JP2020162385A - Boosting chopper circuit, dc power supply device, and boosting method - Google Patents

Abstract

To suppress rush currents without requiring many additional components.SOLUTION: First and second capacitor terminals 106a, 106b of a capacitor 106 are electrically connected to first and second connection points 104, 105 respectively. A first coil terminal 108a of a coil 108 is electrically connected to the first connection point. A second diode terminal 109b of a backflow prevention diode 109 is electrically connected to the second connection point. A second coil terminal 108b of the coil, a first diode terminal 109a of the backflow prevention diode and a first switch element terminal 111a of a switch element 111 are electrically connected to a third connection point 107. A forth connection point 110 is electrically connected to a second DC input terminal and a second DC output terminal 103. A second switch element terminal 111b of the switch element is electrically connected to the fourth connection point 110. The switch element switches a state between an on-state and an off-state.SELECTED DRAWING: Figure 1

Description

The present invention relates to a boost chopper circuit, a DC power supply, and a boost method.

The conventional boost chopper circuit described in Japanese Patent Application Laid-Open No. 2015-142485 includes a boost inductor, a switching element, a rectifying diode and a smoothing output capacitor (paragraphs 0002 and 0003 and FIG. 9). In the boost chopper circuit, when the input voltage recovers from a momentary interruption when the output voltage is lower than the input voltage, an excessive input current rushes into the output capacitor from the DC power supply that supplies the input voltage through the rectifying diode. And flow in (paragraph 0005).

Further, in the step-up chopper circuit described in Japanese Patent Application Laid-Open No. 2015-142485, the anode of the bypass diode is connected to the input terminal (paragraphs 0016 and 0017). Also, the cathode of the bypass diode is connected to the output terminal (paragraphs 0016 and 0017). Further, the resistance element and the output capacitor are connected in series (paragraph 0018). Further, a switch is connected in parallel to the resistance element (paragraph 0018). In addition, when the DC power supply, which is the source of the input voltage, temporarily disappears and the input voltage is interrupted momentarily, the output capacitor is discharged and the voltage of the output capacitor becomes lower than the input voltage. The switch is controlled to the off state (paragraph 0022). In addition, after the voltage of the output capacitor becomes lower than the input voltage due to the discharge of the output capacitor, the switch is turned on after the difference between the voltage applied to the output capacitor and the input voltage is reduced to a predetermined value or less. Be made to (paragraph 0022). Thereby, the inrush current generated when the input voltage recovers from the momentary interruption can be suppressed without excessively limiting the current contributing to the charging / discharging of the output capacitor (paragraph 0030).
Japanese Unexamined Patent Publication No. 2015-142485

According to the step-up chopper circuit described in JP-A-2015-142485, the inrush current can be suppressed. However, the boost chopper circuit described in Japanese Patent Application Laid-Open No. 2015-142485 requires a large number of additional components that cause an increase in cost.

The present invention has been made in view of the above-mentioned problems. An object to be solved by the present invention is to provide a step-up chopper circuit, a DC power supply device, and a step-up method capable of suppressing an inrush current without requiring a large number of additional parts.

One exemplary aspect of the invention relates to a step-up chopper circuit.

The step-up chopper circuit includes a first DC input terminal, a second DC input terminal, a first DC output terminal, a second DC output terminal, a first connection point, a second connection point, a capacitor, and a third. It includes a connection point, a coil, a backflow prevention diode, a fourth connection point, and a switch element.

The first connection point is electrically connected to the first DC input terminal. The second connection point is electrically connected to the first DC output terminal.

The first capacitor terminal of the capacitor is electrically connected to the first connection point. The second capacitor terminal of the capacitor is electrically connected to the second connection point.

The first coil terminal of the coil is electrically connected to the first connection point. The second coil terminal of the coil is electrically connected to the third connection point.

The first diode terminal of the backflow prevention diode is electrically connected to the third connection point. The second diode terminal of the backflow prevention diode is electrically connected to the second connection point.

The fourth connection point is electrically connected to the second DC input terminal and the second DC output terminal.

The first switch element terminal of the switch element is electrically connected to the third connection point. The second switch element terminal of the switch element is electrically connected to the fourth connection point. The switch element is in a state between an on state in which the first switch element terminal and the second switch element terminal are conductive and an off state in which the first switch element terminal and the second switch element terminal are not conductive. To switch.

