JP2008306786A5 - - Google Patents

Description

Boost chopper device

  The present invention relates to a boost chopper device in which a plurality of boost chopper circuits are connected in parallel, and in particular, the DC reactor portion of a plurality of boost chopper circuits is reduced in size and weight without adversely affecting boost chopper operation. In particular, the present invention relates to a boost chopper device that can be reduced in size, weight, and cost.

  Conventionally, a boost chopper circuit has been used as a boosting means for boosting a voltage supplied to a load. In order to stabilize the output voltage when the output voltage of the boost chopper circuit is increased, a plurality of boost chopper circuits are connected in parallel.

  For example, Japanese Patent Laid-Open No. 11-206112 describes a switching regulator having four boost chopper circuits connected in parallel. FIG. 18 is a circuit diagram showing a specific configuration of this switching regulator.

In the switching regulator 100, a DC reactor 102 to 105 and a commutation diode 106 to 109 are connected in series in this order between an input terminal a to which a DC power supply 101 is connected and an output terminal b to which a load 116 is connected. Four series circuits are connected in parallel. A smoothing capacitor 114 is connected between the output terminal b and the ground point c, and four field effects are provided between the DC reactor of each series circuit and each of the connection points d to g of the diode and the ground point c. Transistors (hereinafter referred to as FETs) 110 to 113 are connected to each other. A PWM control circuit 115 for controlling the on / off operation is connected to the gates of the four FETs 110 to 113. The voltage Vo at the output terminal b is input to the PWM control circuit 115.

  A step-up chopper circuit that boosts the voltage of the DC power supply 101 by four series circuits composed of four DC reactors 102 to 105 and four diodes 106 to 109, four FETs 110 to 113, and a smoothing capacitor 114. A is configured. Since the boosting operation is performed by one series circuit, the FET connected in parallel to the connection point in the series circuit, and the capacitor 114 connected to the output side (the cathode of the diode) of the series circuit, the boosting chopper The circuit A has a configuration in which four boost chopper circuits are equivalently connected in parallel.

  One step-up chopper circuit in the step-up chopper circuit A, for example, a step-up chopper circuit composed of the DC reactor 102, the diode 106, the FET 110, and the capacitor 114 receives the DC energy output from the DC power supply 101 during the ON period of the FET 110. Once accumulated in the DC reactor 102, the DC energy accumulated in the DC reactor 102 is discharged to the capacitor 114 and the load 116 during the OFF period following the ON period. The other three boost chopper circuits perform the same operation.

  The PWM control circuit 115 generates a predetermined drive pulse and inputs it to the gates of the four FETs 110 to 113 so that the voltage output from the boost chopper circuit A becomes a predetermined boost voltage. Specifically, the PWM control circuit 115 shifts a drive pulse of a predetermined duty ratio (on period / (on period + off period)) (75% in the example) by ¼ period to change the four FETs 110 to 113. The operation of sequentially inputting to each gate is repeated.

  By controlling the drive pulses for the FETs 110 to 113 of the PWM control circuit 115 described above, the FETs 110 to 113 are shifted off by a quarter cycle and sequentially turned off for a quarter cycle when the duty ratio is 75%. As a result, the DC energy accumulated in the DC reactors 102 to 105 during the ON period of the FETs 110 to 113 is sequentially discharged to the capacitor 114 and supplied to the load 116.

Since the switching regulator 100 is configured to supply the DC power stored in the DC reactors 102 to 105 to the load 116 while sequentially discharging the DC energy to the capacitor 114 during the ON period of the FETs 110 to 113, the boosting chopper is substantially provided. In the circuit A, four boost chopper circuits connected in parallel are operated in a time division manner.

JP 11-206112 A

The step-up chopper circuit A of the switching regulator 100 is considered to be obtained by simply connecting four step-up chopper circuits in parallel. Therefore, the size and weight of the step-up chopper circuit A are larger than those of a single step-up chopper circuit having the same performance. There is a problem of increasing. This problem is that when a plurality of booster chopper devices with relatively large capacities are connected in parallel to form a booster chopper device with a larger capacity, not only the size and weight of the entire device but also the manufacturing cost is increased. It is important because it increases.

  Note that Patent Document 1 only describes that the current flowing through the capacitor 114 is equalized by driving control of the FETs 110 to 113 by the PWM control circuit 115 to reduce the burden on the capacitor 114 and avoid a low life. No mention is made of the above problems.

  The present invention has been conceived under the circumstances described above, and is a boost chopper device formed by connecting a plurality of boost chopper circuits in parallel, and can be downsized without adversely affecting the boost chopper operation. It is an object of the present invention to provide a boost chopper device that can be reduced in weight and cost.

In the present invention, equivalently, a plurality of series circuits in which a DC reactor and a diode are connected in series in this order are connected in parallel between an input terminal to which a DC power source is connected and an output terminal to which a load is connected, A step-up chopper circuit in which a capacitor is connected between the output end and a ground point, and a switching element is connected between a DC reactor of each series circuit, a connection point of a diode, and the ground point; In the step-up chopper device configured with a control circuit that centrally controls the on / off operation of each switch element, the DC reactor of each step-up chopper circuit is configured by winding each DC reactor winding around a common core. The control circuit shifts a pulse signal having the same waveform with a predetermined duty ratio in the same phase or a predetermined phase to the plurality of switch elements. It was characterized by outputting (claim 1).

  In the step-up chopper device according to claim 1, the DC reactor of each step-up chopper circuit is a common core composed of one iron core formed by connecting both ends of rod-shaped magnetic members corresponding to the number of reactors. Each DC reactor is wound in a depolarized manner, and the control circuit may output a pulse signal having the same waveform with a predetermined duty ratio to the plurality of switch elements in the same phase ( Claim 2). Here, the duty ratio is a ratio of on-time to one cycle of on / off as represented by on-time / (on-time + off-time).

  Further, in the step-up chopper device according to claim 1, the DC reactor of each step-up chopper circuit has a common core composed of one iron core in which both ends of rod-shaped magnetic members corresponding to the number of reactors are connected to each other. Each of the DC reactors is wound in a depolarized manner, and the control circuit outputs a pulse signal having the same waveform with a predetermined duty ratio to each of the plurality of switch elements by shifting the predetermined phase. Each switch element may be turned on in different periods (claim 3).

  Further, in the boost chopper device according to claim 1, the DC reactor of each boost chopper circuit is added to a common core composed of one iron core in which both ends of two rod-shaped magnetic members are connected to each other. Each DC reactor is wound with a polarity, and the control circuit outputs a pulse signal having a predetermined duty ratio to one switch element, and the pulse signal obtained by inverting the level of the pulse signal is output to the other switch. It is preferable that each switch element is operated so that the on / off operation is reversed by outputting to the element.

  Further, in the boost chopper device according to claim 1, the DC reactor of each boost chopper circuit is added to a common core composed of one iron core in which both ends of two rod-shaped magnetic members are connected to each other. Each DC reactor is wound with a polarity, and the control circuit is configured to output a pulse signal having the same waveform with a predetermined duty ratio to the plurality of switch elements by shifting the predetermined phase. (Claim 5).

