WO2017159435A1 - Three-phase ac power source apparatus - Google Patents

Three-phase ac power source apparatus Download PDF

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Publication number
WO2017159435A1
WO2017159435A1 PCT/JP2017/008868 JP2017008868W WO2017159435A1 WO 2017159435 A1 WO2017159435 A1 WO 2017159435A1 JP 2017008868 W JP2017008868 W JP 2017008868W WO 2017159435 A1 WO2017159435 A1 WO 2017159435A1
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Prior art keywords
phase
current
distribution line
load
series circuit
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PCT/JP2017/008868
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French (fr)
Japanese (ja)
Inventor
三野　和明
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株式会社村田製作所
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Publication of WO2017159435A1 publication Critical patent/WO2017159435A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output

Definitions

  • the present invention relates to a three-phase AC power supply device including a three-phase AC generator.
  • Patent Document 1 in a configuration in which a single-phase load is connected to each phase of a three-phase AC power supply, an inverter circuit is provided to supply a current from a phase with a small load current to a phase with a large load current. Is disclosed. This patent document 1 makes it possible to balance the current flowing in each phase by reducing the unbalance of the phase current of the three-phase current.
  • Patent Document 1 since the inverter circuit is always driven to constantly balance the phase current, power consumption by the inverter circuit is large, and heat generation of the inverter circuit is large, so heat dissipation is considered. There is a need. Therefore, when a heat dissipation mechanism is provided, there is a problem that the apparatus becomes large.
  • an object of the present invention is to provide a three-phase AC power supply apparatus that can be reduced in size by reducing power consumption and suppressing heat generation.
  • the three-phase alternating current power supply device is a three-phase alternating current in which a first load is connected to the first phase distribution line, a second load is connected to the second phase distribution line, and a third load is connected to the third phase distribution line.
  • Supply current excess determining means for determining whether any of the current exceeds the rated current, the distribution line of the phase through which the supply current determined by the supply current excess determining means exceeds the rated current, and the other two-phase Current supply means for forming a current path between at least one of the distribution lines.
  • At least one of the distribution line of the phase (hereinafter sometimes referred to as “one distribution line”) through which the supply current determined by the supply current excess determination means exceeds the rated current and the other two-phase distribution lines is provided.
  • a current path By configuring a current path with one, a part of the current flowing in one of the connected distribution lines is supplied to the other, or conversely, a part of the current is supplied from the other.
  • the part which exceeds a rated current among the electric currents which flow through one distribution line can be supplemented with the electric current which flows into the distribution line of another phase.
  • the three-phase AC generator does not need to be driven so that a current exceeding the rated current is output, and fuel consumption can be suppressed.
  • the control by the current supply means is performed after exceeding the rated current, the power consumption can be suppressed as compared with the case where the control is always performed, and as a result, the fuel consumption can be suppressed.
  • the control since the control is not always performed, heat generation of the control unit can be suppressed.
  • the current supply means includes a plurality of switching elements connected in series, a connection point of the first series circuit connected to the first phase distribution line, a connection point of the plurality of switching elements of the first series circuit, A first choke coil provided between the first phase distribution line and a plurality of switching elements are connected in series, and a connection point of the first choke coil is connected to the second phase distribution line, and the second series A second choke coil provided between a connection point of the plurality of switching elements of the circuit and the second phase distribution line and a plurality of switching elements are connected in series, and the connection point is connected to the third phase distribution line.
  • a third choke coil provided between the third series circuit to be connected, a connection point of the plurality of switching elements of the third series circuit, and the third phase distribution line, the first series circuit, the first 2 Control means for controlling switching of each switching element of the column circuit and the third series circuit, and the first series circuit, the second series circuit, and the third series circuit may be connected in parallel. .
  • Switching elements of each of the first series circuit, the second series circuit, and the third series circuit are provided in a common heat sink, and the control means is a switching element connected to a phase in which a supply current exceeding a rated current flows.
  • the switching control may be performed on the switching element provided at the most thermally separated position.
  • heat concentration can be suppressed, the failure rate of switching elements can be reduced, the service life can be extended, and the cooling parts such as heat sinks and fans can be downsized.
  • the switching elements of the first series circuit, the second series circuit, and the third series circuit are provided at equal intervals on a common heat sink, and the control means is connected to the other two-phase distribution line. Each switching element may be subjected to switching control.
  • This configuration can prevent the heat generated by the switching element from being concentrated locally.
  • the control means may alternately control switching between a switching element connected to one of the other two-phase distribution lines and a switching element connected to the other of the other two-phase distribution lines.
  • This configuration can prevent the heat generated by the switching element from being concentrated locally.
  • the current supply means performs control after the rated current is exceeded, the inverter circuit is not always driven. Therefore, power consumption can be suppressed. Further, heat generation of the inverter circuit can be suppressed. Therefore, the heat dissipation mechanism can be reduced, which can contribute to the downsizing of the device.
  • FIG. 1 is a diagram illustrating a three-phase AC power supply apparatus according to the first embodiment.
  • FIG. 2 is a circuit diagram of the three-phase AC power supply device.
  • FIG. 3 is a diagram illustrating a waveform of a load current and a waveform of a current equal to or lower than the rated current per phase.
  • FIG. 4 is a diagram showing a current path of the three-phase AC power supply device at timing (I) in FIG.
  • FIG. 5 is a diagram illustrating a current path of the three-phase AC power supply device at timing (II) in FIG.
  • FIG. 6 is a diagram showing the current value of each phase of the generator that changes with time.
  • FIG. 7 is a diagram illustrating a structure of a three-phase AC power supply device.
  • FIG. 1 is a diagram illustrating a three-phase AC power supply apparatus according to the first embodiment.
  • FIG. 2 is a circuit diagram of the three-phase AC power supply device.
  • FIG. 3 is a diagram
  • FIG. 8 is a flowchart of processing executed by the control unit.
  • FIG. 9 is a diagram illustrating a current path of the three-phase AC power supply device.
  • FIG. 10 is a diagram showing the current value (amplitude value) of each phase of the generator that changes with time.
  • FIG. 11 is a diagram showing the current value (amplitude value) of each phase of the generator that changes with time.
  • FIG. 1 is a diagram showing a three-phase AC power supply device 1 according to the present embodiment.
  • the three-phase AC power supply 1 generates power using a heat engine generator and supplies it to each power consumer.
  • Loads 11, 12, and 13 illustrated in FIG. 1 are electric power consumers and the like to which electric power is supplied from the three-phase AC power supply device 1.
  • the three-phase AC power supply device 1 includes a diesel engine 2, a generator (motor generator) 3 connected to the diesel engine 2 via a shaft mechanism 2A, current detection circuits 4A, 4B, 4C, and a load current supply circuit 5.
  • the control unit 6 is provided.
  • the generator 3 is an example of the “three-phase AC generator” according to the present invention.
  • the generator 3 is a three-phase AC generator using a diesel engine 2 as a drive source.
  • the drive source of the generator 3 may be a gasoline engine, a gas turbine engine, or the like.
  • Loads 11, 12, and 13 are connected to distribution lines of each phase (R phase, T phase, and S phase) of the generator 3.
  • a load 11 is connected to the R-phase distribution line of the generator 3.
  • a load 12 is connected to the T-phase distribution line of the generator 3.
  • a load 13 is connected to the S-phase distribution line of the generator 3.
  • the R-phase distribution line is an example of the “first-phase distribution line” according to the present invention.
  • the T-phase distribution line is an example of the “second phase distribution line” according to the present invention.
  • the S-phase distribution line is an example of the “third-phase distribution line” according to the present invention.
  • the load 11 is an example of the “first load” according to the present invention.
  • the load 12 is an example of a “second load” according to the present invention.
  • the load 13 is an example of a “third load” according to the present invention.
  • the current detection circuits 4 ⁇ / b> A, 4 ⁇ / b> B, and 4 ⁇ / b> C are provided on the R-phase, T-phase, and S-phase distribution lines of the generator 3.
  • the current detection circuits 4 ⁇ / b> A, 4 ⁇ / b> B, and 4 ⁇ / b> C have a current transformer, for example, and detect currents flowing through the distribution lines of each phase of the generator 3.
  • the current flowing through the distribution lines of each phase is supplied to the loads 11, 12, and 13.
  • load currents supplied to the loads 11, 12, and 13 are represented by I R , I T , and I S , respectively.
  • Load current I R, I T, I S varies depending on the severity (power consumption of each electric power consumer) of each load 11, 12 and 13.
  • the current detection circuits 4A, 4B, and 4C are examples of the “supply current detection unit” according to the present invention.
  • the currents detected by the current detection circuits 4A, 4B, and 4C are the load currents I R , I T , I S.
  • the load current supply circuit 5 is connected to each of the R-phase, S-phase, and T-phase distribution lines, and constitutes a current path between the one-phase distribution line and the other-phase distribution lines. And a part of electric current which flows into the distribution line of one phase is supplied to the distribution line of another phase. A specific configuration of the load current supply circuit 5 will be described later.
  • the load current supply circuit 5 is an example of the “current supply unit” according to the present invention.
  • the control unit 6 includes a microcomputer or the like, and determines whether there is a current exceeding the rated current per phase of the generator 3 among the currents of the respective phases detected by the current detection circuits 4A, 4B, and 4C. .
  • the control unit 6 seems to form a current path between the distribution line of the phase through which the current flows and the distribution line of the other phase.
  • the load current supply circuit 5 is controlled. As a result, of the current flowing through one distribution line, the portion exceeding the rated current per phase is supplemented by the current flowing through the distribution line of the other phase.
  • the diesel engine 2 drives the generator 3 in accordance with the largest load, and the fuel consumption is not substantially changed until the current output from the generator 3 reaches the rated current per phase.
  • the generator 3 is driven in a state where the current output from the generator 3 exceeds the rated current per phase, the windings of the phase in which the rated current per phase of the generator 3 exceeds the temperature are high. As a result, the generator burns out or stops due to the operation of the temperature protection circuit.
  • the load current I R, I T, among the I S, more than the rated current per phase minute by so compensated by the current flowing through the distribution line of the other phase, the load current Even if I R , I T , and I S exceed the rated current per phase, the current output from the generator 3 can be suppressed. For this reason, the diesel engine 2 does not need to drive the generator 3 so that a current exceeding the rated current per phase is output, and the operation continues without stopping the power generation or damaging the generator. Can be made.
  • the control unit 6 is an example of “supply current excess determination means”, “current supply means”, and “control means” according to the present invention.
  • FIG. 2 is a circuit diagram of the three-phase AC power supply device 1.
  • the load current supply circuit 5 includes a series circuit of switching elements Q1 and Q2, a series circuit of switching elements Q3 and Q4, a series circuit of switching elements Q5 and Q6, and a capacitor C1.
  • the series circuit of the switching elements Q1 and Q2 is an example of the “first series circuit” according to the present invention.
  • the series circuit of the switching elements Q3 and Q4 is an example of the “second series circuit” according to the present invention.
  • the series circuit of the switching elements Q5 and Q6 is an example of the “third series circuit” according to the present invention.
  • each series circuit includes two switching elements, but the present invention is not limited to only two switching elements.
  • two switching elements connected in series on the high side may be arranged, and two switching elements connected in series on the low side may be arranged, and each series circuit may be configured by a total of four switching elements.
  • two switching elements connected in parallel on the high side may be arranged with two switching elements connected in parallel on the low side.
  • the switching elements Q1 to Q6 are MOSFETs or IGBTs, and their control terminals (gates) are connected to the control unit 6.
  • the switching elements Q1 to Q6 are turned on and off when a control signal is input to the control terminal from the control unit 6.
