JP2021036737A - Boost chopper circuit and dc power supply device - Google Patents

Abstract

To provide a boost chopper circuit capable of reducing current flowing through a switching element.SOLUTION: In a boost chopper circuit 1, a first coil terminal of a first coil 13 is connected to a first DC input terminal. A third coil terminal of a second coil 15 is connected to a first switching element terminal of a switching element 14. A second switching element terminal of the switching element and one terminal of a fourth coil terminal of the second coil are connected to a second coil terminal of the first coil. The second switching element terminal and the other terminal of the fourth coil terminal are connected to a second DC input terminal 12. A first diode terminal of a backflow prevention diode 16 is connected to the one terminal mentioned above. A first DC output terminal 17 is connected to a second diode terminal of the backflow prevention diode. A second DC output terminal 18 is connected to the other terminal mentioned above. The second coil is magnetically coupled to the first coil.SELECTED DRAWING: Figure 1

Description

The present invention relates to a step-up chopper circuit and a DC power supply device.

In the step-up chopper circuit, in many cases, a coil and a backflow prevention diode are inserted in the first conductive path from the DC input terminal of the positive electrode to the DC output terminal of the positive electrode. Further, a switching element is bridged between the section of the first conductive path between the coil and the backflow prevention diode and the second conductive path from the DC input terminal of the negative electrode to the DC output terminal of the negative electrode. Is done.

In the step-up chopper circuit, while the switching element is in the ON state, an input current flows from the DC input terminal of the positive electrode to the DC input terminal of the negative electrode via the coil and the switching element in sequence. Further, while the switching element is in the off state, the DC output terminal of the positive electrode is sequentially passed from the DC output terminal of the negative electrode to the DC input terminal of the negative electrode, and from the DC input terminal of the positive electrode via the coil and the backflow prevention diode. Output current flows up to.

In the step-up switching power supply device described in International Publication No. 98/35432, one end of the first coil portion is connected to one terminal of the power supply. Further, the other end of the first coil portion is connected to one pole of the output smoothing capacitor via the first diode. Also, a capacitor is connected to the load resistor to supply the output to the load resistor. Further, one end of the second coil portion is connected to the first coil portion. Further, the other end of the second coil portion is connected to one end of the switch element via the second coil. Further, the other end of the switch element is connected to the other terminal of the power supply. The first coil portion and the second coil portion are composed of windings wound around the same magnetic core. The winding direction of the first coil portion and the second coil portion is determined so as to have opposite polarities to each other (the title of the invention, and pages 13, 12-14, 17). ..
International Publication No. 98/35432

In the boost chopper circuit described above, the input current becomes large. Therefore, in the boost chopper circuit described above, the current flowing through the switching element that switches the input current becomes large. When the current flowing through the switching element becomes large, the conduction loss of the switching element becomes large, the current capacity of the switching element must be increased, and the cost of the switching element increases.

The present invention has been made in view of this problem. An object to be solved by the present invention is to provide a step-up chopper circuit capable of reducing the current flowing through the switching element.

One exemplary embodiment of the invention is directed to a boost chopper circuit.

The boost chopper circuit includes a first DC input terminal, a second DC input terminal, a first coil, an element group, a backflow prevention diode, a first DC output terminal, and a second DC output terminal.

The element group includes a switching element and a second coil.

The first coil includes a first coil terminal and a second coil terminal. The first coil terminal is electrically connected to the first DC input terminal.

The switching element includes a first switching element terminal and a second switching element terminal. The switching element switches between a state in which the first switching element terminal and the second switching element terminal are conductive and a state in which the first switching element terminal and the second switching element terminal are not conductive. ..

The second coil includes a third coil terminal and a fourth coil terminal. The third coil terminal is electrically connected to the first switching element terminal. The second coil is magnetically coupled to the first coil.

One terminal of the second switching element terminal and the fourth coil terminal is electrically connected to the second coil terminal. The other terminal of the second switching element terminal and the fourth coil terminal is electrically connected to the second DC input terminal. The coil terminal near the second coil terminal of the third coil terminal and the fourth coil terminal has the same polarity as the polarity of the first coil terminal.

The backflow prevention diode includes a first diode terminal and a second diode terminal. The first diode terminal is electrically connected to one of the second switching element terminal and the fourth coil terminal.

The first DC output terminal has the same polarity as the polarity of the first DC input terminal. The first DC output terminal is electrically connected to the second diode terminal.

The second DC output terminal has the same polarity as the polarity of the second DC input terminal. The second DC output terminal is electrically connected to the other terminal of the second switching element terminal and the fourth coil terminal.

One exemplary embodiment of the invention is also directed to a DC power supply with the boost chopper circuit described above.

According to one exemplary embodiment of the present invention, in a boost chopper circuit, in a state where the first switching element terminal and the second switching element terminal are conducting, they are guided to the second coil. A part of the exciting current flowing through the first coil is canceled by the induced current. As a result, the current flowing through the switching element can be reduced in a state where the first switching element terminal and the second switching element terminal are conducting.

