiment will be described. First, the multi-voltage generator according to this embodiment has three operation modes. The first mode is a charging mode for the storage battery 18, the second mode is an engine mode for supplying power from the engine 11 to an external device, and the third operation mode is a storage battery for supplying power from the storage battery 18 to an external device. Mode. First, at the time of operation in the first charging mode, the controller 19 first drives the motor generator 12 and starts the engine 11 connected thereto. As a result, the power of the engine 11 is transmitted to the motor generator 12. By performing phase control of the inverter 13, a three-phase alternating current or a single-phase alternating current can be obtained. Then, a DC voltage having a slightly higher level than that of the storage battery 18 is generated by controlling the rotation speed and phase, and the switch 17 is turned on to charge the storage battery 18. Then, the battery voltage is recognized, and the charging operation is stopped when a predetermined voltage is reached.

  Next, when the type of electric power to be output to the operation unit 20, that is, any one of three-phase AC, single-phase AC, and DC voltage, and a voltage and frequency are input, this operation is performed in the second and third operation modes. The voltage generator 10 is operated. At this time, the operation is performed in one of the second and third modes according to the required voltage and the type thereof.

(1) DC voltage output higher than the storage battery voltage When a DC voltage higher than the storage battery 18 is requested from the outside via the operation unit 20, this voltage value is input to the controller 19. Since the third storage battery mode cannot output a higher DC voltage than when the storage battery is used as it is, the engine mode is used. The controller 19 drives the motor generator 12 to start the engine 11 and transmits the rotational force to the motor generator 12. Here, the rotational speed of the engine 11 is changed in accordance with a required voltage. A high DC voltage can be obtained by rectification by the inverter 13 and output to the outside from the connector 16. When outputting a voltage higher than that of the storage battery, the switch 17 is turned off. However, when a charger (not shown) is connected between the DC output connector 16 and the storage battery 18, the storage battery 18 may be charged at the same time by turning on the switch 17.

(2) DC voltage output equal to or lower than the storage battery voltage When a DC voltage having a level lower than that of the storage battery 18 is requested from the outside via the operation unit 20, this voltage value is input to the controller 19. Since the third storage battery mode cannot output a lower DC voltage than when the storage battery 18 is used as it is, the engine mode is used. Also in this case, by performing phase control in the inverter 13, a low voltage from 0 V to an arbitrary voltage level can be output. When a voltage lower than the voltage of the storage battery 18 is output to the outside, the switch 17 is turned off.

  When supplying substantially the same DC voltage as that of the storage battery, the engine 11 is stopped and the switch 17 is turned on to supply the DC voltage as it is from the storage battery 18.

(3) AC voltage output higher than the voltage of the storage battery In this case, both the second and third modes can be used. The second mode is used when the capacity of the storage battery 18 is reduced. In this case, the engine 11 is started, the motor generator 12 is driven based on the output from the engine 11, and the rotation speed is controlled. Then, by performing phase control, a voltage required for three-phase alternating current or single-phase alternating current can be output from the connector 14 or 15 to the outside.

  The third mode is suitable for use in a case where the capacity of the storage battery 18 is sufficient or in an environment where quietness is required. In the third mode, the switch 17 is turned on, and the output from the storage battery 18 is boosted by the inverter 13 to output three-phase alternating current or single-phase alternating current. Various voltages can be output to the outside by performing phase control of the inverter 13.

(4) AC voltage output lower than storage battery voltage In this case, both the second and third modes can be used. When the second engine mode is used, the switch 17 is turned off, the storage battery 18 is disconnected, the engine 11 is rotated, and the motor generator 12 is driven. Then, by performing phase control with the inverter 13 to obtain a necessary voltage, a low three-phase AC or single-phase AC voltage can be output to the outside from the connector 14 or 15.

The third mode is suitable for use in a case where the capacity of the storage battery 18 is sufficient or in an environment where quietness is required. In the third mode, when the voltage output from the storage battery is V _dc , a three-phase alternating current having a line voltage up to √3 / 2 · V _dc can be output.

  According to the present invention, various voltages can be output to the outside by using one inverter, an engine, and a storage battery. Therefore, the present invention can be suitably used for various industrial machines such as agricultural machines and lawn mowers.

DESCRIPTION OF SYMBOLS 11 Engine 12 Motor generator 13 Inverter 14,15,16 Connector 17 Switch 18 Storage battery 19 Controller 20 Operation part

Claims (2)

Engine,
A three-phase motor generator coupled to the engine;
An inverter that drives the motor generator to convert three-phase alternating current and direct current;
A storage battery connected to a DC terminal of the inverter via a switch;
An operation unit for inputting the type of power supply and the required voltage value;
A multi-voltage generator comprising: a controller that controls the rotation speed of the inverter and the type of voltage to be output for either one of the output from the engine or the output from the storage battery according to a voltage level. The controller is
When outputting a DC voltage different from the voltage of the storage battery, the motor generator is driven by the engine, and the inverter is phase-controlled to generate a necessary DC voltage and output it to the outside.
2. The multi-voltage generator according to claim 1, wherein the AC voltage output is based on an output from a storage battery, or the motor generator is driven by the engine, and the inverter is phase-controlled to output an AC voltage to a necessary output. .

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