JP4148744B2 - Power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the technical field of power supply devices, and more particularly, to a power supply device with high transformer use efficiency.
[0002]
[Prior art]
Reference numeral 102 in FIG. 25 is a conventional power supply device using a choke coil.
In general, the switching type power supply apparatus 102 is divided into a primary side circuit and a secondary side circuit, and is insulated by a transformer 121 between them. In the transformer 121, primary windings W that are magnetically coupled to each other.₁And secondary winding W₂Is arranged.
[0003]
The primary side includes a DC voltage source 110 obtained by rectifying and smoothing a commercial power source, and a primary winding W.₁In addition, a switch circuit 107 constituting an H bridge is disposed.
[0004]
In the switch circuit 107, four transistors Q₁~ Q_Four, And a set of two forward transistors Q₁, Q₂And transistor Q in the opposite direction_Three, Q_FourHowever, the primary winding W from the DC voltage source 110 is alternately conducted by one set at a time.₁It is comprised so that an alternating current may be sent through.
[0005]
Secondary winding W₂Is connected to the output circuit 108 and the primary winding W₁AC current flows through the secondary winding W₂When an AC voltage is induced in the output circuit 108, the induced voltage is applied to the output circuit 108.
The output circuit 108 includes a choke coil L₁, L₂And rectifying element 136₁136₂Are two rectifier circuits 124 and 125 connected in series.
[0006]
Secondary winding W₂Both ends of the choke coil L of the two rectifier circuits 124 and 125₁, L₂And rectifying element 136₁136₂Are connected to connection points connected to each other. The power supply device 102 is a power supply that outputs a positive voltage,
[0007]
Rectifier element 136₁136₂The cathode terminal side is the choke coil L₁, L₂Connected to one end of the choke coil L₁, L₂Is connected to a first output terminal 138 from which a positive voltage is output.
[0008]
Rectifier element 136₁136₂Is connected to the second output terminal 139 that is at the ground potential, and the secondary winding W₂When a positive voltage is applied to one rectifier circuit 124 and a negative voltage is applied to the other rectifier circuit 125, the choke coil L of the rectifier circuit 124 to which the positive voltage is applied is applied.₁Secondary winding W₂Is supplied with current. The current is the rectifier element 136 of the rectifier circuit 125 to which the negative voltage is applied.₂Flowing through. The rectifier element 136 of the rectifier circuit 124 to which the positive voltage is applied.₁Are reverse-biased and no current flows.
[0009]
Next, the secondary winding W₂When the polarity of the voltage applied to each rectifier circuit 124, 125 is reversed, the other choke coil L₂And rectifying element 136₁Is supplied with current. The first choke coil L₁When the current is supplied to the other choke coil L₂The choke coil L₂The current generated by is flowing.
[0010]
A capacitor C is connected in parallel to the output circuit 108, and a DC voltage smoothed by the capacitor C appears between the first and second output terminals 138 and 139, and this DC voltage is supplied to the load 128. .
[0011]
Unlike the power supply device 102 described above, when the diode bridge is used, the secondary winding W₂In the power supply apparatus 102 as described above, the current generated by the induced voltage is equal to the two rectifying elements 136 compared to the current flowing through the two rectifying elements connected in series.₁136₂Since only one of them flows and is supplied to the load 16, the loss is small and a highly efficient power supply device can be obtained.
[0012]
A reference numeral 103 in FIG. 26 is a power supply apparatus in which two power supply apparatuses 102 as described above are connected in parallel to the load 16 in order to increase the output current.
[0013]
In this power supply device 103, two transformers 121 are provided.₁121₂Each has a switch circuit 107.₁107₂Are connected to each switch circuit 107.₁107₂Transformer 121₁121₂Is configured to supply an alternating current.
[0014]
Also, each transformer 121₁121₂Output circuit 108₁, 108₂Are connected to each other, and each output circuit 108₁, 108₂To the load 16 in parallel.
[0015]
However, in the parallel power supply device 103 as described above, each transformer 121₁121₂The maximum voltage and maximum current specifications have the disadvantage that the transformer 121 is the same as one power supply device 102 and the use efficiency of the transformer is poor.
[0016]
[Problems to be solved by the invention]
The present invention was created to solve the above-described disadvantages of the prior art, and an object of the present invention is to provide a switching power supply with high use efficiency of a transformer.
