JP2003304680A - Two-way step-up/down converter both for alternating current and for direct current - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a completely novel two-way step-up/down converter both for alternating current and for direct current, which increases or decreases alternating- current, direct-current, or both current-superposed input voltage; is provided with an automatic voltage regulating function and thus compatible with conventional alternating-current transformers; is capable of directly increasing/decreasing and converting in two ways direct-current voltages and direct currents, such as those in fuel cells and photovoltaic power generation, as well as in 400-Hz power supplies; and is of small size and light-weight and efficient. <P>SOLUTION: The two-way step-up/down converter both for alternating current and for direct current is so constituted that an alternating-current, direct-current, or both current-superposed input voltage is modulated at a frequency higher that at least an input frequency, and the modulated voltage is applied to a high-frequency autotransformer. The voltage is then increased or decreased and demodulated, and then smoothed. Thus, the converter is capable of increasing and decreasing the original alternating-current, direct-current, or both current-superposed input voltage and letting electric power energy flow in either of directions, normal direction or reverse direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bidirectional buck-boost converter for both AC and DC. More specifically, the invention of this application is widely used in home appliances, business equipment, and various other electronic devices, and can be used for several hundreds of hours from direct current.
AC-AC having a function of converting voltage up to AC z and current
The present invention relates to an entirely new AC / DC bidirectional buck-boost converter useful as a DC / DC bidirectional positive / reverse bidirectional converter.

[0002]

2. Description of the Related Art Conventionally, an AC transformer has been widely used as an AC voltage / current converter and has reached the present. on the other hand,
As the DC / DC converter, a dedicated device using a semiconductor switch is generally used as various industrial devices such as communication and information devices.

[0003]

However, these conventional AC converters and DC / DC converters have the following problems in practical use.

That is, first of all, the AC transformer is made of iron and steel materials, has a long life (MTBF), has a large short-time overload capacity, and has little noise on the line. On the other hand, in the case of 50 Hz, it has a capacity of about 1 kW and a volume of more than 3 liters and a weight of about 10 kg, which is large and heavy.

On the other hand, since the DC / DC converter uses a semiconductor high-frequency switching technique to turn on / off the DC power, the volume and weight of the DC / DC converter are several times smaller and lighter than those of an AC transformer of the same capacity. Although it contributes to resource saving in that it has been made possible, it has only a one-way transmission function of power energy from the input terminal side to the output terminal side, and the anti (reverse) electromotive force that may occur at the output terminal side is generated. The current situation is that power cannot be regenerated on the input terminal side, and means such as absorption by a dedicated heat radiation resistor is required.

The invention of this application has been made in view of the above circumstances, solves the problems of the prior art, and is of course small in size, lightweight, highly efficient and highly reliable. It is an object of the present invention to provide a completely new bidirectional buck-boost converter for both AC and DC, capable of stepping up and down and automatically adjusting the voltage of DC as well as AC / DC combined voltage.

[0007]

In order to solve the above-mentioned problems, the invention of the present application firstly modulates an alternating current, a direct current or an input voltage superposed thereon with a frequency higher than at least the input frequency. In addition to the high frequency autotransformer, it can boost or step down the original AC or DC or its superimposed input voltage by stepping up or down and demodulating and then smoothing, and the direction of power energy flow is positive. , A bidirectional buck-boost converter for both AC and DC, characterized in that it is configured to be flowable in both reverse directions. Second, in the converter according to claim 1, a semiconductor switch on·
The spike pulse energy generated in the off and the spike pulse generated due to the inductance contained in the circuit is stored in the snapper capacitor using the multi-input full-wave bridge diode and the snapper capacitor which have the connection points as input terminals. Provided is a bidirectional buck-boost converter for both AC and DC, which is characterized in that a control circuit is driven by stored power energy. Thirdly, according to the invention of this application, in the converter according to claim 1, a high frequency current transformer is provided in a path of a high frequency current generated by modulation, and a signal voltage generated in the secondary winding is used to change the input voltage. An AC / DC bidirectional buck-boost converter is provided which performs overcurrent protection or constant current control regardless of AC / DC or a composite voltage thereof. Fourthly, in the converter according to claim 1, high frequency An AC / DC bidirectional step-up / down transformer, which is characterized in that an autotransformer is provided with a changeover tap and a changeover switch to freely select a step-up / step-down voltage ratio. Fifth, in the converter according to claim 1, a drive pulse of a modulation / demodulation bidirectional semiconductor switch for driving a primary winding side by adding a secondary winding and a bidirectional semiconductor switch to a high frequency autotransformer. By controlling the drive phase of the additional semiconductor switch from almost 0 phase to nearly 180 ° with respect to the phase, in the case of AC input / output, from the maximum value of the positive phase to zero to the maximum value of the opposite phase, while the DC In the case of input / output, the input / output voltage ratio is further increased by continuously controlling from the maximum value of the positive polarity to zero to almost the maximum value of the negative polarity and adding this output voltage to the forward / reverse bidirectional buck-boost voltage. A bidirectional buck-boost converter for both AC and DC, which is characterized by fine control.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a basic main circuit of the present invention, and FIG. 2 shows an example of its control circuit.