  • connection point of the switching elements Q1, Q2 is connected to the R-phase distribution line of the generator 3 via the choke coil L1.
  • a connection point between the switching elements Q3 and Q4 is connected to a T-phase distribution line of the generator 3 through a choke coil L2.
  • the connection point of the switching elements Q5 and Q6 is connected to the S-phase distribution line of the generator 3 via the choke coil L3.
  • the choke coil L1 is an example of the “first choke coil” according to the present invention.
  • the choke coil L2 is an example of the “second choke coil” according to the present invention.
  • the choke coil L3 is an example of the “third choke coil” according to the present invention.
  • the control unit 6 is connected to the gates of the switching elements Q1 to Q6.
  • the control unit 6 outputs a gate signal to the switching elements Q1 to Q6 based on the current detected by the current detection circuits 4A, 4B, and 4C, and performs switching control of the switching elements Q1 to Q6.
  • the control unit 6 determines whether there is a current exceeding the rated current per phase of the generator 3 among the currents detected by the current detection circuits 4A, 4B, and 4C.
  • the load 11 is heavy load
  • the load 12 is a light load
  • the load currents I R supplied to the load 11 exceeds a rated current per phase of the generator 3 described To do.
  • the three-phase AC power supply device 1 turns on and off each switching element of the load current supply circuit 5 so that a current path is configured between the R-phase distribution line and the T-phase distribution line. Then, the load current I minute exceeding the rated current per phase of R, compensates for some of the current flowing in the distribution line of the T-phase, rated current per phase current output from the R-phase of the generator 3 Make sure that: As a result, the generator 3 can be driven so as not to exceed the rated current per phase, and as a result, a generator with a small rated capacity can be applied, so that deterioration in fuel consumption of the diesel engine 2 can be suppressed.
  • the current of each phase of the generator 3 below the rated current per phase is represented by I R1 , I S1 , and IT 1 , respectively.
  • the load current I R is a diagram showing the waveform of I S, the waveform of I T, the current below the rated current per phase I R1, I S1, I T1 .
  • FIG. 4 is a diagram illustrating a current path of the three-phase AC power supply device 1 at the timing (I) in FIG.
  • FIG. 5 is a diagram illustrating a current path of the three-phase AC power supply device 1 at the timing (II) in FIG.
  • the waveform of the current I R1, I S1, I T1 of FIG. 3 shows a current waveform when the three-phase alternating current from the generator 3 and equilibrated.
  • the three-phase currents output from the generator 3 at equilibrium have the same amplitude and a phase difference of 120 °.
  • no current is supplied from the other phase distribution line to the S phase distribution line, and the current flowing through the S phase distribution line is not supplied to the other phase distribution line.
  • the current I S1 input / output to / from the S phase of the machine 3 is always the same as the load current I S to the load 13.
  • the load current I R is positive, the load current I T is negative, the load current I S is zero.
  • the load current I R supplied to the load 11 flows to distribution line of the load 12 through the T-phase.
  • the control unit 6 turns on the switching elements Q2, Q3 of the load current supply circuit 5.
  • the R-phase distribution line and the T-phase distribution line are connected via the choke coils L1 and L2.
  • a portion of the load current I T flowing through the distribution line of the T-phase (the current I T2) is a choke coil L2, switching element Q3, capacitor C1, switching element Q2, the choke It flows in the order of the coil L1, and is supplied to the R-phase distribution line.
  • the load current I R is negative, the load current I T is positive, the load current I S is zero. That is, the timing (I) shown in FIG. 3 and the polarity of the current are opposite.
  • the load current I R is negative, the load current I T is zero, the load current I S is positive.
  • the load current I S to be supplied to the load 13, through the load 11 to the distribution lines as R phase.
  • the control unit 6 turns on the switching elements Q1, Q4 of the load current supply circuit 5.
  • the R-phase distribution line and the T-phase distribution line are connected via the choke coils L1 and L2. As indicated by arrows in FIG.
  • a portion of the load current I R flowing through the distribution line of the R-phase (the current I R2) is a choke coil L1, switching elements Q1, capacitor C1, switching element Q4, a choke It flows in the order of the coil L2, and is supplied to the T-phase distribution line.
  • the load current I R is positive, the load current I T is zero, the load current I S is negative. That is, the timing (II) shown in FIG. 3 and the polarity of the current are opposite.
  • a part of the current flowing through the T-phase distribution line flows in the order of the choke coil L2, the switching element Q4, the capacitor C1, the switching element Q1, and the choke coil L1, contrary to the arrow in FIG. Supplied to the electric wire.
  • the arbitrary timing is extracted and described. However, at any timing, the load current exceeding the rated current per phase is allocated to the other phases.
  • the AC current output from the generator 3 can be compensated with a part of the current flowing through the electric wire so that it is equal to or lower than the rated current per phase.
  • FIG. 6 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
  • the control unit 6 drives the load current supply circuit 5 as described above.
  • the current is interchanged between the R-phase distribution line and the T-phase distribution line.
  • the output current from the R phase of the generator 3 decreases to the rated current per phase.
  • the output current from the T phase of the generator 3 increases after the control delay time B has elapsed.
  • the control unit 6 loads the load current according to the timing.
  • the currents I R1 , I S1 , and IT 1 for each phase of the generator 3 can be suppressed below the rated current per phase.
  • the current I R1 , I S1 and IT 1 can be balanced three-phase alternating current.
  • the output current from each phase of the generator 3 can be suppressed below the rated current per phase of the generator 3, and the fuel consumption reduction of the diesel engine 2 can be suppressed. Further, since the load current supply circuit 5 is driven only when the load current exceeds the rated current per phase of the generator 3, the load current supply circuit 5 is compared with the case where the load current supply circuit 5 is always driven. Power consumption can be suppressed.
  • the load current I R is greater than the rated current per phase
  • a distribution line of the distribution line and T-phase of the R-phase but are connected via a choke coil L1, L2, R
  • the phase distribution line and the S phase distribution line may be connected via choke coils L1 and L3.
  • FIG. 7 is a diagram showing the structure of the three-phase AC power supply device 1.
  • elements including choke coils L1, L2, L3, switching elements Q1 to Q6, and the like are mounted on the substrate 20.
  • the switching elements Q1 to Q6 are attached to a common heat sink 21 provided on the substrate 20.
  • the switching elements Q1 to Q6 are connected to the heat sink 21 and arranged at substantially equal intervals.
  • the control unit 6 when the load current I R is greater than the rated current per phase, the control unit 6, the switching of the switching element Q1, thermally distant switching element Q3 from Q2, Q4 connected to the distribution line of the R-phase Control.
  • the heat generation is large and heat concentration is likely to occur.
  • the heat source can be dispersed and the thermal stress on the switching element is reduced. Can be lowered.
  • the failure rate of the switching element can be reduced and the life can be extended.
  • it is possible to configure without using a fan it is possible to extend the service life.
  • control unit 6 When switching elements Q5 and Q6 have a structure provided at a position thermally distant from switching elements Q1 and Q2, control unit 6 performs switching control of switching elements Q5 and Q6 so that an R-phase distribution line and What is necessary is just to make it a current path be comprised between the distribution lines of S phase.
  • FIG. 8 is a flowchart of processing executed by the control unit 6.
  • the control unit 6 acquires the current detected by the current detection circuits 4A, 4B, 4C (S1). The control unit 6 determines whether any of the detected currents exceeds the rated current per phase (S2). When exceeding (S2: YES), the control unit 6 controls the load current supply circuit 5 to connect the distribution line of the phase in which the load current exceeding the rated current per phase flows and the distribution line of the other phase. (S3).
  • the control unit 6 determines whether or not the current detected by the current detection circuits 4A, 4B, and 4C is equal to or lower than the rated current per phase (S4).
  • the control unit 6 continues to drive the load current supply circuit 5.
  • the control unit 6 stops driving the load current supply circuit 5 (S5).
  • Embodiment 2 The present embodiment is different from the first embodiment in that both the distribution line of the phase in which the load current exceeding the rated current per phase flows and the other two-phase distribution lines are connected via the choke coil. .
  • FIG. 9 is a diagram illustrating a current path of the three-phase AC power supply device 1.
  • the load 13 is a heavy load, shows an example in which the load current I S is greater than the rated current per phase.
  • I S the load current
  • FIG. 9 it is assumed that the current flows in the direction from the generator 3 to the loads 11, 12, and 13.
  • Load current I R is positive is I T, at the timing the load current I S is negative, the load current I R, I T flows through the load 13 to the distribution line of the street S phase.
  • control unit 6 turns on switching elements Q2, Q3, and Q5.
  • the R-phase distribution line and the S-phase distribution line are connected via the choke coils L1, L3, and the T-phase distribution line and the S-phase distribution line are connected via the choke coils L2, L3.
  • Is done. 9 a part of the current I R1 output from the R phase of the generator 3 (referred to as current I R2 ) is a choke coil L1, a switching element Q2, a capacitor C1, and a switching element Q5.
  • the choke coil L3 flows in this order and is supplied to the S-phase distribution line. That is,
  • the total current of the current I R2 from the R-phase distribution line and the current I T2 from the T-phase distribution line is input to the S-phase distribution line. Considering the direction of current (positive or negative), it can be expressed by
  • FIG. 10 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
  • the control unit 6 drives the load current supply circuit 5 as described above, Current is interchanged between the S-phase distribution line and the R and T-phase distribution lines.
  • the output current from the S phase of the generator 3 decreases to the rated current per phase.
  • the output current from the R and T phases of the generator 3 increases after the control delay time D has elapsed.
  • the increase in the output current from the T phase is substantially the same as the increase in the output current from the R phase.
  • each of the generators 3 is similar to the first embodiment.
  • the currents I R1 , I S1 , and IT 1 for the phases can be suppressed to be equal to or lower than the rated current per phase. As a result, the diesel engine 2 can be continuously operated safely.
  • the switching elements Q5 and Q6 connected to the S-phase distribution line, the switching elements Q1 and Q2, and the switching elements Q3 and Q4 Is approximately the same distance thermally. For this reason, by controlling the switching of each of the switching elements Q1 and Q2 and the switching elements Q3 and Q4, it is possible to suppress the heat concentration as compared with the case where only one of them is controlled. By suppressing the heat concentration, the failure rate of the switching element can be reduced and the life can be extended.
  • the load current supply circuit 5 is driven only when the load current exceeds the rated current per phase of the generator 3, the load current supply circuit 5 is compared with the case where the load current supply circuit 5 is always driven. Can be suppressed.
  • the S-phase distribution line and the R and T-phase distribution lines are connected simultaneously, but the R and T-phase distribution lines are alternately connected to the S-phase distribution line. You may make it do.
  • the period for supplying current by turning on the switching elements Q2 and Q5 and the period for supplying current by turning on the switching elements Q3 and Q5 are alternately repeated. That is, current supply from the R phase and current supply from the T phase are alternately performed (see FIG. 11).
  • a current twice as large as the current IR2 in the case of FIG. 9 flows from the R-phase distribution line to the S-phase distribution line, and from the T-phase distribution line to the S-phase distribution line in FIG.
  • the constant is set so that a current twice as large as the current IT2 flows.
  • FIG. 11 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
  • the output current from the S-phase of the generator 3 is reduced to the rated current per phase.
  • the output current from the 3 R and T phases repeats increasing and decreasing alternately.
  • the currents I R1 , I S1 , and I T1 for each phase of the generator 3 are obtained. It can be suppressed below the rated current per phase. As a result, the diesel engine 2 can be continuously operated safely.
  • the three-phase AC power supply apparatus 1 is shown in FIG.
  • local heat concentration can be suppressed.