It is a circuit diagram which illustrates the step-up chopper circuit of 1st Embodiment of this invention. It is a circuit diagram which illustrates a part of the step-up chopper circuit of 1st Embodiment of this invention. FIG. 5 is a waveform diagram illustrating an example of a waveform of a coil current flowing through a first coil provided in a step-up chopper circuit of a first embodiment of the present invention and a reference example. It is a circuit diagram which illustrates the step-up chopper circuit of the 1st modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 2nd modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 3rd modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 4th modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 5th modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 6th modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 7th modification of 1st Embodiment of this invention. It is a circuit diagram which illustrates the DC power supply device which comprises the step-up chopper circuit of 1st Embodiment of this invention. It is a circuit diagram which illustrates the step-up chopper circuit of a reference example.

1 First Embodiment 1.1 Boost Chopper Circuit FIG. 1 is a circuit diagram illustrating a boost chopper circuit according to an exemplary first embodiment of the present invention.

A direct current is input to the step-up chopper circuit 1 of the first embodiment illustrated in FIG. Direct current is output from the boost chopper circuit 1. The output DC voltage is higher than the input DC voltage.

The step-up chopper circuit 1 includes a first DC input terminal 11, a second DC input terminal 12, a first coil 13, a switching element 14, a second coil 15, a backflow prevention diode 16, and a first DC output terminal 17. And a second DC output terminal 18.

The switching element 14 and the second coil 15 are electrically connected in series with each other to form an element group 31. Therefore, the boost chopper circuit 1 includes an element group 31 including a switching element 14 and a second coil 15.

The first pole 51a of the DC source 51 is electrically connected to the first DC input terminal 11. The second pole 51b of the DC source 51 is electrically connected to the second DC input terminal 12. As a result, direct current is input between the first direct current input terminal 11 and the second direct current input terminal 12.

In the step-up chopper circuit 1 illustrated in FIG. 1, the first DC input terminal 11 is a DC input terminal of a positive electrode. Further, the second DC input terminal 12 is a DC input terminal of the negative electrode. Further, the first electrode 51a is a positive electrode. Further, the second electrode 51b is a negative electrode.

The first coil 13 includes a first coil terminal 13a and a second coil terminal 13b.

The first coil terminal 13a is electrically connected to the first DC input terminal 11.

The switching element 14 includes a first switching element terminal 14a and a second switching element terminal 14b.

In the switching element 14, there is no conduction between the first switching element terminal 14a and the second switching element terminal 14b and between the first switching element terminal 14a and the second switching element terminal 14b. Switch between states.

In the step-up chopper circuit 1 illustrated in FIG. 1, the switching element 14 is an N-channel metal oxide semiconductor field effect transistor (MOSFET). Further, the first switching element terminal 14a is a drain. The second switching element terminal 14b is a source. The switching element 14 may be a switching element other than the N-channel MOSFET. For example, the switching element 14 may be a P-channel MOSFET, an insulated gate bipolar transistor (IGBT), or the like.

The second coil 15 is magnetically coupled to the first coil 13.

The first coil 13 and the second coil 15 are magnetically coupled to each other by winding the windings provided in the first coil 13 and the second coil 15 around a common core. Therefore, the first coil 13 and the second coil 15 constitute a single component. Therefore, it is possible to avoid an increase in the number of parts constituting the boost chopper circuit 1 because the boost chopper circuit 1 includes the first coil 13 and the second coil 15. The windings provided in the first coil 13 and the second coil 15 may be two non-continuous windings or two portions constituting the continuous windings. When the windings provided in the first coil 13 and the second coil 15 form two continuous windings, the continuous windings are provided with taps.

The second coil 15 includes a third coil terminal 15a and a fourth coil terminal 15b.

The third coil terminal 15a is electrically connected to the first switching element terminal 14a. As a result, the switching element 14 and the second coil 15 are electrically connected in series with each other.

One terminal 31a of the second switching element terminal 14b and the fourth coil terminal 15b is electrically connected to the second coil terminal 13b. The other terminal 31b of the second switching element terminal 14b and the fourth coil terminal 15b is electrically connected to the second DC input terminal 12.

In the boost chopper circuit 1 illustrated in FIG. 1, one terminal 31a electrically connected to the second coil terminal 13b is a fourth coil terminal 15b. The other terminal 31b electrically connected to the second DC input terminal 12 is the second switching element terminal 14b.

The coil terminal 15i located closer to the second coil terminal 13b of the third coil terminal 15a and the fourth coil terminal 15b has the same polarity as the polarity of the first coil terminal 13a.

In the boost chopper circuit 1 illustrated in FIG. 1, the coil terminal 15i located closer to the second coil terminal 13b of the third coil terminal 15a and the fourth coil terminal 15b is a fourth coil terminal 15b. is there.

The DC source 51, the first coil 13, the second coil 15, and the switching element 14 are electrically connected in series in a loop. Therefore, when the first switching element terminal 14a and the second switching element terminal 14b are in a conductive state, the DC source 51, the first coil 13, the second coil 15, and the switching element 14 are connected. A closed circuit is formed through.