  Further, in the step-up chopper device according to any one of claims 2 to 5, the direct current reactor of each step-up chopper circuit has a rod-shaped first magnetic member corresponding to the number of reactors arranged in the center instead of a common core. A common core composed of a single iron core having a structure that is arranged around the rod-shaped second magnetic member and whose both ends are respectively connected to both ends of the second magnetic member; You may comprise, respectively winding the winding of a direct current reactor (Claim 6).

  According to the present invention, the DC reactor of each step-up chopper circuit is a common core composed of one iron core formed by connecting both ends of rod-shaped magnetic members for the number of reactors, or a rod-shaped for the number of reactors. The first magnetic member has a structure in which the first magnetic member is arranged around the rod-shaped second magnetic member arranged in the center, and both end portions thereof are respectively connected to both end portions of the second magnetic member. Since each DC reactor winding is wound around a common core consisting of a single iron core, each boost chopper circuit DC reactor is composed of a single DC reactor wound around a separate core Compared to the case, the size and weight can be reduced.

  According to the second aspect of the present invention, the windings of the DC reactors are wound around the common core with depolarization, and the control circuit applies pulse signals having the same waveform with a predetermined duty ratio to the plurality of switch elements. Since the signals are output in the same phase, the switch elements are simultaneously turned on, and the plurality of boost chopper circuits simultaneously store DC energy in the DC reactor and release the stored energy to the capacitor without substantially interfering with each other. The operation is performed, and the boosting performance of the entire apparatus is not significantly impaired.

  According to a third aspect of the present invention, the windings of the DC reactors are wound around a common core with depolarization, and the control circuit applies pulse signals having the same waveform with a predetermined duty ratio to a plurality of switch elements. A plurality of step-up chopper circuits are operated to store DC energy in a DC reactor in a time-division manner without substantially interfering with each other, because each switch element is turned on during a different period by outputting with a predetermined phase shift. The stored energy is discharged to the capacitor, and the boosting performance of the entire device is not significantly impaired.

  According to the invention of claim 4, the windings of the DC reactors are wound around the common core with a polarity, and the control circuit outputs a pulse signal having a predetermined duty ratio to one of the switch elements. Since the pulse signal obtained by inverting the level of the pulse signal is output to the other switch element to operate each switch element so that the on / off operation is reversed, the two boost chopper circuits substantially interfere with each other. If one step-up chopper circuit stores DC energy in the DC reactor, the other step-up chopper circuit performs the step-up chopper operation simultaneously because the other step-up chopper circuit discharges the DC energy stored in the DC reactor to the capacitor. As a result, the boosting performance of the entire apparatus is not significantly impaired.

  The DC current input from the DC power source is a sum of currents flowing through the DC reactors of the two boost chopper circuits. When the switch element of one boost chopper circuit is on, the DC current of the boost chopper circuit is Since the monotonically increasing current flows through the reactor and the switching element of the other step-up chopper circuit is off, the monotonically decreasing current flows through the DC reactor, so the input current becomes almost flat and suppresses the fluctuation amount. be able to.

  According to the invention described in claim 6, the magnetic flux generated in the first magnetic member around which the winding is wound when a current flows through each winding is mainly the first magnetic member and the second magnetic member. Therefore, the mutual inductance between the windings can be reduced. Thereby, the adverse effect on the boosting performance of the entire apparatus due to the mutual inductance can be reduced.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an equivalent electric circuit configuration of a first embodiment of a boost chopper device according to the present invention.

A boost chopper device 2 shown in FIG. 1 boosts the voltage Vin of the DC power source 1 to a voltage Vo (≧ Vin) and supplies it to a load 3. In this step-up chopper circuit 2, DC reactors L1, L2 and commutation diodes D1, D2 are connected in series in this order between an input terminal a to which a DC power source 1 is connected and an output terminal b to which a load 3 is connected. Two connected series circuits are connected in parallel. A smoothing capacitor C is connected between the output terminal b and the ground line c, and two switch elements SW1, SW1 are connected between the DC reactor and diode connection points d and e of each series circuit and the ground line c. SW2 is connected to each other.

  In FIG. 1, IGBTs (insulated gate bipolar transistors) are used as the switch elements SW1 and SW2, but field effect transistors may be used. A control circuit 22 for controlling the on / off operation is connected to each control terminal (gate terminal in FIG. 1) of the switch elements SW1 and SW2. The control circuit 22 receives the voltage across the capacitor C, that is, the voltage Vo at the output terminal b.

  As is well known, the basic circuit configuration of the step-up chopper circuit includes a series circuit of a DC reactor and a diode, a switching element connected to a connection point in the series circuit and a ground line, and an output side of the series circuit ( A cathode of the diode) and a smoothing capacitor connected to the ground line. Therefore, the boost chopper device 2 has a configuration in which two boost chopper circuits are equivalently connected in parallel.

That is, in the step-up chopper device 2, a first step-up chopper circuit is configured by the series circuit of the DC reactor L1 and the diode D1, the switch element SW1, and the capacitor C1, and the series circuit of the DC reactor L2 and the diode D2, the switch element SW2, and the capacitor A second boost chopper circuit is configured by C2. Since the capacitor C1 and the capacitor C2 are connected in parallel to the output terminal b and the ground line c, only one capacitor C obtained by synthesizing both capacitors C1 and C2 is shown in FIG.

  Further, as shown in FIG. 2, the DC reactors L1 and L2 have a common core 211 and a winding 212 of one DC reactor L1 (hereinafter referred to as “first DC reactor L1”) and the other DC reactor L2. (Hereinafter referred to as “second DC reactor L <b> 2”) 213 is wound. The core 211 has a vertically long rectangular shape in which both ends of two rod-like members are connected to each other. The core 211 is made of, for example, a magnetic member made of an amorphous alloy. Two rod-like portions 211a and 211b opposite to each other in the longitudinal direction are leg portions, and a portion 211c connecting both ends of the leg portions 211a and 211b is a yoke portion.

A winding 212 of the first DC reactor L1 and a winding 213 of the second DC reactor L2 are wound around the legs 211a and 211b, respectively. As shown in FIG. 3, the windings 212 and 213 are wound in opposite directions. That is, the first DC reactor L1 and the second DC reactor L2 have the same structure as a depolarizing transformer. The diameters and lengths of the windings of the first and second DC reactors L1 and L2 are substantially the same, and the self inductances L _L1 and L _L2 of the first and second DC reactors L1 and _L2 are substantially the same value. Yes.

  Note that the first DC reactor L1 and the second DC reactor L2 are configured integrally with a common core 211 and are handled as one component in the manufacture of the boost chopper device 2, and therefore in FIG. The entire first and second DC reactors L 1 and L 2 are used as a DC reactor 21. The black circles on the left side of the first DC reactor L1 and the second DC reactor L2 in the DC reactor 21 indicate that the DC reactor 21 has the same structure as a depolarizing transformer.