  • the failure rate of the switching element can be reduced and the life can be extended.
  • the current detection circuits 4A, 4B, and 4C are configured to detect supply currents to the first, second, and third loads.
  • a two-phase current is used. Can be obtained by calculation.
  • two supply currents are detected using the current detection circuits (4A, 4B), and the remaining one-phase supply current is determined as the current.
  • a method of calculating by the calculating means and detecting the supply current may be used.
  • the current detection circuits 4A and 4B and the current calculation unit described above are an example of the “supply current detection unit” according to the present invention.
  • a three-phase AC power source is generated using a generator powered by a heat engine such as a diesel engine, and a single-phase load is connected to each phase.
  • a heat engine such as a diesel engine
  • a single-phase load is connected to each phase.
  • the lead-in wire from the wire to the interior is three-phase, and it is not converted into single-phase alternating current in the house, and each phase has a single-phase load. May be connected.
  • current imbalance occurs, a large current exceeding the rating flows in a part of the lead-in wire, and the electric wire may generate heat and the insulating coating of the electric wire may be deteriorated.
  • the present invention is applied, the deterioration can be suppressed.

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Abstract

A three-phase AC power source apparatus (1) detects currents flowing through power distribution lines at the respective phases of a generator (3), and determines whether or not any one of the detected currents exceeds a rated current. The three-phase AC power source apparatus (1) controls switching of the respective switching elements (Q1-Q6) of a load current supply circuit (5) so as to form a current path passing through choke coils (L1, L2, L3) between a power distribution line of the phase in which the current determined to exceed the rated current flows and at least one of the power distribution lines of the other two phases.

Description

三相交流電源装置Three-phase AC power supply
　本発明は、三相交流発電機を備えた三相交流電源装置に関する。 The present invention relates to a three-phase AC power supply device including a three-phase AC generator.
　特許文献１には、三相交流電源の各相に単相負荷が接続された構成において、インバータ回路を設けて、負荷電流が小さい相からの電流を負荷電流が大きい相へ供給する平衡化装置が開示されている。この特許文献１は、三相電流の相電流の不平衡を小さくして、各相に流れる電流の平衡化を可能としている。 In Patent Document 1, in a configuration in which a single-phase load is connected to each phase of a three-phase AC power supply, an inverter circuit is provided to supply a current from a phase with a small load current to a phase with a large load current. Is disclosed. This patent document 1 makes it possible to balance the current flowing in each phase by reducing the unbalance of the phase current of the three-phase current.
実開平２－１２５５４８号公報Japanese Utility Model Publication No. 2-125548
　しかしながら、特許文献１では、インバータ回路を常時駆動して、常時相電流の平衡化を行っているため、インバータ回路による消費電力が大きく、また、インバータ回路の発熱が大きくなるため、放熱を考慮する必要がある。そのために放熱機構を設けると、機器が大型化するといった課題もある。 However, in Patent Document 1, since the inverter circuit is always driven to constantly balance the phase current, power consumption by the inverter circuit is large, and heat generation of the inverter circuit is large, so heat dissipation is considered. There is a need. Therefore, when a heat dissipation mechanism is provided, there is a problem that the apparatus becomes large.
　そこで、本発明の目的は、消費電力を低減し、発熱を抑えることで小型化可能な三相交流電源装置を提供することにある。 Therefore, an object of the present invention is to provide a three-phase AC power supply apparatus that can be reduced in size by reducing power consumption and suppressing heat generation.
　本発明に係る三相交流電源装置は、第１相配電線に第１負荷が接続され、第２相配電線に第２負荷が接続され、第３相配電線に第３負荷が接続される三相交流発電機と、前記三相交流発電機から前記第１負荷、前記第２負荷及び前記第３負荷それぞれへの供給電流を検出する供給電流検出手段と、前記供給電流検出手段が検出する供給電流の何れかが、定格電流を超えたか否かを判定する供給電流超過判定手段と、前記供給電流超過判定手段が定格電流を超えたと判定した供給電流が流れる相の配電線と、他の二相の配電線の少なくとも一方との間に電流経路を構成する電流供給手段と、を備えることを特徴とする。 The three-phase alternating current power supply device according to the present invention is a three-phase alternating current in which a first load is connected to the first phase distribution line, a second load is connected to the second phase distribution line, and a third load is connected to the third phase distribution line. A generator, supply current detection means for detecting a supply current from the three-phase AC generator to the first load, the second load, and the third load, and a supply current detected by the supply current detection means Supply current excess determining means for determining whether any of the current exceeds the rated current, the distribution line of the phase through which the supply current determined by the supply current excess determining means exceeds the rated current, and the other two-phase Current supply means for forming a current path between at least one of the distribution lines.
　この構成では、供給電流超過判定手段が定格電流を超えたと判定した供給電流が流れる相の配電線（以下「一の配電線」ということがある。）と、他の二相の配電線の少なくとも一方との間に電流経路が構成されることで、接続される配電線の一方に流れる電流の一部が他方へ供給され、又はその逆に電流の一部が他方から供給される。これにより、一の配電線に流れる電流のうち定格電流を超える分を、他の相の配電線に流れる電流で補うことができる。その結果、三相交流発電機は、定格電流を超える電流が出力されるように駆動する必要がなく、燃費を抑えることができる。また、定格電流を超えてから、電流供給手段による制御を行うため、常時制御を行う場合と比べて、消費電力を抑えることができ、結果、燃費を抑えることができる。また、常時制御を行わないため、制御部の発熱を抑えることができる。 In this configuration, at least one of the distribution line of the phase (hereinafter sometimes referred to as “one distribution line”) through which the supply current determined by the supply current excess determination means exceeds the rated current and the other two-phase distribution lines is provided. By configuring a current path with one, a part of the current flowing in one of the connected distribution lines is supplied to the other, or conversely, a part of the current is supplied from the other. Thereby, the part which exceeds a rated current among the electric currents which flow through one distribution line can be supplemented with the electric current which flows into the distribution line of another phase. As a result, the three-phase AC generator does not need to be driven so that a current exceeding the rated current is output, and fuel consumption can be suppressed. Further, since the control by the current supply means is performed after exceeding the rated current, the power consumption can be suppressed as compared with the case where the control is always performed, and as a result, the fuel consumption can be suppressed. In addition, since the control is not always performed, heat generation of the control unit can be suppressed.
　前記電流供給手段は、複数のスイッチング素子が直列接続され、その接続点が前記第１相配電線に接続される第１直列回路と、前記第１直列回路の前記複数のスイッチング素子の接続点と、前記第１相配電線との間に設けられた第１チョークコイルと、複数のスイッチング素子が直列接続され、その接続点が前記第２相配電線に接続される第２直列回路と、前記第２直列回路の前記複数のスイッチング素子の接続点と、前記第２相配電線との間に設けられた第２チョークコイルと、複数のスイッチング素子が直列接続され、その接続点が前記第３相配電線に接続される第３直列回路と、前記第３直列回路の前記複数のスイッチング素子の接続点と、前記第３相配電線との間に設けられた第３チョークコイルと、前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子をスイッチング制御する制御手段と、を備え、前記第１直列回路、前記第２直列回路及び前記第３直列回路は並列接続されている、構成でもよい。 The current supply means includes a plurality of switching elements connected in series, a connection point of the first series circuit connected to the first phase distribution line, a connection point of the plurality of switching elements of the first series circuit, A first choke coil provided between the first phase distribution line and a plurality of switching elements are connected in series, and a connection point of the first choke coil is connected to the second phase distribution line, and the second series A second choke coil provided between a connection point of the plurality of switching elements of the circuit and the second phase distribution line and a plurality of switching elements are connected in series, and the connection point is connected to the third phase distribution line. A third choke coil provided between the third series circuit to be connected, a connection point of the plurality of switching elements of the third series circuit, and the third phase distribution line, the first series circuit, the first 2 Control means for controlling switching of each switching element of the column circuit and the third series circuit, and the first series circuit, the second series circuit, and the third series circuit may be connected in parallel. .
　この構成では、定格電流を超えてから、スイッチング素子のスイッチング制御を行うため、常時スイッチング素子をスイッチングする場合と比べて、消費電力を抑えることができる。 In this configuration, since switching control of the switching element is performed after the rated current is exceeded, power consumption can be suppressed as compared with the case where the switching element is constantly switched.
　前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子は、共通のヒートシンクに設けられ、前記制御手段は、定格電流を超える供給電流が流れる相に接続されるスイッチング素子から、熱的に最も離れた位置に設けられるスイッチング素子をスイッチング制御する、構成でもよい。 Switching elements of each of the first series circuit, the second series circuit, and the third series circuit are provided in a common heat sink, and the control means is a switching element connected to a phase in which a supply current exceeding a rated current flows. In other words, the switching control may be performed on the switching element provided at the most thermally separated position.
　この構成では、熱集中を抑えることができ、スイッチング素子の故障率の低減、長寿命化、ヒートシンクやファンなどの冷却部品の小型化を実現できる。 In this configuration, heat concentration can be suppressed, the failure rate of switching elements can be reduced, the service life can be extended, and the cooling parts such as heat sinks and fans can be downsized.
　前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子は、共通のヒートシンクに等間隔で設けられ、前記制御手段は、前記他の二相の配電線に接続されるスイッチング素子をそれぞれスイッチング制御してもよい。 The switching elements of the first series circuit, the second series circuit, and the third series circuit are provided at equal intervals on a common heat sink, and the control means is connected to the other two-phase distribution line. Each switching element may be subjected to switching control.
　この構成では、スイッチング素子の発熱が局所的に集中しないようにできる。 This configuration can prevent the heat generated by the switching element from being concentrated locally.
　前記制御手段は、前記他の二相の配電線の一方に接続されるスイッチング素子と、前記他の二相の配電線の他方に接続されるスイッチング素子とを交互にスイッチング制御してもよい。 The control means may alternately control switching between a switching element connected to one of the other two-phase distribution lines and a switching element connected to the other of the other two-phase distribution lines.
　この構成では、スイッチング素子の発熱が局所的に集中しないようにできる。 This configuration can prevent the heat generated by the switching element from being concentrated locally.
　本発明によれば、定格電流を超えてから、電流供給手段による制御を行うため、インバータ回路を常時駆動させない。従って、消費電力を抑えることができる。また、インバータ回路の発熱を抑えることもできる。よって、放熱機構を小さくすることもでき、機器の小型化に寄与することができる。 According to the present invention, since the current supply means performs control after the rated current is exceeded, the inverter circuit is not always driven. Therefore, power consumption can be suppressed. Further, heat generation of the inverter circuit can be suppressed. Therefore, the heat dissipation mechanism can be reduced, which can contribute to the downsizing of the device.
図１は、実施形態１に係る三相交流電源装置を示す図である。FIG. 1 is a diagram illustrating a three-phase AC power supply apparatus according to the first embodiment. 図２は、三相交流電源装置の回路図である。FIG. 2 is a circuit diagram of the three-phase AC power supply device. 図３は、負荷電流の波形と、１相あたりの定格電流以下の電流の波形とを示す図である。FIG. 3 is a diagram illustrating a waveform of a load current and a waveform of a current equal to or lower than the rated current per phase. 図４は、図３のタイミング（Ｉ）での三相交流電源装置の電流経路を示す図である。FIG. 4 is a diagram showing a current path of the three-phase AC power supply device at timing (I) in FIG. 図５は、図３のタイミング（II）での三相交流電源装置の電流経路を示す図である。FIG. 5 is a diagram illustrating a current path of the three-phase AC power supply device at timing (II) in FIG. 図６は、時間経過に伴い変化する発電機の各相の電流値を示す図である。FIG. 6 is a diagram showing the current value of each phase of the generator that changes with time. 図７は、三相交流電源装置の構造を示す図である。FIG. 7 is a diagram illustrating a structure of a three-phase AC power supply device. 図８は、制御部が実行する処理のフローチャートである。FIG. 8 is a flowchart of processing executed by the control unit. 図９は、三相交流電源装置の電流経路を示す図である。FIG. 9 is a diagram illustrating a current path of the three-phase AC power supply device. 図１０は、時間経過に伴い変化する発電機の各相の電流値（振幅値）を示す図である。FIG. 10 is a diagram showing the current value (amplitude value) of each phase of the generator that changes with time. 図１１は、時間経過に伴い変化する発電機の各相の電流値（振幅値）を示す図である。FIG. 11 is a diagram showing the current value (amplitude value) of each phase of the generator that changes with time.
