JP6155179B2 - Rectifier, alternator and power converter - Google Patents

Description

  The present invention relates to a rectifier of an autonomous synchronous rectifier MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an alternator using the rectifier, and a power converter.

  A diode has been used as a rectifying element in an alternator that generates electricity in an automobile. Although the diode is inexpensive, it has a forward voltage drop and a large loss. On the other hand, in recent years, MOSFETs in which forward current rises from 0 V without forward voltage drop instead of diodes have begun to be used as rectifiers for alternators.

In the power supply device, the frequency of the AC power is constant. Therefore, when a MOSFET is used as the rectifying element of the power supply device, the MOSFET on / off control can be performed in synchronization with the clock. However, in the alternator, the frequency of the AC power generated by the coil is not constant. Therefore, when a MOSFET is used as the rectifier element of the alternator, it is necessary to perform on / off control of the MOSFET in synchronization with the frequency at that time, not simply in synchronization with the clock as in the case of use in a power supply device or the like.
Therefore, a method of controlling the MOSFET by detecting the position of the motor using a Hall element can be considered, but since the Hall element is required, the current rectifier cannot be replaced as it is, and the alternator must be changed greatly. Don't be.

  Claim 1 of Patent Document 1 includes a “cathode terminal (K1), an anode terminal (A1), and an electronic circuit provided between the cathode terminal and the anode terminal. Rectifier circuit characterized in that it includes a MOS transistor (T1) incorporating an (Inversdiode) (D6), a capacitor (C1) and differential amplifiers (T2, T3, R1, R2, R3). It is described. Paragraph 0018 of Patent Document 1 states that “when the potential of the cathode terminal K1 of the rectifier circuit is more positive than the potential of the anode terminal A1 of the rectifier circuit and the potential difference exceeds the value set by the Zener diode D4, The potential on the input side of the current amplification stage composed of the transistors T4 and T5 is raised, whereby the voltage between the gate and source of the MOS transistor T1 also rises so that current flows between the drain and source of the MOS transistor T1. It becomes ". Here, the method described in Patent Document 1 is referred to as an autonomous type.

Special table 2011-507468 gazette

  The autonomous synchronous rectification MOSFET described in Patent Document 1 has an advantage that a rectifying element (rectifying device) can be provided at low cost. However, chattering in which the MOSFET is repeatedly turned on and off is a problem.

Specifically, chattering is caused as follows. When the MOSFET is turned on at the start of the rectifying operation, first, a current flows through the high-resistance built-in diode, and the on-voltage increases. When the on-voltage reaches a determination criterion for turning on the MOSFET, the MOSFET is turned on and synchronous rectification starts. As a result of synchronous rectification, a current flows through the low-resistance MOSFET and the on-voltage decreases. When the criterion for turning off the MOSFET is reached because the on-voltage is too low, the MOSFET is turned off and the synchronous rectification ends. Upon completion of the synchronous rectification, a current flows through the built-in diode and the on-voltage increases. The on-voltage reaches a criterion for turning on the MOSFET, the MOSFET is turned on, and synchronous rectification starts. In this way, the ON / OFF determination of the MOSFET is repeated. The same applies when the MOSFET is controlled to be turned off at the end of the rectification operation.
Chattering causes a current to flow through the high-resistance built-in diode, reducing the power efficiency. Since the comparator and the gate driver are repeatedly turned on and off by chattering, a capacitor that is a power source of the autonomous rectifier is required to have a large capacity. Further, noise due to chattering may adversely affect the operation of the electronic component.

As a method for preventing chattering, it is conceivable to fix the output of the gate driver during a period in which chattering occurs. However, if this is applied to the rectifier of the alternator, it is necessary to cope with a wide range of AC power of the alternator, and therefore it is extremely difficult to set a period for fixing the output of the gate driver.
As another method for preventing chattering, there is a method for removing chattering noise. However, a circuit for removing noise has to be added, which increases the circuit scale.

  Therefore, an object of the present invention is to provide a rectifier capable of easily preventing chattering with a simple circuit configuration, and an alternator and a power converter using the rectifier.

A first invention for solving the above-described problem is a rectifier connected to a high side and a low side of a bridge-type rectifier circuit in which a DC terminal is connected to an energy storage unit and an AC terminal is connected to an AC power supply. Rectifier has a drain connected to the positive electrode side main terminal, a MOSFET having a source connected to the negative electrode side main terminal, the negative electrode side of said MOSFET and a gate driver for on-off control, from the positive electrode side main terminal of the pre-Symbol MOSFET A comparator that turns on the MOSFET if the voltage between the main terminals is equal to or lower than the reference voltage by generating a comparison signal that compares the voltage between the main terminals to the main terminal and a reference voltage and outputting the comparison signal to the gate driver; . When the reference voltage is greater than 0V and the main-terminal voltage from the positive-side main terminal to the negative-side main terminal is negative, the MOSFET passes a forward current and the main-terminal voltage is positive. If the voltage is lower than the reference voltage, the MOSFET passes a current in the reverse direction.

  The second invention is an alternator, wherein a DC terminal is connected to the energy storage unit, an AC terminal is connected to an AC power supply, the bridge type rectifier circuit, and the rectifier circuit connected to the high side and the low side, respectively. A rectifier. The energy storage unit is a battery.

A third invention is a power converter, wherein a direct current terminal is connected to the energy storage unit, an alternating current terminal is connected to an alternating current power supply, the bridge type rectifier circuit, and a high side and a low side of the rectifier circuit, respectively. The rectifier is provided.
Other means will be described in the embodiment for carrying out the invention.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the rectifier which can prevent chattering easily with a simple circuit structure, the alternator using this rectifier, and a power converter device.

It is a circuit diagram which shows schematic structure of the alternator using the autonomous rectifier in 1st Embodiment. It is a circuit diagram which shows the rectifier of the autonomous type synchronous rectification MOSFET in 1st Embodiment. It is a circuit diagram which shows the comparator of the autonomous type rectifier in 1st Embodiment. It is a graph which shows the U phase waveform of the alternator using the autonomous type rectifier in 1st Embodiment. It is a figure which shows the charge phase of the alternator using the autonomous type rectifier in 1st Embodiment. It is a figure which shows the recirculation | reflux phase of an alternator using the autonomous type rectifier in 1st Embodiment. It is a figure which shows the next charge phase of the alternator using the autonomous type rectifier in 1st Embodiment. It is a graph which shows the U phase waveform of the alternator at the time of a small electric current. It is a circuit diagram which shows the rectifier of the autonomous type synchronous rectification MOSFET in 2nd Embodiment. It is a circuit diagram which shows the rectifier of the autonomous type synchronous rectification MOSFET in 3rd Embodiment. It is a circuit diagram which shows the rectifier of the autonomous type synchronous rectification MOSFET in 4th Embodiment. It is a circuit diagram which shows schematic structure of the power converter device using the autonomous rectifier in 5th Embodiment. It is a circuit diagram which shows the rectifier of the autonomous type synchronous rectification MOSFET of a comparative example. It is a graph which shows the U phase waveform of the alternator using the autonomous type rectifier of the comparative example. It is a graph which shows the U phase waveform of the alternator at the time of a small electric current.

  Hereinafter, a comparative example and an embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols in the drawings for describing the embodiments, and repetitive description thereof will be omitted as appropriate. In the following description of the embodiments, the description of the same or similar parts is omitted as appropriate unless particularly necessary.

FIG. 1 is a circuit diagram showing a schematic configuration of an alternator using an autonomous rectifier. The configuration of this alternator is common to the comparative example and each embodiment.
As shown in FIG. 1, an alternator 140 using an autonomous synchronous rectification MOSFET rectifier includes a power generation unit including a rotor coil 109 and stator coils 110uv, 110vw, and 110wu, a rectifier circuit 130, It has.
The power generation unit includes a rotor coil 109 and three stator coils 110uv, 110vw, and 110wu that are Δ-connected. The midpoint wiring of the U phase 131u is drawn from the node where the stator coils 110wu and 110uv are connected. The midpoint wiring of the V-phase 131v is drawn out from the node where the stator coils 110uv and 110vw are connected. The midpoint wiring of the W phase 131w is drawn from the node where the stator coils 110vw and 110wu are connected. In addition, the connection of each stator coil 110uv, 110vw, 110wu may be Y connection instead of Δ connection, and is not limited.

The rectifier circuit 130 includes a U-phase 131u, a V-phase 131v, and a W-phase 131w, and rectifies the three-phase alternating current between the nodes Nu, Nv, and Nw into a direct current and flows it between the nodes Np and Nn. . The node Nu of the midpoint wiring of the U-phase 131u is connected to the rectifier 132uh on the high side and to the rectifier 132ul on the low side. The node Nv of the midpoint wiring of the V phase 131v has a rectifier 132vh connected to the high side and a rectifier 132vl connected to the low side. The node Nw of the midpoint wiring of the W phase 131w has a rectifier 132wh connected to the high side and a rectifier 132wl connected to the low side. The high-side rectifiers 132uh, 132vh, and 132wh are connected to the positive-side terminal of the battery 111 (energy storage unit) via a DC positive-side node Np. The low-side rectifiers 132ul, 132vl, and 132wl are connected to the negative-side terminal of the battery 111 through the DC negative-side node Nn.
The battery 111 (energy storage unit) is, for example, a vehicle-mounted battery, and its operating range is, for example, about 10.8V to 14V.