  The control circuit 22 centrally controls the on / off operations of the two switch elements SW1 and SW2. The control circuit 22 generates two drive pulses S1, S2 having the same frequency and duty ratio, and sets the drive pulses S1, S2 to a high level period (a period in which the switch elements SW1, SW2 are turned on. The gate terminals of the switch element SW1 (hereinafter referred to as “first switch element SW1”) and the switch element SW2 (hereinafter referred to as “second switch element SW2”) so that the “on period” is overlapped. To supply. Hereinafter, the drive pulse S1 for the first switch element SW1 is referred to as “first drive pulse S1”, and the drive pulse S2 for the second switch element SW2 is referred to as “second drive pulse S2”.

As is well known, in the step-up chopper circuit, when the period of the drive pulse is T, the ON period of the switch element is T _ON , the OFF period is T _OFF , the input voltage is Ein, and the output voltage is Eout, the boost rate β = Eout / Ein is represented by β = T / _TOFF . Since the duty ratio D is T _ON / T, the boost ratio β = T / T _OFF = 1 / (1-D)> 1 and the output voltage Eout is expressed by Ein / (1-D). The

  The control circuit 22 fixes the frequency (for example, fixed at about 5 kHz), and controls the output voltage Vo by changing the duty ratio D of the first and second drive pulses S1, S2. For example, when the duty ratio D [%] is 25%, the output voltage Vo is approximately 1.3 Vin, and when the duty ratio D [%] is 50%, the output voltage Vo is 2 Vin and the duty ratio D [% ] Is 75%, the output voltage Vo is 4Vin. The duty ratio D [%] is a percentage display of the duty ratio D.

  Next, the operation of the boost chopper device 2 of the first embodiment will be described.

In the boost chopper device 2 of the first embodiment, since the first and second DC reactors L1 and L2 are constituted by the DC reactor 21 shown in FIG. 2, the first and second DC reactors L1 and L2 are respectively provided. When current flows, not only self-inductance but also mutual inductance occurs. For this reason, when current I _L1 and current I _L2 flow through winding 212 and winding 213, respectively, reactor voltage V _L1 of first DC reactor _L1 (hereinafter referred to as “first reactor voltage V _L1 ”). reactor voltage V _L2 of the second DC reactor L2 (hereinafter, referred to as a "second reactor voltage V _L2".) is the following (1), is expressed by equation (2). In equations (1) and (2), L _L1 and L _L2 are self-inductances, and M is a mutual inductance. Further, the resistance of the windings 212 and 213 is ignored.

When the first switch element SW1 is turned on, the potential of the P1 terminal on the power supply side of the first DC reactor L1 is Vin, and the P2 terminal on the load side is substantially at the ground level (0 V), so the first DC reactor L1. , A current I _L1 flows so that the first reactor voltage V _L1 is balanced with the power supply voltage Vin. The same applies to the current I _L2 flowing through the second DC reactor L2 when the second switch element SW2 is turned on.

Since the self-inductance L _{L1 of} the first DC reactor L1 and the self-inductance L _L2 of the second DC reactor _L2 are substantially the same, when the first and second switch elements SW1, SW2 are simultaneously turned on. When the transient currents I _L1 and I _L2 flow in substantially the same way, and L _L1 = L _L2 = L and dI _L1 / dt = dI _L2 / dt = dI _L / dt, the first and second The current I _L flows through the DC reactors L1 and L2 so as to satisfy the following expression (3).

In the above equation (3), the self-inductances L _L1 and L _L2 of the first and second DC reactors L1 and _L2 are (L + M), and the mutual relationship between the first DC reactor L1 and the second DC reactor L2 This is equivalent to the relational expression when the first boost chopper circuit and the second boost chopper circuit are operated simultaneously so that no induction occurs.

Accordingly, the first embodiment, the first parallel connection of the second step-up chopper circuit having a second DC reactor L2 of the first step-up chopper circuit and a self-inductance L _L2 having a DC reactor L1 of self-inductance L _L1 The first step-up chopper circuit having a first DC reactor L1 having a self-inductance (L + M) and a second DC reactor L2 having a self-inductance (L + M) are provided. The boost chopper circuit is configured to operate independently of each other.

On the other hand, when the first switch element SW1 is turned off, the polarity of the first reactor voltage V _{L1 at} the off timing is reversed, so the voltage at the P2 terminal on the load side of the first DC reactor L1 is (Vin + V _L1 ), and this voltage (Vin + V _L1 ) is applied to the capacitor C via the diode D1. The same applies to the case where the second switch element SW2 is turned off. When the second switch element SW2 is turned off, the voltage at the P4 terminal on the load side of the second DC reactor L2 becomes (Vin + V _L2 ). A voltage (Vin + V _L2 ) is applied to the capacitor C through the diode D2.

Accordingly, the current I _L1 flowing through the first DC reactor L1 monotonously increases from I _ON to I _OFF during the ON period of the first switch element SW1, and from I _OFF to I _ON during the OFF period of the first switch element SW1. It becomes a triangular wave waveform that decreases monotonically. It becomes a second similar triangular waveform current I _L2 also current I _L1 flowing to DC reactor L2, yet the same phase as the current I _L1.

4 to 6 are waveform diagrams showing the power supply operation of the step-up chopper device 2 of the first embodiment. The first and second drive pulses S1 and S2, the first and second DC reactors L1 and L2 are shown in FIG. The waveforms of flowing currents I _L1 and I _L2 , input current Iin, voltages Vd and Ve at connection points d and e, and output voltage Vo are shown. 4 shows a case where the duty ratio D [%] of the first and second drive pulses S1, S2 is 33%, and FIG. 5 shows the duty ratio D of the first and second drive pulses S1, S2. FIG. 6 shows the case where [%] is set to 50%, and FIG. 6 shows the case where the duty ratio D [%] of the first and second drive pulses S1, S2 is set to 75%.

As shown in FIGS. 4 to 6, in the first embodiment, the current I _L1 of the first DC reactor L1 current I _L2 of the second DC reactor L2 shows the same waveform, the self-inductance of the (L + M) It can be seen that the first step-up chopper circuit having the first DC reactor L1 and the second step-up chopper circuit having the second DC reactor L2 having the self-inductance (L + M) operate independently of each other.

Further, in the first embodiment, the input current Iin from the DC power source 1 is equally divided into two parts, and is used independently for the boost chopper operation in the first boost chopper circuit and the second boost chopper circuit, respectively. The waveform of the input current Iin is obtained by adding the triangular waveform of the current I _L1 of the first DC reactor L1 and the triangular waveform of the current I _L2 of the second DC reactor L2.

Since the inclination angles of the currents I _L1 and I _L2 of the first and second DC reactors L1 and L2 in the ON period of the first and second switch elements SW1 and SW2 are substantially the same regardless of the duty ratio D, The longer the ON period, the larger the change width of the currents I _L1 and I _L2 (the difference between I _ON and I _OFF in FIGS. 4 to 6). Therefore, the change width of the input current Iin also increases as the ON period is longer, that is, as the step-up rate β is larger.