The backflow prevention diode 16 includes a first diode terminal 16a and a second diode terminal 16b.

The first diode terminal 16a is electrically connected to one terminal 31a of the second switching element terminal 14b and the fourth coil terminal 15b.

In the step-up chopper circuit 1 illustrated in FIG. 1, the first diode terminal 16a is an anode. The second diode terminal 16b is a cathode.

The first DC output terminal 17 has the same polarity as the polarity of the first DC input terminal 11. The first DC output terminal 17 is electrically connected to the second diode terminal 16b.

The second DC output terminal 18 has the same polarity as the polarity of the second DC input terminal 12. The second DC output terminal 18 is electrically connected to the other terminal 31b of the second switching element terminal 14b and the fourth coil terminal 15b.

In the step-up chopper circuit 1 illustrated in FIG. 1, the first DC output terminal 17 is a DC output terminal of a positive electrode. The second DC output terminal 18 is a DC output terminal of the negative electrode.

The loads electrically connected to the DC source 51, the first coil 13, the backflow prevention diode 16, and the first DC output terminal 17 and the second DC output terminal 18 are electrically connected in series in a loop. Will be done. Therefore, when the first switching element terminal 14a and the second switching element terminal 14b do not conduct with each other, the DC source 51, the first coil 13, the backflow prevention diode 16 and the load are closed. A circuit is formed.

The boost chopper circuit 1 further includes a drive circuit 19.

The drive circuit 19 inputs a drive signal to the switching element 14 to drive the switching element 14 by pulse width modulation (PWM). The switching element 14 is in a state where the first switching element terminal 14a and the second switching element terminal 14b are electrically connected according to the input drive signal, and the first switching element terminal 14a and the second switching element 14a. The state is switched between a state in which there is no conduction with the terminal 14b.

The boost chopper circuit 1 further includes a capacitor 20.

The capacitor 20 includes a first capacitor terminal 20a and a second capacitor terminal 20b.

The first capacitor terminal 20a is electrically connected to the first DC output terminal 17. The second capacitor terminal 20b is electrically connected to the second DC output terminal 18.

As a result, the direct current output from between the first direct current output terminal 17 and the second direct current output terminal 18 is smoothed.

According to the step-up chopper circuit 7 illustrated in FIG. 1, the potential of the first DC input terminal 12 which is the negative electrode of the DC input is applied to the second switching element terminal 14b such as the source of the MOSFET. Therefore, the control power of the drive circuit 19 can be easily generated from the DC input, and the drive circuit 19 can be simplified.

1.2 Operation of the step-up chopper circuit As described above, when the first switching element terminal 14a and the second switching element terminal 14b are in a conductive state, the DC source 51 and the first coil 13 , A closed circuit is formed through the second coil 15 and the switching element 14. As a result, the current I1 flows through the first coil 13, the second coil 15, and the switching element 14. As a result, energy is stored in the first coil 13 and the second coil 15.

Further, as described above, when the connection between the first switching element terminal 14a and the second switching element terminal 14b becomes non-conducting, the DC source 51, the first coil 13, the backflow prevention diode 16 and the backflow prevention diode 16 A closed circuit is formed through the load. As a result, the energy stored in the first coil 13 and the second coil 15 is released. As a result, the current I2 flows through the first coil 13 and the backflow prevention diode 16. The direction of the backflow prevention diode 16 is such that the current I2 becomes a forward current.

As a result, the boost chopper circuit 1 outputs direct current from between the first direct current output terminal 17 and the second direct current output terminal 18.

1.3 Current flowing through the first coil and the second coil FIG. 2 is a circuit diagram illustrating a part of a step-up chopper circuit according to an exemplary first embodiment of the present invention.

As described above, the first coil 13 is magnetically coupled to the second coil 15. Therefore, the first coil 13 and the second coil 15 form a transformer. Further, the first coil terminal 13a has the same polarity as the polarity of the fourth coil terminal 15b. Therefore, as shown in FIG. 2, the first switching element terminal 14a and the second switching element terminal 14b are in a conductive state, and the fourth coil terminal 15b to the third coil terminal 15a are in a conductive state. When the current Ia directed toward the second coil 15 flows, the induced current component Ib directed from the second coil terminal 13b toward the first coil terminal 13a tends to flow through the first coil 13.

On the other hand, as described above, when the first switching element terminal 14a and the second switching element terminal 14b are in a conductive state, the DC source 51, the first coil 13, and the second coil A closed circuit is formed through the 15 and the switching element 14. Therefore, when the current Ia flows through the second coil 15 in a state where the first switching element terminal 14a and the second switching element terminal 14b are conductive, the magnitude is the same as the magnitude of the current Ia. The current from the first coil terminal 13a to the second coil terminal 13b must flow through the first coil 13. Therefore, when the current Ia flows through the second coil 15 in a state where the first switching element terminal 14a and the second switching element terminal 14b are conductive, the first is larger than the induced current component Ib. The exciting current component Ic from the coil terminal 13a to the second coil terminal 13b is generated in the first coil 13, and eventually, Ia = Ic- toward the second coil terminal 13b from the first coil terminal 13a. The current of Ib will flow.

