WO2016151800A1 - Power generating device - Google Patents

Abstract

A power generating device is provided with a plurality of starter generators connected to a plurality of respective crankshafts drivingly connected so as to be rotatable synchronously with each other. The starter generators each have the same number of a plurality of phase coils, wherein the phase coils having the same phase in the plurality of starter generators are connected to each other. The power generating device is also provided with a power conversion unit shared by the plurality of starter generators.

Description

Power generator

The present invention relates to a power generation apparatus including a starter generator connected to an engine output shaft.

2. Description of the Related Art Conventionally, in addition to generating electricity by being rotationally driven by an engine output shaft, there is a power generator equipped with a starter generator that is also used as a starter motor that rotationally drives the engine output shaft when the engine is started. In such a power generator, when AC power from the system power supply is supplied to the starter generator, the frequency and voltage of the AC power are changed through a power conversion unit configured by an inverter or the like. Further, when the AC power generated by the starter generator is supplied to the system power supply, the generated AC power is converted into system power through the power conversion unit.

Also, there is an opposed piston engine in which a pair of pistons are accommodated in a cylinder so that their top surfaces face each other (see, for example, Patent Document 1). In the opposed piston engine, the reciprocating motion of the pair of pistons is converted into the rotational motion of the pair of crankshafts via the connecting rod. In the opposed piston engine described in Patent Document 1, the output shaft of one generator is connected to one crankshaft. Further, the rotation directions of the pair of crankshafts are set to be opposite to each other. The pair of crankshafts are connected to each other via an idle gear, a timing belt, or the like. When the pair of crankshafts are synchronously rotated in opposite directions, the inertial force and torque of the crankshafts cancel each other, and engine vibration is reduced.

Japanese Patent No. 5508604

By the way, in a power generator in which a starter generator is connected to a plurality of engine output shafts that are driven and connected to each other so as to be able to rotate synchronously as in the above-described opposed piston engine, a power conversion unit is provided for each starter generator. For this reason, there are problems that the number of parts constituting the power generation device increases, the size of the power generation device increases, and the cost increases.

An object of the present invention is to provide a power generation apparatus that can reduce the number of power conversion units as compared with the number of starter generators.

In order to achieve the above object, a power generator includes a plurality of starter generators connected to a plurality of engine output shafts that are driven and connected to each other so as to be synchronously rotatable with each other. A plurality of phase coils, and phase coils having the same phase in the plurality of starter generators are connected to each other, and the power generator is used in common for the plurality of starter generators. It has.

According to this configuration, a plurality of starter generators can be driven by controlling one power conversion unit, and a plurality of engine output shafts connected to these starter generators can be rotationally driven. For this reason, it is not necessary to provide a power conversion unit for each starter generator.

In this case, it is preferable that the phase coils having the same phase are connected in series with each other.
According to this aspect, it is possible to suppress the AC power supplied to the phase coil of each starter generator from becoming unstable, and to reduce the phase shift of the rotating magnetic field and the torque difference of each starter generator. it can. Therefore, engine vibration can be effectively reduced.

According to the present invention, the number of power conversion units can be made smaller than the number of starter generators.

The perspective view of the engine to which the said apparatus is applied about one Embodiment of an electric power generating apparatus. (A) is a schematic diagram centering on gears interposed between crankshafts, (b) is a cross-sectional view showing a plurality of gears interposed between crankshafts. The circuit diagram of the electric power generating apparatus of the embodiment. The schematic diagram which shows the winding state of the phase coil of the starter generator of the embodiment.

Hereinafter, an embodiment will be described with reference to FIGS.
First, the configuration of an opposed piston engine (hereinafter abbreviated as the engine 30) to which the power generation apparatus 10 is applied will be described.

As shown in FIG. 1, the engine 30 includes a block 38 having two cylinders 31 arranged in parallel to each other. In each cylinder 31, a pair of pistons 32A and 32B are accommodated, and the top surfaces of these pistons 32A and 32B are opposed to each other.

In the block 38, an intake port 35 and an exhaust port 36 communicating with each cylinder 31 are formed. The block 38 is provided with an intake valve (not shown) for switching the communication between the intake port 35 and the cylinder 31 corresponding to each cylinder 31. Further, the block 38 is provided with an exhaust valve (not shown) corresponding to each cylinder 31 for switching between communication and shutoff between the exhaust port 36 and the cylinder 31. Each block 31 is provided with a spark plug 37 for igniting an air-fuel mixture in which air sucked through the intake port 35 and fuel injected from a fuel injection valve (not shown) are mixed. Yes.