When the first and second switch elements SW1 and SW2 are turned on, the voltages Vd and Ve at the connection points d and e are at the ground level (the level of the ground line c) . The voltage Vce is between the collector and emitter of the switch elements SW1 and SW2. On the other hand, when the first and second switch elements SW1 and SW2 are turned off, the voltages Vd and Ve add the first and second reactor voltages V _L1 and V _L2 at the off timing to the input voltage Vin. Voltage. This voltage is β · Vin, and the voltages Vd and Ve are substantially β · Vin during the OFF period of the first and second switch elements SW1 and SW2.

Further, since the capacitor C has a large capacity, the output voltage Vo is held at β × Vin. When the duty ratio is 33%, 50%, and 75%, the step-up rate β is 1.5, 2.0, and 4.0, respectively. Therefore, in FIGS. 4 to 6, the output voltage Vo is 1.5. × Vin, 2 × Vin, 4
× Vin.

In the first embodiment, the first DC reactor L1 and the second DC reactor L2 are independently manufactured, and the first boost chopper circuit and the second boost chopper circuit are completely independently connected in parallel. In contrast to the configuration in which the first switch element SW1 and the second switch element SW2 are simultaneously turned on / off in the structure (hereinafter, this configuration is referred to as “standard configuration”), the first embodiment is compared with the standard configuration. The self-inductances of the first and second DC reactors L1 and L2 are considered to be different from L _L1 and L _L2 to (L + M).

As is apparent from the above equation (3), dI _L / dt when the self-inductance is (L + M) is smaller than when the self-inductance is L (that is, the slope of the current I _L becomes more gradual). Thus, the first embodiment is characterized in that the slopes of the currents I _L1 and I _L2 flowing through the first and second DC reactors L1 and L2 can be suppressed as compared with the standard configuration.

The two step-up chopper circuit connected in parallel configuration, the input current waveform Iin becomes to the sum of triangular the waveforms of the current I _L1, I _L2, the variation width of the waveform of the current I _L1, I _L2 As the (difference between I _OFF and I _ON ) increases, the fluctuation range of the input current Iin increases. However, the first embodiment has an advantage that the fluctuation range of the input current Iin can be suppressed with respect to the standard configuration.

  In the first embodiment, the configuration in which two boost chopper circuits are connected in parallel has been described. However, the above can also be applied to a case in which three or more boost chopper circuits are connected in parallel.

For example, FIG. 7 shows a power supply operation when three boost chopper circuits are connected in parallel and the three switch elements SW1, SW2, and SW3 are simultaneously turned on / off with a drive pulse having a duty ratio of 50%. It is a waveform diagram. In this case, the three DC reactors L1, L2, and L3 are connected to each other so that the legs 211a ', 211b', and 211c 'of the common core 211' are depolarized as shown in FIG. It is produced as a reactor L1, L2, DC reactor 21, each winding 212, 213, and 214 were wound each L3 '.

As shown in FIG. 7, even in a configuration in which three boost chopper circuits are connected in parallel, the currents I _L1 , I _L2 , and I _L3 of the first to third DC reactors L1, L2, and _L3 have substantially the same triangular wave shape. The voltage on the load side of each of the reactors L1, L2, and L3 also changes to a ground level during the on period of the first to third drive pulses S1, S2, and S3, and changes to β × Vin during the off period. Therefore, even in a configuration in which three boost chopper circuits are connected in parallel, the first to third boost chopper circuits are substantially operated simultaneously and independently from each other, and DC energy is supplied to the load 3 by the boost voltage by each boost chopper circuit. The supplying operation can be performed.

  Next, a second embodiment of the boost chopper device according to the present invention will be described.

  The second embodiment differs from the first embodiment only in the first and second drive pulses S1 and S2, and the configuration of an equivalent electric circuit is the same as that shown in FIG. Therefore, hereinafter, the power supply operation of the boost chopper device by the first and second drive pulses S1 and S2 will be described with reference to the waveform diagram of FIG. FIG. 9 is a waveform diagram showing the power supply operation of the step-up chopper device 2 of the second embodiment, and is when the duty ratio of the first and second drive pulses S1, S2 is 25%.

  In the second embodiment, the control circuit 22 uses the first switch element SW1 and the second switch pulse SW1 and the second drive pulse S1 and the second drive pulse S1 and S2 with a fixed frequency and a predetermined duty ratio so that the ON periods do not overlap each other. Is supplied to each gate terminal of the switch element SW2. Specifically, the control circuit 22 supplies the same drive pulse to the first switch element SW1 and the second switch element SW2 by shifting the phase by 180 °.

In the first embodiment, the first and second drive pulses S1 and the first and second drive pulses S1 and 1 are set so that the first DC reactor L1 and the second DC reactor L2 simultaneously repeat the accumulation of the DC energy and the release of the accumulated energy. Since the on / off operation of the second switch elements SW1 and SW2 is controlled, as shown in (3) above, the mutual inductance M between the first DC reactor L1 and the second DC reactor L2 is respectively The self-inductances L _L1 and L _L2 (= L) were increased.

  In the second embodiment, when the duty ratio D [%] is smaller than 50%, for example, as shown in FIG. 9, the first switch element SW1 and the second switch element SW2 are (SW1, SW2): ( (OFF, OFF) → (ON, OFF) → (OFF, OFF) → (OFF, ON) → (OFF, OFF) When one switch element is OFF, the other switch element is turned ON. For this reason, the above equation (3) cannot be applied to the ON periods of the first and second switch elements SW1 and SW2.

In the second embodiment, when one switch element performs an on / off operation, the other switch element is always in an off state. Boost chopper circuit, current I _L increases monotonically to accumulate DC energy to the DC reactor during the ON period of the switching element flows, release the DC energy stored in the DC reactor in the OFF period of the switching element to the capacitor and the load current I _L decreases monotonically to flow. Therefore, in the second embodiment, when the first switch element SW1 is turned on, the second switch element SW2 is turned off, so that the DC energy stored in the second DC reactor L2 is transferred to the capacitor C When the current I _L2 that monotonously decreases so as to be discharged to the load 3 flows, the current I _L1 that monotonously increases so as to accumulate DC energy in the first DC reactor L1 flows. The same applies to the reverse case.

For example, in the state where the second switch element SW2 is off, the voltage Ve at the P4 terminal on the load side of the second DC reactor L2 is (Vin + V _L2 ). If the current I _L1 does not flow through the first DC reactor L1 when the first switch element SW1 is in the OFF state, the second reactor voltage V _L2 of the second DC reactor _L2 is expressed by dI _{L1 in the} above equation (2). Since it is expressed by L _L2 · dI _L2 / dt with / dt = 0, and dI _L2 / dt <0, the P4 terminal on the load side of the second DC reactor L2 has a positive polarity (for example, (Refer to the timing level immediately before (a) of the voltage Ve in FIG. 9).

In this state, when the first switch element SW1 is turned on (see, for example, the timing in FIG. 9A), the power supply voltage Vin of the DC power supply 1 is applied to the first DC reactor L1, and dI _L1 / dt (> 0) current I _L1 flows, so that the current I _L2 of the second DC reactor L2 is suddenly reduced to zero in order to induce a voltage in the second DC reactor L2 so that the P3 terminal on the power supply side has a positive polarity. To lower. When the current I _L2 becomes zero (see the timing of FIG. 9B), the current I _L1 of the first DC reactor L1 causes a voltage of M · dI _L1 / dt to flow across the second DC reactor L2. Induced.