Then, when the current Ia does not flow to the second coil 15 due to the non-conduction between the first switching element terminal 14a and the second switching element terminal 14b, the induced current component Ib becomes the first. It stops flowing to the coil 13, and only the exciting current component Ic flows to the first coil 13. Therefore, when the connection between the first switching element terminal 14a and the second switching element terminal 14b becomes non-conducting, the current flowing out from the first DC output terminal 17 is a current corresponding to the exciting current component Ic. is there.

As a result, the exciting current component Ic flowing out of the first DC output terminal 17 can be increased without increasing the current Ia flowing through the second coil 15, that is, the current Ia flowing through the switching element 14.

1.4 Differences with and without the second coil FIG. 12 is a circuit diagram illustrating a buck-boost chopper circuit of a reference example.

The step-up chopper circuit 9 of the reference example shown in FIG. 12 is a step-up chopper circuit in which the second coil 15 is deleted from the step-up chopper circuit 1 of the first embodiment shown in FIG.

In the boost chopper circuit 9 illustrated in FIG. 12, the inductance of the first coil 13 is L, the PWM drive cycle is T, the length of the PWM drive on period is Ton, and the PWM drive on period is When the amount of increase in the current flowing through the first coil 13 as a whole is ΔI, the input DC voltage Vin is represented by the equation (1).

Vin = L · ΔI / Ton ・ ・ ・ (1)

Further, while the boost chopper circuit 9 is performing steady operation, the amount of decrease in the current flowing through the first coil 13 during the entire PWM drive off period is also ΔI, so that the output DC voltage Vout is determined. Equation (2) is satisfied.

Vout-Vin = L · ΔI / (T-Ton) ・ ・ ・ (2)

From the formulas (1) and (2), the boost ratio Vout / Vin is represented by the formula (3).

Vout / Vin = T / (T-Ton) ... (3)

The PWM drive duty ratio Ton / T is represented by the equation (4).

Ton / T = (Vout-Vin) / Vout ... (4)

From equations (3) and (4), in the boost chopper circuit 9 shown in FIG. 12, when the boost ratio Vout / Vin is 1.1, the duty ratio Ton / T of PWM drive is about 9. It can be understood that it is 1%.

In the boost chopper circuit 1 illustrated in FIG. 1, focusing exclusively on the exciting current component, the inductance of the first coil 13 is L, the PWM drive cycle is T, and the length of the PWM drive on period is Ton. Let ΔI be the amount of increase in the current flowing through the first coil 13 during the entire PWM drive on period, m be the number of windings of the first coil 13, and n be the number of windings of the second coil 15. If so, the voltage Vin · m / (m + n) applied to the first coil 13 during the PWM drive on period is represented by the equation (5).

Vin · m / (m + n) = L · ΔI / Ton ... (5)

Further, the output DC voltage Vout satisfies the equation (6) as in the equation (2).

Vout-Vin = L · ΔI / (T-Ton) ・ ・ ・ (6)

Equation (7) is derived from equations (5) and (6).

(Vout-Vin) (T-Ton) = Ton ・ Vin ・ m / (m + n) ・ ・ ・ (7)

The PWM drive duty ratio Ton / T is represented by the equation (8).

Ton / T = (Vout-Vin) / {Vout-Vin ・ n / (m + n)} ... (8)

From equations (7) and (8), in the boost chopper circuit 1 illustrated in FIG. 1, when the boost ratio Vout / Vin is 1.1 and m = n, the duty ratio of PWM drive is Ton. It can be understood that / T is about 16.7%.

The denominator Vout-Vin · n / (m + n) on the right side of the equation (8) is smaller than the denominator Vout on the right side of the equation (4). This means that the PWM drive duty ratio Ton / T in the boost chopper circuit 1 shown in FIG. 1 is larger than that in the boost chopper circuit 9 shown in FIG. Therefore, the current flowing through the switching element 14 provided in the boost chopper circuit 1 shown in FIG. 1 is smaller than the current flowing through the switching element 14 provided in the boost chopper circuit 9 shown in FIG.

FIG. 3 is a waveform diagram illustrating an example of a waveform of a coil current flowing through a first coil provided in a step-up chopper circuit of a first embodiment of the present invention and a reference example.

In the step-up chopper circuit 9 of the reference example shown in FIG. 12, the coil current flowing through the first coil 13 is the first switching element terminal 14a and the second switching element terminal as shown in FIG. During the on-period P1 in which the connection with the 14b is conductive, the value increases as time elapses, and the connection between the first switching element terminal 14a and the second switching element terminal 14b becomes non-conducting. During the off period P2, it becomes smaller as time passes.

