JP2011130521A - Dc-dc converter - Google Patents

Abstract

A high-efficiency DCDC converter capable of supporting four-quadrant operation is provided.
A DCDC converter in which a primary power source is connected to a primary side of an isolation transformer and a first load is connected to a secondary side, the bridge-shaped primary side switch group and one end having a common potential point. An inductor connected to the other end of the first load connected to the first side, a secondary side first switch connecting the first polarity side of the secondary winding of the isolation transformer and the inductor, and a secondary side winding of the isolation transformer A secondary second switch for connecting the first polarity side of the wire and the common potential point, a secondary third switch for connecting the second polarity side of the secondary winding of the isolation transformer and the inductor, and insulation Control for generating a pulse wave that opens and closes each switch on the primary side and each switch on the secondary side, the fourth switch on the secondary side that connects the second polarity side of the secondary winding of the transformer and the common potential point A part.
[Selection] Figure 1

Description

  The present invention relates to a power supply device, and more particularly to a high-efficiency DCDC converter that can cope with a four-quadrant operation suitable for a measurement power supply.

  Insulated DCDC converters are widely used as power supply devices. FIG. 20 is a diagram showing a conventional configuration of a general full-bridge full-wave rectification type converter that is one type of insulated DCDC converter. The full-bridge full-wave rectification type converter shown in this figure is composed of a primary power source 1, a bypass capacitor 2 for voltage stabilization, a MOS-FET, etc., and a first switch 3a connected in a bridge shape. , Second switch 3b, third switch 3c, fourth switch 3d, isolation transformer 4, and first diode 5a, second diode 5b, third diode 5c, fourth diode constituting diode bridge 5 for full-wave rectification. A diode 5d, a bypass capacitor 6, a load 7, and a control unit 8 are provided.

  The primary power source 1 and the bypass capacitor 2 are connected in parallel, and the first switch 3a for switching the input to the first polarity side of the primary winding of the insulation transformer 4 is connected to these positive polarity sides. And a third switch 3c for switching the input to the second polarity side of the primary winding of the insulating transformer 4 is connected in parallel. The negative polarity side is connected to the first common potential point, the second switch 3b for switching the input to the first polarity side of the primary side winding of the isolation transformer 4, and the primary side winding of the isolation transformer 4 A fourth switch 3d for switching the input to the second polarity side of the line is connected in parallel.

  A bypass capacitor 6 and a load 7 are connected in parallel to the secondary winding of the insulating transformer 4 to a diode bridge 5 that performs full-wave rectification in a direction in which the first polarity side is positive. The negative polarity side of the load 7 and the other end of the bypass capacitor 6 are connected to a second common potential point.

  The control unit 8 senses the voltage at the end of the load 7 and generates a pulse waveform that periodically opens and closes the switches 3a to 3d so that the voltage at the end of the load 7 becomes constant. In the following, the display and description of the sense line for sensing the voltage at the end of the load 7 are omitted.

  FIG. 21 is a diagram showing a configuration of a conventional full-wave rectifying converter in which the secondary side circuit is of another type. In the example of this figure, an insulating transformer 41 having an intermediate tap on the secondary winding is used. The configuration on the primary winding side is the same as the example shown in FIG.

  The anodes of the diode 42 and the diode 43 are connected to the first polarity side and the second polarity side of the secondary winding of the insulating transformer 41, respectively, and the cathodes of both diodes are connected to the smoothing inductor 44. A bypass capacitor 45 and a load 46 are connected in parallel to the other end of the smoothing inductor 44. The negative polarity side of the load 7 and the other end of the bypass capacitor 45 are connected to the intermediate tap of the insulating transformer 41 and to the second common potential point.

  FIG. 22 shows an operation example of the first switch 3a, the second switch 3b, the third switch 3c, and the fourth switch 3d in the conventional insulated full-wave rectifier converter shown in FIGS. Each of the switches 3a to 3d is repeatedly turned on / off with a periodic pulse having a duty ratio of 50%, the second switch 3b is an inversion operation of the first switch 3a, and the fourth switch 3d is the third switch 3c. Inversion operation.

  The power conversion rate is maximized when the phase difference between the drive pulses of the first switch 3a and the third switch 3c is 180 degrees, but the control unit 8 can control the power conversion rate by shifting the phase of the drive pulse. It is like that.

JP-A-10-191624

  The above-described isolated DCDC converter is widely used as a power supply device because of its low circuit loss and high efficiency. However, since a diode is used for rectification on the secondary side, only unidirectional voltage / current generation occurs. I can't do it.

  For this reason, it is not suitable for use as a measurement power source that requires the generation of positive and negative polarities and the four-quadrant operation required to deal with positive and negative polarities in the current direction.

  For example, in a conventional insulation type DCDC converter, when a semiconductor test apparatus inspects a wafer, a voltage is applied in order to measure a basic characteristic of how much current flows when a DC voltage is applied to a transistor or a resistor. It is difficult to apply to a parametric measurement unit (PMU) power source or the like that is required to cope with four-quadrant operations for all positive and negative combinations in a plane with the current taken along the axis.

  Therefore, an object of the present invention is to provide a high-efficiency DCDC converter that can cope with four-quadrant operation.