In one exemplary embodiment of the present invention, immediately after the DC voltage input to the first DC input terminal and the second DC input terminal rises, the first DC output terminal is subjected to capacitively coupling by a capacitor. The potential of is increased with the potential of the first DC input terminal. Therefore, a direct current having a large voltage is not applied to the capacitor. Therefore, the capacitor is hardly charged. Therefore, the inrush current can be suppressed.

Further, in one exemplary embodiment of the present invention, the inrush current can be suppressed by the capacitor. Therefore, the inrush current can be suppressed without requiring a large number of additional parts.

FIG. 5 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to an exemplary embodiment of the present invention. It is a figure explaining the inrush current flowing through the step-up chopper circuit of the exemplary embodiment of this invention. It is a figure explaining the current flowing through the step-up chopper circuit of the exemplary embodiment of this invention. It is a figure explaining the current flowing through the step-up chopper circuit of the exemplary embodiment of this invention. FIG. 5 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to a first modification of an exemplary embodiment of the present invention. It is a circuit diagram which illustrates the DC power supply device which comprises the step-up chopper circuit of the 2nd modification of the Example Embodiment of this invention. It is a circuit diagram which illustrates the DC power supply device which comprises the step-up chopper circuit of the 3rd modification of the Example Embodiment of this invention. FIG. 5 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to a fourth modification of an exemplary embodiment of the present invention. It is a timing chart which illustrates the time change of the state of the switch element and the synchronous rectification switch element of the step-up chopper circuit of the 4th modification of the example embodiment of this invention. It is a figure explaining the current flowing through the step-up chopper circuit of the 4th modification of the example embodiment of this invention. It is a figure explaining the current flowing through the step-up chopper circuit of the 4th modification of the example embodiment of this invention. It is a figure explaining the inrush current flowing through the step-up chopper circuit compared with the step-up chopper circuit of the exemplary embodiment of this invention.

1 DC power supply device FIG. 1 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to an exemplary embodiment of the present invention.

The DC power supply device 1 illustrated in FIG. 1 includes a step-up chopper circuit 10 and a DC source 11.

The DC source 11 includes a first pole 11a and a second pole 11b.

In this embodiment, the first electrode 11a of the DC source 11 is a positive electrode. Further, the second pole 11b of the DC source 11 is a negative electrode.

The step-up chopper circuit 10 includes a first DC input terminal 100, a second DC input terminal 101, a first DC output terminal 102, a second DC output terminal 103, a first connection point 104, and a second connection point. It includes 105, a capacitor 106, a third connection point 107, a coil 108, a backflow prevention diode 109, a fourth connection point 110, and a switch element 111.

In this embodiment, the first DC input terminal 100 is a positive input terminal. The second DC input terminal 101 is a negative input terminal. Further, the first DC output terminal 102 is a positive output terminal. The second DC output terminal 103 is a negative output terminal.

The load 12 includes a first load terminal 12a and a second load terminal 12b.

The first pole 11a of the DC source 11 is electrically connected to the first DC input terminal 100 of the step-up chopper circuit 10. The second pole 11b of the DC source 11 is electrically connected to the second DC input terminal 101 of the step-up chopper circuit 10.

The first load terminal 12a of the load 12 is electrically connected to the first DC output terminal 102 of the boost chopper circuit 10. The second load terminal 12b of the load 12 is electrically connected to the second DC output terminal 103 of the boost chopper circuit 10.

The DC source 11 is a battery, a DC generator, a DC power source including an AC source and a rectifier circuit, and the like. The DC source 11 generates a DC voltage. The generated DC voltage is output between the first pole 11a of the DC source 11 and the second pole 11b of the DC source 11. The output DC voltage is input between the first DC input terminal 100 and the second DC input terminal 101 of the boost chopper circuit 10. The step-up chopper circuit 10 boosts the input DC voltage and generates the boosted DC voltage. The boosted DC voltage is output between the first DC output terminal 102 and the second DC output terminal 103 of the boost chopper circuit 10. The output DC voltage is input between the first load terminal 12a of the load 12 and the second load terminal 12b of the load 12.

1.1 Boost Chopper Circuit The first connection point 104 is electrically connected to the first DC input terminal 100. Further, the second connection point 105 is electrically connected to the first DC output terminal 102.

The capacitor 106 includes a first capacitor terminal 106a and a second capacitor terminal 106b. The first capacitor terminal 106a is electrically connected to the first connection point 104. The second capacitor terminal 106b is electrically connected to the second connection point 105.