In FIG. 1, terminals <1> and <2> (indicated by circled numbers in the figure, the same applies hereinafter) are low-voltage side input / output terminals,
<11> and <12> are high-voltage side output / input terminals, and when <1> and <2> terminals are input side, <11> and <12> are output terminals, and conversely <11> and <12> are output terminals.
When the>, <12> terminals are the input side, the <1>, <2> terminals are the output side, and the power energy is transmitted in both forward and reverse directions. Further, the power frequency applied to the <1>, <2> terminals or the <11>, <12> terminals can be freely applied from 0 to several hundreds of alternating current AC. For example, in the case of f = 0, that is, a DC input, a step-up or step-down DC output voltage and current of the same polarity can be extracted regardless of whether the polarity is positive or reverse.

In FIG. 1, F ₁ is a low-voltage side filter, F ₂ is a high-voltage side filter, and S _A , S _B , S _C and S _D are bidirectional switches, each of which is a rear face of two MOS FET switches. Butt connection.

In FIG. 1, an auxiliary C-R snapper circuit is added to this.

CT is a current detector, T ₁ is a high frequency step-up / down transformer, D _{1 to} D ₁₀ are 5-input full-wave rectification bridge circuits, C ₂ is a main snapper capacitor, and <16> is an auxiliary power supply for control circuit. This DC / DC converter operates by the snapper energy generated at the <9> and <10> terminals, and it operates at <13>, <14> and <
Generates + E, 0, -E control voltages at the 15> terminal.

FIG. 2 shows the result of this snapper energy.
An example of a driving circuit <18> that operates, an IC₁Is
T, which is the most typical PWM control IC used for 20 years
An example circuit using L-494 is shown.
I'm not particular about it. This IC has a pulse duty ratio of 4
To operate at about 9%, pulse transformer PT ₁
The voltage generated in the fourth winding of the diode D₁₁Rectified with
Resistance R₂, Capacitor C ₆Variable resistance VR after smoothing with₁
Adjust with, C₇Re-smoothed with and added to control terminal 4 of IC
It

Tr ₁ and Tr ₃ are normal NPN transistors, Tr ₂ and Tr ₄ are PNP transistors, and pulse transformers PT ₁ and PT ₁ are connected by totem pole connection, respectively.
PT ₂ is driven in two phases with a duty ratio of around 49%.

Since the other end of the pulse transformer is connected to the zero potential terminal of the auxiliary power supply <18> for the control circuit, the pulse transformer has a positive half cycle + E, a duty of about 49%, and a negative half cycle -E. Since a rectangular wave with a duty of about 51% is applied, DC bias is generated in the core of the pulse transformer. In order to avoid this, a bias voltage is generated by R ₃ , C ₉ and R ₄ , C ₁₀ to prevent DC bias magnetization. Also, the overcurrent detection control circuit <17> rectifies and smoothes the high frequency signal power from the secondary winding terminals X and Y of the current transformer CT, and when it exceeds the Zener diode voltage, it goes to the 4th terminal of IC _1. The pulse duty cycle (duty) is reduced by adding the above to prevent overload of the entire buck-boost converter (hereinafter referred to as converter). The current value at this time is adjusted by, for example, VR ₂ .