  In order to solve the above-described problem, the DCDC converter according to the first aspect of the present invention has an insulating transformer, a primary power source is connected to the primary side of the insulating transformer, and the secondary side of the insulating transformer is connected. A DCDC converter for connecting a first load, wherein a negative polarity side is connected to a first common potential point and a positive polarity side of the primary power supply and a first polarity side of a primary winding of the isolation transformer are connected. A primary side first switch to be connected, a primary side second switch for connecting the first polarity side of the primary side winding of the isolation transformer and the first common potential point, and a positive electrode of the primary side power source A primary side third switch for connecting the active side and the second polarity side of the primary side winding of the isolation transformer, the second polarity side of the primary side winding of the isolation transformer and the first common potential point A primary side fourth switch for connecting the first and second terminals before one end is connected to the second common potential point An inductor connected to the other end of the first load, a secondary first switch connecting the first polarity side of the secondary winding of the isolation transformer and the inductor, and a secondary winding of the isolation transformer A second secondary switch that connects the first polarity side of the second transformer to the second common potential point, and a second secondary switch that connects the second polarity side of the secondary winding of the isolation transformer and the inductor. A switch, a secondary side fourth switch for connecting the second polarity side of the secondary winding of the isolation transformer and the second common potential point, the primary side switch, and the secondary side switch And a control unit for generating a pulse wave for opening and closing.

  Here, the control unit is configured so that the primary side second switch performs the reversing operation of the primary side first switch, and the primary side fourth switch performs the reversing operation of the primary side third switch. A section in which both the primary side first switch and the primary side third switch are on is referred to as section A, and the primary side first switch is on and the primary side third switch is on. The section in which the primary side first switch and the primary side third switch are both off are referred to as the C section, and the primary side first switch Is the section where the primary third switch is turned on and is referred to as section D, the first state is either on / off, and the second state is different from the first state, During the period corresponding to the A section and the D section, the secondary side first switch and the front switch The secondary side fourth switch is set to the first state, the secondary side second switch and the secondary side third switch are set to the second state, and during the period corresponding to the B section and the C section, the secondary side second switch One switch and the secondary side fourth switch can be set to the second state, and the secondary side second switch and the secondary side third switch can be set to the first state.

  Alternatively, during the period corresponding to section A, the secondary side first switch and the secondary side second switch are set to the first state, and the secondary side third switch and the secondary side fourth switch are set to the second state. During the period corresponding to section B, the secondary side first switch and the secondary side fourth switch are set to the first state, and the secondary side second switch and the secondary side third switch are set to the first state. During the period corresponding to section C, the secondary side first switch and the secondary side second switch are set to the second state, and the secondary side third switch and the secondary side fourth switch are The secondary side first switch and the secondary side fourth switch are set to the second state, and the secondary side second switch and the secondary side third switch are set to the first state during a period corresponding to the D section. May be in the first state.

  In order to solve the above problems, a DCDC converter according to a first aspect of the present invention includes an insulating transformer having an intermediate tap, and a primary power source is connected to a primary side of the insulating transformer, A DC-DC converter for connecting a first load to a secondary side, wherein a negative polarity side is connected to a first common potential point, a positive polarity side of the primary power supply and a first winding of a primary side winding of the isolation transformer. A primary-side first switch that connects the polarity side, a primary-side second switch that connects the first polarity side of the primary-side winding of the isolation transformer and the first common potential point, and the primary A primary third switch for connecting a positive polarity side of the power supply to a second polarity side of the primary winding of the isolation transformer, a second polarity side of the primary winding of the isolation transformer and the first polarity A fourth switch on the primary side that connects the first common potential point and a second common potential at one end. And an inductor connected to the other end of the first load connected to the intermediate tap, a secondary first switch connecting the inductor and the first polarity side of the secondary winding of the isolation transformer, A secondary second switch for connecting the second polarity side of the secondary winding of the isolation transformer and the inductor, a secondary third switch for connecting the intermediate tap and the inductor, and the primary And a controller for generating a pulse wave for opening and closing each switch on the secondary side and each switch on the secondary side.

  Here, the control unit sets the secondary side first switch to the first state, sets the secondary side second switch to the second state, and outputs the secondary side during the period corresponding to the A section and the D section. The third switch is turned off, and the secondary side first switch is set in the second state, the secondary side second switch is set in the first state, and the secondary side 3 switches can be turned off.

  Alternatively, during the period corresponding to the A section, the secondary side first switch and the secondary side second switch are turned off, the secondary side third switch is turned on, and during the period corresponding to the B section, The secondary side first switch is set to the first state, the secondary side second switch is set to the second state, the secondary side third switch is turned off, and during the period corresponding to section C, the secondary side The first switch and the secondary side second switch are turned off, the secondary side third switch is turned on, and during the period corresponding to section D, the secondary side first switch is set to the second state, and the 2 The secondary second switch may be in the first state, and the secondary third switch may be turned off.