The first capacitor terminal 106a is electrically connected to the first DC input terminal 100 via the first connection point 104. Further, the second capacitor terminal 106b is electrically connected to the first DC output terminal 102 via the second connection point 105. As a result, a direct current having a voltage corresponding to the difference between the potential of the first direct current input terminal 100 and the potential of the first direct current output terminal 102 is applied to the capacitor 106.

The coil 108 includes a first coil terminal 108a and a second coil terminal 108b. The first coil terminal 108a is electrically connected to the first connection point 104. The second coil terminal 108b is electrically connected to the third connection point 107.

The backflow prevention diode 109 includes a first diode terminal 109a and a second diode terminal 109b. The first diode terminal 109a is electrically connected to the third connection point 107. The second diode terminal 109b is electrically connected to the second connection point 105.

In this embodiment, the first diode terminal 109a is the anode. The second diode terminal 109b is a cathode.

The coil 108 and the backflow prevention diode 109 are electrically connected in series via a third connection point 107. The first coil terminal 108a, which is one terminal of the coil 108 electrically connected in series and the backflow prevention diode 109, is electrically connected to the first DC input terminal 100 via the first connection point 104. To. The second diode terminal 109b, which is the other terminal of the coil 108 electrically connected in series and the backflow prevention diode 109, is electrically connected to the first DC output terminal 102 via the second connection point 105. To. As a result, the current generated by releasing the energy to the coil 108 can flow from the first DC input terminal 100 toward the first DC output terminal 102 via the coil 108 and the backflow prevention diode 109. it can. Further, the potential of the first DC output terminal 102 can be the sum of the potential of the first DC input terminal 100 and the electromotive force induced in the coil 108. That is, the potential of the first DC output terminal 102 can be made higher than the potential of the first DC input terminal 100. Further, a forward current can be passed from the first DC input terminal 100 to the first DC output terminal 102 via the backflow prevention diode 109. Further, it is possible to prevent the reverse current from flowing from the first DC output terminal 102 toward the first DC input terminal 100 via the backflow prevention diode 109.

The fourth connection point 110 is electrically connected to the second DC input terminal 101 and the second DC output terminal 103.

The second DC output terminal 103 is electrically connected to the second DC input terminal 101 via the fourth connection point 110. As a result, the potential of the second DC output terminal 103 can be set to the potential of the second DC input terminal 101.

The switch element 111 includes a first switch element terminal 111a and a second switch element terminal 111b. The first switch element terminal 111a is electrically connected to the third connection point 107. The second switch element terminal 111b is electrically connected to the fourth connection point 110. The switch element 111 has an on state in which the first switch element terminal 111a and the second switch element terminal 111b are conductive, and an off state in which the first switch element terminal 111a and the second switch element terminal 111b are not conductive. Switch the state between ,.

In this embodiment, the switch element 111 is a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or the like. When the switch element 111 is an N-type MOSFET, the first switch element terminal 111a is a drain. Further, the second switch element terminal 111b is a source. When the switch element 111 is an IGBT, the first switch element terminal 111a is a collector. Further, the second switch element terminal 111b is an emitter.

The coil 108 and the switch element 111 are electrically connected in series via a third connection point 107. The first coil terminal 108a, which is one terminal of the coil 108 electrically connected in series and the switch element 111, is electrically connected to the first DC input terminal 100 via the first connection point 104. .. The coil 108 electrically connected in series and the second switch element terminal 111b, which is the other terminal of the switch element 111, are electrically connected to the second DC input terminal 101 via the fourth connection point 110. To. As a result, when the state of the switch element 111 is on, a current can flow from the first DC input terminal 100 toward the second DC input terminal 101 via the coil 108 and the switch element 111. .. As a result, energy can be stored in the coil 108 when the switch element 111 is in the ON state.

The boost chopper circuit 10 further includes a control circuit 113.

The control circuit 113 is composed of a microcontroller or the like. The control circuit 113 inputs a signal for switching the state of the switch element 111 between the on state and the off state to the switch element 111. The control circuit 113 preferably pulse-width-modulates (PWM) the input signal. Therefore, the control circuit 113 preferably PWM-controls the switch element 111.