Since the polarity of the voltage of M · dI _L1 / dt is opposite to that of the voltage of L _L2 · dI _L2 / dt, the second DC reactor L2 has an M polarity so that the P3 terminal on the power supply side has a positive polarity. A voltage of dI _L1 / dt is induced. Therefore, the voltage Ve at the P4 terminal on the load side of the second DC reactor L2 is substantially zero (Vin−V _L2 ≈0) when the first switch element SW1 is on (the voltage Ve of FIG. Refer to the timing level immediately after b).

  In other words, the second switch element SW2 is turned off, and the first switch element SW1 is turned on while the DC energy accumulated in the second DC reactor L2 is released to the capacitor C and the load 3 during the off period. , Immediately, the discharge of the stored energy to the capacitor C and the load 3 is stopped. Thereafter, no DC energy is stored in the second DC reactor L2 until the second switch element SW2 is turned on, and the capacitor C Neither is it discharged into the load 3.

  As a result, in the second embodiment, the ON operation of the first switch element SW1 performs a function of switching the energy supply operation by the second boost chopper circuit to the energy supply operation by the first boost chopper circuit. The same applies to the case where the first switch element SW1 is turned off and the second switch element SW2 is turned on (for example, refer to the timing in FIG. 9D).

That is, in the waveform diagram of FIG. 9, for example, the first switching element SW1 at a timing of (a) is turned on, is induced by the current I _L1 of the first DC reactor L1 to the second DC reactor L2 M The current I _L2 discharged from the second DC reactor L2 to the capacitor C and the load 3 at the voltage of dI _L1 / dt is immediately stopped, and the second switch element SW2 is turned on from the timing (b) ( The operation is switched to the energy supply operation by the first boost chopper circuit until the timing d).

During the period from (b) to (d), when DC energy is accumulated in the first DC reactor L1 until the timing of (c) when the first switch element SW1 is turned off, and the first switch element SW1 is turned off. The stored energy is released to the capacitor C and the load 3. The discharge of the stored energy to the capacitor C and the load 3 is continued until the timing (f) when the first switch element SW1 is turned on next unless the second switch element SW2 is turned on. Since the second switch element SW2 is turned on at the timing (d), the current I _L1 discharged from the first DC reactor L1 to the capacitor C and the load 3 is immediately stopped, and the second switching element SW2 is turned on from the timing (e). The switching operation is switched to the energy supply operation by the second step-up chopper circuit until the timing (f) when the first switch element SW1 is turned on next.

By performing the operation as described above, the voltage Ve repeats the following waveform changes. That is, the voltage Ve is substantially zero (Vin−V _L2 ≈0) when the first switch element SW1 is turned on, and is maintained at substantially zero (Vin−V _L2 ≈0) during the on period. When the first switch element SW1 is turned off, it is almost inverted to β × Vin (Vin + V _L2 ≈β × Vin), and then the second switch element SW2 is turned on, and the step-up chopper operation is performed in the second chopper circuit. is switched, once, it drops to the ground level. When the second switch element SW2 is turned off, the voltage Ve returns to the level of β × Vin. After that, when the first switch element SW1 is turned on, the voltage Ve is substantially zero (Vin−V _L2 ≈0). descend.

The voltage Vd repeats the same waveform change. That is, the voltage Vd becomes substantially zero (Vin−V _L1 ≈0) when the second switch element SW2 is turned on, and is kept substantially zero (Vin−V _L1 ≈0) during the on period. When the second switch element SW2 is turned off, the inversion is approximately β × Vin (Vin + V _L1 ≈β × Vin), and then the first switch element SW1 is turned on, and the boost chopper operation is performed in the first chopper circuit. is switched, once, it drops to the ground level. When the first switch element SW1 is turned off, the voltage Vd returns to the level of β × Vin. After that, when the second switch element SW2 is turned on, the voltage Vd is almost zero (Vin−V _L1 ≈0). descend.

  In the second embodiment, the step-up rate β is β = 1 / (1−N × D) (N is the number of step-up chopper circuits in parallel). Therefore, in FIG. 9, the boost rate β = 1 / (1-2 × 0.25) = 2.0.

On the other hand, the current I _L1 of the first DC reactor L1, the first switch element SW1 is turned on, soaring as rapidly to zero current I _L2 of the second DC reactor L2, the current I _L2 From the timing when becomes zero, it increases monotonically so as to satisfy Vin = L1 × dI _L1 / dt, and DC energy is accumulated in the first DC reactor L1. Thereafter, when the first switch element SW1 is turned off, the current I _L1 turns to monotonously decrease, and the accumulated DC energy is released to the capacitor C and the load 3 ((a) to (d) of the current I _{L1 in} FIG. 9). Refer to the waveform for the period of When the second switch element SW2 is turned on, the current I _L2 flows through the second DC reactor L2, thereby causing the current I _L1 to suddenly become zero.

The current I _L1 of the first DC reactor L1 does not flow until the first switch element SW1 is turned on after the second switch element SW2 is turned on and the current I _L1 becomes zero, and the first switch element SW1 is turned on. The above change is performed from when SW1 is turned on until the second switch element SW2 is turned on, and such change is repeated thereafter.

The current I _{L2 of} the second DC reactor L2 changes in the same way as the current I _{L1 of} the first DC reactor L1, but after the first switch element SW1 is turned on and the current I _L2 becomes zero, the second current _{L L2} is zero. The current does not flow until the switching element SW2 of the first DC reactor L1 is turned on, and the current I _{L1 of} the first DC reactor L1 is changed from the second switching element SW2 to the turning on of the first switching element SW1. And different.

In the second embodiment, since the waveforms of the currents I _L1 and I _L2 flowing through the first and second DC reactors L1 and L2 are triangular, during the period in which each step-up chopper circuit is operating, the current I period of the triangular waveform of the input current Iin obtained by adding the _L1 and the current I _L2 is a half relative to the period of the triangular waveform of the input current Iin of the first embodiment. Therefore, in the second embodiment, the fluctuation range of the input current Iin can be made smaller than in the first embodiment. On the other hand, in the second embodiment, each boost chopper circuit performs intermittent operation alternately every half cycle of the first and second drive pulses S1, S2, so that the drive efficiency of each boost chopper circuit is the first. It is lower than the embodiment.

  When the duty ratio D [%] is 50%, the first switch element SW1 and the second switch element SW2 repeat (SW1, SW2): (ON, OFF) → (OFF, ON). The period during which both switch elements are simultaneously (off, off) is eliminated.

  In the waveform diagram shown in FIG. 9, when the duty ratio D [%] is gradually increased from 25% to 50%, the first switch element SW1 and the second switch element SW2 are simultaneously turned off (for example, FIG. 9). (Period from (c) to (d)), the period during which the DC energy stored in the DC reactor is released to the capacitor C and the load 3 is reduced during the period in which each boost chopper circuit is operating as a boost chopper. become. When the duty ratio D [%] is set to 50%, it is considered that the period for discharging the DC energy to the capacitor C is lost.