  Further, the primary side third switch and the primary side fourth switch are replaced with capacitors, and a section where both the primary side first switch and the primary side third switch are off is defined as an AC section. The section in which the primary first switch is on and the primary third switch is off is referred to as section B, and the primary first switch is off and the primary third switch is off. When the section that is turned on is referred to as section D, the first state is either on / off, and the second state is different from the first state, the control unit is a period corresponding to the AC section. The secondary side first switch and the secondary side second switch are turned off, the secondary side third switch is turned on, and the secondary side first switch is turned on during the period corresponding to the B section. In the first state, the secondary side second switch is in the second state. The secondary side third switch is turned off, the secondary side first switch is set to the second state, the secondary side second switch is set to the first state during the period corresponding to the section D, and the 2 The secondary third switch may be turned off.

  In either case, it can further comprise a second load connected in parallel with the primary power source. Further, an isolator for insulating each of the primary side switch and the secondary side switch may be further provided.

  According to the present invention, a high-efficiency DCDC converter capable of supporting four-quadrant operation is provided.

It is a figure which shows the structure of the power supply device which is 1st Example of this invention. FIG. 6 is a timing diagram illustrating a control operation of the control unit when a positive voltage is applied to the first load and current flows into the load in the first embodiment. It is a figure which shows the flow of the electric current during the period corresponded to B area and C area. It is a figure which shows the flow of the electric current during the period corresponded to A area and D area. In 1st Example, it is a timing diagram explaining the control operation | movement of the control part in the case of sucking an electric current from the 1st load which generate | occur | produces a positive voltage. It is a figure which shows the flow of the electric current during the period corresponded to A area. It is a figure which shows the flow of the electric current during the period corresponded to B area. It is a figure which shows the flow of the electric current during the period corresponded to C area. It is a figure which shows the flow of the electric current during the period corresponded to D area. It is a figure which shows the structure of the power supply device which is 2nd Example of this invention. In 2nd Example, it is a timing diagram explaining the control operation | movement of a control part when a positive voltage is given to 1st load and an electric current flows into load. It is a figure which shows the flow of the electric current during the period corresponded to B area and C area. It is a figure which shows the flow of the electric current during the period corresponded to A area and D area. In 2nd Example, it is a timing diagram explaining the control operation | movement of the control part in the case of drawing in an electric current from the 1st load which generate | occur | produces a positive voltage. It is a figure which shows the flow of the electric current during the period corresponded to A area. It is a figure which shows the flow of the electric current during the period corresponded to B area and C area. It is a figure which shows the flow of the electric current during the period corresponded to D area. It is a figure which shows another structure of a power supply device. It is a timing diagram explaining control operation of a control part in another composition. It is a figure which shows the conventional structure of the general full bridge full wave rectification type | mold converter which is 1 type of an insulation type DCDC converter. It is a figure which shows the structure of the conventional full wave rectification type | mold converter in which the circuit of the secondary side is another system. It is a timing diagram which shows the operation example of the 1st switch in a conventional converter, a 2nd switch, a 3rd switch, and a 4th switch.

Embodiments of the present invention will be described with reference to the drawings.
<First embodiment>
FIG. 1 is a diagram showing a configuration of a power supply apparatus according to a first embodiment of the present invention. The power supply device shown in the figure includes a primary side power switch 11, a bypass capacitor 12 for voltage stabilization, and a primary side first switch 13a, Secondary side first switch 13b, primary side third switch 13c, primary side fourth switch 13d, insulating transformer 14, and secondary side first switch each configured by a MOS-FET or the like and connected in a bridge shape 15a, secondary side second switch 15b, secondary side third switch 15c, secondary side fourth switch 15d, inductor 16, bypass capacitor 17, first load 18, control unit 19, and isolator for insulation 20 and a second load 21.

  The primary side power supply 11 and the bypass capacitor 12 are connected in parallel, and on the positive polarity side, the primary side switch that switches the input to the first polarity side of the primary side winding of the insulation transformer 14 is connected. 1 switch 13a and the primary 3rd switch 13c which switches the input to the 2nd polarity side of the primary side coil of insulation transformer 14 are connected in parallel. The negative polarity side is connected to the first common potential point, and the primary side second switch 13b for switching the input to the first polarity side of the primary side winding of the insulation transformer 14; A primary side fourth switch 13d for switching input to the second polarity side of the secondary winding is connected in parallel. Further, a second load 21 is connected in parallel with the primary power supply 11. The second load 21 is used to consume power regenerated from the first load 18 on the secondary side.

  The inductor 16 is connected to the first polarity side of the secondary winding of the isolation transformer 4 via the secondary first switch 15a, and is connected to the second common potential point via the secondary second switch 15b. Has been. The second polarity side is connected to the same end of the inductor 16 via the secondary side third switch 15c, and is connected to the second common potential point via the secondary side fourth switch 15d. A bypass capacitor 17 and a first load 18 are connected in parallel to the other end of the inductor 16. The other end of the first load 18 and the other end of the bypass capacitor 17 are connected to a second common potential point.

  The controller 19 generates a pulse waveform that opens and closes the primary switches 13a to 13d and the secondary switches 15a to 15d. The control unit 19 senses the voltage at the end of the first load 18 or the current flowing through the first load 18 and controls the phase and duty ratio of the pulse waveform. As described above, the sense lines are not shown.

  An isolator 20 for ensuring insulation between the primary side and the secondary side is provided between the controller 19 and each of the switches 15a to 15d on the secondary side. However, the isolator 20 may be provided between the control unit 19 and the primary side switches 13a to 13d.