1.2 Suppression of inrush current FIG. 12 is a diagram illustrating an inrush current flowing through a boost chopper circuit compared with the boost chopper circuit of the exemplary embodiment of the present invention. FIG. 2 is a diagram illustrating an inrush current flowing through a step-up chopper circuit according to an exemplary embodiment of the present invention.

In the boost chopper circuit 90 illustrated in FIG. 12, the first pole 11a and the second pole 11b of the DC source 11 are electrically connected to the first DC input terminal 100 and the second DC input terminal 101, respectively. At that time, the DC voltage VIN input between the first DC input terminal 100 and the second DC input terminal 101 rises. Therefore, a direct current having a voltage substantially the same as the voltage VIN is applied to the coil 108 and the smoothing capacitor 900 electrically connected in series. Therefore, the DC voltage VOUT output between the first DC output terminal 102 and the second DC output terminal 103 reaches about twice the voltage VIN due to the resonance between the coil 108 and the smoothing capacitor 900. there is a possibility. Therefore, a direct current having a high voltage VOUT is applied to the smoothing capacitor 900. Therefore, if the withstand voltage of the smoothing capacitor 900 and the load is insufficient, they may be destroyed. Further, when the DC source 111 is connected, the smoothing capacitor 900 is rapidly charged. Therefore, it is difficult to suppress the inrush current IR.

Also in the step-up chopper circuit 10 illustrated in FIG. 2, the first pole 11a and the second pole 11b of the DC source 11 are electrically connected to the first DC input terminal 100 and the second DC input terminal 101, respectively. At that time, the DC voltage VIN input between the first DC input terminal 100 and the second DC input terminal 101 rises. However, as the voltage VIN rises, the potential of the first DC output terminal 102 rises together with the potential of the first DC input terminal 100 due to capacitive coupling by the capacitor 106. Therefore, a high potential difference does not occur between the first capacitor terminal 106a of the capacitor 106 and the second capacitor terminal 106b of the capacitor 106. Therefore, the capacitor 106 is hardly charged. Therefore, the inrush current IR can be suppressed. Since only a small amount of current flows through the coil 108, the DC voltage VOUT output between the first DC output terminal 102 and the second DC output terminal 103 is limited to almost the same voltage as the voltage VIN. Does not rise.

In this embodiment, the inrush current IR can be suppressed by one capacitor 106. Therefore, the inrush current IR can be suppressed without requiring a large number of additional parts. This means that the boost chopper circuit 10 can be configured at low cost.

1.3 Withstand voltage of capacitor In the boost chopper circuit 90 shown in FIG. 12, the boosted direct current is applied to the smoothing capacitor 900 while the boost chopper circuit 90 boosts the input direct current. ..

On the other hand, in the boost chopper circuit 10 illustrated in FIG. 2, the capacitor 106 receives the potential of the first DC input terminal 100 while the boost chopper circuit 10 boosts the input direct current. A direct current having a voltage corresponding to the difference from the potential of the first direct current output terminal 102 is applied.

Therefore, the withstand voltage of the capacitor 106 of the boost chopper circuit 10 may be lower than the withstand voltage of the smoothing capacitor 900 of the boost chopper circuit 90. This means that the boost chopper circuit 10 can be configured at low cost.

1.4 Improvement of behavior at the time of short circuit In the step-up chopper circuit 90 shown in FIG. 12, when the smoothing capacitor 900 is short-circuited, the first pole 11a and the second pole 11b of the DC source 11 are replaced with the coil 108. And short circuit through the backflow prevention diode 109. Therefore, a large current flows.

On the other hand, in the boost chopper circuit 10 shown in FIG. 2, when the capacitor 106 is short-circuited, it is between the first coil terminal 108a of the coil 108 and the second diode terminal 109b of the backflow prevention diode 109. Is merely a short circuit, and a current larger than that of the DC source 11 does not continue to flow. The flowing current is limited to the current generated by discharging the capacitor 106.

Therefore, the boost chopper circuit 10 has high safety.

1.5 Boosting Operation FIGS. 3 and 4 are diagrams illustrating a current flowing through a boosting chopper circuit according to an exemplary embodiment of the present invention. FIG. 3 describes the current that flows when the state of the switch element is the ON state. FIG. 4 describes the current that flows when the state of the switch element is in the off state.

The boosting method using the boosting chopper circuit 10 includes a step of turning on the state of the switch element 111 in the boosting chopper circuit 10.