The high-side rectifier 132uh of the U phase 131u includes a MOSFET 101uh, a built-in diode 102uh, a control IC 108uh, and a capacitor 107uh. Similarly, the low-side rectifier 132ul of the U phase 131u includes a MOSFET 101ul, a built-in diode 102ul, a control IC 108ul, and a capacitor 107ul.
The high-side rectifier 132vh of the V phase 131v includes a MOSFET 101vh, a built-in diode 102vh, a control IC 108vh, and a capacitor 107vh. Similarly, the low-side rectifier 132vl of the V phase 131v includes a MOSFET 101vl, a built-in diode 102vl, a control IC 108vl, and a capacitor 107vl.

The high-side rectifier 132wh of the W phase 131w includes a MOSFET 101wh, a built-in diode 102wh, a control IC 108wh, and a capacitor 107wh. Similarly, the low-side rectifier 132wl of the W phase 131w includes a MOSFET 101wl, a built-in diode 102wl, a control IC 108wl, and a capacitor 107wl.
The low-side rectifiers 132ul, 132vl, and 132wl of each phase can be supplied from the outside without using the capacitors 107ul, 107vl, and 107wl because the power supply to the control ICs 108ul, 108vl, and 108wl is easy from the outside. .
Hereinafter, when the rectifiers 132uh to 132wl are not particularly distinguished, they are described as a rectifier 132z in the comparative example and as rectifiers 132 and 132a to 132c in the embodiments.
When the control ICs 108uh to 108wl are not particularly distinguished, the control ICs 108uh to 108wl are described as the control IC 108z in the comparative example, and the control ICs 108 and 108a to 108c are described in the embodiments.
When the MOSFETs 101uh to 101wl are not particularly distinguished, they are simply referred to as MOSFETs 101. When the built-in diodes 102uh to 102wl are not particularly distinguished, they are simply referred to as the built-in diodes 102. When the capacitors 107uh to 107wl are not particularly distinguished, they are simply referred to as capacitors 107.

FIG. 13 is a circuit diagram showing a rectifier of an autonomous type synchronous rectification MOSFET of a comparative example.
As shown in FIG. 13, the autonomous synchronous rectifier MOSFET rectifier 132z of the comparative example includes a MOSFET 101, a built-in diode 102 built in the chip of the MOSFET 101, a comparator 103z, a negative reference voltage generator 125, a gate A driver 105, a diode 106, and a capacitor 107 are included. The rectifying device 132z allows a current to flow from the negative-side main terminal TL to the positive-side main terminal TH.

The MOSFET 101 uses a power MOSFET to flow a large current generated by the power generation unit of the alternator 140. MOSFET 101 has a drain connected to positive-side main terminal TH and a source connected to negative-side main terminal TL. Accordingly, the built-in diode 102 of the MOSFET 101 has an anode connected to the negative main terminal TL and a cathode connected to the positive main terminal TH.
The comparator 103z has a non-inverting input terminal IN + connected to the drain of the MOSFET 101, and an inverting input terminal IN− connected to the source of the MOSFET 101 via the negative reference voltage generator 125. The output terminal of the comparator 103z is connected to the input terminal of the gate driver 105. The comparison signal Vcomp is output from the output terminal of the comparator 103z. The comparator 103z may be a comparator having a general function, and generates the comparison signal Vcomp from the voltage ΔV between the non-inverting input terminal IN + and the inverting input terminal IN−. Thus, the comparator 103z outputs a comparison result between the voltage obtained by adding the voltage of the negative reference voltage generator 125 to the voltage V1 of the negative main terminal TL and the voltage V2 of the positive main terminal TH. The comparator 103z is preferably highly accurate in terms of performance.

The output terminal of the gate driver 105 is connected to the gate terminal of the MOSFET 101. The gate driver 105 outputs a gate voltage Vgs.
The diode 106 is connected in the direction from the positive main terminal TH to the positive terminal of the capacitor 107. The positive terminal of the capacitor 107 is connected to the power supply terminal of the comparator 103z and the gate driver 105 to supply DC power. The gate driver 105 has a simple circuit configuration of one-stage or two-stage CMOS (Complementary MOS), and is a general gate driver.

  The negative reference voltage generator 125 applies a negative reference voltage to the inverting input terminal IN− of the comparator 103z with respect to the source of the MOSFET 101. However, the present invention is not limited to this, and the rectifier 132z may not include the negative reference voltage generation unit 125, and the inverting input terminal IN− of the comparator 103z may be directly connected to the source of the MOSFET 101.

  The control IC 108z includes a comparator 103z, a negative reference voltage generator 125, a gate driver 105, and a diode 106.

  The capacitor 107 supplies power for driving the control IC 108z. By using the capacitor 107 as a power source, the number of terminals of the rectifier 132z is two, and compatibility with the terminals of the conventional rectifier diode used in the alternator 140 can be achieved. Thereby, the performance of the alternator 140 can be improved by replacing the conventional rectifier diode with the rectifier 132z.

On the high side of each phase of the alternator 140 shown in FIG. 1, the positive main terminal TH of the rectifier 132z is connected to the positive terminal of the battery 111 via the node Np. The negative-side main terminal TL of the rectifier 132z is connected to the nodes Nu, Nv, and Nw that are the midpoint wirings of the respective phases.
On the low side of each phase, the positive side main terminal TH of the rectifier 132z is connected to the nodes Nu, Nv, and Nw that are the midpoint wirings of the respective phases. The negative main terminal TL of the rectifier 132z is connected to the negative terminal of the battery 111 via the node Nn.

FIGS. 14A to 14G are graphs showing waveforms of the U phase 131u of the alternator 140 using the autonomous rectifier 132z of the comparative example. The horizontal axes of FIGS. 14A to 14G indicate a common time t.
FIG. 14A is a graph showing the waveform of the voltage Vu of the midpoint wiring (node Nu) of the U phase 131u.
FIG. 14B is a graph showing a waveform of the comparison signal VcompH of the comparator 103z of the rectifier 132uh on the high side.
FIG. 14C is a graph showing a waveform of the gate voltage VgsH of the gate driver 105 of the rectifier 132uh on the high side. The gate voltage VgsH is based on the source voltage of the MOSFET 101uh.
FIG. 14D is a graph showing the drain current IdH flowing through the rectifier 132uh on the high side.
FIG. 14E is a graph showing a waveform of the comparison signal VcompL of the comparator 103z of the low-side rectifier 132ul.
FIG. 14F is a graph showing the waveform of the gate voltage VgsL of the gate driver 105 of the low-side rectifier 132ul. The gate voltage VgsL is based on the source voltage of the MOSFET 101ul.
FIG. 14G is a graph showing the drain current IdL flowing through the low-side rectifier 132ul.
The voltage and current of the V phase 131v have the same waveform with a phase shifted by 120 ° from that of the U phase 131u. The voltage and current of the W phase 131w have the same waveform with a phase shifted by 240 ° from that of the U phase 131u.

With reference to the alternator 140 shown in FIG. 1 as appropriate, the operation of each part by voltage and current will be described.
In the alternator 140, the rotor coil 109 rotates in the stator coils 110uv, 110vw, and 110wu to generate power. At this time, AC power is generated in the stator coils 110uv, 110vw, and 110wu.
As shown in FIG. 14A, the voltage Vu of the midpoint wiring (node Nu) of the U-phase 131u periodically rises and falls by the AC power of the stator coils 110uv, 110vw, and 110wu.
The rectifying device 132z of the comparative example operates so as not to flow a current in a direction opposite to the rectifying direction in order to prevent a through current.
When the voltage Vu becomes smaller than 0 V, before the MOSFET 101ul is controlled to be turned on at the start of synchronous rectification, first, a current flows through the high-resistance built-in diode 102ul, and the on-voltage increases.
At time t10, when the voltage Vu becomes lower than the negative reference voltage and reaches the determination criterion for turning on the MOSFET 101ul, the MOSFET 101ul of the low-side rectifier 132ul is turned on and synchronous rectification starts. Then, a current flows through the low-resistance MOSFET 101ul, and the on-voltage decreases. If the on-voltage is too low, the criterion for turning off the MOSFET 101ul is reached. The MOSFET 101ul is turned off and the synchronous rectification ends. As a result, a current flows through the built-in diode 102ul to increase the on-voltage, the MOSFET 101ul is turned on, and synchronous rectification starts again. As described above, the MOSFET 101ul is repeatedly turned on and off until the voltage Vu becomes sufficiently small.
When the voltage Vu becomes higher than the negative reference voltage at time t11, when the determination criterion for turning off the MOSFET 101ul is reached, the MOSFET 101ul of the rectifier 132ul on the low side is turned off, and the synchronous rectification is finished. Then, a current flows through the built-in diode 102ul, the on-voltage increases, the MOSFET 101ul turns on, and synchronous rectification starts again. As described above, the MOSFET 101ul is repeatedly turned on and off until the voltage Vu becomes sufficiently large.
When the voltage Vu becomes higher than the threshold value obtained by subtracting the negative reference voltage from the voltage VB at time t12, the MOSFET 101uh of the rectifier 132uu on the high side repeats ON and OFF similarly.
When the voltage Vu becomes lower than the threshold value obtained by subtracting the negative reference voltage from the voltage VB at time t13, the MOSFET 101ul of the rectifier 132ul on the high side repeats ON and OFF in the same manner.