  Next, the operation of the power supply device in the first embodiment will be described. The control unit 19 performs the same control as that for the conventional switches 13a to 13d on the primary side. That is, the primary side switches 13a to 13d are repeatedly turned on / off by a periodic pulse with a duty ratio of 50%, and the primary side second switch 13b is an inversion operation of the primary side first switch 13a. The primary side fourth switch 13d is inversion operation of the primary side third switch 13c.

  The power conversion rate is maximized when the phase difference between the drive pulses of the primary side first switch 13a and the primary side third switch 13c is 180 degrees. The conversion rate can be controlled.

  Here, a section in which both the primary side first switch 13a and the primary side third switch 13c are on is referred to as section A, and the primary side first switch 13a is on and the primary side third switch 13c is on. Is a section B, and a section in which both the primary first switch 13a and the primary third switch 13c are both off is referred to as a section C, and the primary first switch 13a. A section in which is turned off and the primary third switch 13c is turned on is referred to as a D section.

In the present embodiment, the control unit 19 changes the timing for opening and closing each of the secondary switches 15 a to 15 d depending on whether the current flows into the first load 18 or when the current is sucked from the first load 18.
<1-1>
First, a control operation of the control unit 19 when a positive voltage is applied to the first load 18 and a current flows into the first load 18 will be described with reference to the timing chart of FIG. When a positive voltage is applied to the first load 18 and a current flows into the first load 18, for example, when a load that consumes general power is used as the first load 18, or as the first load 18 For example, charging is performed when a battery is used.

  During the period corresponding to the B section and the C section, as shown in FIG. 2, the secondary side first switch 15a and the secondary side fourth switch 15d are turned on, and the secondary side second switch 15b and the secondary side second switch 3 Switch 15c is turned off.

  FIG. 3 shows the current flow at this time. Note that the current flow on the primary side indicates the B section. During this period, a positive voltage is induced on the first polarity side of the secondary winding of the insulating transformer 14 by the pulse voltage with the first polarity of the primary winding of the insulating transformer 14 being the positive side. A positive voltage is applied to the first load 18 by the first side switch 15 a, and current flows into the first load 18.

  During the period corresponding to the A section and the D section, as shown in FIG. 2, the secondary side first switch 15a and the secondary side fourth switch 15d are turned off, and the secondary side second switch 15b and the secondary side first switch are turned off. 3 Switch 15c is turned on.

  FIG. 4 shows the current flow at this time. The primary current flow indicates the D section. During this period, a positive voltage is induced on the second polarity side of the secondary winding of the insulating transformer 14 by the pulse voltage with the second polarity of the primary winding of the insulating transformer 14 being the positive side. A positive voltage is applied to the first load 18 by the first side switch 15 c, and a current flows into the first load 18.

  When the control unit 19 repeats these operations, a current continuously flows into the first load 18. This operation can be regarded as performing the full-wave rectification operation conventionally performed by the diode bridge 5 by switching the secondary side switches 15a to 15d on / off.

  In addition, what is necessary is just to reverse on / off control of each switch 15a-15d of a secondary side about the case where a negative voltage is given to the 1st load 18 and an electric current flows into the 1st load 18. FIG. That is, during the period corresponding to the B section and the C section, the secondary side first switch 15a and the secondary side fourth switch 15d are turned off, and the secondary side second switch 15b and the secondary side third switch 15c are turned on. To. During the period corresponding to the A section and the D section, the secondary side first switch 15a and the secondary side fourth switch 15d are turned on, and the secondary side second switch 15b and the secondary side third switch 15c are turned off. To.

Therefore, when a current flows into the first load 18, both positive and negative voltages can be applied to the first load 18.
<1-2>
Next, in the first embodiment, a control operation of the control unit 19 when current is sucked from the first load 18 that generates a positive voltage will be described with reference to the timing chart of FIG. In the case of sucking current from the first load 18, for example, when discharging a battery that supplies power as the first load 18, or a higher-voltage separate power source is connected to the first load 18. This is the case.

  During the period corresponding to section A, as shown in FIG. 5, the secondary side first switch 15a and the secondary side second switch 15b are turned on, the secondary side third switch 15c and the secondary side fourth switch 15d. Turn off.

  FIG. 6 shows the current flow at this time. The energy supplied from the first load 18 is stored in the inductor 16.

  During the period corresponding to section B, as shown in FIG. 5, the secondary side first switch 15a and the secondary side fourth switch 15d are turned on, the secondary side second switch 15b and the secondary side third switch 15c. Turn off.

  FIG. 7 shows the current flow at this time. The energy supplied from the first load 18 and the energy accumulated in the inductor 16 are regenerated to the primary side through the insulating transformer 14 in the direction in which the first polarity side of the insulating transformer 14 becomes positive. . The regenerated energy is consumed by the second load 21 via the primary side first switch 13a.

  During the period corresponding to section C, as shown in FIG. 5, the secondary side first switch 15a and the secondary side second switch 15b are turned off, the secondary side third switch 15c and the secondary side fourth switch 15d. Turn on.

  FIG. 8 shows the current flow at this time. The energy supplied from the first load 18 is stored in the inductor 16 again.