In this step, as shown in FIG. 3, a first current I1 is input to the boost chopper circuit 10. Further, in this step, a part of the current I11 of the input first current I1 is passed through the coil 108 to store energy in the coil 108. Further, in this step, a second current I12 is generated by discharging the capacitor 106. Further, in this step, at least a part of the generated second current I12 is output from the boost chopper circuit 10.

The first current I1 includes a current I11 and a second current I12.

If the boost chopper circuit 10 does not include the input capacitor 114 described below, ideally the first current I1 corresponds to the combined current I11 and second current I12. When the boost chopper circuit 10 does not include the output capacitor 115 described below, ideally, the current output from the boost chopper circuit 10 coincides with the second current I12.

The current I11 flows from the first DC input terminal 100 to the second DC input terminal 101 via the coil 108 and the switch element 111.

The second current I12 flows from the first DC input terminal 100 to the second DC input terminal 101 via the capacitor 106 and the load 12.

Further, the boosting method using the boosting chopper circuit 10 includes a step of turning off the state of the switch element 111 in the boosting chopper circuit 10.

The step causes the coil 108 to release energy to generate a third current I3, as illustrated in FIG. Further, in this step, a part of the generated current I31 of the third current I3 is passed through the capacitor 106 to charge the capacitor 106. Further, in this step, at least a part of the remaining current I32 of the generated third current I3 is output from the boost chopper circuit 10.

The third current I3 includes a current I31 and a current I32.

When the boost chopper circuit 10 does not have the input capacitor 114 and the output capacitor 115 described below, ideally, the current input to the boost chopper circuit 10 and the current output from the boost chopper circuit 10 become the current I32. Match.

The current I32 flows from the first DC input terminal 100 to the second DC input terminal 101 via the coil 108, the backflow prevention diode 109, and the load 12.

The current I31 circulates through the coil 108, the backflow prevention diode 109, and the capacitor 106.

According to the boosting method using the boost chopper circuit 10, the first DC input terminal 100 and the first DC input terminal 100 and the first DC input terminal 100 and the third current I3 generated by releasing energy to the coil 108 are output from the boost chopper circuit 10. The DC having the sum voltage VIN + VL of the DC voltage VIN input between the two DC input terminals 101 and the electromotive force VL induced in the coil 108 is the first DC output terminal 102 and the second DC output. It is output between the terminal 103 and the terminal 103.

Further, according to the boosting method using the boosting chopper circuit 10, the third current I3 generated by releasing energy to the coil 108 is generated by discharging the capacitor 106 during the period when the boosting chopper circuit 10 does not output the third current I3. The second current I12 to be generated is output from the step-up chopper circuit 10. As a result, direct current is continuously output from the boost chopper circuit 10. Further, the capacitor 106 is a smoothing capacitor that suppresses pulsation contained in direct current.

1.6 Replacing Plus and Minus FIG. 5 is a circuit diagram illustrating a DC power supply device including a boost chopper circuit according to a first modification of an exemplary embodiment of the present invention.

In the first modification, the first electrode 11a of the DC source 11 is a negative electrode. The second electrode 11b of the DC source 11 is a positive electrode.

Further, in the first modification, the first DC input terminal 100 is a negative input terminal. The second DC input terminal 101 is a positive input terminal. The first DC output terminal 102 is a negative output terminal. The second DC output terminal 103 is a positive output terminal. Further, the first diode terminal 109a is a cathode. The second diode terminal 109b is an anode.

Further, in the first modification, when the switch element 111 is an N-type MOSFET, the first switch element terminal 111a is a source. Further, the second switch element terminal 111b is a drain. When the switch element 111 is an IGBT, the first switch element terminal 111a is an emitter. Further, the second switch element terminal 111b is a collector.

1.7 Addition of Input Capacitor FIG. 6 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit of a second modification of an exemplary embodiment of the present invention.

The boost chopper circuit 30 illustrated in FIG. 6 further includes an input capacitor 114.

The input capacitor 114 includes a first input capacitor terminal 114a and a second input capacitor terminal 114b. The first input capacitor terminal 114a is electrically connected to the first DC input terminal 100. The second input capacitor terminal 114b is electrically connected to the second DC input terminal 101.

The input capacitor 114 has a small impedance with respect to a high frequency component included in the direct current input between the first direct current input terminal 100 and the second direct current input terminal 101. Therefore, the input capacitor 114 bypasses the high frequency component. As a result, noise is suppressed. In addition, the operation of the boost chopper circuit 30 is stable.