  FIG. 10 is a waveform diagram when the duty ratio D [%] is 50% in the second embodiment.

As shown in the figure, each time the first and second switch elements SW1 and SW2 are turned on, the currents I _L1 and I _L2 flowing through the first and second DC reactors L1 and _L2 are alternately switched, Either one of the currents flows. This is the same when the duty ratio is made smaller than 50%. However, when the duty ratio is made 50%, the first DC reactor is respectively used in the ON period of the first and second switch elements SW1 and SW2. Only DC energy is stored in the L1 or the second DC reactor L2, and theoretically no DC energy is discharged to the capacitor C and the load 3. However, in practice, since the current cannot be switched instantaneously, DC energy is supplied to the capacitor C and the load 3 at a short period during which the current switches, and the step-up ratio at that time becomes very large. . Even when the duty ratio is greater than 50%, there is no period in which the first and second switch elements SW1 and SW2 are simultaneously turned off. Therefore, it can be analogized that the above operation is similarly performed at a duty ratio of 50% or more. be able to. Therefore, the second embodiment is suitable for the step-up chopper operation when the duty ratio D [%] is in a range smaller than 50%.

  As described above, the second embodiment differs from the first embodiment in that the first boost chopper circuit and the second boost chopper circuit are 1/2 of the first drive pulse S1 or the second drive pulse S2. It is configured to operate alternately with a period.

  In the first embodiment, the first boost chopper circuit and the second boost chopper circuit simultaneously perform the boost chopper operation, so that the capacitor C can be shared by the first boost chopper circuit and the second boost chopper circuit. However, in the second embodiment, the capacitor C is shared by the first boost chopper circuit or the second boost chopper circuit in a time-sharing manner, so that it has a large capacity as in the first embodiment. No element is required.

  In the second embodiment, the configuration in which two boost chopper circuits are connected in parallel has been described. However, the above description can also be applied to a case in which three or more boost chopper circuits are connected in parallel.

For example, FIG. 11 shows a power supply when three boost chopper circuits are connected in parallel and the three switch elements SW1, SW2 and SW3 are turned on / off simultaneously with a drive pulse having a duty ratio of 20%. It is a wave form diagram which shows supply operation | movement. In this case, the configuration of the three DC reactors L1, L2, and L3 is the same as that shown in FIG. Further, in FIG. 11, the step-up rate β = 1 / (1−3 × 0.20) = 2.5.

  As shown in FIG. 11, even in a configuration in which three boost chopper circuits are connected in parallel, the first to third boost chopper circuits are operated in a time-sharing manner for each 1/3 period and boosted by each boost chopper circuit. It turns out that the operation | movement which supplies DC energy to the load 3 with a voltage can be made.

  In general, if the number of boost chopper circuits connected in parallel is N, each boost chopper circuit is switched and operated at equal intervals. Therefore, the switch elements of each boost chopper circuit are turned on by 360 ° / N each other. It is good to make it shift. In this way, the fluctuation range of the input current Iin can be effectively suppressed.

  Next, a third embodiment of the boost chopper device according to the present invention will be described.

  The third embodiment differs from the first embodiment in the structure of the DC reactor 21 and the first and second drive pulses S1, S2. The difference in the structure of the DC reactor 21 is that the winding 212 of the first DC reactor L1 and the winding 213 of the second DC reactor L2 are wound in the same direction as shown in FIG. It is. That is, the first DC reactor L1 and the second DC reactor L2 of the third embodiment have the same structure as that of the additive-polarity transformer.

  Therefore, although not shown, the equivalent electric circuit configuration of the third embodiment is that the position of the black circle of the second DC reactor L2 in the DC reactor 21 is changed to the P4 terminal side in FIG. The position of the black circle of the first DC reactor L1 in the reactor 21 is changed to the P2 terminal side.

  In the third embodiment, the control circuit 22 is connected to the first switch element SW1 so that the ON periods of the first and second drive pulses S1 and S2 having a fixed frequency and a duty ratio of 50% do not overlap each other. The voltage is supplied to each gate terminal of the second switch element SW2. When the duty ratio is 50%, the second drive pulse S2 is turned off when the first drive pulse S1 is turned on, and the second drive pulse S2 is turned off when the first drive pulse S1 is turned off. Since they are turned on, the same drive pulse is supplied to the first switch element SW1 and the second switch element SW2 with the phase shifted by 180 °, respectively, or the duty ratio supplied to the first switch element SW1 is 50%. It may be said that the drive pulse level is inverted and supplied to the second switch element SW2. Alternatively, it may be said that the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 so that the on / off states are reversed.

The DC reactor 21 of the first embodiment has a structure similar to that of a depolarizing transformer, whereas the DC reactor 21 of the third embodiment has a structure similar to that of a positive polarity transformer. Therefore, when the first drive pulse S1 and the second drive pulse S2 have the same phase (the ON periods overlap) as in the first embodiment, the first and second switch elements SW1, SW2 Are simultaneously turned on, dI _L1 / dt = dI _L2 / dt = dI _L / dt> 0, but the voltage M · dI _L2 / dt induced across the first DC reactor L1 by mutual induction. The polarity of is opposite to that in the first embodiment. The polarity of the voltage M · dI _L1 / dt induced at both ends of the second DC reactor L2 by mutual induction is also the same.

Accordingly, when the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 in the same phase, the expression corresponding to the above expression (3) becomes the following expression (4). . According to the following equation (4), since thereby the voltage generated by self-induction _(L × dI L / dt) is offset by a voltage generated by mutual induction _{(M × dI L / dt)} , substantially first This is equivalent to the reduction of the self-inductance of the direct current reactor L1 from L to (LM). The same applies to the second DC reactor L2.

When the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 in the same phase, for example, in the ON period of the first and second switch elements SW1 and SW2, (4) so as to satisfy the formula, first with a very large rate of change, it will respectively applying a current I _L to the second DC reactors L1, L2. Therefore, in this case, it is necessary to provide the DC reactor 21 that can withstand this current, the first and second switch elements SW1 and SW2, and the diodes D1 and D2.

  On the other hand, when the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 so that the on / off states are reversed, the first switch element SW1 is turned on. When the DC energy is stored in the first DC reactor L1, the second switch element SW2 is turned off, so that the DC energy stored in the second DC reactor L2 is discharged from the capacitor C and the load 3 When the second switch element SW2 is on (direct current energy is stored in the second direct current reactor L2), the first switch element SW1 is off, so the first direct current reactor L1 The DC energy stored in is discharged to the capacitor C and the load 3.