  During the period corresponding to section D, as shown in FIG. 5, the secondary side first switch 15a and the secondary side fourth switch 15d are turned off, the secondary side second switch 15b and the secondary side third switch 15c. Turn on.

  FIG. 9 shows the current flow at this time. The energy supplied from the first load 18 and the energy accumulated in the inductor 16 are regenerated to the primary side through the insulating transformer 14 in the direction in which the second polarity side of the insulating transformer 14 becomes positive. . The regenerated energy is consumed by the second load 21 via the primary third switch 13c.

  When the control unit 19 repeats these operations, the current is continuously sucked from the first load 18. As described above, even when the first load 18 is a load that supplies electric power, it is possible to operate at a constant current or a constant voltage by regenerating the electric power to the primary side.

  The adjustment of the current value or voltage value in this case can be performed by adjusting the phase and duty ratio of the pulses that determine the A section, B section, C section, and D section. The control when the current is sucked from the first load 18 is performed in the operation of the A section and the B section corresponding to FIGS. 6 and 7, or the operation of the C section and the D section corresponding to FIGS. It is also possible to repeat the above, but it is preferable to perform the above-mentioned operation from the problem of the demagnetization of the insulating transformer 14.

  In addition, what is necessary is just to reverse on / off control of each switch 15a-15d of a secondary side about the case where an electric current is suck | inhaled from the 1st load 18 which generate | occur | produces a negative voltage.

  That is, during the period corresponding to section A, the secondary side first switch 15a and the secondary side second switch 15b are turned off, and the secondary side third switch 15c and the secondary side fourth switch 15d are turned on. During the period corresponding to the B section, the secondary side first switch 15a and the secondary side fourth switch 15d are turned off, and the secondary side second switch 15b and the secondary side third switch 15c are turned on. During the period corresponding to section C, the secondary side first switch 15a and the secondary side second switch 15b are turned on, and the secondary side third switch 15c and the secondary side fourth switch 15d are turned off. During the period corresponding to section D, the secondary side first switch 15a and the secondary side fourth switch 15d are turned on, and the secondary side second switch 15b and the secondary side third switch 15c are turned off.

Therefore, when the current is sucked from the first load 18, the first load 18 can cope with both positive and negative voltages. As described above, the power supply device according to the first embodiment can realize the four-quadrant operation. If the second load 21 is not a load that simply consumes power, but is a power regenerative circuit, and the regenerated power is regenerated to a system power supply or a line power supply, the overall power consumption of the apparatus is reduced. can do.
<Second embodiment>
Next, a second embodiment of the present invention will be described. FIG. 10 is a diagram showing a configuration of a power supply apparatus according to the second embodiment of the present invention. In the second embodiment, an insulating transformer 51 having an intermediate tap on the secondary winding is used. The configuration on the primary winding side is the same as in the first embodiment.

  The first polarity side, the second polarity side, and the intermediate tap of the secondary side winding of the insulating transformer 51 are respectively connected to the secondary side first switch 52, the secondary side second switch 53, and the secondary side third switch 54. An inductor 55 is connected via the via. A bypass capacitor 56 and a first load 57 are connected in parallel to the other end of the inductor 55.

  The other end of the first load 57 and the other end of the bypass capacitor 56 are connected to the intermediate tap and to the second common potential point.

  The controller 58 generates a pulse waveform that opens and closes the primary switches 13a to 13d and the secondary switches 52, 53, and 54. The control unit 58 senses the voltage at the end of the first load 57 or the current flowing through the first load 57 and controls the phase and duty ratio of the pulse waveform. As described above, the sense lines are not shown.

  An isolator 59 for ensuring insulation between the primary side and the secondary side is provided between the control unit 58 and each of the switches 52, 53, 54 on the secondary side. However, the isolator 59 may be provided between the controller 58 and the primary switches 13a to 13d.

  Next, the operation of the power supply device in the second embodiment will be described. The control unit 58 performs the same control as that of the first embodiment for each of the switches 13a to 13d on the primary side.

In the present embodiment, the control unit 58 changes the timing for opening and closing the secondary switches 52, 53, and 54 depending on whether the current flows into the first load 57 and the current is sucked from the first load 57.
<2-1>
First, the control operation of the control unit 58 when a positive voltage is applied to the first load 57 and a current flows into the first load 57 will be described with reference to the timing chart of FIG.

  During the period corresponding to the B section and the C section, as shown in FIG. 11, the secondary side first switch 52 is turned on and the secondary side second switch 53 and the secondary side third switch 54 are turned off.

  FIG. 12 shows the current flow at this time. Note that the current flow on the primary side indicates the B section. During this period, a positive voltage is induced on the first polarity side of the secondary winding of the insulation transformer 51 by the pulse voltage with the first polarity of the primary winding of the insulation transformer 51 as the positive side. A positive voltage is applied to the first load 57 by the first side switch 52, and a current flows into the first load 57.

  During the period corresponding to the A section and the D section, as shown in FIG. 11, the secondary side second switch 53 is turned on and the secondary side first switch 52 and the secondary side third switch 54 are turned off.

  FIG. 13 shows the current flow at this time. The primary current flow indicates the D section. During this period, a positive voltage is induced on the second polarity side of the secondary winding of the insulation transformer 14 by the pulse voltage with the second polarity of the primary winding of the insulation transformer 51 as the positive side. A positive voltage is applied to the first load 57 by the second side switch 53, and a current flows into the first load 57.