The input capacitor 114 preferably has a capacitance of 0.01 times or more and 0.2 times or less the capacity of the capacitor 106. When the capacity of the input capacitor 114 is smaller than 0.01 times the capacity of the capacitor 106, it becomes difficult to obtain the effect of suppressing noise and stabilizing the operation of the step-up chopper circuit 30. When the capacity of the input capacitor 114 is larger than 0.2 times the capacity of the capacitor 106, it becomes difficult to obtain the effect of suppressing the inrush current IR.

The first input capacitor terminal 114a and the second input capacitor terminal 114b are close to the first connection point 104 and the fourth connection point 110, respectively. As a result, the high frequency component can be effectively flowed to the input capacitor 114.

1.8 Addition of Output Capacitor FIG. 7 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to a third modification of an exemplary embodiment of the present invention.

The boost chopper circuit 40 illustrated in FIG. 7 further includes an output capacitor 115.

The output capacitor 115 includes a first output capacitor terminal 115a and a second output capacitor terminal 115b. The first output capacitor terminal 115a is electrically connected to the first DC output terminal 102. The second output capacitor terminal 115b is electrically connected to the second DC output terminal 103.

The output capacitor 115 has a small impedance with respect to a high frequency component included in the direct current output between the first direct current output terminal 102 and the second direct current output terminal 103. Therefore, the output capacitor 115 bypasses the high frequency component. As a result, noise is suppressed. Moreover, the operation of the step-up chopper circuit 40 is stable.

The output capacitor 115 preferably has a capacitance of 0.01 times or more and 0.2 times or less the capacity of the capacitor 106. When the capacity of the output capacitor 115 is smaller than 0.01 times the capacity of the capacitor 106, it becomes difficult to obtain the effect of suppressing noise and stabilizing the operation of the step-up chopper circuit 40. When the capacity of the output capacitor 115 is larger than 0.2 times the capacity of the capacitor 106, it becomes difficult to obtain the effect of suppressing the inrush current IR.

The first output capacitor terminal 115a and the second output capacitor terminal 115b are close to the second connection point 105 and the fourth connection point 110, respectively. As a result, the high frequency component can be effectively flowed to the output capacitor 115.

The boost chopper circuit 40 may include an input capacitor 114 in addition to the output capacitor 115.

1.9 Addition of Synchronous Rectifier Switch Element FIG. 8 is a circuit diagram illustrating a DC power supply device including a step-up chopper circuit according to a fourth modification of an exemplary embodiment of the present invention.

The boost chopper circuit 50 illustrated in FIG. 8 further includes a synchronous rectification switch element 116.

The synchronous rectification switch element 116 includes a first synchronous rectification switch element terminal 116a and a second synchronous rectification switch element terminal 116b. The first synchronous rectification switch element terminal 116a is electrically connected to the first diode terminal 109a. The second synchronous rectifier switch element terminal 116b is electrically connected to the second diode terminal 109b. The synchronous rectifier switch element 116 is in an on state in which the first synchronous rectifier switch element terminal 116a and the second synchronous rectifier switch element terminal 116b are conductive, and the first synchronous rectifier switch element terminal 116a and the second synchronous rectifier switch. The state is switched between the off state in which the element terminal 116b is not conductive and the off state.

In the fourth modification, the synchronous rectification switch element 116 is a MOSFET, an IGBT, or the like. When the synchronous rectification switch element 116 is an N-type MOSFET, the first synchronous rectification switch element terminal 116a is a source. Further, the second synchronous rectification switch element terminal 116b is a drain. The built-in diode of the MOSFET may be used as the diode 109. When the synchronous rectification switch element 116 is an IGBT, the first synchronous rectification switch element terminal 116a is an emitter. Further, the second synchronous rectification switch element terminal 116b is a collector.

The boost chopper circuit 10 further includes a freewheeling diode 112.

The freewheeling diode 112 includes a first freewheeling diode terminal 112a and a second freewheeling diode terminal 112b. The first freewheeling diode terminal 112a is electrically connected to the first switch element terminal 111a. The second freewheeling diode terminal 112b is electrically connected to the second switch element terminal 111b.

In this fourth modification, the first freewheeling diode terminal 112a is a cathode. Further, the second freewheeling diode terminal 112b is an anode.

The set of the switch element 111 and the freewheeling diode 112 may be replaced with a switch element containing a parasitic diode having a role similar to that of the freewheeling diode 112.