（実施形態１）
　図１は、本実施形態に係る三相交流電源装置１を示す図である。 (Embodiment 1)
FIG. 1 is a diagram showing a three-phase AC power supply device 1 according to the present embodiment.
　三相交流電源装置１は、熱機関発電機を利用して発電し、各電力需要家に供給する。図１に示す負荷１１，１２，１３は、三相交流電源装置１から電力が供給される電力需要家等である。 The three-phase AC power supply 1 generates power using a heat engine generator and supplies it to each power consumer. Loads 11, 12, and 13 illustrated in FIG. 1 are electric power consumers and the like to which electric power is supplied from the three-phase AC power supply device 1.
　三相交流電源装置１は、ディーゼルエンジン２と、軸機構２Ａを介してディーゼルエンジン２に接続する発電機（モータジェネレータ）３と、電流検出回路４Ａ，４Ｂ，４Ｃと、負荷電流供給回路５と、制御部６とを備えている。発電機３は、本発明に係る「三相交流発電機」の一例である。 The three-phase AC power supply device 1 includes a diesel engine 2, a generator (motor generator) 3 connected to the diesel engine 2 via a shaft mechanism 2A, current detection circuits 4A, 4B, 4C, and a load current supply circuit 5. The control unit 6 is provided. The generator 3 is an example of the “three-phase AC generator” according to the present invention.
　発電機３はディーゼルエンジン２を駆動源とする三相交流発電機である。なお、発電機３の駆動源は、ディーゼルエンジン２以外に、ガソリンエンジン、ガスタービンエンジンなどであってもよい。発電機３の各相（Ｒ相、Ｔ相、Ｓ相）の配電線には負荷１１，１２，１３が接続されている。発電機３のＲ相の配電線には負荷１１が接続されている。発電機３のＴ相の配電線には負荷１２が接続されている。発電機３のＳ相の配電線には負荷１３が接続されている。 The generator 3 is a three-phase AC generator using a diesel engine 2 as a drive source. In addition to the diesel engine 2, the drive source of the generator 3 may be a gasoline engine, a gas turbine engine, or the like. Loads 11, 12, and 13 are connected to distribution lines of each phase (R phase, T phase, and S phase) of the generator 3. A load 11 is connected to the R-phase distribution line of the generator 3. A load 12 is connected to the T-phase distribution line of the generator 3. A load 13 is connected to the S-phase distribution line of the generator 3.
　Ｒ相の配電線は、本発明に係る「第１相配電線」の一例である。Ｔ相の配電線は、本発明に係る「第２相配電線」の一例である。Ｓ相の配電線は、本発明に係る「第３相配電線」の一例である。負荷１１は、本発明に係る「第１負荷」の一例である。負荷１２は、本発明に係る「第２負荷」の一例である。負荷１３は、本発明に係る「第３負荷」の一例である。 The R-phase distribution line is an example of the “first-phase distribution line” according to the present invention. The T-phase distribution line is an example of the “second phase distribution line” according to the present invention. The S-phase distribution line is an example of the “third-phase distribution line” according to the present invention. The load 11 is an example of the “first load” according to the present invention. The load 12 is an example of a “second load” according to the present invention. The load 13 is an example of a “third load” according to the present invention.
　電流検出回路４Ａ，４Ｂ，４Ｃは、発電機３のＲ相、Ｔ相、Ｓ相それぞれの配電線に設けられている。電流検出回路４Ａ，４Ｂ，４Ｃは、例えばカレントトランスを有し、発電機３の各相の配電線を流れる電流を検出する。各相の配電線を流れる電流は、負荷１１，１２，１３へ供給される。以下では、負荷１１，１２，１３へ供給される負荷電流を、それぞれＩＲ，ＩＴ，ＩＳで表す。負荷電流ＩＲ，ＩＴ，ＩＳは、各負荷１１，１２，１３の軽重（各電力需要家の電力消費）に応じて変化する。電流検出回路４Ａ，４Ｂ，４Ｃは、本発明に係る「供給電流検出手段」の一例である。なお、以下に説明する本実施形態の制御を行わない場合（負荷電流供給回路５を駆動しない場合）、電流検出回路４Ａ，４Ｂ，４Ｃが検出する電流は、負荷電流ＩＲ，ＩＴ，ＩＳである。 The current detection circuits 4 </ b> A, 4 </ b> B, and 4 </ b> C are provided on the R-phase, T-phase, and S-phase distribution lines of the generator 3. The current detection circuits 4 </ b> A, 4 </ b> B, and 4 </ b> C have a current transformer, for example, and detect currents flowing through the distribution lines of each phase of the generator 3. The current flowing through the distribution lines of each phase is supplied to the loads 11, 12, and 13. Hereinafter, load currents supplied to the loads 11, 12, and 13 are represented by I R , I T , and I S , respectively. Load current I R, I T, I S varies depending on the severity (power consumption of each electric power consumer) of each load 11, 12 and 13. The current detection circuits 4A, 4B, and 4C are examples of the “supply current detection unit” according to the present invention. When the control of the present embodiment described below is not performed (when the load current supply circuit 5 is not driven), the currents detected by the current detection circuits 4A, 4B, and 4C are the load currents I R , I T , I S.
　負荷電流供給回路５は、Ｒ相、Ｓ相、Ｔ相それぞれの配電線に接続されていて、一の相の配電線と他の相の配電線との間に電流経路を構成する。そして、一の相の配電線に流れる電流の一部を、他の相の配電線に供給する。負荷電流供給回路５の具体的な構成については後述する。負荷電流供給回路５は、本発明に係る「電流供給手段」の一例である。 The load current supply circuit 5 is connected to each of the R-phase, S-phase, and T-phase distribution lines, and constitutes a current path between the one-phase distribution line and the other-phase distribution lines. And a part of electric current which flows into the distribution line of one phase is supplied to the distribution line of another phase. A specific configuration of the load current supply circuit 5 will be described later. The load current supply circuit 5 is an example of the “current supply unit” according to the present invention.
　制御部６はマイコン等を有し、電流検出回路４Ａ，４Ｂ，４Ｃが検出する各相の電流のうち、発電機３の１相あたりの定格電流を超えたものがあるか否かを判定する。発電機３の１相あたりの定格電流を超えた電流がある場合、制御部６は、その電流が流れる相の配電線と、他の相の配電線との間に電流経路が形成されるように、負荷電流供給回路５を制御する。その結果、一の配電線を流れる電流のうち、１相あたりの定格電流を超える分が、他の相の配電線を流れる電流により補われるようになる。 The control unit 6 includes a microcomputer or the like, and determines whether there is a current exceeding the rated current per phase of the generator 3 among the currents of the respective phases detected by the current detection circuits 4A, 4B, and 4C. . When there is a current exceeding the rated current per phase of the generator 3, the control unit 6 seems to form a current path between the distribution line of the phase through which the current flows and the distribution line of the other phase. In addition, the load current supply circuit 5 is controlled. As a result, of the current flowing through one distribution line, the portion exceeding the rated current per phase is supplemented by the current flowing through the distribution line of the other phase.
　ディーゼルエンジン２は、最も大きい負荷に合わせて発電機３を駆動し、発電機３から出力される電流が、１相あたりの定格電流となるまでは燃費は略変わらない。しかしながら、発電機３から出力される電流が、１相あたりの定格電流を超えた状態で発電機３を駆動すると、発電機３の１相あたりの定格電流が超えた相の巻線などが高温になり、発電機が焼損したり、温度保護回路の作動により停止したりしてしまう。そこで、前記のように、負荷電流ＩＲ，ＩＴ，ＩＳのうち、１相あたりの定格電流を超える分を、他の相の配電線を流れる電流で補うようにすることで、負荷電流ＩＲ，ＩＴ，ＩＳが１相あたりの定格電流を超えていても、発電機３から出力する電流は抑えられる。このため、ディーゼルエンジン２は、１相あたりの定格電流を超える電流が出力されるように発電機３を駆動する必要がなく、発電が停止したり、発電機が破損したりすることなく継続動作させることができる。 The diesel engine 2 drives the generator 3 in accordance with the largest load, and the fuel consumption is not substantially changed until the current output from the generator 3 reaches the rated current per phase. However, when the generator 3 is driven in a state where the current output from the generator 3 exceeds the rated current per phase, the windings of the phase in which the rated current per phase of the generator 3 exceeds the temperature are high. As a result, the generator burns out or stops due to the operation of the temperature protection circuit. Therefore, as described above, the load current I R, I T, among the I S, more than the rated current per phase minute, by so compensated by the current flowing through the distribution line of the other phase, the load current Even if I R , I T , and I S exceed the rated current per phase, the current output from the generator 3 can be suppressed. For this reason, the diesel engine 2 does not need to drive the generator 3 so that a current exceeding the rated current per phase is output, and the operation continues without stopping the power generation or damaging the generator. Can be made.
　制御部６は、本発明に係る「供給電流超過判定手段」、「電流供給手段」及び「制御手段」の一例である。 The control unit 6 is an example of “supply current excess determination means”, “current supply means”, and “control means” according to the present invention.
　図２は、三相交流電源装置１の回路図である。 FIG. 2 is a circuit diagram of the three-phase AC power supply device 1.
　負荷電流供給回路５は、スイッチング素子Ｑ１，Ｑ２の直列回路と、スイッチング素子Ｑ３，Ｑ４の直列回路と、スイッチング素子Ｑ５，Ｑ６の直列回路と、キャパシタＣ１とが並列接続されて構成されている。スイッチング素子Ｑ１，Ｑ２の直列回路は、本発明に係る「第１直列回路」の一例である。スイッチング素子Ｑ３，Ｑ４の直列回路は、本発明に係る「第２直列回路」の一例である。スイッチング素子Ｑ５，Ｑ６の直列回路は、本発明に係る「第３直列回路」の一例である。 The load current supply circuit 5 includes a series circuit of switching elements Q1 and Q2, a series circuit of switching elements Q3 and Q4, a series circuit of switching elements Q5 and Q6, and a capacitor C1. The series circuit of the switching elements Q1 and Q2 is an example of the “first series circuit” according to the present invention. The series circuit of the switching elements Q3 and Q4 is an example of the “second series circuit” according to the present invention. The series circuit of the switching elements Q5 and Q6 is an example of the “third series circuit” according to the present invention.
　なお、本実施形態では、各直列回路はそれぞれ二つのスイッチング素子からなっているが、本発明は、二つのスイッチング素子のみに限定されない。たとえば、ハイサイド側に直列に接続された二つのスイッチング素子が、ローサイド側に直列に接続された二つのスイッチング素子が配置され、計４つのスイッチング素子により、各直列回路が構成されていてもよい。また、ハイサイド側に並列に接続された二つのスイッチング素子が、ローサイド側に並列に接続された二つのスイッチング素子が配置される構成でも構わない。 In the present embodiment, each series circuit includes two switching elements, but the present invention is not limited to only two switching elements. For example, two switching elements connected in series on the high side may be arranged, and two switching elements connected in series on the low side may be arranged, and each series circuit may be configured by a total of four switching elements. . Further, two switching elements connected in parallel on the high side may be arranged with two switching elements connected in parallel on the low side.