[0017]
[Means for Solving the Problems]
  In order to solve the above-described problem, the invention according to claim 1, the plurality of primary windings,A switch circuit for supplying an alternating voltage to the primary winding, a secondary winding magnetically coupled to the primary winding, and a plurality of rectifier circuits in which a choke coil and a rectifier element are connected in series, The secondary windings are connected in series, the connection points between the secondary windings, and the connection points between the choke coils of the rectification circuit and the rectification circuit at both ends of the series connection circuit of the secondary windings. The end of the rectifier circuit on the choke coil side is connected to a first output terminal, the end of the rectifier element side is connected to a second output terminal, and between the first and second output terminals Is connected to a capacitor, a voltage of the same polarity is induced in the secondary winding, and a series voltage obtained by adding the voltages induced in the secondary windings is added to both ends of the series connection circuit of the secondary windings. When generated, the load connected to the first and second terminals includes Configured serial series voltage is appliedPower supply unit.
  The invention according to claim 2A current sensor provided at one or both of the first and second output terminals, and a control circuit for controlling the phase of the AC voltage applied to the primary winding; When the first upper limit value is set and the measured value of the current sensor is equal to or lower than the first upper limit value, the series voltage is applied to the load with the phase of the AC voltage applied to the primary winding being aligned, When the upper limit of 1 is exceeded, the phase is shifted and the voltage supplied to the load is reduced.The power supply device according to claim 1.
  The invention described in claim 3A voltage sensor for measuring a voltage between the first and second output terminals, wherein the control circuit is configured to supply a constant power to a load from the measured values of the current sensor and the voltage sensor; Increase the amount of deviationA power supply device according to claim 2.
  The invention described in claim 4In the control circuit, the output current when the voltage between the first and second output terminals is ½ of the induced voltage of the secondary winding is set as the second upper limit value. The control circuit controls the switch circuit when the output current exceeds the second upper limit value, so that the voltage at the first and second output terminals decreases while a constant current is supplied to the load. 4. A period of an alternating voltage applied to the primary winding is shortened.It is a power supply device of any one of these.
[0018]
The present invention is configured as described above. When supplying a low current at a high voltage to a load, an induced voltage of each secondary winding is applied in series to the load.
[0019]
When supplying a large current to the load at a low voltage, an induced voltage of each secondary winding is applied in parallel to the load, and a current is supplied in parallel to the load from each secondary winding.
[0020]
In the meantime, that is, when supplying a medium current at a medium voltage, the period in which the induced voltage of the secondary winding is applied in series to the load and the period in which it is applied in parallel are mixed in one cycle. The output voltage is controlled at the ratio.
[0021]
In this case, the current supplied to the load is measured, and the output voltage can be lowered as the current increases.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
A power supply device of the present invention will be described with reference to the drawings.
Reference numeral 1 in FIG. 1 (a) denotes a power supply device of a first example of the present invention, and a plurality (two in this case) of transformers 21 are shown.₁, 21₂have.
[0023]
Each transformer 21₁, 21₂In the primary winding 31₁, 31₂And each primary winding 31₁, 31₂Secondary windings 32 magnetically coupled to each other₁, 32₂And are arranged.
[0024]
Reference numeral 29 denotes a DC voltage source that outputs a DC voltage by DC smoothing of a commercial voltage source.₁, 31₂Includes a switch circuit 26 connected to a DC voltage source 29.₁, 26₂Are connected one by one.
[0025]
Switch circuit 26₁, 26₂Is shown in FIG.
Each switch circuit 26₁, 26₂Each has four transistors each consisting of an n-channel MOS transistor (MOSFET). Symbol Q in the figure₁~ Q_FourShows these four transistors.
[0026]
Here, the symbol Q₁, Q_FourTransistors and Q_Three, Q₂The transistors are connected in series.
[0027]
Transistor Q₁, Q_FourOr transistor Q₂, Q_ThreeOne primary winding 31 is provided at a connection portion where the two are connected to each other.₁, 31₂The four transistors Q are connected to the ends of₁~ Q_FourAnd one primary winding 31₁Or 31₂And the H bridge circuit is configured.
[0028]
Transistor Q₁, Q_FourOr transistor Q₂, Q_ThreeThe series connection circuit is connected in parallel to the DC voltage source 29 and is configured such that the DC voltage output from the DC voltage source 29 is applied to the H-bridge circuit.
[0029]
Sign Q₁And Q₂And the symbol Q_ThreeAnd Q_FourOf the primary winding 31₁Also 31₂Is a combination of transistors in which a positive voltage is applied to one end and a negative voltage is applied to the other end.₁, 31₂An AC voltage is applied to.
[0030]
This AC voltage is, for example, one set of transistors Q₁And Q₂And the other set of transistors Q_ThreeAnd Q_FourWhen the polarity of the voltage when the circuit is cut off is positive, one set of transistors Q₁And Q₂And the other set of transistors Q_ThreeAnd Q_FourWhen it is made conductive, it becomes negative.
[0031]
Primary winding 31₁, 31₂When an AC voltage is applied to the primary winding 31,₁, 31₂Secondary winding 32 magnetically coupled to₁, 32₂AC voltage is induced in
[0032]
In this power supply device 1, each secondary winding 32.₁, 32₂Are connected in series.