As shown in FIG. 14B, the comparison signal VcompH is at the H level before the time t12, and after the time t12, the L level and the H level are repeated for a while and then becomes stable at the L level. The comparison signal VcompH is stabilized at the H level after repeating the L level and the H level for a while after the time t13.
As shown in FIG. 14C, the gate voltage VgsH is at the L level before the time t12, and after the time t12, the H level and the L level are repeated for a while and then becomes stable at the H level. The gate voltage VgsH is stabilized at the L level after repeating the H level and the L level for a while after the time t13. When the gate voltage VgsH is at the H level, the MOSFET 101uh performs synchronous rectification.

  As shown in FIG. 14 (d), the drain current IdH flows when the voltage Vu shown in FIG. 14 (a) exceeds the voltage VB of the battery 111.

As shown in FIG. 14E, the comparison signal VcompL is at the H level before the time t10, and after the time t10, the L level and the H level are repeated for a while and then becomes stable at the L level. The comparison signal VcompL is stabilized at the H level after repeating the L level and the H level for a while after the time t11.
As shown in FIG. 14F, the gate voltage VgsH is at the L level before the time t10, and after the time t10 for a while, the H voltage and the L level are repeated and then stabilized at the H level. The gate voltage VgsH is stabilized at the L level after repeating the L level and the H level for a while after the time t11. When the gate voltage VgsH is at the H level, the MOSFET 101uh performs synchronous rectification.
As shown in FIG. 14 (g), the drain current IdL flows when the voltage Vu shown in FIG. 14 (a) becomes smaller than 0V.

FIGS. 15A to 15G are graphs showing the U-phase waveform of the alternator when the current is small. The horizontal axis in FIGS. 15A to 15G shows a common time t.
FIG. 15A is a graph showing a waveform of the voltage Vu of the midpoint wiring (node Nu) of the U phase 131u.
FIG. 15B is a graph showing a waveform of the comparison signal VcompH of the comparator 103z of the rectifier 132uh on the high side.
FIG. 15C is a graph showing a waveform of the gate voltage VgsH of the gate driver 105 of the rectifier 132uh on the high side. The gate voltage VgsH is based on the source voltage of the MOSFET 101uh.
FIG. 15D is a graph showing the drain current IdH flowing through the rectifier 132uh on the high side.

FIG. 15E is a graph showing a waveform of the comparison signal VcompL of the comparator 103z of the low-side rectifier 132ul.
FIG. 15F is a graph showing a waveform of the gate voltage VgsL of the gate driver 105 of the low-side rectifier 132ul. The gate voltage VgsL is based on the source voltage of the MOSFET 101ul.
FIG. 15G is a graph showing the drain current IdL flowing through the low-side rectifier 132ul.

The basic operations in FIGS. 15A to 15G are the same as those in FIGS. 14A to 14G. However, compared with the case of FIG. 14D, the drain current IdH shown in FIG. Compared to the case of FIG. 14G, the drain current IdL shown in FIG.
For example, the drain current IdH flowing through the high-side MOSFET 101uh of the U-phase 131u includes a current flowing from the low-side MOSFET 101vl of the V-phase 131v and a current flowing from the low-side MOSFET 101wl of the W-phase 131w. If these currents are small, both currents do not continue in time, and therefore a period in which the drain current IdH does not flow through the MOSFET 101uh occurs.

As shown in FIG. 15 (d), from time t24 to t25, the current flowing from the low-side MOSFET 101vl of the V-phase 131v becomes the drain current IdH in the high-side MOSFET 101uh of the U-phase 131u.
From time t25 to t26, the drain current IdH does not flow through the high-side MOSFET 101uh of the U-phase 131u.
From time t26 to t27, the current flowing from the low-side MOSFET 101wl of the W phase 131w becomes the drain current IdH in the high-side MOSFET 101uh of the U phase 131u.

Similarly, the drain current IdL flowing through the low-side MOSFET 101ul of the U-phase 131u shown in FIG. 15G is composed of a current flowing from the high-side MOSFET 101vh of the V-phase 131v and a current flowing from the high-side MOSFET 101wh of the W-phase 131w. . When these currents are small, both currents do not continue in time, and therefore a period occurs during which the drain current IdL does not flow through the MOSFET 101ul.
From time t20 to t21, the current flowing from the high-side MOSFET 101vh of the V-phase 131v becomes the drain current IdL of the low-side MOSFET 101ul of the U-phase 131u.
From time t21 to t22, the drain current IdL does not flow through the low-side MOSFET 101ul of the U-phase 131u.
From time t22 to t23, the current flowing from the high-side MOSFET 101wh of the W-phase 131w becomes the drain current IdL of the low-side MOSFET 101ul of the U-phase 131u.

As shown in FIG. 15A, the voltage Vu is equal to or lower than the voltage VB and equal to or higher than 0 V before the time t20.
From time t20 to t21, the voltage Vu is less than 0V. The low-side MOSFET 101ul performs synchronous rectification.
From time t21 to t22, the voltage Vu again becomes equal to or lower than the voltage VB and equal to or higher than 0V. The low-side MOSFET 101ul finishes synchronous rectification.
From time t22 to t23, the voltage Vu again becomes less than 0V. The low-side MOSFET 101ul performs synchronous rectification.

From time t23 to t24, the voltage Vu is equal to or lower than the voltage VB and equal to or higher than 0V.
From time t24 to t25, the voltage Vu is equal to or higher than the voltage VB. The high-side MOSFET 101uh performs synchronous rectification.
At times t25 to t26, the voltage Vu again becomes equal to or lower than the voltage VB and equal to or higher than 0V. The high-side MOSFET 101uh stops synchronous rectification.
From time t26 to t27, the voltage Vu becomes equal to or higher than the voltage VB again. The high-side MOSFET 101uh performs synchronous rectification.
After time t27, voltage Vu is equal to or lower than voltage VB and equal to or higher than 0V.

As shown in FIG. 15B, the comparison signal VcompH is at the H level before time t24. The comparison signal VcompH becomes L level at times t24 to t25, becomes H level at times t25 to t26, becomes L level at times t26 to t27, and becomes H level after time t27.
As shown in FIG. 15C, the gate voltage VgsH is at the L level before time t24. The gate voltage VgsH becomes the H level from time t24 to t25, becomes the L level from time t25 to t26, becomes the H level from time t26 to t27, and becomes the L level after time t27.

  As shown in FIG. 15E, the comparison signal VcompL is at the H level before time t20. The comparison signal VcompL becomes L level at times t20 to t21, becomes H level at times t21 to t22, becomes L level at times t22 to t23, and becomes H level after time t23.

  As shown in FIG. 15F, the gate voltage VgsL is at the L level before time t20. The gate voltage VgsL becomes H level at times t20 to t21, becomes L level at times t21 to t22, becomes H level at times t22 to t23, and becomes L level after time t23.

  As described above, when the comparison signals VcompH, VcompL and the gate voltages VgsH, VgsL output from the comparator 103z rise and fall a plurality of times in one rectification operation, energy (charge) stored in the capacitor 107 is consumed. As a result, the capacitor 107 must have a larger capacity, the mounting area increases, and the cost of the rectifier 132z increases.

Hereinafter, how chattering occurs in the rectifier 132z of the comparative example will be described.
When the rectifier 132z starts a rectification operation, the MOSFET 101 is in an off state, and a rectification current starts to flow through the built-in diode 102. A large voltage determined by the forward voltage drop (about 0.7 V) of the built-in diode 102 appears in the ON voltage of the rectifier 132z. Thereafter, the MOSFET 101 is turned on, and the rectified current flows through the low-resistance MOSFET 101. The on-voltage of the rectifier 132z rapidly decreases to a voltage determined by the low on-resistance of the MOSFET 101. At this time, the MOSFET 101 is turned off when the criterion for turning the MOSFET 101 off again is satisfied. When the MOSFET 101 is turned off, a rectification current flows through the built-in diode 102, and the ON voltage of the rectifier 132z becomes a large voltage determined by the built-in diode 102. As described above, the rectifier 132z repeatedly turns on and off the MOSFET 101, and thus chattering occurs.

Immediately before the rectifier 132z finishes the rectification operation, the MOSFET 101 is on. The on-voltage of the rectifier 132z is a small voltage determined by the low on-resistance of the MOSFET 101. When the rectifier 132z finishes the rectification operation, the MOSFET 101 is turned off while the rectification current is flowing through the MOSFET 101. When the MOSFET 101 is turned off, the rectified current flows through the built-in diode 102. The on-voltage of the rectifier 132z is rapidly changed to a large voltage determined by the built-in diode 102. When the ON voltage of the rectifier 132z increases and the determination criterion for turning on the MOSFET 101 is satisfied, the MOSFET 101 is turned on and the rectified current flows again. When the MOSFET 101 is turned on, the on-voltage of the rectifier 132z changes to a small voltage determined by the low on-resistance of the MOSFET 101. When the on-voltage of the rectifier 132z satisfies the criterion for turning off the MOSFET 101, the MOSFET 101 is turned off again.
Thus, chattering occurs because the rectifier 132z repeats the determination of the MOSFET 101 off and on.

FIG. 2 is a circuit diagram showing a rectifier of the autonomous type synchronous rectification MOSFET in the first embodiment.
As shown in FIG. 2, the autonomous synchronous rectification MOSFET rectifier 132 according to the first embodiment is built in the two terminals of the positive-side main terminal TH and the negative-side main terminal TL, the MOSFET 101, and the MOSFET 101. The built-in diode 102, the comparator 103, the gate driver 105, the diode 106, and the capacitor 107 are included.