　スイッチング素子Ｑ１～Ｑ６はＭＯＳＦＥＴ又はＩＧＢＴであって、それぞれの制御端子（ゲート）は制御部６に接続されている。スイッチング素子Ｑ１～Ｑ６は、制御端子に制御部６から制御信号が入力されることで、オンオフする。 The switching elements Q1 to Q6 are MOSFETs or IGBTs, and their control terminals (gates) are connected to the control unit 6. The switching elements Q1 to Q6 are turned on and off when a control signal is input to the control terminal from the control unit 6.
　スイッチング素子Ｑ１，Ｑ２の接続点は、チョークコイルＬ１を介して発電機３のＲ相の配電線に接続されている。スイッチング素子Ｑ３，Ｑ４の接続点は、チョークコイルＬ２を介して発電機３のＴ相の配電線に接続されている。スイッチング素子Ｑ５，Ｑ６の接続点は、チョークコイルＬ３を介して発電機３のＳ相の配電線に接続されている。チョークコイルＬ１は、本発明に係る「第１チョークコイル」の一例である。チョークコイルＬ２は、本発明に係る「第２チョークコイル」の一例である。チョークコイルＬ３は、本発明に係る「第３チョークコイル」の一例である。 The connection point of the switching elements Q1, Q2 is connected to the R-phase distribution line of the generator 3 via the choke coil L1. A connection point between the switching elements Q3 and Q4 is connected to a T-phase distribution line of the generator 3 through a choke coil L2. The connection point of the switching elements Q5 and Q6 is connected to the S-phase distribution line of the generator 3 via the choke coil L3. The choke coil L1 is an example of the “first choke coil” according to the present invention. The choke coil L2 is an example of the “second choke coil” according to the present invention. The choke coil L3 is an example of the “third choke coil” according to the present invention.
　制御部６には、スイッチング素子Ｑ１～Ｑ６のゲートが接続されている。制御部６は、電流検出回路４Ａ，４Ｂ，４Ｃが検出する電流に基づいて、スイッチング素子Ｑ１～Ｑ６にゲート信号を出力し、スイッチング素子Ｑ１～Ｑ６をスイッチング制御する。 The control unit 6 is connected to the gates of the switching elements Q1 to Q6. The control unit 6 outputs a gate signal to the switching elements Q1 to Q6 based on the current detected by the current detection circuits 4A, 4B, and 4C, and performs switching control of the switching elements Q1 to Q6.
　具体的には、制御部６は、電流検出回路４Ａ，４Ｂ，４Ｃが検出した電流のなかで、発電機３の１相あたりの定格電流を超えたものがあるか否かを判定する。以下に、負荷１１が重負荷であり、負荷１２，１３が軽負荷であって、負荷１１に供給される負荷電流ＩＲが、発電機３の１相あたりの定格電流を超えた場合について説明する。 Specifically, the control unit 6 determines whether there is a current exceeding the rated current per phase of the generator 3 among the currents detected by the current detection circuits 4A, 4B, and 4C. Hereinafter, the load 11 is heavy load, the load 12 is a light load, the load currents I R supplied to the load 11 exceeds a rated current per phase of the generator 3 described To do.
　この場合、三相交流電源装置１は、例えば、Ｒ相の配電線とＴ相の配電線との間に電流経路が構成されるように、負荷電流供給回路５の各スイッチング素子をオンオフする。そして、負荷電流ＩＲの１相あたりの定格電流を超える分を、Ｔ相の配電線に流れる電流の一部で補い、発電機３のＲ相から出力される電流が１相あたりの定格電流以下となるようにする。これにより、１相あたりの定格電流を超えないように発電機３を駆動することができ、結果として定格容量が小さい発電機を適用できるので、ディーゼルエンジン２の燃費の悪化を抑制できる。以下では、１相あたりの定格電流以下の発電機３の各相の電流をそれぞれＩＲ１，ＩＳ１，ＩＴ１で表す。 In this case, for example, the three-phase AC power supply device 1 turns on and off each switching element of the load current supply circuit 5 so that a current path is configured between the R-phase distribution line and the T-phase distribution line. Then, the load current I minute exceeding the rated current per phase of R, compensates for some of the current flowing in the distribution line of the T-phase, rated current per phase current output from the R-phase of the generator 3 Make sure that: As a result, the generator 3 can be driven so as not to exceed the rated current per phase, and as a result, a generator with a small rated capacity can be applied, so that deterioration in fuel consumption of the diesel engine 2 can be suppressed. In the following, the current of each phase of the generator 3 below the rated current per phase is represented by I R1 , I S1 , and IT 1 , respectively.
　図３は、負荷電流ＩＲ，ＩＳ，ＩＴの波形と、１相あたりの定格電流以下の電流ＩＲ１，ＩＳ１，ＩＴ１の波形とを示す図である。図４は、図３のタイミング（Ｉ）での三相交流電源装置１の電流経路を示す図である。図５は、図３のタイミング（II）での三相交流電源装置１の電流経路を示す図である。 3, the load current I R, is a diagram showing the waveform of I S, the waveform of I T, the current below the rated current per phase I R1, I S1, I T1 . FIG. 4 is a diagram illustrating a current path of the three-phase AC power supply device 1 at the timing (I) in FIG. FIG. 5 is a diagram illustrating a current path of the three-phase AC power supply device 1 at the timing (II) in FIG.
　なお、図３の電流ＩＲ１，ＩＳ１，ＩＴ１の波形は、発電機３からの三相交流電流を平衡化したときの電流波形を示す。平衡時の発電機３から出力される三相電流はそれぞれの振幅が同じで、それぞれの位相差が１２０°の関係となる。また、以下の例では、他の相の配電線からＳ相の配電線には電流を供給せず、また、Ｓ相の配電線に流れる電流を他の相の配電線に供給しないため、発電機３のＳ相に入出力される電流ＩＳ１は、負荷１３への負荷電流ＩＳと常に同じである。 The waveform of the current I R1, I S1, I T1 of FIG. 3 shows a current waveform when the three-phase alternating current from the generator 3 and equilibrated. The three-phase currents output from the generator 3 at equilibrium have the same amplitude and a phase difference of 120 °. In the following example, no current is supplied from the other phase distribution line to the S phase distribution line, and the current flowing through the S phase distribution line is not supplied to the other phase distribution line. The current I S1 input / output to / from the S phase of the machine 3 is always the same as the load current I S to the load 13.
　図３に示すタイミング（Ｉ）では、負荷電流ＩＲは正であり、負荷電流ＩＴは負であり、負荷電流ＩＳはゼロである。なお、負荷１１に供給される負荷電流ＩＲは負荷１２を通りＴ相の配電線に流れる。このタイミング（Ｉ）では、制御部６は、負荷電流供給回路５のスイッチング素子Ｑ２，Ｑ３をオンにする。これにより、Ｒ相の配電線とＴ相の配電線とがチョークコイルＬ１，Ｌ２を介して接続される。そして、図４の矢印で示すように、Ｔ相の配電線に流れる負荷電流ＩＴの一部（電流ＩＴ２とする）が、チョークコイルＬ２、スイッチング素子Ｑ３、キャパシタＣ１、スイッチング素子Ｑ２、チョークコイルＬ１の順に流れ、Ｒ相の配電線に供給される。 At a timing (I) shown in FIG. 3, the load current I R is positive, the load current I T is negative, the load current I S is zero. The load current I R supplied to the load 11 flows to distribution line of the load 12 through the T-phase. At this timing (I), the control unit 6 turns on the switching elements Q2, Q3 of the load current supply circuit 5. As a result, the R-phase distribution line and the T-phase distribution line are connected via the choke coils L1 and L2. As indicated by arrows in FIG. 4, a portion of the load current I T flowing through the distribution line of the T-phase (the current I T2) is a choke coil L2, switching element Q3, capacitor C1, switching element Q2, the choke It flows in the order of the coil L1, and is supplied to the R-phase distribution line.
　電流ＩＴ２がＲ相の配電線に供給されることにより、重負荷の負荷１１には定格電流を超える負荷電流ＩＲが供給されるが、発電機３が出力する電流ＩＲ１は電流ＩＴ２分だけＩＲよりも小さくなる。このとき、｜ＩＲ１｜＝｜ＩＲ｜－｜ＩＴ２｜で表せる。また、負荷電流ＩＴの一部（電流ＩＴ２）がＲ相の配電線に供給されることにより、発電機３のＴ相には、負荷電流ＩＴから電流ＩＴ２だけ小さい電流ＩＴ１が入力される。すなわち、｜ＩＴ１｜＝｜ＩＴ｜－｜ＩＴ２｜で表せる。 By current I T2 is supplied to the distribution line of the R-phase, although the load 11 of the heavy load is supplied load current I R that exceeds the rated current, a current I R1 output from the generator 3 a current I T2 It is smaller than the amount corresponding I R. At this time, | I R1 | = | I R | − | I T2 | Further, since the portion of the load current I T (current I T2) is supplied to the distribution line of the R phase, the T-phase of the generator 3, the load current current from the I T I T2 only a small current I T1 are Entered. That is, | I T1 | = | I T | − | I T2 |
　図３に示すタイミング（III）では、負荷電流ＩＲは負であり、負荷電流ＩＴは正であり、負荷電流ＩＳはゼロである。すなわち、図３に示すタイミング（Ｉ）と電流の極性が反対である。この場合、図４の矢印と反対に、Ｒ相の配電線に流れる負荷電流ＩＲの一部が、チョークコイルＬ１、スイッチング素子Ｑ２、キャパシタＣ１、スイッチング素子Ｑ３、チョークコイルＬ２の順に流れ、Ｔ相の配電線に供給される。 At a timing (III) shown in FIG. 3, the load current I R is negative, the load current I T is positive, the load current I S is zero. That is, the timing (I) shown in FIG. 3 and the polarity of the current are opposite. In this case, as opposed to the arrow in FIG. 4, a portion of the load current I R flowing through the distribution line of the R-phase, the choke coil L1, the switching element Q2, capacitor C1, switching element Q3, in this order of the choke coil L2, T Supplied to phase distribution lines.
　図３に示すタイミング（II）では、負荷電流ＩＲは負であり、負荷電流ＩＴはゼロであり、負荷電流ＩＳは正である。なお、負荷１３に供給される負荷電流ＩＳは、負荷１１を通りＲ相の配電線に流れる。このタイミング（II）では、制御部６は、負荷電流供給回路５のスイッチング素子Ｑ１，Ｑ４をオンにする。これにより、Ｒ相の配電線とＴ相の配電線とがチョークコイルＬ１，Ｌ２を介して接続される。そして、図５の矢印で示すように、Ｒ相の配電線に流れる負荷電流ＩＲの一部（電流ＩＲ２とする）が、チョークコイルＬ１、スイッチング素子Ｑ１、キャパシタＣ１、スイッチング素子Ｑ４、チョークコイルＬ２の順に流れ、Ｔ相の配電線に供給される。 At a timing (II) shown in FIG. 3, the load current I R is negative, the load current I T is zero, the load current I S is positive. The load current I S to be supplied to the load 13, through the load 11 to the distribution lines as R phase. At this timing (II), the control unit 6 turns on the switching elements Q1, Q4 of the load current supply circuit 5. As a result, the R-phase distribution line and the T-phase distribution line are connected via the choke coils L1 and L2. As indicated by arrows in FIG. 5, a portion of the load current I R flowing through the distribution line of the R-phase (the current I R2) is a choke coil L1, switching elements Q1, capacitor C1, switching element Q4, a choke It flows in the order of the coil L2, and is supplied to the T-phase distribution line.