  As the control unit 58 repeats these operations, a current continuously flows into the first load 57. This operation can be regarded as performing the full-wave rectification operation conventionally performed by the diode bridge 5 by turning on / off the secondary side first switch 52 and the secondary side second switch 53.

  When a negative voltage is applied to the first load 57 and a current flows into the first load 57, the on / off control of the secondary side first switch 52 and the secondary side second switch 53 may be switched. The secondary side third switch 54 remains off. That is, during the period corresponding to the B section and the C section, the secondary side first switch 52 and the secondary side third switch 54 are turned off, and the secondary side second switch 53 is turned on. Further, during the period corresponding to the A section and the D section, the secondary side second switch 53 and the secondary side third switch 54 are turned off, and the secondary side first switch 52 is turned on.

Therefore, when a current flows into the first load 57, either positive or negative voltage can be applied to the first load 57.
<2-2>
Next, in the second embodiment, the control operation of the control unit 58 when current is sucked from the first load 57 that generates a positive voltage will be described with reference to the timing chart of FIG.

  During the period corresponding to the section A, as shown in FIG. 14, the secondary side first switch 52 and the secondary side second switch 53 are turned off, and the secondary side third switch 54 is turned on.

  FIG. 15 shows the current flow at this time. The energy supplied from the first load 57 is accumulated in the inductor 55.

  During the period corresponding to the B section, as shown in FIG. 14, the secondary side first switch 52 is turned on, and the secondary side second switch 53 and the secondary side third switch 54 are turned off.

  FIG. 16 shows the current flow at this time. The energy supplied from the first load 57 and the energy accumulated in the inductor 55 are regenerated to the primary side through the insulating transformer 51 in the direction in which the first polarity side of the insulating transformer 51 is positive. . The regenerated energy is consumed by the second load 21 via the primary side first switch 13a.

  During the period corresponding to section C, as shown in FIG. 14, the secondary side first switch 52 and the secondary side second switch 53 are turned off and the secondary side third switch 54 is turned on. The current flow at this time is the same as the current flow in section A shown in FIG. The energy supplied from the first load 57 is accumulated in the inductor 55.

  During the period corresponding to section D, as shown in FIG. 14, the secondary side first switch 52 and the secondary side third switch 54 are turned off, and the secondary side second switch 53 is turned on.

  FIG. 17 shows the current flow at this time. The energy supplied from the first load 57 and the energy accumulated in the inductor 55 are regenerated to the primary side through the insulating transformer 51 in the direction in which the second polarity side of the insulating transformer 51 is positive. . This regenerated energy is consumed by the second load 21 via the primary third switch 13c.

  When the control unit 19 repeats these operations, the current is continuously sucked from the first load 57. As described above, even when the first load 57 is a load that supplies electric power, it is possible to operate at a constant current or a constant voltage by regenerating the electric power to the primary side.

  The adjustment of the current value or voltage value in this case can be performed by adjusting the phase and duty ratio of the pulses that determine the A section, B section, C section, and D section. The control when the current is sucked from the first load 57 is the operation in the A section and the B section corresponding to FIGS. 15 and 16 or the operation in the C section and the D section corresponding to FIGS. 15 and 17. It is also possible to repeat the above, but it is preferable to perform the above-mentioned operation from the problem of the demagnetization of the insulating transformer 51.

  In the case of sucking current from the first load 57 that generates a negative voltage, the on / off control of the secondary side first switch 52 and the secondary side second switch 53 may be switched. The on / off control of the secondary side third switch 54 is not changed.

  That is, during the period corresponding to section A, the secondary side first switch 52 and the secondary side second switch 53 are turned off, and the secondary side third switch 54 is turned on. During the period corresponding to section B, the secondary side first switch 52 and the secondary side third switch 54 are turned off and the secondary side second switch 53 is turned on. During the period corresponding to section C, the secondary side first switch 52 and the secondary side second switch 53 are turned off, and the secondary side third switch 54 is turned on. During the period corresponding to section D, the secondary side first switch 52 is turned on, and the secondary side second switch 53 and the secondary side third switch 54 are turned off.

  Therefore, when the current is sucked from the first load 57, the first load 57 can cope with both positive and negative voltages. Thus, the power supply circuit in the second embodiment can realize a four-quadrant operation. If the second load 21 is not a load that simply consumes power, but is a power regenerative circuit, and the regenerated power is regenerated to a system power supply or a line power supply, the overall power consumption of the apparatus is reduced. can do.

As described above, the power supply apparatus according to the present embodiment can realize a four-quadrant operation that is essential as a measurement power supply by arranging a plurality of switches on both sides of an insulating transformer to perform a switching operation. In any quadrant, the power consumption of the power supply device itself can be reduced.
<Modification>
The second load 21 may be a power regeneration circuit that regenerates power to a power supply on the higher side. Or primary side power supply 11 itself may absorb the electric power regenerated like what is called a secondary battery.