FIG. 3 shows driving waveforms of the bidirectional switches S _A , S _B , S _C and S _D.

Pulse transformer PT₁Drive waveform A and
Ruth trans PT₂180 ° between the drive waveform B of
Bidirectional switch S with phase difference and waveform A_A, S_D
Are driven simultaneously, while the waveform B causes a bidirectional switch
S_B, S_CAre driven at the same time. Now, for example, commercial exchange
When the frequency of the drive waveform is selected to be sufficiently high with respect to the wave number
An example of the waveform of each part is shown in FIG. Also, in the simplified representation in FIG.
Bidirectional switch S shown _A, S_DIs on (T₁)In
The principle diagram of boosting is shown.

That is, the principle of boosting by the high frequency transformer T ₁ is exactly the same as the principle of boosting by the transformer of commercial frequency. V _1-2 in the figure is an AC voltage waveform between the terminals <1> and <2>, and if the bidirectional switches S _B and S _D alternately turn on and off based on this voltage source, a high frequency single wave is generated. A high frequency ring modulation waveform V _7-8 having an amplitude twice the voltage between the terminals <4> and <6> is generated between the terminals <7> and <8> of the winding transformer T ₁ . This voltage waveform is demodulated by the switches S _A and S _C which are driven simultaneously, and a voltage waveform of V _3-5 is generated between the terminals <3>-<5>. High-frequency component by the high voltage side filter F ₂ is removed, the output terminal <11> - almost twice the amplitude of <2> to the applied commercial AC voltage waveform, - <12> input terminal between <1> Voltages V _11-12 having the same waveform and the same frequency are generated. That is, the function of the transformer boosted to 1 to 2 is realized.

On the contrary, the terminals <11>-<12> are connected to the commercial AC frequency.
Pressure V_11-12, The bidirectional switch S_A, S_DAnd S_B，
S_CHigh frequency autotransformer T by alternating on / off operation of₁
To terminals <7>-<8> of_7-8Generates the waveform shown in
However, V between terminals <6>-<5>_3-5Same as the waveform shown in
A voltage waveform whose width is ½ is generated. Low voltage side fill
Ta F₁Removes the high frequency component, and between terminals <1>-<2>
Almost all commercial AC voltage waveforms applied between terminals <11>-<12>
Voltage V with the same frequency and waveform with half the amplitude _1-2But
Occur. Also, if voltage is applied in the opposite direction, the voltage will drop to 2: 1.
The function of the autotransformer is realized. That is, the time of FIG.
The road performs exactly the same function as a conventional steel autotransformer.
I know that I will do it.

Although the above description has described the function of raising and lowering the commercial AC voltage waveform, the aim of the present invention is not limited to this. That is, the terminals <1>-<2> of the circuit of FIG.
When a voltage V _1-2 with <1> having a positive polarity and <2> having a negative polarity is applied between them, voltages at respective parts as shown in FIG. 6 are generated, and the output terminals <11> − <1
2>, a DC voltage V _11-12 of the same polarity is generated with an amplitude almost twice that of the DC voltage applied to the input terminals <1>-<2> in FIG. On the other hand, when a DC voltage V _11-12 is applied between the terminals <11>-<12>, the voltage at each part as shown in FIG. 7 is generated, and the terminal <1>
A DC voltage of the same polarity is generated with an amplitude of approximately ½ during − <2>.

Up to this point, the voltage rising / falling operation and the bidirectional transmission operation of the power energy have been described for the two types of voltage conversion operation of commercial AC and DC, but the rising / falling operation is correct even if any other waveform is added. We have confirmed by experiment that it will be done. That is, the single-winding step-up / down transformer of the present invention can properly perform the step-up / step-down operation from DC to AC of several hundreds Hz and its superposed waveform in almost proportion to the turn ratio.