FIG. 9 is a timing chart illustrating the time change of the state of the switch element and the synchronous rectification switch element of the boost chopper circuit of the fourth modification of the exemplary embodiment of the present invention.

The control circuit 113 inputs a signal to the switch element 111 and the synchronous rectification switch element 116 that causes the switch element 111 and the synchronous rectification switch element 116 to repeatedly perform the synchronous rectification operation.

While the control circuit 113 causes the switch element 111 and the synchronous rectification switch element 116 to perform one synchronous rectification operation, the state of the switch element 111 is turned on as shown in FIG. 9, and the synchronous rectification switch element 116 After turning off the state, a signal for turning off the state of the switch element 111 and turning on the state of the synchronous rectifying switch element 116 is input to the switch element 111 and the synchronous rectifying switch element 116. As a result, the loss generated when the third current I3 passes through the backflow prevention diode 109 is suppressed, and the efficiency of the step-up chopper circuit 50 can be improved.

Desirably, a period T1 in which the state of the switch element 111 is turned on and the state of the synchronous rectifying switch element 116 is turned off, and a period in which the state of the switch element 111 is turned off and the state of the synchronous rectifying switch element 116 is turned on. A dead time T3 that turns off the states of both the switch element 111 and the synchronous rectifying switch element 116 is sandwiched between the T2 and the T2. As a result, it is possible to suppress that the states of both the switch element 111 and the synchronous rectifying switch element 116 are turned on due to the delay in switching the states of the switch element 111 and the synchronous rectifying switch element 116, and a through current is generated. Therefore, it is possible to prevent the switch element 111 and the synchronous rectification switch element 116 from failing.

The control circuit 113 may input a signal for switching the state of the synchronous rectifying switch element 116 to the synchronous rectifying switch element 116 after the boosting chopper circuit 50 has stopped the boosting operation. As a result, the energy stored in the capacitor 106 can be returned to the DC source 11. Therefore, the energy utilization efficiency can be improved.

10 and 11 are diagrams for explaining the current flowing through the boost chopper circuit of the fourth modification of the exemplary embodiment of the present invention. 10 and 11 show the current that flows when the state of the synchronous rectifier switch is switched after the boost chopper circuit stops the boost operation.

First, a case where the state of the switch element 111 is maintained in the off state will be described.

When the state of the synchronous rectifying switch element 116 is switched and the state of the synchronous rectifying switch element 116 is turned on, the current generated by discharging the capacitor 106 is as shown in FIG. The IA circulates through the capacitor 106, the synchronous rectifier switch element 116, and the coil 108. Therefore, energy is stored in the coil 108.

When the state of the synchronous rectifying switch element 116 is further switched after the state of the synchronous rectifying switch element 116 is turned on and the state of the synchronous rectifying switch element 116 is turned off, as shown in FIG. In addition, the current IB generated by releasing energy to the coil 108 flows from the second DC input terminal 101 to the first DC input terminal 100 via the freewheeling diode 112 and the coil 108. Therefore, the energy stored in the coil 108 is returned to the DC source 11.

Therefore, by turning on the state of the synchronous rectifying switch element 116 and then turning off the state of the synchronous rectifying switch element 116, the energy stored in the capacitor 106 is returned to the DC source 11 via the coil 108. be able to. Further, the state of the synchronous rectifying switch element 116 is turned on and then the state of the synchronous rectifying switch element 116 is turned off until the energy stored in the capacitor 106 is exhausted, so that the state is accumulated in the capacitor 106. Most of the energy present can be returned to the DC source 11.

The control circuit 113 may input a signal for complementaryly switching the states of the switch element 111 and the synchronous rectification switch element 116 to the switch element 111 and the synchronous rectification switch element 116. In this case, the current IB flowing through the freewheeling diode 112 flows through the switch element 111. Therefore, the loss caused by the current IB flowing through the freewheeling diode 112 can be suppressed.

Although the present invention has been described in detail, the above description is exemplary in all aspects and the invention is not limited thereto. It is understood that a myriad of variations not illustrated can be envisioned without departing from the scope of the invention.