The MOSFET 101 uses a power MOSFET to flow a large current generated by the power generation unit of the alternator 140. MOSFET 101 has a drain connected to positive-side main terminal TH and a source connected to negative-side main terminal TL. Accordingly, the built-in diode 102 of the MOSFET 101 has an anode connected to the negative main terminal TL and a cathode connected to the positive main terminal TH.
In the comparator 103 (comparator), the non-inverting input terminal IN + is connected to the drain of the MOSFET 101 and the inverting input terminal IN− is directly connected to the source of the MOSFET 101. The output terminal of the comparator 103 is connected to the input terminal of the gate driver 105. The comparison signal Vcomp is output from the output terminal of the comparator 103. The comparator 103 directly compares the non-inverting input terminal IN + and the inverting input terminal IN− by changing the determination level according to the circuit balance, and outputs a comparison signal Vcomp that determines whether or not the voltage ΔV is equal to or lower than the reference voltage VREF. Is to be generated. The comparator 103 outputs a comparison result between a voltage (V1 + VREF) obtained by adding the reference voltage VREF to the voltage V1 of the negative main terminal TL and the voltage V2 of the positive main terminal TH. The performance of the comparator 103 is preferably highly accurate. The comparator 103 may further provide hysteresis for the on determination and the off determination. Thereby, the chattering prevention effect can be further enhanced.
Reference voltage VREF is set to be less than half of the minimum voltage of the operating range of battery 111 and greater than 0V. Thereby, the through current of the control circuit 130 shown in FIG. 1 can be prevented.

  The output terminal of the gate driver 105 is connected to the gate terminal of the MOSFET 101. The gate driver 105 outputs a gate voltage Vgs. The diode 106 is connected in the direction from the positive main terminal TH to the positive terminal of the capacitor 107. The positive terminal of the capacitor 107 is connected to the power supply terminal of the comparator 103 and the gate driver 105 to supply DC power. The gate driver 105 has a simple circuit configuration of one-stage or two-stage CMOS, and is a general gate driver.

  The control IC 108 includes a comparator 103, a gate driver 105, and a diode 106, and is composed of a single silicon chip. Thus, by using a one-chip IC, advantages of low cost, bottom area, and high noise resistance can be obtained.

  The capacitor 107 supplies power for driving the control IC 108. By using the capacitor 107 as a power source, the number of terminals of the rectifier 132 is two, and compatibility with the terminals of the conventional rectifier diode used in the alternator 140 can be achieved. Thereby, the performance of the alternator 140 can be improved by replacing the conventional rectifier diode with the rectifier 132. Instead of the capacitor 107, one terminal may be added to supply power to the control IC 108 from an external power source. In this way, more stable power can be supplied.

When the rectifier 132 causes chattering, the comparison signal Vcomp output from the comparator 103 and the gate voltage Vgs output from the gate driver 105 oscillate. As a result, the energy (charge) stored in the capacitor 107 is consumed, and the control IC 108 may not operate. Even if chattering occurs, in order to reliably supply power to the control IC 108, the capacitor 107 must have a larger capacity, the mounting area increases, and the cost of the rectifier 132 increases.
The rectifier 132 according to the first embodiment can supply power to the control IC 108 even if the capacitor 107 has a small capacity by preventing chattering, so that the rectifier 132 having a small area and a low cost can be realized. become. Furthermore, generation of noise due to voltage and current vibrations can be suppressed.

The rectifier 132 may further be connected with a diode for surge absorption in parallel with the MOSFET 101. By comprising in this way, the rectifier 132 can be provided with a surge absorption function.
The rectifier 132 may connect the non-inverting input terminal IN + of the comparator 103 to the negative-side main terminal TL and connect the inverting input terminal IN- to the positive-side main terminal TH. That is, the comparison signal Vcomp having the opposite polarity to that of the first embodiment may be output. In this case, the gate driver 105 is configured to output the gate voltage without inverting the input signal.

FIG. 3 is a circuit diagram showing a comparator of the autonomous rectifier in the first embodiment.
The comparator 103 includes a constant current circuit 122, PMOSs 11, 12, 13, 14, and 15, and NMOSs 21, 22, and 23. Power is supplied between the VCC terminal and the GND terminal of the comparator 103 to operate. The comparator 103 determines whether or not the voltage ΔV between the non-inverting input terminal IN + and the inverting input terminal IN− is equal to or lower than the reference voltage VREF.
The PMOSs 11, 12, and 13 constitute a mirror circuit. That is, the drains of the PMOSs 11, 12, and 13 are connected to the VCC terminal. The gates of the PMOSs 11, 12, and 13 and the source of the PMOS 11 are connected to each other and connected to the constant current circuit 122. The constant current circuit 122 is connected so that a current flows from a connection node between the gates of the PMOSs 11, 12, and 13 and the source of the PMOS 11 toward the GND terminal.
The drains of the PMOSs 14 and 15 are connected to the source of the PMOS 12. The back gates of the PMOSs 12, 14, and 15 are connected to the VCC terminal. The inverting input terminal IN− is connected to the gate of the PMOS 14. The gate of the PMOS 15 is connected to the non-inverting input terminal IN +. The source of the PMOS 14 is connected to the source of the NMOS 21 and the gates of the NMOSs 21 and 22. The source of the PMOS 15 is connected to the source of the NMOS 22 and the gate of the NMOS 23. The drains of the NMOSs 21, 22, and 23 are connected to the GND terminal.
The source of the PMOS 13 and the source of the NMOS 23 are connected to the OUT terminal.

Hereinafter, the operation of the comparator 103 will be described.
The constant current circuit 122 determines the current flowing through the PMOS 11. Due to the mirror circuit formed by the PMOS 11, 12, and 13, a constant current corresponding to the ratio of the channel width with the PMOS 11 flows through the PMOS 12 and 13. The current flowing through the PMOS 12 is divided into a current Iin + flowing through the PMOS 15 and a current Iin− flowing through the PMOS 14.
When the voltage at the non-inverting input terminal IN + of the comparator 103 becomes higher than the voltage at the inverting input terminal IN−, the current Iin− flowing in the PMOS 14 becomes larger than the current Iin + flowing in the PMOS 15. When the current Iin− flowing through the PMOS 14 flows through the NMOS 21, the NMOS 21 is turned on. The NMOS 22 to which the same gate voltage as the NMOS 21 is applied is also turned on. When the NMOS 22 is turned on, the gate voltage of the NMOS 23 is lowered and turned off. As a result, a current Ion_out flows from the PMOS 13 to the OUT terminal, and an H level voltage is generated at the OUT terminal.
On the contrary, when the voltage at the non-inverting input terminal IN + of the comparator 103 becomes lower than the voltage at the inverting input terminal IN−, the current Iin− flowing through the PMOS 14 becomes smaller than the current Iin + flowing through the PMOS 15. The current Iin + flowing through the NMOS 21 is also reduced, and the NMOS 21 is turned off. The NMOS 22 to which the same gate voltage as that of the NMOS 21 is applied is also turned off. When the NMOS 22 is turned off, the gate voltage of the NMOS 23 is increased and turned on. As a result, a current Ioff_out flows from the OUT terminal to the NMOS 23, and an L level voltage is generated at the OUT terminal.

  In the comparator 103 shown in FIG. 3, the current Ion_out that flows from the PMOS 13 to the OUT terminal when a high voltage is output to the OUT terminal flows from the OUT terminal to the NMOS 23 when the L level voltage is output to the OUT terminal. By increasing the current Ioff_out, the determination level of the comparator 103 can be shifted by the reference voltage VREF.

  In order to make the current Ioff_out larger than the current Ion_out, it is conceivable to reduce the channel width of the PMOS 13, increase the channel length of the PMOS 13, increase the channel width of the NMOS 23, or decrease the channel length of the NMOS 23. . Alternatively, a resistor may be provided in series with the PMOS 13 at a position other than the path of the current Ion_out and the path of the current Ioff_out.

  As another method, in the comparator 103 shown in FIG. 3, when the voltage of the non-inverting input terminal IN + is equal to the inverting input terminal IN−, the non-inverting input terminal IN + is inverted from the current Iin + flowing in the PMOS 15 connected to the gate. By reducing the current Iin− flowing through the PMOS 14 whose input terminal IN− is connected to the gate, the determination level of the comparator 103 can be shifted by the reference voltage VREF.

  In order to make the current Iin− smaller than the current Iin +, the channel width of the PMOS 14 is made smaller than the channel width of the PMOS 15, the channel length of the PMOS 14 is made larger than the channel length of the PMOS 15, or the channel width of the NMOS 21 is changed to the channel width of the NMOS 22. It can be considered that the channel length of the NMOS 21 is made smaller or larger than the channel length of the NMOS 22. Alternatively, a resistor may be provided in series with the PMOS 14 or the NMOS 21 at a position other than the path of the current Iin− and the path of the current Iin +.

FIGS. 4A to 4G are graphs showing the U-phase waveform of the alternator 140 using the autonomous rectifier 132 in the first embodiment. 4A to 4G correspond to the graphs of the comparative example shown in FIGS. 14A to 14G. The horizontal axes of FIGS. 4A to 4G indicate the common time t.
FIG. 4A is a graph showing the waveform of the voltage Vu of the midpoint wiring (node Nu) of the U phase 131u.
FIG. 4B is a graph showing a waveform of the comparison signal VcompH of the comparator 103z of the high-side rectifier 132uh.
FIG. 4C is a graph showing a waveform of the gate voltage VgsH of the gate driver 105 of the rectifier 132uh on the high side. The gate voltage VgsH is based on the source voltage of the MOSFET 101uh.
FIG. 4D is a graph showing the drain current IdH flowing through the high-side rectifier 132uh.
FIG. 4E is a graph showing a waveform of the comparison signal VcompL of the comparator 103 of the low-side rectifier 132ul.
FIG. 4F is a graph showing the waveform of the gate voltage VgsL of the gate driver 105 of the low-side rectifier 132ul. The gate voltage VgsL is based on the source voltage of the MOSFET 101ul.
FIG. 4G is a graph showing the drain current IdL flowing through the low-side rectifier 132ul.