The fundamental reason for this is that the modulation / demodulation technology, which has been generally used in communication technology, is adopted in the power field. If there is no distortion in the modulation / demodulation, the input signal (voltage)
The waveform is faithfully reproduced on the output side, and any waveform can be directly output to the output side. The most important point in the present invention is that the forward and backward directions of power energy can be transmitted in both directions and the type of input signal (voltage) waveform,
The point is that the polarity does not matter. Furthermore, an electronic autotransformer equivalent to a 1: 2 autotransformer with an output of 500 watts was prototyped,
As a result of comparing the voltage fluctuation rate, the efficiency, and the power factor with the conventional commercial frequency transformer, the voltage fluctuation rate is 2.6%, the efficiency is 94%, the power factor is almost 1 (about 99.4%), and the volume is 0. .6 ~
0.7, weight ratio of 0.2, small and lightweight.

By improving the performance price ratio of electronic parts including semiconductors and improving the performance price ratio of iron cores and copper wires, the cost can be further improved. The above is the description of the first requirement of the present invention.

The second requirement of the present invention is the requirement 5 shown in FIG.
It is connected to the combination of the input diode bridge, the snapper capacitor C ₂ and the auxiliary power supply <16> for the control circuit.

In general, when the ON / OFF operation circuit of a semiconductor switch includes an inductance component, the leakage inductance L causes a spike voltage of Ldi / dt to be superimposed on the waveform, which must increase the breakdown voltage of the semiconductor. In addition, the snapper circuit for absorbing the spike voltage causes a reactive power loss and reduces the efficiency of the entire device.

In the circuit of FIG. 1 of the present application, in order to eliminate this loss and effectively utilize it, in addition to the <6>, <7> and <8> terminals of the autotransformer, the bidirectional semiconductor switches S _A , S _B and S are added. _C and S _D
In order to pull in all the spike voltage generated at both ends, all spike voltage generated between 5 input terminals including <3> and <5> terminals in Fig. 1 are applied to 5 input diode bridges D _{1 to} D ₁₀ . It is drawn in, rectified and stored in the snapper capacitor C ₂ , and this energy is used to operate the isolated DC / DC converter for driving the control circuit to drive the main bidirectional switches S _A , S _B , S _C and S _D. is doing. Therefore, most of the electric power generated in the snapper circuit is effectively used for driving the control circuit, and constitutes a so-called lossless snapper.

Each bidirectional switch S _A , S _B , S _C and S _D
The C-R snapper circuit connected inside is still several tens of nanometers due to the accumulated charge of the fast diodes D _{1 to} D _10.
It is a small-capacity snapper that responds only to an extremely thin pulse generated due to the delay of time of second, and the generated power loss is D
_This value is sufficiently smaller than the power generated by the main snapper circuits of _{1 to} D ₁₀ and ₂ , and has almost no effect on the decrease in the efficiency of the entire device.

The third requirement of the present invention is an overload countermeasure circuit. As shown in CT of FIG. 1, in the circuit of the present invention, since the input voltage is modulated at a high frequency of several tens of kilohertz or more, the secondary winding of the transformer CT for current detection has a small number of turns for current detection. Generates signal voltage. This voltage waveform is independent of input, output voltage crossing, direct current and its composite waveform,
The voltage V ₁ proportional to the current can be taken out.

When the circuit voltage V ₁ shown in <17> in FIG. 2 exceeds the Zener voltage Vz, an overload is identified. For example, the pin 4 of the pulse width control IC ₁ is applied as a positive voltage to drive pulse width. (Duty ratio) is narrowed to limit the output current.

[0030]

FIG. 8 shows a first embodiment of the present invention. S _A , S _B , S _C and S _D in the figure are block diagram representations of a bidirectional switch formed by back-butting the two semiconductor switches shown in FIG. The difference from FIG. 1 here is that the third and fourth windings N ₃ and N ₄ and mechanical switches SW ₁ and SW ₂ for switching the taps are added to the autotransformer T ₁ . It is in. Now, assuming N ₁ and N ₂ to be 100, N ₃ and
N ₄ has 15 windings, and these are 2 sets of changeover switch S
Switching in W _1, SW _2, the terminal <1> - <2> between the terminal <11>
There are four voltage ratios between <12> shown in Table 1.