Further, in the step-up chopper circuit 1 of the first embodiment shown in FIG. 1, the coil current flowing through the first coil 13 is the first switching element terminal 14a and the second switching element terminal 14a as shown in FIG. During the on-period P3 in which the switching element terminal 14b and the switching element terminal 14b of the above are in a conductive state, the value increases as time elapses, and the first switching element terminal 14a and the second switching element terminal 14b become conductive. The off period P4, which is in the non-existing state, becomes smaller as time elapses. However, in the boost chopper circuit 1 of the first embodiment, the coil current flowing through the first coil 13 sharply increases when shifting from the on period P3 to the off period P4, as shown in FIG. .. Therefore, in the boost chopper circuit 1 of the first embodiment, the coil current flowing through the first coil 13 during the on period P3, that is, the current flowing through the switching element 14, is first in the boost chopper circuit 9 of the reference example during the on period P1. It is smaller than the coil current flowing through the coil 13, that is, the current flowing through the switching element 14. Further, in the boost chopper circuit 1 of the first embodiment, the coil current flowing through the first coil 13 during the off period P4 is larger than the coil current flowing through the first coil 13 during the off period P2 in the boost chopper circuit 9 of the reference example. .. As a result, in the step-up chopper circuit 1 of the first embodiment, the current flowing out from the first DC output terminal 17 can be increased while reducing the current flowing through the switching element 14.

1.5 Number of windings of the first coil and the second coil The second coil 15 preferably has a number of windings of 1/10 or more and 10 times or less the number of windings of the first coil 13. However, more preferably, the number of windings of the first coil 13 is 3/10 times or more and 3 times or less the number of windings. When the number of windings of the second coil 15 is less than these ranges, it tends to be difficult to reduce the current flowing through the switching element 14. When the number of windings of the second coil 15 is larger than these ranges, the influence of the leakage inductance component of the second coil becomes large, so that the surge voltage at the time of switching of the switching element 14 becomes large, and the switching loss increases. There is a tendency to do.

1.6 Addition of Snubber Circuit FIGS. 4, 5, 6 and 7 show the first modification, the second modification, the third modification and the fourth modification of the first embodiment of the present invention, respectively. It is a circuit diagram which illustrates the step-up chopper circuit of an example.

The boost chopper circuit 2 of the first modification of the first embodiment shown in FIG. 4, the boost chopper circuit 3 of the second modification of the first embodiment shown in FIG. 5, and the first boost chopper circuit shown in FIG. The boost chopper circuit 4 of the third modification of the embodiment and the boost chopper circuit 5 of the fourth modification of the first embodiment shown in FIG. 7 are illustrated in FIG. 1 in that they further include a snubber circuit 21. It is different from the step-up chopper circuit 1.

The snubber circuit 21 is electrically connected in parallel to at least one of the second coil 15 and the switching element 14.

In the boost chopper circuit 2 illustrated in FIG. 4, the snubber circuit 21 is electrically connected in parallel to the second coil 15. Therefore, the snubber circuit 21 has a first snubber circuit terminal 21a electrically connected to the third coil terminal 15a and a second snubber circuit terminal 21b electrically connected to the fourth coil terminal 15b. To be equipped.

In the step-up chopper circuit 2 illustrated in FIG. 4, the snubber circuit 21 is an RC snubber circuit including a resistor 41 and a capacitor 42. The resistor 41 includes one resistance terminal 41a and the other resistance terminal 41b. The capacitor 42 includes one capacitor terminal 42a and the other capacitor terminal 42b. One of the resistance terminals 41a is a first snubber circuit terminal 21a that is electrically connected to the third coil terminal 15a. The other resistance terminal 41b is electrically connected to one capacitor terminal 42a. The other capacitor terminal 42b becomes a second snubber circuit terminal 21b that is electrically connected to the fourth coil terminal 15b. As a result, the resistor 41 and the capacitor 42 are electrically connected in series with each other. Further, the fourth coil terminal 15b is electrically connected to the third coil terminal 15a via the resistor 41 and the capacitor 42. One resistance terminal 41a may be a second snubber circuit terminal 21b that is electrically connected to the fourth coil terminal 15b. The other capacitor terminal 42b may be the first snubber circuit terminal 21a that is electrically connected to the third coil terminal 15a.

In the boost chopper circuit 2 illustrated in FIG. 4, the snubber circuit 21 can suppress the occurrence of ringing.

In the boost chopper circuit 3 illustrated in FIG. 5, the snubber circuit 21 is electrically connected in parallel to the second coil 15. Therefore, the snubber circuit 21 has a first snubber circuit terminal 21a electrically connected to the third coil terminal 15a and a second snubber circuit terminal 21b electrically connected to the fourth coil terminal 15b. To be equipped.