One end of a connecting rod 33A, 33B is connected to each piston 32A, 32B, a crankshaft 34A is connected to the other end of the two connecting rods 33A, and a crankshaft 34B is connected to the other end of the two connecting rods 33B. Are connected.

As shown in FIGS. 1 and 2A, output shafts 21A and 21B of starter generators 20A and 20B are connected to one ends of crankshafts 34A and 34B, respectively.
As shown in FIGS. 2A and 2B, gears 41A and 41B are fixed to the outer peripheral surfaces of the output shafts 21A and 21B, respectively. A plurality of gears 42, 43, 44, 45 that mesh with each other are interposed between the gears 41A, 41B. These gears 41A, 42, 43, 44, 45, 41B meshing with each other drive-couple the two crankshafts 34A, 34B in opposite directions and in a synchronous manner.

In such an engine 30, when the air-fuel mixture is ignited by the spark plug 37, the air-fuel mixture burns and the pair of pistons 32 </ b> A and 32 </ b> B move in the directions away from each other in the cylinders 31 due to the combustion pressure. . The reciprocating linear motion of the pistons 32A and 32B is converted into rotational motion of the pair of crankshafts 34A and 34B via the connecting rods 33A and 33B.

Next, the configuration of the power generation device 10 will be described.
As shown in FIG. 3, the system power supply 11 is a three-phase AC power supply, and the power conversion unit 12 is connected to the system power supply 11 via first connection lines 15 u, 15 v, and 15 w. The power conversion unit 12 performs AC / AC conversion. Specifically, when power generation is performed by both starter generators 20A and 20B, the generated AC power is converted into system power. In addition, the power generation apparatus 10 includes a control unit 13 that controls the power conversion unit 12. The control part 13 is a processor provided with CPU, RAM, and ROM, for example.

The power converter 12 is connected to first ends of a plurality of phase coils 24uA, 24vA, 24wA provided in the first starter generator 20A via second connection lines 16u, 16v, 16w, respectively. As shown in FIG. 4, the first starter generator 20A includes a cylindrical stator 22A and a rotor 23A inserted in the stator 22A, and phase coils 24uA, 24vA, and 24wA are respectively provided on teeth of the stator 22A. It is wound. The rotor 23A is connected to the output shaft 21A of the first starter generator 20A.

As shown in FIGS. 3 and 4, the first ends of the plurality of phase coils 24uB, 24vB, 24wB provided in the second starter generator 20B are connected to the second ends of the phase coils 24uA, 24vA, 24wA. They are connected via lines 17u, 17v, and 17w, respectively. As shown in FIG. 4, the second starter generator 20B has the same structure as the first starter generator 20A, and includes a stator 22B and a rotor 23B. The phase coils 24uB, 24vB, and 24wB are wound around the teeth of the stator 22B. The rotor 23B is connected to the output shaft 21B of the second starter generator 20B.

The second ends of the three phase coils 24uB, 24vB, 24wB are connected to each other, and a neutral point n is formed.
That is, in the present embodiment, the phase coils 24uA, 24vA, 24wA of the first starter generator 20A have the same phase in the second starter generator 20B via the third connection lines 17u, 17v, 17w. 24vB and 24wB are connected in series.

The power converter 12 includes, for example, a first inverter 12a connected to the first connection lines 15u, 15v, 15w, a second inverter 12b connected to the second connection lines 16u, 16v, 16w, and both inverters 12a, 12b. And a capacitor C connected in parallel to both inverters 12a and 12b. Each inverter 12a, 12b includes switching elements Qa, Qb and freewheeling diodes Da, Db connected in parallel to the switching elements Qa, Qb. Note that when the switching elements Qa and Qb are, for example, IGBTs or power MOSFETs, these parasitic diodes may be used as the free-wheeling diodes Da and Db.

The control unit 13 performs desired power conversion by controlling the switching elements Qa and Qb of the inverters 12a and 12b.
For example, when starting the engine 30, the control unit 13 drives the switching element Qb of the second inverter 12b.

Further, the control unit 13 turns off the switching element Qb of the second inverter 12b when the starter generators 20A and 20B are generating electric power due to the engine 30 being completely exploded and operating independently. .

Note that the control unit 13 always drives the switching element Qa of the first inverter 12a regardless of when the engine 30 is started and when both starter generators 20A and 20B generate power.

Further, the control unit 13 detects the rotation speeds of the crankshafts 34A and 34B for each predetermined period through a rotation sensor (not shown), and determines that the engine 30 has completely exploded when the rotation speed exceeds a predetermined rotation speed. .