[0031]

[Table 1]

If an autotransformer with this voltage ratio is used, it is currently 1
Since it can be used for most household power supply voltages in over 80 countries and is small and lightweight, it is mainly used for overseas travelers, long-term and short-term students, overseas business travelers, and people who are assigned overseas, as well as portable devices. It is expected that it will be widely used in various measuring instruments. Moreover, since input / output can be transformed from DC to about 400 Hz, it can be widely applied to aircraft, ships, leisure boats, electric vehicles, and other industrial equipment where space and weight are important.

FIG. 9 shows a second embodiment of the present invention.
In the figure, between terminals <1>-<2> is the low voltage side of 100V / 115V system,
The point between the terminals <11>-<12> is the boost side of the 200V / 230V system, which is the same as in FIG. 1, but the high frequency transformer T ₁ has N ₃ ,
A secondary side winding of N ₄ is provided, and bidirectional semiconductor switches S _E and S _F are connected as shown in the drawing, and a normal mode filter by L and C ₁₁ and a common mode filter F ₃ on the output side.
Was added to obtain the output V ₀ . Further, the voltages V ₁ and V ₂ on the low voltage side and the voltage side on the boosted side are switched by the e and f contacts of the mechanical switch SW ₃ , and the voltage V _C generated by the additional circuit is added to this voltage.

As a result, when the contact of the switch SW ₃ is closed to the side e, the voltage V ₀ generated between the output terminals <12>-<19> is: V ₀ = V ₁ + V _C ... (1) On the other hand, when the contact of the switch SW ₃ is closed on the f side, the voltage V ₀ generated between the output terminals <12>-<19> Becomes V ₀ = V ₂ + V _C (2) By the way, the V _C voltage is the bidirectional semiconductor switch S _E , S _F
Phase control of ± V _C (in the case of alternating current, it goes from the maximum value of the positive phase to zero to the maximum value of the opposite phase, and in the case of direct current, it goes from the maximum value of positive polarity to the maximum value of negative polarity and goes to zero) Control continuously. The block diagram <22> in FIG. 9 plays that role.

An example of this control circuit is shown in FIG. Figure
IC at 10₁Is a known one such as TL-494 mentioned above.
PWM (pulse width) control IC, <17> is the current detection
Output circuit, <23> is a well-known isolated type operational amplifier RMS
It is an AC / DC voltage detection circuit with a converter added. I
C₁Capacitors and resistors added to the periphery are IC₁
Details as it is a known circuit displayed in the catalog of
Detailed description is omitted. IC₁Is TL-494, <
Signal swing of voltage detection circuit of <23> or current detection circuit of <17>
Depending on the width, the connection point between pin 9 and pin 10 (control signal
5) to 95% variable pulse width signal is generated
It This signal is the inverter IV of the logic circuit.₁, IV₂To
Each monostable multi (OSM₁, OSM₂) And D
Type flip-flop DFF₁, DFF₂Added to
It receives 4 outputs of stable multi and DFF.
Circuit A₁, A₂, A₃And A_FourWorks and outputs respectively
Totem pole transistor through the photo coupler on the side
Drive the pulse transformer after power amplification. Dora
Iber circuit DR₁Is a bidirectional semiconductor switch S_A, S _DThe same
DR when₂Is S_B, S_CDrive simultaneously. Also DR₃When
DR_FourIs S_EAnd S_FDrive only. Each drive tie
The observation positions of the ming and the waveform are shown in Figure 10 and Figure <a>.
<H> (Indicated as circled Roman letters in the figure.
Same. ). The following is a brief description of FIG. 11.

Points <a> and <b> in FIG. 11 are PWM control signals, which are inverted by the inverter. <c> indicates the Q output of the D-type flip-flop DFF ₁ that has received the <a> point signal, and <e> indicates the Q output. At the same time, the Q output of the monostable multi that receives the signal at point <a> has a waveform at point <d>. The pulse width ΔT ₁ at this time is determined by the RC time constant in the figure, but is usually selected in the range of 0.2 to 0.5 μs. The reason is to prevent the bidirectional switches S _A and S _B and S _C and S _{D from} being simultaneously turned on, which is a known technique.