In the on period of the first switching element SW1, a first DC reactor _L1 dI L1 / dt> 0 current I _L1 flows in the current I _L2 of dI _L2 / dt <0 flows through the second DC reactor L2 However, the voltage (M · dI _L2 / dt) induced in the first DC reactor L1 by mutual induction is the same as the voltage (L _L1 · dI _L1 / dt) induced in the first DC reactor L1 by self-induction. Polarity. Similarly, even during the ON period of the second switch element SW2, a current I _L2 of dI _L2 / dt> 0 flows through the second DC reactor L2, and a current I of dI _L1 / dt <0 flows through the first DC reactor L1. _{Although L1} flows, the voltage (M · dI _L1 / dt) induced in the second DC reactor L2 by mutual induction is the voltage (L _L2 · dI _L2 / dt) induced in the second DC reactor L2 by self-induction. ) With the same polarity.

Accordingly, when the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 so that the on / off states are reversed, the first and second switch elements SW1 and SW2 are switched. in SW2 oN period, so as to satisfy the equation (3), first, each from flowing current I _L to the second DC reactors L1, L2, it is possible to normal boosting chopper operation. Moreover, in this case, the first and second drive pulses S1, S2 are set to the same as the first and second switch elements SW1, SW2 with respect to the DC reactor 21 and the first, second switch elements SW1, SW2. there is no need to consider a sudden change in the current I _L as in the case of supplying phase.

For this reason, in the third embodiment, the first and second drive pulses S1 and S2 are supplied to the first and second switch elements SW1 and SW2 so that the on / off states are reversed. As described above, in the third embodiment, the current I _L flows through the first and second DC reactors L1 and L2 so as to satisfy the above expression (3). Therefore, the third embodiment is also the first embodiment. Similar to the configuration, a first step-up chopper circuit having a first DC reactor L1 having a substantially self-inductance (L + M) and a second step-up chopper circuit having a second DC reactor L2 having a self-inductance (L + M); Are operated independently of each other.

  However, in the third embodiment, the second switch element SW2 is off when the first switch element SW1 is on, and the second switch element SW2 is on when the first switch element SW1 is off. When DC energy is accumulated in the first DC reactor L1, the DC energy accumulated from the second DC reactor L2 is discharged to the capacitor C and the load 3, and the DC energy accumulated from the first DC reactor L1. Is discharged to the capacitor C and the load 3, the operation of storing DC energy in the second DC reactor L2 is repeated.

  That is, the third embodiment differs from the first embodiment in that when one boost chopper circuit stores DC energy, the DC energy stored in the other boost chopper circuit is discharged to the capacitor C and the load 3. It operates in a mutually complementary relationship with the storage and release of DC energy.

Accordingly, the waveforms of the currents I _L1 and I _L2 and the input current Iin of the first and second DC reactors L1 and L2 of the third embodiment are also triangular like the first embodiment, but the third embodiment In the embodiment, when the current I _{L1 of} the first DC reactor L1 monotonically increases, the current I _L2 of the second DC reactor L2 monotonously decreases, and the current I _{L1 of} the first DC reactor L1 monotonously decreases. Since the current I _L2 of the second DC reactor L2 monotonically increases when it is, the fluctuation range of the input current Iin obtained by adding the current I _L1 and the current I _L2 is smaller than that of the first embodiment.

  FIG. 13 is a waveform diagram showing the power supply operation of the step-up chopper device 2 of the third embodiment, and is when the duty ratio of the first and second drive pulses S1, S2 is 50%.

As apparent from the comparison between the waveform diagram of FIG. 13 and the waveform diagram of FIG. 5, the waveform diagram of FIG. 13 is the current of the second drive pulse S2 and the second DC reactor L2 in the waveform diagram of FIG. The phase of the waveform of the voltage Ve at I _L2 and the connection point e is delayed by 180 °.

The current I _L1 of the first DC reactor L1 is the waveform of the current I _L2 of the second DC reactor L2 in the same triangular, current I _L2 is because delayed 180 ° relative to the current I _L1, third embodiment In the embodiment, the fluctuation range of the input current Iin obtained by adding the current I _L2 to the current I _L1 can be made substantially zero. Further, when the voltage Vd is at the ground level, the voltage Ve is β × Vin, and when the voltage Ve is at the ground level, the voltage Vd is β × Vin. Therefore , the output voltage Vo in which the waveform of the voltage Ve is superimposed on the waveform of the voltage Vd. The waveform hardly fluctuates and can be stably held at the boost level β × Vin.

  In the third embodiment, since the above operation is performed when the on / off operation of the first switch element SW1 and the second switch element SW2 is opposite to each other, the boost level is changed by changing the duty ratio. In this case, the first drive pulse S1 and the second drive pulse S2 are respectively switched so that the on / off operations of the first switch element SW1 and the second switch element SW2 are opposite to each other. It is good to supply to SW1 and 2nd switch element SW2. That is, in the third embodiment, a drive pulse with a predetermined duty ratio is supplied to one switch element, and the level of the drive pulse is inverted and supplied to the other switch element.

  In the third embodiment, if the duty ratio of one boost chopper circuit is D1 (%), the duty ratio D2 of the other boost chopper circuit is (100−D1) (%). Since the output voltage Vo of the step-up chopper device 2 is considered to be determined by the larger one of the duty ratios D1 and D2, the third embodiment operates at a duty ratio of 50% or more. Therefore, the third embodiment is suitable for the step-up chopper operation when the duty ratio is larger than 50%.

  Next, a fourth embodiment of the boost chopper device according to the present invention will be described.

  The fourth embodiment is a modification of the third embodiment, and the first and second drive pulses S1, S2 are different from the third embodiment. That is, the first and second drive pulses S1 and S2 are the same as those in the second embodiment. The control circuit 22 of the fourth embodiment supplies the same drive pulse with a fixed frequency and a predetermined duty ratio to the first switch element SW1 and the second switch element SW2, respectively, with the phase shifted by 180 °. Therefore, in the fourth embodiment, in the region where the duty ratio exceeds 50%, both the first switch element SW1 and the second switch element SW2 are on, and in the region where the duty ratio is less than 50%, There is a period in which both the first switch element SW1 and the second switch element SW2 are off.

  Since the operation in the period in which the on / off operations of the first and second switch elements SW1 and SW2 are opposite to each other is the same as that in the third embodiment, here, the first switch element SW1 and the second switch element SW2 An operation during a period in which both switch elements SW2 are turned on and off will be described.

  During the period when both the first switch element SW1 and the second switch element SW2 are turned on and off, the first and second drive pulses S1 and S2 are in phase with the first and second switch elements SW1 and SW2. Therefore, the above equation (4) is established. That is, it is substantially equivalent to a reduction in self-inductance of the first DC reactor L1 and self-inductance of the second DC reactor L2 from L to (LM).

Therefore, in the period when both the first switch element SW1 and the second switch element SW2 are turned on and off, the first and second DC reactors are changed at a very large change rate so as to satisfy the above expression (4). The current _{IL is} passed through L1 and L2, respectively.

  As described above, in the fourth embodiment, in the region where the duty ratio exceeds 50% in addition to the operation of the third embodiment, both the first switch element SW1 and the second switch element SW2 are on. And a second step-up chopper circuit having a first DC reactor L1 having a self-inductance (LM) and a second DC reactor L2 having a self-inductance (LM) during that period. At the same time, the operation of accumulating DC energy in the first DC reactor L1 and the second DC reactor L2 is added to the chopper circuit.