1, 2, DC power supply 10, 20, 30, 40, 50 Boost chopper circuit 11 DC source 12 Load 100 1st DC input terminal 101 2nd DC input terminal 102 1st DC output terminal 103 2nd DC output Terminal 104 1st connection point 105 2nd connection point 106 Capacitor
107 Third connection point 108 Coil 109 Backflow prevention diode 110 Fourth connection point 111 Switch element 112 Reflux diode 113 Control circuit 114 Input capacitor 115 Output capacitor 116 Synchronous rectifier switch element

Claims (12)

The first DC input terminal and
With the second DC input terminal,
With the first DC output terminal,
With the second DC output terminal,
A first connection point that is electrically connected to the first DC input terminal,
A second connection point electrically connected to the first DC output terminal,
A capacitor comprising a first capacitor terminal electrically connected to the first connection point and a second capacitor terminal electrically connected to the second connection point.
With the third connection point
A coil comprising a first coil terminal electrically connected to the first connection point and a second coil terminal electrically connected to the third connection point.
A backflow prevention diode comprising a first diode terminal electrically connected to the third connection point and a second diode terminal electrically connected to the second connection point.
A fourth connection point electrically connected to the second DC input terminal and the second DC output terminal,
The first switch includes a first switch element terminal electrically connected to the third connection point and a second switch element terminal electrically connected to the fourth connection point. A switch element that switches the state between an on state in which the element terminal and the second switch element terminal are conductive and an off state in which the first switch element terminal and the second switch element terminal are not conductive.
Boost chopper circuit with. The first DC input terminal is a positive input terminal.
The second DC input terminal is a negative input terminal.
The first DC output terminal is a positive output terminal.
The second DC output terminal is a negative output terminal.
The first diode terminal is an anode and
The step-up chopper circuit according to claim 1, wherein the second diode terminal is a cathode. The first DC input terminal is a negative input terminal.
The second DC input terminal is a positive input terminal.
The first DC output terminal is a negative output terminal.
The second DC output terminal is a positive output terminal.
The first diode terminal is a cathode and has a cathode.
The boost chopper circuit according to claim 1, wherein the second diode terminal is an anode. An input capacitor further comprising a first input capacitor terminal electrically connected to the first DC input terminal and a second input capacitor terminal electrically connected to the second DC input terminal. A boost chopper circuit according to any one of claims 1 to 3. The boost chopper circuit according to claim 4, wherein the input capacitor has a capacity of 0.01 times or more and 0.2 times or less the capacity of the capacitor. An output capacitor further comprising a first output capacitor terminal electrically connected to the first DC output terminal and a second output capacitor terminal electrically connected to the second DC output terminal. A boost chopper circuit according to any one of claims 1 to 5. The boost chopper circuit according to claim 6, wherein the output capacitor has a capacity of 0.01 times or more and 0.2 times or less the capacity of the capacitor. A first synchronous rectifier switch element terminal electrically connected to the first diode terminal and a second synchronous rectifier switch element terminal electrically connected to the second diode terminal are provided. An on state in which the first synchronous rectifier switch element terminal and the second synchronous rectifier switch element terminal are conductive, and an off state in which the first synchronous rectifier switch element terminal and the second synchronous rectifier switch element terminal are not conductive. The boost chopper circuit according to any one of claims 1 to 7, further comprising a synchronous rectifier switch element for switching the state between and. A signal for turning on the state of the switch element, turning off the state of the synchronous rectifying switch element, turning off the state of the switch element, and turning on the state of the synchronous rectifying switch element is transmitted to the switch element and the above. The boost chopper circuit according to claim 8, further comprising a control circuit for inputting to a synchronous rectifier switch element. The boost chopper circuit according to claim 8 or 9, further comprising a control circuit for inputting a signal for switching the state of the synchronous rectifier switch to the synchronous rectifier switch element after the boost chopper circuit stops the boost operation. A boost chopper circuit according to any one of claims 1 to 10.
A DC source comprising a first pole electrically connected to the first DC input terminal and a second pole electrically connected to the second DC input terminal.
A DC power supply equipped with. (a) In any of the boost chopper circuits according to claims 1 to 10, the state of the switch element is turned on, a first current is input to the boost chopper circuit, and a part of the first current is input. A step of passing a current through the coil to store energy in the coil, discharging the capacitor to generate a second current, and outputting at least a part of the second current from the boost chopper circuit. When,
(b) The state of the switch element is turned off, the energy is released to the coil to generate a third current, and a part of the current of the third current is passed through the capacitor to charge the capacitor. Then, in the step of outputting at least a part of the current of the residual portion of the third current from the boost chopper circuit, and
A boosting method that comprises.

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