Due to the AND logic of the <c> point waveform and the <d> point waveform, the photo coupler PC ₁ has T ₁ indicated by the hatched line at the <c> point in FIG.
Driven only for a time, drive pulses A and D having the same time width are generated at the pulse transformer output, and the bidirectional switch S _A ,
Drive S _D at the same time. Similarly, the bidirectional switches S _B and S _D are driven through the driver DR ₂ by the AND logic of the <e> point waveform and the <d> point waveform. In this circuit, even if the duty ratio of the waveform of the <a> point, which is the PWM signal, fluctuates greatly as indicated by the dotted line, there is no fluctuation because it is all operating only at the rising of the <a> point.

Next, D which operates based on the pulse waveform at point <b>
Looking at FF ₃ and OSM ₂ , the rising edge of the pulse at point <b> greatly varies depending on the duty ratio. Therefore, the pulse waveforms at the points <f><g> and <h> can be calculated according to the duty ratio from <f> to <f> ′, <g> to <g> ′, and <h> to <h> ′. It changes a lot. Since the circuit configuration is the same as that of the above-described operation, the drive output waveforms E and F of the pulse transformer naturally change their relative phases with respect to A, B, C and D depending on the duty ratio.

When the relative phases of only S _E and S _F are continuously controlled as shown in FIG. 12, the instantaneous values of the winding voltages of N ₃ and N ₄ generated on the secondary side of the high frequency transformer are shown in the figure. It becomes the form shown by 12 Vi. In the example of FIG. 12, bidirectional switches S _A , S _B ,
When the drive phases of S _C and S _D are fixed and the relative phase of the switches S _E and S _F is delayed by 45 ° (corresponding to a PWM pulse with a duty ratio of 0.25), the LC filter input side (see FIG. 9) ± Vi) is shown. In this case, the voltage waveform averaged through the LC filter becomes ½ of the maximum amplitude of Vi, as shown by V _C in FIG.

[0040]

[Table 2]

The relationship between the phase difference and the V _C voltage is as follows.

That is, when the PWM pulse width is continuously variable from 0.03 to 0.97, in the case of AC voltage, N ₃ ,
It is possible to control continuously from the output voltage of 94% in phase with the voltage Vi generated in the N ₄ winding to the output voltage of 94% in the opposite phase. Therefore, in the circuit of FIG. 9, the contact point of the mechanical switch SW ₃ is e
When closed to the side, V ₁ or terminal < ₁ > between terminals <1> and <2>
When V ₂ is applied between 11>-<12>, the output voltage V ₀ generated between the output terminals <18>-<12> is: V ₀ = V ₁ ± 0.94Vi・ ・ ・ ・ ・ ・ ・ ・ (4) On the other hand, when the contact of SW ₃ is closed on the f side, the terminals <1>-<2>
<11> V ₁ or pin between - <12> when added to V2 between output terminals <18> - <12> _{between, V 0 = V 3 ± 0.94Vi} ······ ..... It is possible to take out the output voltage V ₀ of (4). That is, according to the embodiment of FIG. 9, the output voltage can be continuously and automatically controlled according to the magnitude of the voltage generated in the secondary windings N ₃ and N ₄ of the high frequency transformer T ₁ . Therefore, by properly selecting the turns ratio, it is possible to have an automatic voltage adjustment function in addition to the step-up / down transformer, and each can be used in a wide range of applications.

Of course, the invention of this application is not limited to the above-described embodiments and examples, and various aspects are possible in details.

[0044]

As described above in detail, according to the present invention, it is not only possible to realize a small and lightweight electronic transformer that can use electric power corresponding to almost all household and industrial power sources in the world. A completely new AC / DC bidirectional buck-boost converter is provided that enables the up / down and automatic voltage adjustment of DC, which has been impossible, AC up to several hundreds of hertz, and DC / AC combined voltage. According to this, when new application fields of the power electronics industry are expanded, for example, when distributed power supply by DC power such as fuel cells and solar power generation becomes widespread, it is possible to transform conventional AC including both AC and DC. The step-up / down transformers in the above are extremely important power supply and transformation equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a basic circuit of an AC / DC dual step-up / down transformer of the present invention.