　電流ＩＲ２がＲ相の配電線に供給されることにより、重負荷の負荷１１には１相あたりの定格電流を超える負荷電流ＩＲ（電流ＩＲ１＋電流ＩＲ２）が供給されるが、発電機３へ入力される電流ＩＲ１は電流ＩＲ２の分だけＩＲよりも小さくなる。このとき、電流が流れる方向が発電機３から負荷１１，１２，１３方向のときを正とすると、｜ＩＲ１｜＝｜ＩＲ｜－｜ＩＲ２｜で表せる。また、負荷電流ＩＴはゼロであるが、負荷電流ＩＲの一部（電流ＩＲ２）がＴ相の配電線に供給されることにより、発電機３のＴ相には電流ＩＲ２が入力される。すなわち、｜ＩＴ１｜＝｜ＩＲ２｜で表せる。 By supplying the current I R2 to the R-phase distribution line, a load current I R (current I R1 + current I R2 ) exceeding the rated current per phase is supplied to the load 11 of the heavy load. The current I R1 input to the generator 3 is smaller than I R by the current I R2 . At this time, when the direction in which the current flows is from the generator 3 to the load 11, 12, 13 is positive, it can be expressed by | I R1 | = | I R | − | I R2 |. Although the load current I T is zero, the load current by part of I R (current I R2) is supplied to the distribution line of the T-phase, the current I R2 is input to the T-phase of the generator 3 Is done. That is, | I T1 | = | I R2 |
　図３に示すタイミング（IV）では、負荷電流ＩＲは正であり、負荷電流ＩＴはゼロであり、負荷電流ＩＳは負である。すなわち、図３に示すタイミング（II）と電流の極性が反対である。この場合、図５の矢印と反対に、Ｔ相の配電線に流れる電流の一部が、チョークコイルＬ２、スイッチング素子Ｑ４、キャパシタＣ１、スイッチング素子Ｑ１、チョークコイルＬ１の順に流れ、Ｒ相の配電線に供給される。 At a timing (IV) shown in FIG. 3, the load current I R is positive, the load current I T is zero, the load current I S is negative. That is, the timing (II) shown in FIG. 3 and the polarity of the current are opposite. In this case, a part of the current flowing through the T-phase distribution line flows in the order of the choke coil L2, the switching element Q4, the capacitor C1, the switching element Q1, and the choke coil L1, contrary to the arrow in FIG. Supplied to the electric wire.
　なお、図３、図４及び図５では、任意のタイミングを抽出して説明したが、何れのタイミングであっても、負荷電流の１相あたりの定格電流を超える分を、他の相の配電線に流れる電流の一部で補い、発電機３から出力される交流電流が、１相あたりの定格電流以下となるようにできる。 3, 4, and 5, the arbitrary timing is extracted and described. However, at any timing, the load current exceeding the rated current per phase is allocated to the other phases. The AC current output from the generator 3 can be compensated with a part of the current flowing through the electric wire so that it is equal to or lower than the rated current per phase.
　図６は、時間経過に伴い変化する発電機３の各相の電流値（振幅値）を示す図である。 FIG. 6 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
　負荷１１が重負荷となり、発電機３のＲ相からの出力電流が、１相あたりの定格電流を超えると（タイミングＡ）、前記したように、制御部６は負荷電流供給回路５を駆動し、Ｒ相の配電線とＴ相の配電線との間で電流を融通し合う。その結果、制御遅延時間Ｂの経過後に、発電機３のＲ相からの出力電流は、１相あたりの定格電流まで低下する。また、発電機３のＴ相からの出力電流は、制御遅延時間Ｂの経過後に増加する。 When the load 11 becomes a heavy load and the output current from the R phase of the generator 3 exceeds the rated current per phase (timing A), the control unit 6 drives the load current supply circuit 5 as described above. The current is interchanged between the R-phase distribution line and the T-phase distribution line. As a result, after the control delay time B elapses, the output current from the R phase of the generator 3 decreases to the rated current per phase. Further, the output current from the T phase of the generator 3 increases after the control delay time B has elapsed.
　このように、負荷１１，１２，１３の何れかが重負荷となり、負荷電流が発電機３の１相あたりの定格電流を超えた場合であっても、制御部６がタイミングに応じて負荷電流供給回路５を制御することで、発電機３の各相に対する電流ＩＲ１，ＩＳ１，ＩＴ１を、１相あたりの定格電流以下に抑えることができる。さらに、発電機３の各相の配電線間で融通し合う電流（たとえば、上述の実施形態ではＩＲ２，ＩＴ２）を調整することで、図３の波形に示すように、電流ＩＲ１，ＩＳ１，ＩＴ１を平衡三相交流とすることができる。その結果、発電機３の各相からの出力電流を、発電機３の１相あたりの定格電流以下に抑えることができ、ディーゼルエンジン２の燃費低下を抑制できる。また、負荷電流が発電機３の１相あたりの定格電流を超えたときのみ負荷電流供給回路５を駆動するため、負荷電流供給回路５を常時駆動する場合と対比して、負荷電流供給回路５の消費電力量を抑えることができる。 As described above, even when any one of the loads 11, 12, and 13 becomes a heavy load and the load current exceeds the rated current per one phase of the generator 3, the control unit 6 loads the load current according to the timing. By controlling the supply circuit 5, the currents I R1 , I S1 , and IT 1 for each phase of the generator 3 can be suppressed below the rated current per phase. Further, by adjusting the current (for example, I R2 , IT 2 in the above-described embodiment) interchanged between the distribution lines of each phase of the generator 3, the current I R1 , I S1 and IT 1 can be balanced three-phase alternating current. As a result, the output current from each phase of the generator 3 can be suppressed below the rated current per phase of the generator 3, and the fuel consumption reduction of the diesel engine 2 can be suppressed. Further, since the load current supply circuit 5 is driven only when the load current exceeds the rated current per phase of the generator 3, the load current supply circuit 5 is compared with the case where the load current supply circuit 5 is always driven. Power consumption can be suppressed.
　本実施形態では、負荷電流ＩＲが１相あたりの定格電流を超えた場合、Ｒ相の配電線とＴ相の配電線とを、チョークコイルＬ１，Ｌ２を介して接続しているが、Ｒ相の配電線とＳ相の配電線とをチョークコイルＬ１，Ｌ３を介して接続するようにしてもよい。詳しくは、三相交流電源装置１の構造に応じて、適宜変更することが好ましい。 In the present embodiment, when the load current I R is greater than the rated current per phase, and a distribution line of the distribution line and T-phase of the R-phase, but are connected via a choke coil L1, L2, R The phase distribution line and the S phase distribution line may be connected via choke coils L1 and L3. In detail, it is preferable to change appropriately according to the structure of the three-phase alternating current power supply device 1.
　図７は、三相交流電源装置１の構造を示す図である。この例では、基板２０上にチョークコイルＬ１，Ｌ２，Ｌ３、スイッチング素子Ｑ１～Ｑ６等を含む素子が実装されている。スイッチング素子Ｑ１～Ｑ６は、基板２０上に設けられた共通のヒートシンク２１に取り付けられている。スイッチング素子Ｑ１～Ｑ６は、ヒートシンク２１に略等間隔で接続され配列されている。この場合、負荷電流ＩＲが１相あたりの定格電流を超えた場合、制御部６は、Ｒ相の配電線に接続されるスイッチング素子Ｑ１，Ｑ２から熱的に遠いスイッチング素子Ｑ３，Ｑ４をスイッチング制御する。 FIG. 7 is a diagram showing the structure of the three-phase AC power supply device 1. In this example, elements including choke coils L1, L2, L3, switching elements Q1 to Q6, and the like are mounted on the substrate 20. The switching elements Q1 to Q6 are attached to a common heat sink 21 provided on the substrate 20. The switching elements Q1 to Q6 are connected to the heat sink 21 and arranged at substantially equal intervals. In this case, when the load current I R is greater than the rated current per phase, the control unit 6, the switching of the switching element Q1, thermally distant switching element Q3 from Q2, Q4 connected to the distribution line of the R-phase Control.
　スイッチング素子Ｑ１，Ｑ２をスイッチング制御した場合、その発熱は大きく、熱集中が起こり易くなる。このため、熱的に遠いスイッチング素子Ｑ３，Ｑ４をスイッチング制御して、Ｒ相の配電線とＴ相の配電線とを接続するようにすることで、熱源を分散でき、スイッチング素子に対する熱ストレスを下げることができる。その結果、スイッチング素子の故障率の低減、長寿命化を実現できる。さらに、熱源を分散することによるヒートシンクやファンの小型化、低コスト化も可能になる。また、ファンを使わずに構成することも可能になるため、長寿命化も実現できる。 When the switching elements Q1 and Q2 are subjected to switching control, the heat generation is large and heat concentration is likely to occur. For this reason, by switching the thermally distant switching elements Q3 and Q4 and connecting the R-phase distribution line and the T-phase distribution line, the heat source can be dispersed and the thermal stress on the switching element is reduced. Can be lowered. As a result, the failure rate of the switching element can be reduced and the life can be extended. Furthermore, it is possible to reduce the size and cost of the heat sink and fan by dispersing the heat source. In addition, since it is possible to configure without using a fan, it is possible to extend the service life.
　なお、スイッチング素子Ｑ５，Ｑ６がスイッチング素子Ｑ１，Ｑ２から熱的に遠い位置に設けられる構造である場合には、制御部６はスイッチング素子Ｑ５，Ｑ６をスイッチング制御して、Ｒ相の配電線とＳ相の配電線との間に電流経路が構成されるようにすればよい。 When switching elements Q5 and Q6 have a structure provided at a position thermally distant from switching elements Q1 and Q2, control unit 6 performs switching control of switching elements Q5 and Q6 so that an R-phase distribution line and What is necessary is just to make it a current path be comprised between the distribution lines of S phase.
　図８は、制御部６が実行する処理のフローチャートである。 FIG. 8 is a flowchart of processing executed by the control unit 6.
　制御部６は、電流検出回路４Ａ，４Ｂ，４Ｃが検出した電流を取得する（Ｓ１）。制御部６は検出電流の何れかが１相あたりの定格電流を超えているか否かを判定する（Ｓ２）。超えている場合（Ｓ２：ＹＥＳ）、制御部６は負荷電流供給回路５を制御し、１相あたりの定格電流を超える負荷電流が流れる相の配電線と、他の相の配電線とを接続する（Ｓ３）。 The control unit 6 acquires the current detected by the current detection circuits 4A, 4B, 4C (S1). The control unit 6 determines whether any of the detected currents exceeds the rated current per phase (S2). When exceeding (S2: YES), the control unit 6 controls the load current supply circuit 5 to connect the distribution line of the phase in which the load current exceeding the rated current per phase flows and the distribution line of the other phase. (S3).
　その後、制御部６は、電流検出回路４Ａ，４Ｂ，４Ｃが検出した電流が１相あたりの定格電流以下となった否かを判定する（Ｓ４）。１相あたりの定格電流以下となっていない場合（Ｓ４：ＮＯ）、制御部６は負荷電流供給回路５を駆動し続ける。１相あたりの定格電流以下となった場合（Ｓ４：ＹＥＳ）、制御部６は負荷電流供給回路５の駆動を停止する（Ｓ５）。このように、負荷電流供給回路５は常時駆動しないため、消費電力は抑えられる。 Thereafter, the control unit 6 determines whether or not the current detected by the current detection circuits 4A, 4B, and 4C is equal to or lower than the rated current per phase (S4). When the current is not less than the rated current per phase (S4: NO), the control unit 6 continues to drive the load current supply circuit 5. When it becomes below the rated current per phase (S4: YES), the control unit 6 stops driving the load current supply circuit 5 (S5). Thus, since the load current supply circuit 5 is not always driven, power consumption can be suppressed.