In the step-up chopper circuit 3 illustrated in FIG. 5, the snubber circuit 21 is an RCD snubber circuit including a resistor 41, a capacitor 42, and a diode 43. The resistor 41 includes one resistance terminal 41a and the other resistance terminal 41b. The capacitor 42 includes one capacitor terminal 42a and the other capacitor terminal 42b. The diode 43 includes one diode terminal 43a and the other diode terminal 43b. One resistance terminal 41a and one diode terminal 43a are electrically connected to each other to become a first snubber circuit terminal 21a electrically connected to the third coil terminal 15a. The other resistance terminal 41b and the other diode terminal 43b are electrically connected to each other and electrically connected to one capacitor terminal 42a. The other capacitor terminal 42b becomes a second snubber circuit terminal 21b that is electrically connected to the fourth coil terminal 15b. As a result, the resistor 41 and the diode 43 are electrically connected in parallel to each other to form the parallel connector 50. Further, the parallel connector 50 and the capacitor 42 are electrically connected in series with each other. Further, the fourth coil terminal 15b is electrically connected to the third coil terminal 15a via the parallel connector 50 and the capacitor 42. One resistance terminal 41a and one diode terminal 43a may serve as a second snubber circuit terminal 21b that is electrically connected to the fourth coil terminal 15b. The other capacitor terminal 42b may be the first snubber circuit terminal 21a that is electrically connected to the third coil terminal 15a.

In the step-up chopper circuit 3 illustrated in FIG. 5, the snubber circuit 21 can suppress the occurrence of ringing.

In the step-up chopper circuit 3 illustrated in FIG. 5, the snubber circuit 21 has a second coil when the first switching element terminal 14a and the second switching element terminal 14b are in a non-conducting state. The current that is about to continue flowing to the leakage inductance component of 15 is received, and the received current is passed through the capacitor 42 in a loop shape. Therefore, one diode terminal 43a is an anode. The other diode terminal 43b is a cathode. Further, one resistance terminal 41a and one diode terminal 43a become a second snubber circuit terminal 21b electrically connected to the fourth coil terminal 15b, and the other capacitor terminal 42b becomes a third coil terminal 15a. When it becomes the first snubber circuit terminal 21a electrically connected to, one diode terminal 43a is a cathode and the other diode terminal 43b is an anode.

In the step-up chopper circuit 4 illustrated in FIG. 6, the snubber circuit 21 is electrically connected to the switching element 14 in parallel. Therefore, the snubber circuit 21 is a second snubber circuit that is electrically connected to a first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a and a second snubber circuit terminal 14b that is electrically connected to the second switching element terminal 14b. The terminal 21b is provided.

In the step-up chopper circuit 4 illustrated in FIG. 6, the snubber circuit 21 is an RC snubber circuit including a resistor 41 and a capacitor 42. The resistor 41 includes one resistance terminal 41a and the other resistance terminal 41b. The capacitor 42 includes one capacitor terminal 42a and the other capacitor terminal 42b. One of the resistance terminals 41a becomes a second snubber circuit terminal 21b that is electrically connected to the second switching element terminal 14b. The other resistance terminal 41b is electrically connected to one capacitor terminal 42a. The other capacitor terminal 42b becomes a first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a. As a result, the resistor 41 and the capacitor 42 are electrically connected in series with each other. Further, the second switching element terminal 14b is electrically connected to the first switching element terminal 14a via the resistor 41 and the capacitor 42. One of the resistance terminals 41a may be the first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a. The other capacitor terminal 42b may be the second snubber circuit terminal 21b electrically connected to the second switching element terminal 14b.

In the step-up chopper circuit 4 illustrated in FIG. 6, the snubber circuit 21 can suppress the occurrence of ringing.

In the step-up chopper circuit 5 illustrated in FIG. 7, the snubber circuit 21 is electrically connected to the switching element 14 in parallel. Therefore, the snubber circuit 21 is a second snubber circuit that is electrically connected to a first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a and a second snubber circuit terminal 14b that is electrically connected to the second switching element terminal 14b. The terminal 21b is provided.

In the step-up chopper circuit 5 illustrated in FIG. 7, the snubber circuit 21 is an RCD snubber circuit including a resistor 41, a capacitor 42, and a diode 43. The resistor 41 includes one resistance terminal 41a and the other resistance terminal 41b. The capacitor 42 includes one capacitor terminal 42a and the other capacitor terminal 42b. The diode 43 includes one diode terminal 43a and the other diode terminal 43b. One resistance terminal 41a and one diode terminal 43a are electrically connected to each other to become a second snubber circuit terminal 21b electrically connected to the second switching element terminal 14b. The other resistance terminal 41b and the other diode terminal 43b are electrically connected to each other and electrically connected to one capacitor terminal 42a. The other capacitor terminal 42b becomes a first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a. As a result, the resistor 41 and the diode 43 are electrically connected in parallel to each other to form the parallel connector 50. Further, the parallel connector 50 and the capacitor 42 are electrically connected in series with each other. Further, the second switching element terminal 14b is electrically connected to the first switching element terminal 14a via the parallel connector 50 and the capacitor 42. One resistance terminal 41a and one diode terminal 43a may be the first snubber circuit terminal 21a that is electrically connected to the first switching element terminal 14a. The other capacitor terminal 42b may be the second snubber circuit terminal 21b electrically connected to the second switching element terminal 14b.

In the boost chopper circuit 5 illustrated in FIG. 7, the snubber circuit 21 can suppress the occurrence of ringing.