  On the other hand, in the region where the duty ratio is less than 50%, there is a period in which both the first switch element SW1 and the second switch element SW2 are off, and the first direct current of self-inductance (LM) is in that period. The first step-up chopper circuit having the reactor L1 and the second step-up chopper circuit having the second DC reactor L2 having a self-inductance (LM) are simultaneously operated to release DC energy to the capacitor C and the load 3. It will be.

  FIG. 14 is a waveform diagram showing the power supply operation of the step-up chopper device 2 in the region where the duty ratio exceeds 50% in the fourth embodiment, and the duty ratio of the first and second drive pulses S1, S2 is 75%. It's time.

As shown in the figure, there is a period in which both the first and second switch elements SW1 and SW2 are on, and the currents I _L1 and I2 flowing in the first and second DC reactors L1 and L2 during that period. _L2 jumps greatly, but when the first switch element SW1 or the second switch element SW2 is turned off thereafter, the DC energy accumulated in the first and second DC reactors L1 and L2 is transferred to the capacitor C and the load. It can be seen that the step-up chopper operation is performed without any problem.

  FIG. 15 is a waveform diagram showing the power supply operation of the step-up chopper device 2 in the region where the duty ratio is less than 50% in the fourth embodiment, and the duty ratio of the first and second drive pulses S1, S2 is 25%. It's time.

As shown in the figure, during the period when both the first and second switch elements SW1 and SW2 are turned off, that is, the DC energy accumulated in the first and second DC reactors L1 and L2 is immediately transferred to the capacitor C and the load. DC energy to the first DC reactor L1 or the second DC reactor L2 when the first switch element SW1 or the second switch element SW2 is turned on after that, although there is a period of time to be released to 3 It can be seen that the boosting chopper operation is performed without any problem.

  The fourth embodiment is not limited by the duty ratio as in the third embodiment, but has a feature that the fluctuation range of the input current Iin is larger than that in the third embodiment.

  In the above embodiment, the DC reactor 21 is configured as shown in FIGS. 2 and 8, but may be configured as shown in FIGS. 16 and 17. FIG. 16 is a modification of the DC reactor 21 of FIG. 2, in which a leg portion 215 around which no winding is wound is provided between two leg portions 211 a and 211 b of the core 211. On the other hand, FIG. 17 shows a modification of the DC reactor 21 ′ of FIG. 8, and a leg portion 215 ′ in which no winding is wound around the center of the three leg portions 211a ′, 211b ′, 211c ′ of the core 211 ′. And both ends of the leg portions 211a ′, 211b ′, 211c ′ are respectively connected to both ends of the leg portion 215 ′.

  In the DC reactor 21 ″ shown in FIG. 16, the magnetic field generated in the core 211 due to the current flowing through the windings 212 and 213 mainly passes through the leg portion 215. Therefore, the first DC reactor L1 and the second DC The mutual inductance M between the reactor L2 and the reactor L2 can be reduced. The same applies to the DC reactor 21 "shown in Fig. 17, and the magnetic field generated in the core 211 'mainly due to the current flowing through the windings 212, 213, 214 is mainly. Since the leg portion 215 ′ is passed, the mutual inductance M between the first DC reactor L1, the second DC reactor L2, and the third DC reactor L3 can be reduced.

  When the number of direct current reactors is four or more, in FIG. 17, as many leg portions as the number of direct current reactors are arranged around the leg portion 215 ′, and both ends of the leg portions are connected to both end portions of the leg portion 215 ′. The DC reactor 21 ″ may be manufactured by using the core connected to the base and winding the winding of each DC reactor around each leg around the leg 215 ′.

  When the DC reactor 21 ″ shown in FIGS. 16 and 17 is used, the influence of the mutual inductance M in the boost chopper operation of each boost chopper circuit can be reduced.

  As described above, according to the first to fourth embodiments, a plurality of windings are wound around a common core to integrally configure a plurality of DC reactors, and depending on the polarity of the windings of the DC reactors Since the ON / OFF operations of the plurality of switch elements are appropriately controlled, the boost chopper device 2 can be reduced in size, weight, and cost without adversely affecting the boost chopper operation of each boost chopper circuit. It becomes possible.

  As described above, the first to fourth embodiments have characteristics unique to each embodiment in the characteristics of the step-up chopper operation. Therefore, the embodiments are selectively used according to the load 3 to which the step-up chopper device 2 is applied. It is good to do so.

It is a figure which shows the structure of the equivalent electric circuit of 1st Embodiment of the step-up chopper circuit based on this invention. It is a perspective view which shows the structure of two DC reactors which made the core common. It is a figure for demonstrating how to wind the winding of two DC reactors. It is a wave form diagram which shows power supply operation when the pressure | voltage rise chopper apparatus of 1st Embodiment is driven with the drive pulse of 33% of duty ratio. It is a wave form diagram which shows the power supply operation | movement when the boost chopper apparatus of 1st Embodiment is driven with the drive pulse of 50% of duty ratio. 6 is a waveform diagram showing a power supply operation when the boost chopper device of the first embodiment is driven with a drive pulse having a duty ratio of 75%. FIG. FIG. 7 is a waveform diagram showing a power supply operation of a modification of the first embodiment in which a boost chopper device is connected in parallel with three boost chopper circuits and driven by a drive pulse with a duty ratio of 50%. It is a perspective view which shows the structure of three DC reactors when it is set as the structure which connected the 3 step-up chopper circuits in parallel. FIG. 10 is a waveform diagram showing a power supply operation when the step-up chopper device of the second embodiment is driven with a drive pulse having a duty ratio of 25%. It is a wave form diagram which shows power supply operation when the pressure | voltage rise chopper apparatus of 2nd Embodiment is driven with the drive pulse of 50% of duty ratio. It is a wave form diagram which shows the power supply operation | movement of the modification of 2nd Embodiment which makes a step-up chopper apparatus parallel connection of three step-up chopper circuits, and drives it with the drive pulse of 20% of duty ratio. It is a figure for demonstrating how to wind the winding of two DC reactors of 3rd Embodiment. It is a wave form diagram which shows power supply operation when the pressure | voltage rise chopper apparatus of 3rd Embodiment is driven with the drive pulse of 50% of duty ratio. It is a wave form diagram which shows power supply operation when the pressure | voltage rise chopper apparatus of 4th Embodiment is driven with the drive pulse of 75% of duty ratio. It is a wave form diagram which shows power supply operation when the pressure | voltage rise chopper apparatus of 4th Embodiment is driven with the drive pulse of 25% of duty ratios. It is a figure which shows the modification of the structure of two DC reactors which made the core common. It is a figure which shows the modification of the structure of three direct current reactors which made the core common. It is a figure which shows the structure of the equivalent electric circuit of the conventional boost chopper apparatus.

DESCRIPTION OF SYMBOLS 1 DC power supply 2 Boost chopper device 21, 21 ', 21 "DC reactor 211, 211' Core 212, 213, 214 Winding 22 Control circuit L1 1st DC reactor L2 2nd DC reactor D1, D2 Diode SW1 1st Switch element SW2 second switch element C capacitor 3 load