FIG. 2 is a diagram showing a specific example of the control circuit of FIG.

FIG. 3 is a diagram showing an example of drive voltage waveforms of pulse transformers PT ₁ and PT ₂ for driving a bidirectional semiconductor switch used in an AC / DC dual-voltage step-up / down converter of the present invention.

FIG. 4 is a diagram showing an example of voltage waveforms at main observation points when an AC voltage is applied to the low voltage side of the AC / DC dual step-up / down converter of the present invention.

FIG. 5 is a circuit diagram for explaining a step-up / step-down operation principle of an AC / DC dual step-up / step-down converter of the present invention.

FIG. 6 is a diagram showing waveforms at main observation points when a boosting operation is performed by applying a DC voltage to the low voltage side of the AC / DC dual step-up / down converter of the present invention.

FIG. 7 is a diagram showing an example of waveforms at major observation points when a step-down operation is performed by applying a DC voltage to the high voltage side of the AC / DC dual step-up / down converter of the present invention.

FIG. 8 is a circuit diagram for explaining the basic principle of providing a tap on the high frequency transformer winding of the AC / DC dual step-up / down converter of the present invention and switching the tap with a mechanical contact or the like to perform an arbitrary step-up / down operation. Is.

FIG. 9 is a diagram showing a high-frequency transformer of the AC / DC dual-sided step-up / down converter according to the present invention, which is provided with a secondary winding, and a bidirectional semiconductor switch is combined with the secondary winding to form a drive phase of the bidirectional semiconductor switch group on the primary winding side. FIG. 4 is a diagram showing an example of a basic circuit that controls a drive pulse phase and automatically controls an output voltage.

10 is a diagram showing an embodiment of a control circuit in the basic circuit diagram of the present invention shown in FIG.

11 is a diagram for explaining the basic operation principle, showing operation waveforms at main observation points <a> to <h> of the control circuit of FIG.

FIG. 12 is a diagram for explaining an example of phase control of the bidirectional semiconductor switch in FIG. 9.

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Claims (5)

[Claims] 1. An AC, DC or superposed input voltage thereof is modulated at a frequency higher than at least an input frequency to be applied to a high frequency autotransformer, which is stepped up or down to be demodulated and then smoothed to obtain the original. Both AC and DC, both for AC and DC, characterized by being capable of raising and lowering the input voltage of AC or DC or its superposed input voltage, and being configured so that the flow direction of power energy can be either forward or backward. Directional buck-boost converter. 2. The multi-input full-wave bridge diode according to claim 1, wherein an input terminal is a connection point of all spike pulses generated due to ON / OFF of a semiconductor switch and an inductance included in a circuit. A bidirectional buck-boost converter for both AC and DC use, characterized in that spike pulse energy is stored in the snapper capacitor using the and snapper capacitor, and the control circuit is driven by the power energy stored here. 3. The converter according to claim 1, wherein a high-frequency current transformer is provided in a path of a high-frequency current generated by modulation, and a signal voltage generated in a secondary winding is used to convert an input voltage to an alternating current or a composite voltage thereof. An AC / DC bidirectional buck-boost converter characterized by performing overcurrent protection or constant current control regardless. 4. The converter according to claim 1, wherein the high-frequency autotransformer is provided with a changeover tap and a changeover switch so that the rising / falling voltage ratio can be freely selected. Voltage transformer. 5. The converter pulse according to claim 1, wherein a secondary winding and a bidirectional semiconductor switch are added to the high frequency autotransformer to drive a modulation / demodulation bidirectional semiconductor switch for driving the primary winding side. By controlling the drive phase of the additional semiconductor switch from almost 0 phase to nearly 180 ° with respect to the phase, in the case of AC input / output, from the maximum value of the positive phase to zero to the maximum value of the opposite phase, while the DC In the case of input / output, the input / output voltage ratio is further increased by continuously controlling from the maximum value of the positive polarity to zero to almost the maximum value of the negative polarity and adding this output voltage to the forward / reverse bidirectional buck-boost voltage. A bidirectional buck-boost converter for both AC and DC, characterized by fine control.