With reference to the alternator 140 shown in FIG. 1 as appropriate, the operation of each part by voltage and current will be described.
In the alternator 140, the rotor coil 109 rotates in the stator coils 110uv, 110vw, and 110wu to generate power. At this time, AC power is generated in the stator coils 110uv, 110vw, and 110wu.

As shown in FIG. 4A, the voltage Vu of the midpoint wiring (node Nu) of the U-phase 131u periodically rises and falls due to the AC power of the stator coils 110uv, 110vw, and 110wu.
When the voltage Vu becomes smaller than the reference voltage VREF, when the MOSFET 101ul is controlled to be turned on at the start of synchronous rectification, first, a current flows through the high-resistance built-in diode 102ul, and the on-voltage increases.
At time t30, when the voltage Vu becomes lower than the reference voltage VREF and reaches a determination criterion for turning on the MOSFET 101ul, the MOSFET 101ul of the low-side rectifier 132ul is turned on. At this time, a reverse current flows through the MOSFET 101 ul and circulates in the rectifier circuit 130.
When the voltage Vu becomes lower than 0 V at time t31, a forward current flows through the MOSFET 101ul and synchronous rectification starts.
When the voltage Vu becomes higher than 0V at time t32, a reverse current flows through the MOSFET 101ul and circulates in the rectifier circuit 130.
At time t33, when the voltage Vu becomes higher than the reference voltage VREF and reaches a determination criterion for turning off the MOSFET 101ul, the MOSFET 101ul of the rectifier 132ul on the low side is turned off.
The voltage from the negative-side main terminal TL to the positive-side main terminal TH is an on-voltage when the gate of the MOSFET 101ul is on-controlled from when the rectified current starts to flow until it ends.

The time t34 to t37 is the same as the time t30 to t33.
At time t34, when the voltage Vu becomes higher than the voltage (VB−VREF) obtained by subtracting the reference voltage VREF from the voltage VB and reaches the determination criterion for turning on the MOSFET 101uh, the MOSFET 101uh of the high-side rectifier 132uh is turned on. At this time, a reverse current flows through the MOSFET 101uh and circulates in the rectifier circuit 130.
When the voltage Vu becomes higher than the voltage VB at time t35, a forward current flows through the MOSFET 101uh and synchronous rectification is started.
When the voltage Vu becomes lower than the voltage VB at time t36, a reverse current flows through the MOSFET 101uh and circulates in the rectifier circuit 130.
At time t37, when the voltage Vu becomes lower than the voltage (VB−VREF) obtained by subtracting the reference voltage VREF from the voltage VB and reaches the determination criterion for turning off the MOSFET 101ul, the MOSFET 101uh of the high-side rectifier 132uh is turned off.
The voltage from the negative-side main terminal TL to the positive-side main terminal TH is an on-voltage when the gate of the MOSFET 101uh is on-controlled from when the rectified current starts to flow until it ends.

As shown in FIG. 4B, the comparison signal VcompH is at the H level before the time t34 and becomes the L level at the time t34. Comparison signal VcompH becomes H level at time t37.
As shown in FIG. 4C, the gate voltage VgsH is at the L level before the time t34 and becomes the H level at the time t34. Gate voltage VgsH becomes L level at time t37.

As shown in FIG. 4D, the drain current IdH does not flow before time t34.
From time t34 to t35, the drain current IdH flows in the reverse direction, that is, from the drain to the source. This drain current IdH circulates in the rectifier circuit 130.
From time t35 to t36, the drain current IdH flows in the forward direction.
From time t36 to t37, the drain current IdH flows in the reverse direction. This drain current IdH circulates in the rectifier circuit 130.
After time t37, the drain current IdH does not flow.

As shown in FIG. 4E, the comparison signal VcompL is at the H level before the time t30, and becomes the L level at the time t30. The comparison signal VcompL becomes H level at time t33.
As shown in FIG. 4F, the gate voltage VgsH is at the L level before time t30, and becomes the H level at time t30. Gate voltage VgsH becomes L level at time t33.
As shown in FIG. 4G, the drain current IdL does not flow before time t30.
From time t30 to t31, the drain current IdL flows in the reverse direction, that is, from the drain to the source. This drain current IdH circulates in the rectifier circuit 130.
From time t31 to t32, the drain current IdL flows in the forward direction.
From time t32 to t33, the drain current IdL flows in the reverse direction. This drain current IdL circulates in the rectifier circuit 130.
After time t33, the drain current IdL does not flow.

The operation of each part of the alternator 140 will be described below with reference to FIGS. 1 and 2 as appropriate.
Power generation by the alternator 140 is performed by the rotor coil 109 rotating in the stator coils 110uv, 110vw, and 110wu. At this time, AC power is generated in the stator coils 110uv, 110vw, and 110wu of each phase. Due to the AC power, the voltage Vu of the midpoint wiring of the U phase 131u rises and falls periodically.

The case where the voltage Vu of the midpoint wiring of the U-phase 131u increases and the high-side rectifier 132uh performs rectification operation will be described.
Immediately before time t34, the voltage Vu of the midpoint wiring of the U phase 131u has increased.
At time t34, the voltage Vu is a voltage (VB−) in which the source voltage of the high-side MOSFET 101uh to which the voltage Vu is applied is lower than the drain voltage, which is the voltage VB of the positive terminal of the battery 111, by the reference voltage VREF. VREF) is reached. The comparison signal VcompH at the output terminal of the comparator 103 changes from H level to L level. As a result, the gate voltage VgsH of the MOSFET 101uh changes from the L level to the H level, turning on the MOSFET 101uh. The reference voltage VREF of the comparator 103 is set to exceed 0V and less than half of the voltage VB.

The rectifier 132uh of the first embodiment turns on the MOSFET 101uh in a state where a voltage in the opposite direction to that during rectification is applied between the drain and the source before the source voltage of the MOSFET 101uh crosses the drain voltage. . Immediately after the MOSFET 101uh is turned on, the drain current IdH flows in the direction opposite to the rectification direction, that is, from the drain to the source.
After time t34, the voltage Vu of the midpoint wiring of the U phase 131u further increases.

  At time t35, the voltage Vu exceeds the voltage VB of the positive terminal of the battery 111. A voltage in the rectifying direction is applied between the drain and the source of the MOSFET 101uh. The drain current IdH flows in the rectification direction, that is, from the source to the drain.

After time t35, the voltage Vu of the midpoint wiring of the U phase 131u changes from rising to falling.
At time t36, when the source voltage of the high-side MOSFET 101uh falls below the drain voltage, a voltage in the opposite direction to that during rectification is again applied between the drain and source of the MOSFET 101uh. The drain current IdH flows in the direction opposite to the rectification direction, that is, from the drain to the source.

After time t36, the voltage Vu of the midpoint wiring of the U phase 131u further decreases.
When the voltage Vu of the midpoint wiring of the U-phase 131u reaches a voltage (VB−VREF) lower than the voltage VB applied to the drain of the high-side MOSFET 101uh at time t37, the output terminal of the comparator 103 Comparison signal VcompH changes from L level to H level. As a result, the gate voltage VgsH changes from the H level to the L level, and the MOSFET 101uh is turned off. Since the MOSFET 101uh is turned off, the drain current IdH does not flow.

As described above, when the operation of the MOSFET 101uh is sequentially followed, at time t34, the gate voltage VgsH changes to the H level, and the MOSFET 101uh is turned on.
From time t34 to t35, the drain current IdH in the direction opposite to that during rectification flows through the MOSFET 101uh.
From time t35 to t36, a drain current IdH in the rectifying direction flows through the MOSFET 101uh.
From time t36 to t37, a drain current IdH in the direction opposite to that during rectification flows through the MOSFET 101uh.
At time t37, the gate voltage VgsH changes to the L level, and the MOSFET 101uh is turned off.

In this operation, the drain current IdH in the rectifying direction flows only when the MOSFET 101uh is on. The drain current IdH does not flow through the built-in diode 102uh having a higher resistance than the MOSFET 101uh in the on state. Therefore, the on-voltage of the rectifier 132uh is determined only by the on-resistance of the MOSFET 101uh, and is not determined by the high-resistance built-in diode 102uh. Therefore, the ON voltage of the rectifier 132uh increases monotonously when the drain current IdH increases, and decreases monotonously when the drain current IdH decreases.
A voltage (Vu−VB) obtained by subtracting the voltage VB of the battery 111 from the voltage Vu of the midpoint wiring of the U phase 131u corresponds to the ON voltage of the rectifier 132uh. As shown in FIG. 4A, the ON voltage of the rectifier 132uh in the first embodiment increases monotonously and decreases monotonously. Unlike the rectifier 132z of the comparative example, when the drain current IdH changes from the state flowing through the built-in diode 102uh to the state flowing through the MOSFET 101uh, or when changing from the state flowing through the MOSFET 101uh into the state flowing through the built-in diode 102uh The on-voltage does not change rapidly. Thereby, the rectifier 132uh in 1st Embodiment can prevent the chattering which repeats the erroneous determination of ON and OFF when controlling a rectification operation.