In the boost chopper circuit 5 illustrated in FIG. 7, the snubber circuit 21 has a second coil when the first switching element terminal 14a and the second switching element terminal 14b are in a non-conducting state. The current that is about to continue flowing to the leakage inductance component of 15 is received, and the received current is passed through the capacitor 42. Therefore, one diode terminal 43a is a cathode. The other diode terminal 43b is an anode. Further, one resistance terminal 41a and one diode terminal 43a become the first snubber circuit terminal 21a electrically connected to the first switching element terminal 14a, and the other capacitor terminal 42b becomes the second switching element. When the second snubber circuit terminal 21b is electrically connected to the terminal 14b, one diode terminal 43a is an anode and the other diode terminal 43b is a cathode.

1.7 Swapping the positions of the switching element and the second coil, and swapping the polarities of the first DC input terminal and the second DC input terminal FIGS. 8, 9 and 10, respectively, are exemplary of the present invention. It is a circuit diagram which illustrates the step-up chopper circuit of the 5th modification, the 6th modification and the 7th modification of the 1st embodiment.

The boost chopper circuit 6 of the fifth modification of the first embodiment shown in FIG. 8 is a boost chopper circuit shown in FIG. 1 in that the positions of the switching element 14 and the second coil 15 are interchanged. Different from 1.

Therefore, in the boost chopper circuit 6 illustrated in FIG. 8, one terminal 31a electrically connected to the second coil terminal 13b is the second switching element terminal 14b. The other terminal 31b electrically connected to the second DC input terminal 12 is the fourth coil terminal 15b.

FIG. 1 shows that the boost chopper circuit 7 of the sixth modification of the first embodiment shown in FIG. 9 has the polarities of the first DC input terminal 11 and the second DC input terminal 12 interchanged. It differs from the boost chopper circuit 1 shown.

Therefore, in the step-up chopper circuit 7 shown in FIG. 9, the first DC input terminal 11 is the DC input terminal of the negative electrode. The second DC input terminal 12 is a positive DC input terminal. Further, the first electrode 51a is a negative electrode. The second electrode 51b is a positive electrode.

Along with this, in the step-up chopper circuit 7 illustrated in FIG. 9, the first DC output terminal 17 is a DC output terminal of the negative electrode. The second DC output terminal 18 is a positive DC output terminal.

Further, in the step-up chopper circuit 7 shown in FIG. 9, the first diode terminal 16a is a cathode. The second diode terminal 16b is an anode.

In the step-up chopper circuit 8 of the seventh modification of the first embodiment shown in FIG. 10, the positions of the switching element 14 and the second coil 15 are interchanged, and the first DC input terminal 11 and the first DC input terminal 11 and the first It differs from the step-up chopper circuit 1 shown in FIG. 1 in that the polarities of the DC input terminals 12 of 2 are exchanged.

Therefore, in the boost chopper circuit 8 illustrated in FIG. 10, one terminal 31a electrically connected to the second coil terminal 13b is the second switching element terminal 14b. The other terminal 31b electrically connected to the second DC input terminal 12 is the fourth coil terminal 15b.

Further, in the step-up chopper circuit 8 shown in FIG. 10, the first DC input terminal 11 is a DC input terminal of the negative electrode. The second DC input terminal 12 is a positive DC input terminal. Further, the first electrode 51a is a negative electrode. The second electrode 51b is a positive electrode.

Along with this, in the step-up chopper circuit 8 shown in FIG. 10, the first DC output terminal 17 is a DC output terminal of the negative electrode. The second DC output terminal 18 is a positive DC output terminal.

Further, in the step-up chopper circuit 8 shown in FIG. 10, the first diode terminal 16a is a cathode. The second diode terminal 16b is an anode.

The snubber circuit 21 described above may be added to the boost chopper circuit 6 shown in FIG. 8, the boost chopper circuit 7 shown in FIG. 9, and the boost chopper circuit 8 shown in FIG.

1.8 Application of the boost chopper circuit to the power factor improving circuit FIG. 11 is a circuit diagram illustrating a DC power supply device including the boost chopper circuit of the first embodiment of the present invention.

The DC power supply device 101 provided with the step-up chopper circuit 1 of the first embodiment, which is illustrated in FIG. 11, includes a rectifier circuit 111 and a power factor improving circuit (PFC) 112.

The rectifier circuit 111 includes a first AC input terminal 121, a second AC input terminal 122, a first pulsating output terminal 123, and a second pulsating output terminal 124.

The first terminal 113a of the AC source 113 is electrically connected to the first AC input terminal 121. The second terminal 113b of the AC source 113 is electrically connected to the second AC input terminal 122. As a result, alternating current is input between the first alternating current input terminal 121 and the second alternating current input terminal 122.

The rectifier circuit 111 rectifies the alternating current input between the first alternating current input terminal 121 and the second alternating current input terminal 122 to generate a pulsating current, and the generated pulsating current is used as the first pulsating current output terminal. Output is performed from between 123 and the second pulsating output terminal 124.

In the DC power supply device 101 illustrated in FIG. 11, the rectifier circuit 111 is a diode bridge.