  The primary side switch may not be a full bridge type, but may be a half bridge type including a primary side first switch 13a and a primary side second switch 13b as shown in FIG. In this case, since the power conversion rate or the like due to the phase difference cannot be adjusted as in the full-bridge configuration, the control unit 58 controls the primary side first switch 13a and the primary side second switch 13b. The power conversion rate, the voltage value at the first load 57 end, and the current value flowing through the first load are controlled by the duty ratio of the pulse.

  FIG. 19 shows a timing chart when a positive voltage is applied to the first load 57 in this configuration.

  Here, a section in which both the primary side first switch 13a and the primary side second switch 13b are off is referred to as an AC section, and the primary side first switch 13a is on and the primary side second switch 13c. The section in which is turned off is referred to as section B, and the section in which the primary side first switch 13a is off and the primary side second switch 13b is on is referred to as section D.

  During the period corresponding to the AC section, the secondary side first switch 52 and the secondary side second switch 53 are turned off, and the secondary side third switch 54 is turned on. During the period corresponding to the B section, the secondary side first switch 53 is turned on, and the secondary side second switch 52 and the secondary side third switch 54 are turned off. During the period corresponding to section D, the secondary side first switch 52 and the secondary side third switch 54 are turned off, and the secondary side second switch 53 is turned on.

  This timing is the same when the current flows into the first load 57 and when the current is sucked from the first load 57, and the direction of the current is changed by controlling the timing. Moreover, what is necessary is just to switch the operation timing of the secondary side 1st switch 52, and the operation timing of the secondary side 2nd switch 53 in the operation | movement in the case of applying a negative voltage to the 1st load 57. FIG.

  Further, the present invention may be applied to a resonant converter. In this case, the pulse period can also be controlled.

  When the MOS-FET is used as each of the primary side switches 13a to 13d and each of the secondary side switches 15a to 15d, 52, 53, 54, the influence of the body diode is eliminated to cope with the bipolar voltage. In order to realize the above, two MOS-FETs can be connected in cascade.

DESCRIPTION OF SYMBOLS 1 ... Primary side power supply, 2 ... Bypass capacitor, 3a ... 1st switch, 3b ... 2nd switch, 3c ... 3rd switch, 3d ... 4th switch, 4 ... Insulation transformer, 5 ... Diode bridge, 6 ... Bypass capacitor , 7, load, 8, control unit, 11, primary power supply, 12, bypass capacitor, 13 a, primary side first switch, 13 b, primary side second switch, 13 c, primary side third switch, 13 d ... primary side fourth switch, 14 ... isolation transformer, 15a ... secondary side first switch, 15b ... secondary side second switch, 15c ... secondary side third switch, 15d ... secondary side fourth switch, 16 DESCRIPTION OF SYMBOLS ... Inductor, 17 ... Bypass capacitor, 18 ... First load, 19 ... Control unit, 20 ... Isolator, 21 ... Second load, 41 ... Insulation transformer, 42 ... Diode, 43 ... Diode, 44 Smoothing inductor 45 ... Bypass capacitor 46 ... Load 51 ... Insulating transformer 52 ... Secondary side first switch 53 ... Secondary side second switch 54 ... Secondary side third switch 55 ... Inductor 56 ... Bypass capacitor, 57 ... Second load, 58 ... Control unit, 59 ... Isolator

Claims (9)