Even if the reverse current does not flow through the MOSFET 101uh due to the delay of the gate driver 105, the current does not flow through the built-in diode 102uh, and the on-voltage determined by the built-in diode 102uh does not appear in the on-voltage of the rectifier 132uh. The same effect can be obtained.
Further, in preparation for the case where the delay of the gate driver 105 is large, the comparator 103 of the first embodiment adjusts the circuit balance and sets the determination level to the reference voltage VREF. Thereby, the comparator 103 changes the comparison signal Vcomp from the H level to the L level before the voltage of the inverting input terminal IN− exceeds the voltage of the non-inverting input terminal IN +, and the voltage of the inverting input terminal IN− is non-inverting input. Prior to falling below the voltage at the terminal IN +, the comparison signal Vcomp is changed from L level to H level. Thereby, the occurrence of chattering can be prevented.

Even when the voltage Vu of the midpoint wiring of the U-phase 131u drops and the low-side rectifier 132ul rectifies, the voltage VB of the positive terminal of the battery 111 becomes the voltage 0V of the negative terminal and the direction of the voltage is It works in the same way just by reversing.
When the operation of the MOSFET 101ul is sequentially followed, at time t30, the gate voltage VgsL changes to the H level, and the MOSFET 101ul is turned on.
From time t30 to t31, a drain current IdL in the direction opposite to that during rectification flows through the MOSFET 101ul.
From time t31 to t32, the drain current IdL in the rectifying direction flows through the MOSFET 101ul.
From time t32 to t33, a drain current IdL in the direction opposite to that during rectification flows through the MOSFET 101ul.
At time t33, the gate voltage VgsL changes to the L level, and the MOSFET 101ul is turned off.

  In this operation, the drain current IdL in the rectifying direction flows only when the MOSFET 101ul is on. The drain current IdL does not flow in the built-in diode 102ul having a higher resistance than the MOSFET 101ul in the on state. Therefore, the on-voltage of the rectifier 132ul is determined only by the on-resistance of the MOSFET 101ul, and is not determined by the high-resistance built-in diode 102ul. Therefore, the ON voltage of the rectifier 132ul increases monotonously when the drain current IdL increases, and decreases monotonously when the drain current IdL decreases.

  A voltage (-Vu) in the reverse direction of the voltage Vu of the midpoint wiring of the U phase 131u corresponds to the ON voltage of the rectifier 132ul. As shown in FIG. 4A, the ON voltage of the rectifier 132ul in the first embodiment increases monotonously and decreases monotonously. Unlike the rectifier 132z of the comparative example, when the drain current IdL changes from the state flowing through the built-in diode 102ul to the state flowing through the MOSFET 101ul, or when changing from the state flowing through the MOSFET 101ul into the state flowing through the built-in diode 102ul The on-voltage does not change rapidly. Thereby, the rectifier 132ul in 1st Embodiment can prevent the chattering which repeats the misjudgment of ON and OFF when controlling a rectification operation | movement.

As in the case of the high-side MOSFET 101uh, even if no reverse current flows through the MOSFET 101ul due to the delay of the gate driver 105, no current flows through the built-in diode 102ul, and the on-voltage of the rectifier 132ul is determined by the built-in diode 102ul. If the on-voltage does not appear, the same effect can be obtained.
Further, in preparation for the case where the delay of the gate driver 105 is large, the comparator 103 of the first embodiment adjusts the circuit balance and sets the determination level to the reference voltage VREF. Thereby, the comparator 103 changes the comparison signal Vcomp from the H level to the L level before the voltage of the inverting input terminal IN− exceeds the voltage of the non-inverting input terminal IN +, and the voltage of the inverting input terminal IN− is non-inverting input. Prior to falling below the voltage at the terminal IN +, the comparison signal Vcomp is changed from L level to H level. Thereby, the occurrence of chattering can be prevented.

The reference voltage VREF that is the determination level of the comparator 103 is larger than 0V and smaller than half of the voltage VB of the battery 111.
When the high-side MOSFET 101uh is turned on, the voltage between the positive-side main terminal TH and the negative-side main terminal TL of the high-side rectifier 132uh is smaller than half of the voltage VB. The voltage between the positive-side main terminal TH and the negative-side main terminal TL of the low-side rectifier 132ul is larger than half of the voltage VB. Since the reference voltage VREF which is the determination level of the comparator 103 is smaller than VB / 2, the low-side MOSFET 101ul is never turned on. The same is true when the high side and low side are reversed.
That is, when the autonomous synchronous rectification MOSFET rectifier 132 of the first embodiment is used, both the high-side MOSFET 101uh and the low-side MOSFET 101ul are not simultaneously turned on. Therefore, even if a reverse current flows through the high-side MOSFET 101uh or the low-side MOSFET 101ul, no through current flows from the positive terminal to the negative terminal of the battery 111. Hereinafter, the operation of the current in the reverse direction will be described in detail with reference to FIGS.

FIG. 5 is a diagram illustrating a charging phase of the alternator 140 using the autonomous rectifier 132 in the first embodiment. A thick solid line arrow and a thick broken line arrow indicate currents flowing through the alternator 140, respectively.
A current indicated by a thick solid arrow is a rectified current that flows from the low side of the V phase 131v to the high side of the U phase 131u. This current flows from the negative terminal of the battery 111 to the positive terminal of the battery 111 via the rectifier 132vl, the node Nv, the stator coil 110uv, the node Nu, and the rectifier 132uh. Thereby, the alternator 140 can charge the battery 111.
A current indicated by a thick dashed arrow is a rectified current that flows from the low side of the V phase 131v to the high side of the W phase 131w. This current flows from the negative terminal of the battery 111 to the positive terminal of the battery 111 via the rectifier 132vl, the node Nv, the stator coil 110vw, the node Nw, and the rectifier 132wh. Thereby, the alternator 140 can charge the battery 111.

FIG. 6 is a diagram illustrating a reflux phase of the alternator 140 using the autonomous rectifier 132 in the first embodiment.
The alternator 140 operates in the recirculation phase shown in FIG. 6 after the charging phase shown in FIG.
The current indicated by the thick solid arrow is a circulating current. This circulating current flows through the rectifying device 132uh in the direction opposite to the rectifying direction, and circulates again to the rectifying device 132uh via the node Nu, the stator coil 110uv, the stator coil 110vw, the node Nw, and the rectifying device 132wh.
The current indicated by the thick dashed arrow is the same as the current shown in FIG.

FIG. 7 is a diagram illustrating a next charging phase of the alternator 140 using the autonomous rectifier 132 according to the first embodiment.
The alternator 140 operates in the next charging phase shown in FIG. 7 after the reflux phase shown in FIG.
A current indicated by a thick solid arrow is a charging current, which is a commutation of the circulating current shown in FIG. This charging current flows from the negative terminal of the battery 111 to the positive terminal of the battery 111 through the rectifier 132ul, the node Nu, the stator coil 110uv, the stator coil 110vw, the node Nw, and the rectifier 132wh. In this way, the current flowing through the rectifier 132uh in the direction opposite to the rectification direction finally flows to the battery 111 and charges it.
The current indicated by the thick dashed arrow is the same as the current shown in FIG.
As described above, by using the rectifier 132 in the first embodiment for the bridge-type rectifier circuit 130, it is possible to prevent reverse current from flowing as a through current from the positive terminal to the negative terminal of the battery 111. .

8A to 8G are graphs showing the U-phase waveform of the alternator 140 at a small current. The horizontal axes in FIGS. 8A to 8G indicate the common time t.
FIG. 8A is a graph showing the waveform of the voltage Vu of the midpoint wiring (node Nu) of the U phase 131u.
FIG. 8B is a graph showing a waveform of the comparison signal VcompH of the comparator 103 of the rectifier 132uh on the high side.
FIG. 8C is a graph showing the waveform of the gate voltage VgsH of the gate driver 105 of the rectifier 132uh on the high side. The gate voltage VgsH is based on the source voltage of the MOSFET 101uh.
FIG. 8D is a graph showing the drain current IdH flowing through the rectifier 132uh on the high side.

FIG. 8E is a graph showing the waveform of the comparison signal VcompL of the comparator 103 of the low-side rectifier 132ul.
FIG. 8F is a graph showing a waveform of the gate voltage VgsL of the gate driver 105 of the low-side rectifier 132ul. The gate voltage VgsL is based on the source voltage of the MOSFET 101ul.
FIG. 8G is a graph showing the drain current IdL flowing in the low-side rectifier 132ul.

The basic operations in FIGS. 8A to 8G are the same as those in FIGS. 4A to 4G. However, the drain current IdH shown in FIG. 8D is smaller than that in the case of FIG. Compared to the case of FIG. 4G, the drain current IdL shown in FIG.
For example, the drain current IdH flowing through the high-side MOSFET 101uh of the U-phase 131u includes a current flowing from the low-side MOSFET 101vl of the V-phase 131v and a current flowing from the low-side MOSFET 101wl of the W-phase 131w. If these currents are small, both currents do not continue in time, and therefore a period in which the drain current IdH does not flow through the MOSFET 101uh occurs.

As shown in FIG. 8A, the voltage Vu of the midpoint wiring (node Nu) of the U phase 131u periodically rises and falls due to the AC power of the stator coils 110uv, 110vw, and 110wu.
When the voltage Vu becomes smaller than the reference voltage VREF, when the MOSFET 101ul is controlled to be turned on at the start of synchronous rectification, first, a current flows through the high-resistance built-in diode 102ul, and the on-voltage increases.