　Ｓ２で負荷電流ＩＲ，ＩＴ，ＩＳの何れかも１相あたりの定格電流を超えていないと判定された場合（Ｓ２：ＮＯ）、又は、Ｓ５での負荷電流供給回路５の駆動停止後、制御部６はＳ１の処理を再実行する。 If it is determined in S2 that none of the load currents I R , I T , and I S exceeds the rated current per phase (S2: NO), or after the drive of the load current supply circuit 5 is stopped in S5 The control unit 6 re-executes the process of S1.
（実施形態２）
　本実施形態では、１相あたりの定格電流を超える負荷電流が流れる相の配電線と、他の二相の配電線の両方とをチョークコイルを介して接続する点で、実施形態１と相違する。 (Embodiment 2)
The present embodiment is different from the first embodiment in that both the distribution line of the phase in which the load current exceeding the rated current per phase flows and the other two-phase distribution lines are connected via the choke coil. .
　図９は、三相交流電源装置１の電流経路を示す図である。図９は、負荷１３が重負荷であって、負荷電流ＩＳが１相あたりの定格電流を超えた場合の例を示す。図９では、電流が流れる方向が発電機３から負荷１１，１２，１３方向のときを正とする。 FIG. 9 is a diagram illustrating a current path of the three-phase AC power supply device 1. 9, the load 13 is a heavy load, shows an example in which the load current I S is greater than the rated current per phase. In FIG. 9, it is assumed that the current flows in the direction from the generator 3 to the loads 11, 12, and 13.
　負荷電流ＩＲ，ＩＴが正であり、負荷電流ＩＳが負であるタイミングでは、負荷電流ＩＲ，ＩＴは、負荷１３を通りＳ相の配電線に流れる。このタイミングにおいて、制御部６は、スイッチング素子Ｑ２，Ｑ３，Ｑ５をオンにする。そうすると、Ｒ相の配電線とＳ相の配電線とがチョークコイルＬ１，Ｌ３を介して接続され、また、Ｔ相の配電線とＳ相の配電線とがチョークコイルＬ２，Ｌ３を介して接続される。そして、図９の矢印で示すように、発電機３のＲ相から出力される電流ＩＲ１の一部（電流ＩＲ２とする）が、チョークコイルＬ１、スイッチング素子Ｑ２、キャパシタＣ１、スイッチング素子Ｑ５、チョークコイルＬ３の順に流れ、Ｓ相の配電線に供給される。すなわち、｜ＩＲ１｜＝｜ＩＲ｜＋｜ＩＲ２｜で表せる。 Load current I R, is positive is I T, at the timing the load current I S is negative, the load current I R, I T flows through the load 13 to the distribution line of the street S phase. At this timing, control unit 6 turns on switching elements Q2, Q3, and Q5. Then, the R-phase distribution line and the S-phase distribution line are connected via the choke coils L1, L3, and the T-phase distribution line and the S-phase distribution line are connected via the choke coils L2, L3. Is done. 9, a part of the current I R1 output from the R phase of the generator 3 (referred to as current I R2 ) is a choke coil L1, a switching element Q2, a capacitor C1, and a switching element Q5. The choke coil L3 flows in this order and is supplied to the S-phase distribution line. That is, | I R1 | = | I R | + | I R2 |
　また、発電機３のＴ相から出力される電流ＩＴ１の一部（電流ＩＴ２とする）が、チョークコイルＬ２、スイッチング素子Ｑ３，Ｑ５、チョークコイルＬ３の順に流れ、Ｓ相の配電線に供給される。すなわち、｜ＩＴ１｜＝｜ＩＴ｜＋｜ＩＴ２｜で表せる。 Further, a part of the current IT1 output from the T phase of the generator 3 (referred to as current IT2 ) flows in the order of the choke coil L2, the switching elements Q3 and Q5, and the choke coil L3 to the S phase distribution line. Supplied. That is, | I T1 | = | I T | + | I T2 |
　Ｓ相の配電線には、Ｒ相の配電線からの電流ＩＲ２とＴ相の配電線からの電流ＩＴ２との合計の電流が入力される。電流の方向（正負）を考慮すると、｜ＩＳ１｜＝｜ＩＳ｜－｜ＩＲ２＋ＩＴ２｜で表せる。 The total current of the current I R2 from the R-phase distribution line and the current I T2 from the T-phase distribution line is input to the S-phase distribution line. Considering the direction of current (positive or negative), it can be expressed by | I S1 | = | I S | − | I R2 + I T2 |.
　図１０は、時間経過に伴い変化する発電機３の各相の電流値（振幅値）を示す図である。 FIG. 10 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
　負荷１３が重負荷となり、発電機３のＳ相からの出力電流が１相あたりの定格電流を超えると（タイミングＣ）、前記したように、制御部６は負荷電流供給回路５を駆動し、Ｓ相の配電線とＲ，Ｔ相の配電線との間で電流を融通し合う。なお、この例では、｜ＩＲ２｜＝｜ＩＴ２｜とする。その結果、制御遅延時間Ｄの経過後に、発電機３のＳ相からの出力電流は、１相あたりの定格電流まで低下する。また、発電機３のＲ，Ｔ相からの出力電流は、制御遅延時間Ｄの経過後に増加する。なお、前記のように、｜ＩＲ２｜＝｜ＩＴ２｜であるので、Ｔ相からの出力電流の増加分とＲ相からの出力電流の増加分はほぼ同じである。 When the load 13 becomes a heavy load and the output current from the S phase of the generator 3 exceeds the rated current per phase (timing C), the control unit 6 drives the load current supply circuit 5 as described above, Current is interchanged between the S-phase distribution line and the R and T-phase distribution lines. In this example, | I R2 | = | I T2 |. As a result, after the control delay time D has elapsed, the output current from the S phase of the generator 3 decreases to the rated current per phase. The output current from the R and T phases of the generator 3 increases after the control delay time D has elapsed. As described above, since | I R2 | = | I T2 |, the increase in the output current from the T phase is substantially the same as the increase in the output current from the R phase.
　このように、１相あたりの定格電流を超える負荷電流が流れる相の配電線と、他の二相の配電線の両方とを接続しても、実施形態１と同様に、発電機３の各相に対する電流ＩＲ１，ＩＳ１，ＩＴ１を、１相あたりの定格電流以下に抑えることができる。その結果、ディーゼルエンジン２を安全に継続運転させることができる。 Thus, even if both the phase distribution line in which the load current exceeding the rated current per phase flows and the other two-phase distribution lines are connected, each of the generators 3 is similar to the first embodiment. The currents I R1 , I S1 , and IT 1 for the phases can be suppressed to be equal to or lower than the rated current per phase. As a result, the diesel engine 2 can be continuously operated safely.
　三相交流電源装置１が図７に示す構造である場合、本実施形態のように、Ｓ相の配電線に接続されるスイッチング素子Ｑ５，Ｑ６と、スイッチング素子Ｑ１，Ｑ２及びスイッチング素子Ｑ３，Ｑ４とは熱的に略同じ距離である。このため、スイッチング素子Ｑ１，Ｑ２及びスイッチング素子Ｑ３，Ｑ４それぞれをスイッチング制御することで、一方のみをスイッチング制御する場合と比べて熱集中を抑えることができる。熱集中を抑えることで、スイッチング素子の故障率の低減、長寿命化を実現できる。 When the three-phase AC power supply device 1 has the structure shown in FIG. 7, as in this embodiment, the switching elements Q5 and Q6 connected to the S-phase distribution line, the switching elements Q1 and Q2, and the switching elements Q3 and Q4 Is approximately the same distance thermally. For this reason, by controlling the switching of each of the switching elements Q1 and Q2 and the switching elements Q3 and Q4, it is possible to suppress the heat concentration as compared with the case where only one of them is controlled. By suppressing the heat concentration, the failure rate of the switching element can be reduced and the life can be extended.
　さらに、負荷電流が発電機３の１相あたりの定格電流を超えたときのみ負荷電流供給回路５を駆動するため、負荷電流供給回路５を常時駆動する場合と対比して、負荷電流供給回路５の駆動電力量を抑えることができる。 Furthermore, since the load current supply circuit 5 is driven only when the load current exceeds the rated current per phase of the generator 3, the load current supply circuit 5 is compared with the case where the load current supply circuit 5 is always driven. Can be suppressed.
また、装置の稼働率が低くなるので、長寿命化が可能となる。 In addition, since the operating rate of the apparatus is lowered, the service life can be extended.
　なお、図９での説明では、Ｓ相の配電線と、Ｒ，Ｔ相の配電線とを同時に接続しているが、Ｒ，Ｔ相の配電線を交互に、Ｓ相の配電線と接続するようにしてもよい。例えば、図９で説明したタイミングでは、スイッチング素子Ｑ２，Ｑ５をオンすることで、電流を供給する期間と、スイッチング素子Ｑ３，Ｑ５をオンすることで、電流を供給する期間とを交互に繰り返す。すなわち、Ｒ相からの電流供給とＴ相からの電流供給とを交互に行う（図１１参照）。このとき、Ｒ相の配電線からＳ相の配電線には、図９の場合の電流ＩＲ２の２倍の電流が流れ、Ｔ相の配電線からＳ相の配電線には、図９の場合の電流ＩＴ２の２倍の電流が流れるように定数設定される。 In the description of FIG. 9, the S-phase distribution line and the R and T-phase distribution lines are connected simultaneously, but the R and T-phase distribution lines are alternately connected to the S-phase distribution line. You may make it do. For example, at the timing described with reference to FIG. 9, the period for supplying current by turning on the switching elements Q2 and Q5 and the period for supplying current by turning on the switching elements Q3 and Q5 are alternately repeated. That is, current supply from the R phase and current supply from the T phase are alternately performed (see FIG. 11). At this time, a current twice as large as the current IR2 in the case of FIG. 9 flows from the R-phase distribution line to the S-phase distribution line, and from the T-phase distribution line to the S-phase distribution line in FIG. The constant is set so that a current twice as large as the current IT2 flows.
　図１１は、時間経過に伴い変化する発電機３の各相の電流値（振幅値）を示す図である。 FIG. 11 is a diagram showing the current value (amplitude value) of each phase of the generator 3 that changes with time.
　Ｒ相の配電線と、Ｔ相の配電線とを交互にＳ相の配電線に接続する場合、発電機３のＳ相からの出力電流は、１相あたりの定格電流まで低下し、発電機３のＲ，Ｔ相からの出力電流は、交互に増加と減少を繰り返す。 When the R-phase distribution line and the T-phase distribution line are alternately connected to the S-phase distribution line, the output current from the S-phase of the generator 3 is reduced to the rated current per phase. The output current from the 3 R and T phases repeats increasing and decreasing alternately.
　このように、Ｒ相の配電線とＴ相の配電線とを交互にＳ相の配電線に接続する場合であっても、発電機３の各相に対する電流ＩＲ１，ＩＳ１，ＩＴ１を、１相あたりの定格電流以下に抑えることができる。その結果、ディーゼルエンジン２を安全に継続運転させることができる。 Thus, even when the R-phase distribution line and the T-phase distribution line are alternately connected to the S-phase distribution line, the currents I R1 , I S1 , and I T1 for each phase of the generator 3 are obtained. It can be suppressed below the rated current per phase. As a result, the diesel engine 2 can be continuously operated safely.