The PFC 112 includes a boost chopper circuit 1 illustrated in FIG. The boost chopper circuit 1 provided in the PFC 112 is the boost chopper circuit 2 shown in FIG. 4, the boost chopper circuit 3 shown in FIG. 5, the boost chopper circuit 4 shown in FIG. 6, and the boost chopper circuit shown in FIG. It may be replaced with the chopper circuit 5, the boost chopper circuit 6 shown in FIG. 8, the boost chopper circuit 7 shown in FIG. 9, or the boost chopper circuit 8 shown in FIG.

The first DC input terminal 11 is electrically connected to the first pulsating output terminal 123. The second DC input terminal 12 is electrically connected to the second pulsating output terminal 124.

The drive circuit 19 inputs a drive signal for operating the boost chopper circuit 1 as the PFC 112 to the switching element 14.

When the boost chopper circuit is applied to the PFC, even if the output DC voltage is higher than the input AC voltage, for example, the input AC voltage is close to the zero crossing point, from AC to DC. Power conversion can be performed. Therefore, it is possible to convert electric power having a high power factor.

However, when the boost chopper circuit 9 illustrated in FIG. 12 is applied to the PFC, the timing at which the boost ratio, which is the ratio of the output DC voltage to the input AC voltage, becomes low, for example, the input AC. When the voltage of is close to the peak point, the power converted by the boost chopper circuit becomes maximum. In addition, the current flowing through the boost chopper circuit 9 increases. Therefore, the current flowing through the switching element 14 becomes large. Therefore, a switching element 14 having a large current capacity is required.

On the other hand, when the boost chopper circuit 1 shown in FIG. 1 is applied to the PFC, the duty of PWM drive is compared with the case where the boost chopper circuit 9 shown in FIG. 12 is applied to the PFC. The ratio can be increased and the current flowing through the switching element 14 can be reduced. Therefore, the switching element 14 having a small current capacity can be used. As a result, the cost of the switching element 14 can be reduced.

1.9 Effect of the Invention of the First Embodiment According to the invention of the exemplary first embodiment of the present invention, in the step-up chopper circuit 1, the first switching element terminal 14a and the second switching element terminal 14b In the state where the intervals are conducting, a part of the exciting current flowing through the first coil is canceled by the induced current induced in the second coil 15. As a result, the current flowing through the switching element 14 can be reduced in a state where the first switching element terminal 14a and the second switching element terminal 14b are conducting.

1,2,3,4,5,6,7,8,9 Boost chopper circuit 11 1st DC input terminal 12 2nd DC input terminal 13 1st coil 14 Switching element 15 2nd coil 16 Backflow prevention Diode 17 1st DC output terminal 18 2nd DC output terminal 19 Drive circuit 20 Capacitor 21 Element group 31 Snubber circuit 41 Resistance 42 Capacitor 43 Diode 101 DC power supply 111 rectifier circuit 112 Power factor improvement circuit (PFC)

Claims (5)

The first DC input terminal and
With the second DC input terminal,
A first coil including a first coil terminal electrically connected to the first DC input terminal and a second coil terminal.
A state in which the first switching element terminal and the second switching element terminal are provided and the first switching element terminal and the second switching element terminal are conductive, and the first switching element terminal and the second switching element terminal are provided. The first coil terminal is provided with a switching element that switches between a state in which there is no conduction between the switching element terminals and a third coil terminal and a fourth coil terminal that are electrically connected to the first switching element terminal. A second coil magnetically coupled to the coil is provided, and one of the second switching element terminal and the fourth coil terminal is electrically connected to the second coil terminal, and the second coil terminal is electrically connected to the second coil terminal. The switching element terminal and the other terminal of the fourth coil terminal are electrically connected to the second DC input terminal, and the second of the third coil terminal and the fourth coil terminal. A group of elements in which the coil terminal near the coil terminal has the same polarity as that of the first coil terminal.
A backflow prevention diode including a first diode terminal electrically connected to one of the terminals and a second diode terminal.
A first DC output terminal having the same polarity as the first DC input terminal and electrically connected to the second diode terminal,
A second DC output terminal having the same polarity as the second DC input terminal and electrically connected to the other terminal.
A boost chopper circuit with. The boost chopper circuit according to claim 1, further comprising a snubber circuit electrically connected in parallel to at least one of the second coil and the switching element. The boost chopper circuit according to claim 1 or 2, wherein the second coil has a winding number of 1/10 times or more and 10 times or less the number of windings of the first coil. The first DC input terminal is a positive DC input terminal.
The second DC input terminal is a negative electrode DC input terminal.
The first DC output terminal is a positive DC output terminal.
The second DC output terminal is a negative electrode DC output terminal.
The one terminal is the fourth coil terminal.
The other terminal is the second switching element terminal.
The first diode terminal is an anode and
The second diode terminal is a step-up chopper circuit according to any one of claims 1 to 3, which is a cathode. A rectifier circuit including a first AC input terminal, a second AC input terminal, a first pulsating output terminal, and a second pulsating output terminal.
The step-up chopper circuit according to any one of claims 1 to 4 is provided, the first DC input terminal is electrically connected to the first pulsating output terminal, and the second DC input terminal is the second. Power factor improvement circuit that is electrically connected to the pulse flow output terminal of
DC power supply with.

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