Next, the operation of this embodiment will be described.
When starting the engine 30, the power conversion unit 12 is controlled as described above, whereby AC power is generated using the electric charge stored in the capacitor C, and the AC power is converted into both starter generators 20 </ b> A, 20B. Thereby, both starter generators 20A and 20B are rotationally driven in synchronization. That is, both starter generators 20A and 20B are rotationally driven in a state where the electrical angles are aligned with each other.

Thereafter, when the engine 30 completes explosion and shifts to a self-sustaining operation, the supply of AC power using the electric charge of the capacitor C is stopped. Then, by controlling power conversion unit 12 as described above, AC power generated by both starter generators 20A and 20B is converted into system power by power conversion unit 12. In this case, the capacitor C smoothes the DC power converted by the freewheeling diode Db of the second inverter 12b.

According to the power generator according to the present embodiment described above, the following effects can be obtained.
(1) Each starter generator 20A, 20B has a plurality (three) of phase coils 24uA, 24vA, 24wA, 24uB, 24vB, 24wB. The plurality of phase coils of each starter generator 20A, 20B have different phases. In the plurality of starter generators 20A and 20B, phase coils having the same phase, that is, phase coils 24uA and 24uB, phase coils 24vA and 24vB, and phase coils 24wA and 24wB are connected to each other. The power generation apparatus 10 includes a power conversion unit 12 that is commonly used for the plurality of starter generators 20A and 20B.

According to such a configuration, the two starter generators 20A and 20B can be driven by controlling one power conversion unit 12 common to the two starter generators 20A and 20B. For this reason, it is not necessary to provide the power converter 12 for each starter generator 20A, 20B. Therefore, the number of power conversion units 12 can be made smaller than the number of starter generators 20A and 20B. Therefore, it can suppress that the physique of the electric power generating apparatus 10 becomes large, or cost increases.

(2) The phase coils 24uA, 24vA, 24wA of the first starter generator 20A are connected in series with the phase coils 24uB, 24vB, 24wB having the same phase in the second starter generator 20B.

According to such a configuration, it is possible to suppress the AC power supplied to the phase coils 24uA, 24vA, 24wA, 24uB, 24vB, and 24wB of the starter generators 20A and 20B from becoming unstable, and the rotating magnetic field The phase shift and the torque difference between the starter generators 20A and 20B can be reduced. Therefore, the vibration of the engine 30 can be effectively reduced.

<Modification>
In addition, the said embodiment can also be changed as follows, for example.
For example, in the case of an engine having four crankshafts, a starter generator may be provided for each of the four crankshafts, and phase coils of the same phase in these four starter generators may be connected in series with each other.

The system power supply 11 can be changed to a single-phase AC power supply.
For example, in an in-vehicle engine, a storage battery may be employed instead of the capacitor C, and the system power supply 11 and the first inverter 12a may be omitted. In this case, a power conversion unit that converts the DC power input from the storage battery into AC power and supplies it to the two starter generators 20A and 20B may be employed. Specifically, a DC / DC converter may be employed instead of the first inverter 12a.

-Phase coils of a plurality of starter generators can be connected in parallel to each other.
The first starter generator 20A of the embodiment has a so-called three-phase structure having three phase coils 24uA, 24vA, and 24wA, but is not limited thereto, and may be two-phase. The same applies to the second starter generator 20B.

DESCRIPTION OF SYMBOLS 10 ... Power generation device, 11 ... System power supply, 12 ... Power conversion part, 12a ... 1st inverter, 12b ... 2nd inverter, Qa, Qb ... Switching element, Da, Db ... Freewheeling diode, C ... Capacitor, 13 ... Control part 15 ... first connection line, 16 ... second connection line, 17 ... third connection line, 20A ... first starter generator, 20B ... second starter generator, 21A, 21B ... output shaft, 22A, 22B ... stator, 23A , 23B ... rotor, 24uA, 24uB, 24vA, 24vB, 24wA, 24wB ... phase coil, 30 ... engine, 31 ... cylinder, 32A, 32B ... piston, 33A, 33B ... connecting rod, 34A, 34B ... crankshaft (engine output) Shaft), 35 ... intake port, 36 ... exhaust port, 37 ... spark plug, 38 ... block 41A, 41B ... gear, 42-45 ... gear.

Claims (2)

1. In a power generator including a plurality of starter generators coupled to a plurality of engine output shafts that are driven and coupled to each other so as to be synchronously rotatable,
   Each of the starter generators has the same number of phase coils.
   In the plurality of starter generators, phase coils having the same phase are connected to each other,
   The power generation device includes a power conversion unit that is commonly used for a plurality of the starter generators.
   Power generation device.
2. The phase coils having the same phase are connected in series with each other,
   The power generation device according to claim 1.

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