At time t40, when the voltage Vu becomes lower than the reference voltage VREF and reaches a determination criterion for turning on the MOSFET 101ul, the MOSFET 101ul of the low-side rectifier 132ul is turned on. At this time, a reverse current flows through the MOSFET 101 ul and circulates in the rectifier circuit 130.
When the voltage Vu becomes lower than 0 V at time t41, a forward current flows through the MOSFET 101ul and synchronous rectification starts.
When the voltage Vu becomes higher than 0V at time t42, a reverse current flows through the MOSFET 101ul and circulates in the rectifier circuit 130.
When the voltage Vu becomes lower than 0 V at time t43, a forward current flows through the MOSFET 101ul and synchronous rectification starts.
At time t44, the voltage Vu becomes substantially 0 V, and no current flows through the MOSFET 101ul.
At time t45, when the voltage Vu becomes higher than the reference voltage VREF and reaches a determination criterion for turning off the MOSFET 101ul, the MOSFET 101ul of the low-side rectifier 132ul is turned off.

The time t46 to t51 is the same as the time t40 to t45.
At time t46, when the voltage Vu becomes higher than the voltage obtained by subtracting the reference voltage VREF from the voltage VB (VB−VREF) and reaches the determination criterion for turning on the MOSFET 101uh, the MOSFET 101uh of the high-side rectifier 132uh is turned on. At this time, a reverse current flows through the MOSFET 101uh and circulates in the rectifier circuit 130.
When the voltage Vu becomes higher than the voltage VB at time t47, a forward current flows through the MOSFET 101uh and synchronous rectification starts.
At time t48, the voltage Vu becomes substantially 0 V, and no current flows through the MOSFET 101uh.
When the voltage Vu becomes higher than the voltage VB at time t49, a forward current flows through the MOSFET 101uh and synchronous rectification starts.
When the voltage Vu becomes lower than the voltage VB at time t50, a reverse current flows through the MOSFET 101uh and circulates in the rectifier circuit 130.
At time t51, when the voltage Vu becomes lower than the voltage (VB−VREF) obtained by subtracting the reference voltage VREF from the voltage VB and reaches a determination criterion for turning off the MOSFET 101ul, the MOSFET 101uh of the high-side rectifier 132uh is turned off.

As shown in FIG. 8B, the comparison signal VcompH is at the H level before the time t46, and becomes the L level at the time t46. Comparison signal VcompH becomes H level at time t51.
As shown in FIG. 9C, the gate voltage VgsH is at the L level before time t46, and becomes the H level at time t46. Gate voltage VgsH becomes L level at time t51.

As shown in FIG. 8D, the drain current IdH does not flow before time t46.
From time t46 to t47, the drain current IdH flows in the reverse direction, that is, from the drain to the source. This drain current IdH circulates in the rectifier circuit 130.

From time t47 to t48, the drain current IdH flows in the forward direction.
From time t48 to t49, the drain current IdH stops flowing.
From time t49 to t50, the drain current IdH flows in the forward direction.
From time t50 to t51, the drain current IdH flows in the reverse direction. This drain current IdH circulates in the rectifier circuit 130.
After time t51, the drain current IdH does not flow.

As shown in FIG. 8E, the comparison signal VcompL is at the H level before the time t40 and becomes the L level at the time t40. The comparison signal VcompL becomes H level at time t45.
As shown in FIG. 8F, the gate voltage VgsH is at the L level before time t40, and becomes the H level at time t40. Gate voltage VgsH becomes L level at time t45.

As shown in FIG. 8G, the drain current IdL does not flow before time t40.
From time t40 to t41, the drain current IdL flows in the reverse direction, that is, from the drain to the source. This drain current IdH circulates in the rectifier circuit 130.
From time t41 to t42, the drain current IdL flows in the forward direction.
From time t42 to t43, the drain current IdL stops flowing.
From time t41 to t42, the drain current IdL flows in the forward direction.
From time t44 to t45, the drain current IdL flows in the reverse direction. This drain current IdL circulates in the rectifier circuit 130.
After time t45, the drain current IdL does not flow.

Hereinafter, the current flow of the rectifier circuit 130 will be described with reference to FIG. 1 as appropriate.
Immediately before time t46, the high-side MOSFET 101uh of the U-phase 131u is turned off. At this time, the drain current IdH does not flow.
From time t46 to t47, the high-side MOSFET 101uh of the U-phase 131u is on. At this time, the drain current IdH flows in the direction opposite to the rectification direction, that is, in the direction from the drain to the source, and circulates through the rectifier circuit 130.
From time t47 to t48, the drain current IdH flows through the high-side MOSFET 101uh of the U-phase 131u. This flows from the low-side MOSFET 101vl of the V phase 131v.

From time t48 to t49, the high-side MOSFET 101uh of the U-phase 131u is on, but the drain current IdH does not flow.
From time t49 to t50, the drain current IdH flows through the high-side MOSFET 101uh of the U-phase 131u. This flows from the low-side MOSFET 101wl of the W phase 131w.
From time t50 to t51, the high-side MOSFET 101uh of the U-phase 131u is on. At this time, the drain current IdH flows in the direction opposite to the rectification direction, that is, in the direction from the drain to the source, and circulates through the rectifier circuit 130.
The same applies to the current flowing through the low-side MOSFET 101ul of the U-phase 131u. The current flowing to the high-side MOSFET 101vh of the V-phase 131v and the current flowing to the high-side MOSFET 101wh of the W-phase 131w are temporally related. Not continuous.

  When the rectifier 132 of the first embodiment is used in the rectifier circuit 130 of the alternator 140, even if there is a period during which no current flows during the rectification operation, the comparator as shown in FIGS. 8B and 8E. 103 comparison signals VcompH, VcompL are not switched. As shown in FIGS. 8C and 8F, the gate voltages VgsH and VgsL do not become L level. This is because the comparator 103 changes the determination level according to the circuit balance, and the comparison signals VcompH and VcompL are not switched unless the voltage ΔV between the non-inverting input terminal IN + and the inverting input terminal IN− is not lower than the reference voltage VREF. .

  On the other hand, when the rectifier 132z of the comparative example is used for the rectifier circuit 130 of the alternator 140, if there is a period during which no current flows during the rectification operation, as shown in FIGS. 15B and 15E, The comparison signals VcompH and VcompL of the comparator 103z are not switched. As shown in FIGS. 15C and 15F, after the gate voltages VgsH and VgsL become L level, they become H level again. This is because the comparator 103 switches the comparison signals VcompH and VcompL according to the voltage ΔV between the non-inverting input terminal IN + and the inverting input terminal IN−.

In the rectifier 132z of the comparative example, the comparison signals VcompH and VcompL and the gate voltages VgsH and VgsL are raised and lowered a plurality of times by one rectification operation. By this operation, the control IC 108z consumes energy (charge) stored in the capacitor 107. As a result, the capacitor 107 must have a larger capacity, the mounting area increases, and the cost of the rectifier 132z increases.
When the rectifier 132 according to the first embodiment is used, the comparison signals VcompH and VcompL and the gate voltages VgsH and VgsL are only raised and lowered once by one rectification operation. The control IC 108z can effectively use the electric power stored in the capacitor 107. Therefore, the capacitor 107 can have a small capacity, and a small area and low cost rectifier can be realized.

FIG. 9 is a circuit diagram showing a rectifier 132a of an autonomous type synchronous rectification MOSFET in the second embodiment. Elements identical to those of the rectifier 132 of the first embodiment shown in FIG.
As shown in FIG. 9, the rectifier 132a of the second embodiment includes a control IC 108a different from the first embodiment, and is otherwise the same as the rectifier 132 of the first embodiment.
The control IC 108a of the second embodiment includes a comparator 103a different from that of the first embodiment, and further includes a positive reference voltage generator 104.
The comparator 103a (comparison unit) is a general comparator, and determines whether or not the voltage ΔV between the non-inverting input terminal IN + and the inverting input terminal IN− is 0 V or more, and generates a comparison signal Vcomp. Is.
The positive reference voltage generator 104 generates a positive reference voltage VREF. The positive reference voltage generator 104 is connected to apply a positive reference voltage VREF in the direction from the negative main terminal TL to the inverting input terminal IN−. The positive reference voltage generation unit 104 includes, for example, a voltage dividing resistor connected to the positive terminal side of the capacitor 107 and a band gap reference circuit.
With this configuration, the rectifier 132a of the second embodiment can use a general comparator 103a.

  The voltage waveform and the current waveform showing the operation of the rectifier circuit 130 of the alternator 140 using the rectifier 132a of the autonomous synchronous rectifier MOSFET in the second embodiment are shown in FIGS. 4 (a) to 4 (g) and FIG. 8 (a). To (g). Thereby, chattering can be prevented similarly to the case where the rectifier 132 of the first embodiment is used.

FIG. 10 is a circuit diagram showing a rectifier 132b of an autonomous type synchronous rectification MOSFET in the third embodiment. Elements identical to those of the rectifier 132 of the first embodiment shown in FIG.
As shown in FIG. 10, the rectifier 132b of the third embodiment includes a control IC 108b different from the first embodiment, and is otherwise the same as the rectifier 132 of the first embodiment.
The control IC 108b according to the third embodiment includes a pair of bipolar transistors 115 and 116, resistors R1 to R3, diodes 117 and 118, and a voltage drop unit 119 instead of the comparator 103 according to the first embodiment. A differential amplifier circuit (comparator) is provided. This differential amplifier circuit determines whether the MOSFET 101 is on or off.
The collector of the bipolar transistor 115 is pulled up by the resistor R1, and the emitter is connected to the drain of the MOSFET 101 and the positive side main terminal TH via a diode 117 connected in the forward direction. The base of the bipolar transistor 115 is connected to the base of the bipolar transistor 116 and is pulled up by the resistor R2.
The collector of the bipolar transistor 116 is pulled up by the resistor R3, and the emitter is connected to the source of the MOSFET 101 and the negative main terminal TL via the diode 118 and the voltage drop unit 119 connected in the forward direction. The collector of the bipolar transistor 116 further outputs a comparison signal Vcomp to the gate driver 105.