　また、Ｒ相の配電線に接続されるスイッチング素子Ｑ１，Ｑ２と、Ｔ相に接続されるスイッチング素子Ｑ５，Ｑ６とを交互にスイッチング制御するため、三相交流電源装置１が、例えば図７に示す構造である場合、局所的な熱集中を抑えることができる。熱集中を抑えることで、スイッチング素子の故障率の低減、長寿命化を実現できる。 Further, in order to perform switching control alternately between the switching elements Q1 and Q2 connected to the R-phase distribution line and the switching elements Q5 and Q6 connected to the T-phase, the three-phase AC power supply apparatus 1 is shown in FIG. In the case of the structure shown, local heat concentration can be suppressed. By suppressing the heat concentration, the failure rate of the switching element can be reduced and the life can be extended.
　なお、上述の実施形態では、電流検出回路４Ａ，４Ｂ，４Ｃが第１、第２、第３負荷それぞれへの供給電流を検出する構成としているが、３相３線の場合、２相の電流を検出すれば、残りの相の供給電流は演算により求めることが可能である。よって、例えば、第１、第２、第３負荷それぞれへの供給電流のうち、電流検出回路（４Ａ、４Ｂ）を使って２つの供給電流を検出し、残りの１相の供給電流を、電流算出手段により演算し供給電流を検出するという方法でも構わない。この場合、上述の電流検出回路４Ａ、４Ｂ及び電流算出手段が、本発明に係る「供給電流検出手段」の一例となる。 In the above-described embodiment, the current detection circuits 4A, 4B, and 4C are configured to detect supply currents to the first, second, and third loads. However, in the case of a three-phase three-wire, a two-phase current is used. Can be obtained by calculation. Thus, for example, among the supply currents to the first, second, and third loads, two supply currents are detected using the current detection circuits (4A, 4B), and the remaining one-phase supply current is determined as the current. A method of calculating by the calculating means and detecting the supply current may be used. In this case, the current detection circuits 4A and 4B and the current calculation unit described above are an example of the “supply current detection unit” according to the present invention.
　本発明の適用例を以下に記載する。 Examples of application of the present invention are described below.
　（１）電力系統が整備されていない離島等の地域では、例えばディーゼルエンジン等の熱機関を動力にした発電機を用いて三相交流電源を生成し、各相に単相負荷が接続されるというケースがある。このような場合、電流不平衡が起こると、ディーゼルエンジンの燃費悪化に直結してしまうため、本発明を適用して燃費悪化を低減することができる。また、電流不平衡が起こらなくなれば、ディーゼルエンジンの容量を小さくすることも可能となるので、さらなる燃費向上が図られる。 (1) In areas such as remote islands where power systems are not maintained, for example, a three-phase AC power source is generated using a generator powered by a heat engine such as a diesel engine, and a single-phase load is connected to each phase. There is a case. In such a case, when current imbalance occurs, the fuel efficiency of the diesel engine is directly deteriorated. Therefore, the fuel efficiency deterioration can be reduced by applying the present invention. Further, if current imbalance does not occur, the capacity of the diesel engine can be reduced, so that the fuel efficiency can be further improved.
　（２）欧州やその他日本国外では家庭用であっても、電線から屋内への引き込み線が三相になっており、家屋内で単相交流に変換されることなく、各相に単相負荷が接続される構成になっている場合がある。このような場合、電流不平衡が起こると、引き込み線の一部に定格を超える大電流が流れ、電線が発熱して電線の絶縁被覆が劣化するおそれがある。本発明を適用すれば、当該劣化を抑制することも可能となる。 (2) Even if it is for home use outside Europe and other countries in Japan, the lead-in wire from the wire to the interior is three-phase, and it is not converted into single-phase alternating current in the house, and each phase has a single-phase load. May be connected. In such a case, when current imbalance occurs, a large current exceeding the rating flows in a part of the lead-in wire, and the electric wire may generate heat and the insulating coating of the electric wire may be deteriorated. When the present invention is applied, the deterioration can be suppressed.
Ｂ，Ｄ…制御遅延時間
Ｃ１…キャパシタ
ＩＲ，ＩＳ，ＩＴ…負荷電流
ＩＲ１，ＩＳ１，ＩＴ１…相電流
ＩＲ２，ＩＴ２…電流
Ｌ１，Ｌ２，Ｌ３…チョークコイル
Ｑ１，Ｑ２，Ｑ３，Ｑ４，Ｑ５，Ｑ６…スイッチング素子
１…三相交流電源装置
２…ディーゼルエンジン
２Ａ…軸機構
３…発電機（三相交流発電機）
４Ａ，４Ｂ，４Ｃ…電流検出回路（供給電流検出手段）
５…負荷電流供給回路
６…制御部（供給電流超過判定手段、電流供給手段）
１１，１２，１３…負荷
２０…基板
２１…ヒートシンク B, D ... control delay time C1 ... capacitor I R, I S, I T ... load current I R1, I S1, I T1 ... phase current I R2, I T2 ... current L1, L2, L3 ... choke coil Q1, Q2 , Q3, Q4, Q5, Q6 ... switching element 1 ... three-phase AC power supply device 2 ... diesel engine 2A ... shaft mechanism 3 ... generator (three-phase AC generator)
4A, 4B, 4C ... Current detection circuit (supply current detection means)
5 ... Load current supply circuit 6 ... Control unit (supply current excess determination means, current supply means)
11, 12, 13 ... load 20 ... substrate 21 ... heat sink

Claims (5)

  1. 　第１相配電線に第１負荷が接続され、第２相配電線に第２負荷が接続され、第３相配電線に第３負荷が接続される三相交流発電機と、
    　前記三相交流発電機から前記第１負荷、前記第２負荷及び前記第３負荷それぞれへの供給電流を検出する供給電流検出手段と、
    　前記供給電流検出手段が検出する供給電流の何れかが、定格電流を超えたか否かを判定する供給電流超過判定手段と、
    　前記供給電流超過判定手段が定格電流を超えたと判定した供給電流が流れる相の配電線と、他の二相の配電線の少なくとも一方との間に電流経路を構成する電流供給手段と、
    　を備える三相交流電源装置。     A three-phase AC generator in which a first load is connected to the first phase distribution line, a second load is connected to the second phase distribution line, and a third load is connected to the third phase distribution line;
    Supply current detection means for detecting supply current from the three-phase AC generator to the first load, the second load, and the third load;
    Supply current excess determination means for determining whether any of the supply currents detected by the supply current detection means exceeds a rated current;
    A current supply means that constitutes a current path between the distribution line of the phase through which the supply current determined that the supply current excess determination means exceeds the rated current, and at least one of the other two-phase distribution lines;
    A three-phase AC power supply device.
  2. 　前記電流供給手段は、
    　複数のスイッチング素子が直列接続され、その接続点が前記第１相配電線に接続される第１直列回路と、
    　前記第１直列回路の前記複数のスイッチング素子の接続点と、前記第１相配電線との間に設けられた第１チョークコイルと、
    　複数のスイッチング素子が直列接続され、その接続点が前記第２相配電線に接続される第２直列回路と、
    　前記第２直列回路の前記複数のスイッチング素子の接続点と、前記第２相配電線との間に設けられた第２チョークコイルと、
    　複数のスイッチング素子が直列接続され、その接続点が前記第３相配電線に接続される第３直列回路と、
    　前記第３直列回路の前記複数のスイッチング素子の接続点と、前記第３相配電線との間に設けられた第３チョークコイルと、
    　前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子をスイッチング制御する制御手段と、
    　を備え、
    　前記第１直列回路、前記第２直列回路及び前記第３直列回路は並列接続されている、
    　請求項１に記載の三相交流電源装置。     The current supply means includes
    A plurality of switching elements are connected in series, and a first series circuit in which a connection point is connected to the first phase distribution line;
    A first choke coil provided between a connection point of the plurality of switching elements of the first series circuit and the first phase distribution line;
    A second series circuit in which a plurality of switching elements are connected in series, the connection point of which is connected to the second phase distribution line;
    A second choke coil provided between a connection point of the plurality of switching elements of the second series circuit and the second phase distribution line;
    A plurality of switching elements connected in series, a third series circuit whose connection point is connected to the third phase distribution line;
    A third choke coil provided between a connection point of the plurality of switching elements of the third series circuit and the third phase distribution line;
    Control means for controlling switching of the switching elements of the first series circuit, the second series circuit, and the third series circuit;
    With
    The first series circuit, the second series circuit, and the third series circuit are connected in parallel.
    The three-phase alternating current power supply device according to claim 1.
  3. 　前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子は、共通のヒートシンクに設けられ、
    　前記制御手段は、
    　定格電流を超える供給電流が流れる相に接続されるスイッチング素子から、熱的に最も離れた位置に設けられるスイッチング素子をスイッチング制御する、
    　請求項２に記載の三相交流電源装置。     The switching elements of the first series circuit, the second series circuit, and the third series circuit are provided in a common heat sink,
    The control means includes
    Switching control is performed on a switching element provided at a position thermally farthest from a switching element connected to a phase in which a supply current exceeding the rated current flows.
    The three-phase alternating current power supply device according to claim 2.
  4. 　前記第１直列回路、前記第２直列回路及び前記第３直列回路それぞれのスイッチング素子は、共通のヒートシンクに等間隔で設けられ、
    　前記制御手段は、
    　前記他の二相の配電線に接続されるスイッチング素子をそれぞれスイッチング制御する、
    　請求項２に記載の三相交流電源装置。     The switching elements of the first series circuit, the second series circuit, and the third series circuit are provided at equal intervals on a common heat sink,
    The control means includes
    Switching control each switching element connected to the other two-phase distribution line,
    The three-phase alternating current power supply device according to claim 2.
  5. 　前記制御手段は、
    　前記他の二相の配電線の一方に接続されるスイッチング素子と、前記他の二相の配電線の他方に接続されるスイッチング素子とを交互にスイッチング制御する、
    　請求項４に記載の三相交流電源装置。     The control means includes
    Switching control is alternately performed between a switching element connected to one of the other two-phase distribution lines and a switching element connected to the other of the other two-phase distribution lines.
    The three-phase alternating current power supply device according to claim 4.
PCT/JP2017/008868 2016-03-17 2017-03-07 Three-phase ac power source apparatus WO2017159435A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3535589A (en) * 1966-10-18 1970-10-20 Bendix Corp Unbalanced load protection circuit for ac generator
US4264856A (en) * 1979-03-23 1981-04-28 Basler Electric Company System for maintaining excitation of an alternating current generator during excessive output current conditions
JPS6077224U (en) * 1983-10-28 1985-05-30 澤藤電機株式会社 Engine generator overvoltage/overcurrent prevention device
JP2004320861A (en) * 2003-04-14 2004-11-11 Denso Corp Controller for three-phase motor-generator for vehicle
JP2012191802A (en) * 2011-03-11 2012-10-04 Toshiba Mach Co Ltd Inverter power generation apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3535589A (en) * 1966-10-18 1970-10-20 Bendix Corp Unbalanced load protection circuit for ac generator
US4264856A (en) * 1979-03-23 1981-04-28 Basler Electric Company System for maintaining excitation of an alternating current generator during excessive output current conditions
JPS6077224U (en) * 1983-10-28 1985-05-30 澤藤電機株式会社 Engine generator overvoltage/overcurrent prevention device
JP2004320861A (en) * 2003-04-14 2004-11-11 Denso Corp Controller for three-phase motor-generator for vehicle
JP2012191802A (en) * 2011-03-11 2012-10-04 Toshiba Mach Co Ltd Inverter power generation apparatus

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