A DCDC converter having an insulating transformer, connecting a primary power source to a primary side of the insulating transformer, and connecting a first load to a secondary side of the insulating transformer;
A primary-side first switch that connects a positive-polarity side of the primary-side power source with a negative-polarity side connected to a first common potential point and a first polarity side of the primary-side winding of the isolation transformer;
A primary second switch for connecting the first polarity side of the primary winding of the isolation transformer and the first common potential point;
A primary third switch that connects a positive polarity side of the primary power supply and a second polarity side of the primary winding of the isolation transformer;
A primary fourth switch for connecting the second polarity side of the primary winding of the isolation transformer and the first common potential point;
An inductor connected to the other end of the first load, one end of which is connected to a second common potential point;
A secondary first switch for connecting the first polarity side of the secondary winding of the isolation transformer and the inductor;
A secondary side second switch for connecting the first polarity side of the secondary side winding of the isolation transformer and the second common potential point;
A secondary third switch that connects the inductor and the second polarity side of the secondary winding of the isolation transformer;
A secondary side fourth switch for connecting the second polarity side of the secondary side winding of the isolation transformer and the second common potential point;
A DCDC converter comprising: a control unit that generates a pulse wave that opens and closes each switch on the primary side and each switch on the secondary side. The control unit controls the primary side second switch to be an inversion operation of the primary side first switch and the primary side fourth switch to be an inversion operation of the primary side third switch,
A section in which both the primary side first switch and the primary side third switch are on is referred to as section A, the primary side first switch is on and the primary side third switch is off. The section in which the primary side first switch and the primary side third switch are both off is referred to as the section C, and the primary side first switch is off. When the section where the primary side third switch is on is referred to as section D, the first state is either on / off, and the second state is different from the first state,
During the period corresponding to the A section and the D section, the secondary side first switch and the secondary side fourth switch are set to the first state, and the secondary side second switch and the secondary side third switch are set to the first state. 2 state,
During the period corresponding to the B section and the C section, the secondary side first switch and the secondary side fourth switch are set to the second state, and the secondary side second switch and the secondary side third switch are set to the first state. 2. The DCDC converter according to claim 1, wherein the DCDC converter is in a state. The control unit controls the primary side second switch to be an inversion operation of the primary side first switch and the primary side fourth switch to be an inversion operation of the primary side third switch,
A section in which both the primary side first switch and the primary side third switch are on is referred to as section A, the primary side first switch is on and the primary side third switch is off. The section in which the primary side first switch and the primary side third switch are both off is referred to as the section C, and the primary side first switch is off. When the section where the primary side third switch is on is referred to as section D, the first state is either on / off, and the second state is different from the first state,
During the period corresponding to section A, the secondary side first switch and the secondary side second switch are set to the first state, and the secondary side third switch and the secondary side fourth switch are set to the second state. ,
During the period corresponding to section B, the secondary side first switch and the secondary side fourth switch are set to the first state, and the secondary side second switch and the secondary side third switch are set to the second state. ,
During the period corresponding to section C, the secondary side first switch and the secondary side second switch are set to the second state, and the secondary side third switch and the secondary side fourth switch are set to the first state. ,
During the period corresponding to section D, the secondary side first switch and the secondary side fourth switch are set to the second state, and the secondary side second switch and the secondary side third switch are set to the first state. The DCDC converter according to claim 1, wherein: A DCDC converter having an isolation transformer having an intermediate tap, connecting a primary power source to a primary side of the isolation transformer, and connecting a first load to a secondary side of the isolation transformer;
A primary-side first switch that connects a positive-polarity side of the primary-side power source with a negative-polarity side connected to a first common potential point and a first polarity side of the primary-side winding of the isolation transformer;
A primary second switch for connecting the first polarity side of the primary winding of the isolation transformer and the first common potential point;
A primary third switch that connects a positive polarity side of the primary power supply and a second polarity side of the primary winding of the isolation transformer;
A primary fourth switch for connecting the second polarity side of the primary winding of the isolation transformer and the first common potential point;
An inductor having one end connected to a second common potential point and the other end of the first load connected to the intermediate tap;
A secondary first switch for connecting the first polarity side of the secondary winding of the isolation transformer and the inductor;
A secondary side second switch that connects a second polarity side of the secondary side winding of the isolation transformer and the inductor;
A secondary third switch for connecting the intermediate tap and the inductor;
A DCDC converter comprising: a control unit that generates a pulse wave that opens and closes each switch on the primary side and each switch on the secondary side. The control unit controls the primary side second switch to be an inversion operation of the primary side first switch and the primary side fourth switch to be an inversion operation of the primary side third switch,
A section in which both the primary side first switch and the primary side third switch are on is referred to as section A, the primary side first switch is on and the primary side third switch is off. The section in which the primary side first switch and the primary side third switch are both off is referred to as the section C, and the primary side first switch is off. When the section where the primary side third switch is on is referred to as section D, the first state is either on / off, and the second state is different from the first state,
During the period corresponding to the A section and the D section, the secondary side first switch is set to the first state, the secondary side second switch is set to the second state, the secondary side third switch is turned off,
During the period corresponding to the B section and the C section, the secondary side first switch is set to the second state, the secondary side second switch is set to the first state, and the secondary side third switch is turned off. The DCDC converter according to claim 4. The control unit controls the primary side second switch to be an inversion operation of the primary side first switch and the primary side fourth switch to be an inversion operation of the primary side third switch,
A section in which both the primary side first switch and the primary side third switch are on is referred to as section A, the primary side first switch is on and the primary side third switch is off. The section in which the primary side first switch and the primary side third switch are both off is referred to as the section C, and the primary side first switch is off. When the section where the primary side third switch is on is referred to as section D, the first state is either on / off, and the second state is different from the first state,
During the period corresponding to section A, the secondary side first switch and the secondary side second switch are turned off, the secondary side third switch is turned on,
During the period corresponding to section B, the secondary side first switch is set to the first state, the secondary side second switch is set to the second state, the secondary side third switch is turned off,
During the period corresponding to section C, the secondary side first switch and the secondary side second switch are turned off, the secondary side third switch is turned on,
During the period corresponding to section D, the secondary side first switch is set to the second state, the secondary side second switch is set to the first state, and the secondary side third switch is turned off. The DCDC converter according to claim 4. Replacing the primary side third switch and the primary side fourth switch with capacitors;
A section in which both the primary side first switch and the primary side third switch are off is referred to as an AC section. The primary side first switch is on and the primary side third switch is off. The section in which the primary side first switch is off and the primary side third switch is on is referred to as the D section, and the first state is either on / off. When the second state is different from the first state,
The control unit turns off the secondary side first switch and the secondary side second switch and turns on the secondary side third switch during a period corresponding to the AC section,
During the period corresponding to section B, the secondary side first switch is set to the first state, the secondary side second switch is set to the second state, the secondary side third switch is turned off,
During the period corresponding to section D, the secondary side first switch is set to the second state, the secondary side second switch is set to the first state, and the secondary side third switch is turned off. The DCDC converter according to claim 4.   The DCDC converter according to any one of claims 1 to 7, further comprising a second load connected in parallel with the primary power supply.   9. The DCDC converter according to claim 1, further comprising an isolator for insulating each of the switches on the primary side and each switch on the secondary side.