The voltage drop unit 119 is configured by a resistor or a diode. When the voltage drop unit 119 is configured by a resistor, the resistance value RREF is selected so that the voltage drop due to the current IREF flowing during control is less than half of the voltage VB and exceeds 0V. That is, the product of the current IREF and the resistance value RREF is set to be less than half of the voltage VB and more than 0V.
When the voltage drop unit 119 is formed of a diode, one or a plurality of diodes are connected in series, and the total forward voltage drop of these diodes is set to be less than half of the voltage VB and greater than 0V. .

  The voltage waveform and the current waveform showing the operation of the rectifier circuit 130 of the alternator 140 using the rectifier 132b of the autonomous synchronous rectifier MOSFET in the third embodiment are shown in FIGS. 4 (a) to 4 (g) and FIG. 8 (a). To (g). Thereby, chattering can be prevented similarly to the case where the rectifier 132 of the first embodiment is used.

FIG. 11 is a circuit diagram showing a rectifier 132c of an autonomous type synchronous rectification MOSFET in the fourth embodiment.
As shown in FIG. 11, the rectifier 132c of the fourth embodiment includes a control IC 108c different from the first embodiment, and is otherwise the same as the rectifier 132 of the first embodiment.
The control IC 108c according to the fourth embodiment includes a MOSFET 120 (comparator) and a resistor R4 instead of the comparator 103 according to the first embodiment. The MOSFET 120 determines whether the MOSFET 101 is on or off.
The gate of MOSFET 120 is connected to the drain of MOSFET 101. The source of the MOSFET 120 is connected to the source of the MOSFET 101. The drain of the MOSFET 120 is pulled up via the resistor R4.

  The circuit is configured by selecting the characteristics of the MOSFET 120 so that the difference between the gate voltage VG of the MOSFET 120 and the source voltage VS plus the threshold voltage VTH of the MOSFET 120 is less than half of the voltage VB and exceeds 0 V. To do. Thereby, the comparison signal Vcomp can be generated with an extremely simple circuit configuration.

  The voltage waveform and current waveform showing the operation of the rectifier circuit 130 of the alternator 140 using the rectifier 132c of the autonomous synchronous rectifier MOSFET in the fourth embodiment are shown in FIGS. 4 (a) to 4 (g) and FIG. 8 (a). To (g). Thereby, chattering can be prevented similarly to the case where the rectifier 132 of the first embodiment is used.

FIG. 12 is a circuit diagram illustrating a schematic configuration of a power converter 141 using the autonomous rectifier in the fifth embodiment. The same elements as those of the alternator 140 of the first embodiment shown in FIG.
The power converter 141 of the fifth embodiment includes AC power supplies 122uv, 122vw, 122wu, a rectifier circuit 130, a smoothing capacitor 123, and a DC load 124.
The AC power supplies 122uv, 122vw, and 122wu are power supplies that supply three-phase AC. The AC power supplies 122uv, 122vw, and 122wu are Δ-connected. AC power supplies 122 wu and 122 uv are connected to node Nu of rectifier circuit 130. AC power supplies 122uv and 122vw are connected to node Nv of rectifier circuit 130. AC power supplies 122vw and 122wu are connected to node Nw of rectifier circuit 130.

The rectifier circuit 130 is a bridge circuit that rectifies three-phase alternating current into direct current, and is configured similarly to the rectifier circuit 130 of the alternator 140 shown in FIG. In the rectifier circuit 130, a smoothing capacitor 123 (energy storage unit) and a DC load 124 are connected in parallel between nodes Np and Nn, which are DC terminals, and DC power is supplied.
The smoothing capacitor 123 is a capacitor that smoothes the DC voltage. The DC load 124 is an arbitrary load that is driven by receiving DC power, and is, for example, a motor or illumination.
In the fifth embodiment, the rectifier 132 sets the reference voltage VREF so as to satisfy a condition that is less than half of the minimum voltage of the operating range of the smoothing capacitor 123 and greater than 0V.

  Also in the power converter 141 in the fifth embodiment, the rectifiers 132 and 132a to 132c of the respective embodiments can be used. At this time, the voltage waveform and the current waveform indicating the operation of the rectifier circuit 130 are the same as those in FIGS. 4A to 4G and FIGS. 8A to 8G. Thereby, chattering can be prevented.

101 MOSFET
102 Built-in diode 103 Comparator (Comparator)
104 Positive reference voltage generator 105 Gate driver 106 Diode 107 Capacitor 108 Control IC
109 Rotor coil 110uv, 110vw, 110wu Stator coil (AC power supply)
111 battery (energy storage unit)
119 Voltage drop unit 120 MOSFET (comparison unit)
122 uv, 122 vw, 122 wu AC power supply 123 smoothing capacitor (energy storage unit)
124 DC load 125 Negative reference voltage generator 130 Rectifier circuit 131u U-phase 131v V-phase 131w W-phase 132 Rectifier 140 alternator 141 Power converter Nu, Nv, Nw, Np, Nn Node TH Positive-side main terminal TL Negative-side main terminal VREF Reference voltage RREF Resistance 11-15 PMOS
21-23 NMOS
Iin +, Iin− current Ion_out, Ioff_out current Vu voltage VB voltage VG voltage VS voltage ΔV voltage IN− inverting input terminal IN + non-inverting input terminal VTH threshold voltages Vgs, VgsH, VgsL gate voltages Vcomp, VcompH, VcompL, comparison signals Id, IdH, IdL drain current

Claims (15)

A rectifier connected to a high side and a low side of a bridge-type rectifier circuit in which a DC terminal is connected to an energy storage unit and an AC terminal is connected to an AC power source,
A MOSFET whose drain is connected to the positive main terminal and whose source is connected to the negative main terminal ;
A gate driver for controlling on / off of the MOSFET;
By generating and outputting the comparison signal obtained by comparing the voltage with a reference voltage between the main terminals of the positive electrode side main terminal wherein the negative electrode side main terminal of the pre-Symbol MOSFET to the gate driver, the inter-main terminal voltage the A comparator that turns on the MOSFET if it is below the reference voltage;
With
The reference voltage is greater than 0V;
When the voltage between the main terminals from the positive-side main terminal to the negative-side main terminal is negative, the MOSFET passes a forward current, the main-terminal voltage is positive, and is equal to or lower than the reference voltage. The MOSFET passes a reverse current.
A rectifier characterized by that. The reference voltage is less than half the minimum voltage of the energy storage unit operating range and greater than 0V;
The rectifier according to claim 1. The comparison unit is a comparator that compares whether the voltage between the main terminals is equal to or lower than the reference voltage.
The rectifier according to claim 1. The comparator is configured by changing the circuit balance so as to directly compare whether or not the first input terminal and the second input terminal of the comparator are equal to or lower than the reference voltage.
The rectifier according to claim 3. A reference voltage generator for generating the reference voltage;
The first input terminal of the comparator is connected to the negative main terminal via the reference voltage generator,
A second input terminal of the comparator is connected to the positive-side main terminal;
The rectifier according to claim 3. The reference voltage generator generates the reference voltage by resistance-dividing a power supply voltage supplied to the comparator;
The rectifier according to claim 5. The reference voltage generator includes a band gap reference circuit.
The rectifier according to claim 5. The reference voltage generation unit is configured to include a resistor, and a voltage across the resistor is equal to or less than half of the minimum voltage of the operating range of the energy storage unit and greater than 0V.
The rectifier according to claim 5. The reference voltage generator includes a series connection of one or a plurality of diodes,
The sum of the forward voltages of each of the diodes is less than or equal to half of the minimum voltage of the energy storage unit,
The rectifier according to claim 5. The comparison unit includes a determination MOSFET,
The source terminal of the determination MOSFET is connected to the negative electrode side main terminal,
The gate terminal of the determination MOSFET is connected to the positive-side main terminal,
The drain terminal of the determination MOSFET is pulled up and connected to the input side of the gate driver.
The rectifier according to claim 1. When a threshold voltage is added to the difference between the gate voltage and the source voltage of the determination MOSFET, a condition that is less than half of the minimum voltage of the energy storage unit and greater than 0 V is satisfied.
The rectifier according to claim 10. A capacitor for storing a power supply voltage to be supplied to the comparison unit;
The rectifier according to claim 1. The voltage from the negative-side main terminal to the positive-side main terminal is an on-voltage when the MOSFET gate is on-controlled from the start of the rectification current to the end of the flow.
The rectifier according to claim 1. A bridge-type rectifier circuit in which a DC terminal is connected to the energy storage unit and an AC terminal is connected to an AC power supply;
The rectifier according to any one of claims 1 to 12, connected to a high side and a low side of the rectifier circuit, respectively.
With
The energy storage unit is a battery.
An alternator characterized by that. A bridge-type rectifier circuit in which a DC terminal is connected to the energy storage unit, and an AC terminal is connected to an AC power supply;
The rectifier according to any one of claims 1 to 12, connected to a high side and a low side of the rectifier circuit, respectively.
A power conversion device comprising:

Images