A symbol a in FIG.₁, 32₂Are the end points at both ends of the circuit connected in series, and the symbol b denotes the secondary winding 32.₁, 32₂A connection point where the two are connected to each other is shown.
[0033]
In the power supply device 1, at least the number of rectifier circuits equal to or greater than the sum of the number of end points a and the number of connection points b is provided.
[0034]
Reference 22₁~ 22_ThreeIndicates the rectifier circuit, and each rectifier circuit 22 is shown.₁~ 22_ThreeIs one choke coil 35₁, 35₂, 35_ThreeAnd one rectifying element 36₁, 36₂, 36_ThreeAre connected in series. Rectifier element 36₁~ 36_ThreeIs an element having a rectifying action, such as a pn junction diode or a Schottky junction diode.
[0035]
Secondary winding 32₁, 32₂At least one rectifier circuit 22 is provided at the end point a and the connection point b of the series connection circuit.₁~ 22_ThreeChoke coil 35₁~ 35_ThreeAnd rectifying element 36₁~ 36_ThreeThe part where and are connected is connected.
[0036]
Each rectifier circuit 22₁~ 22_ThreeOf both ends of the choke coil 35₁~ 35_ThreeThe terminal on the side is connected to the first output terminal 38 and the rectifying element 36₁~ 36_ThreeThe terminal on the side is connected to the second output terminal 39.
[0037]
An output capacitor 14 is provided between the first output terminal 38 and the second output terminal 39, and each secondary winding 32 is provided.₁, 32₂As will be described later, the AC voltage induced in the rectifier circuit 22₁~ 22_ThreeAnd rectified and smoothed by the output capacitor 14 to be a DC voltage and output between the first output terminal 38 and the second output terminal 39.
[0038]
A load 16 is connected between the first and second output terminals 38 and 39.
Here, each rectifying element 36₁~ 36_ThreeIs connected to the second output terminal 39, and current flows from the load 16 to the second output terminal 39. Therefore, the second output terminal 39 is at the ground potential, One output terminal outputs a voltage higher than the ground potential.
[0039]
The power supply device 1 has a control circuit 24. Each switch circuit 26₁, 26₂Is connected to the control circuit 24, and the switch circuit 26 is connected by the control circuit 24.₁, 26₂Transistor Q in₁~ Q_FourContinuity and interruption are individually controlled, whereby each switch circuit 26 is controlled.₁, 26₂To primary winding 31₁, 31₂The phase and frequency of the AC voltage supplied to the are controlled. Each switch circuit 26 by the control circuit 24₁, 26₂Are independent, and each switch circuit 26 is controlled.₁, 26₂Secondary winding 32 connected to₁, 32₂The currents flowing through are controlled individually.
[0040]
Each primary winding 31₁, 31₂10 to 12 show examples of voltage waveforms applied to. The symbol T in each figure indicates each primary winding 31.₁, 31₂AC voltage V31 applied to₁, V31₂The period of 1 cycle is shown. Reference sign D indicates the primary winding 31 when the polarity of the AC voltage is reversed.₁, 31₂Current flowing through the secondary winding 32 is zero.₁, 32₂This is a period during which the voltage induced at 0 becomes zero. This period D is set to be very short and can be ignored in the operation of the power supply device 1.
[0041]
In the power supply device 1 of the present invention, each switch circuit 26₁, 26₂To each primary winding 31₁, 31₂The frequency of the alternating voltage applied to is equal, and the lengths of the positive and negative periods of the alternating voltage are equal.
[0042]
As described above, the primary winding 31₁, 31₂Since the period D in which the current flowing through is zero is negligibly short, each primary winding 31₁, 31₂It is assumed that either a positive polarity voltage or a negative polarity voltage is applied.
[0043]
Reference numerals S in the timing charts shown in FIGS. 10 and 11 indicate the primary windings 31.₁, 31₂Are applied to each secondary winding 32.₁, 32₂Is a period in which a voltage of the same polarity is induced.
[0044]
In FIG. 11 and FIG. 12, symbol P denotes a secondary winding 32 connected in series.₁, 32₂Among these periods, voltages having opposite polarities are induced in adjacent secondary windings.
[0045]
As shown in FIG. 10, each primary winding 31₁, 31₂When the phase of the AC voltage applied to each other is the same and the phase difference is zero, each secondary winding 32 is₁, 32₂Of the secondary winding 32 are of the same polarity.₁, 32₂Each of the secondary windings 32 is located between the end points a and a of the series connection circuit.₁, 32₂A voltage is generated by adding the induced voltages to each secondary winding 32.₁, 32₂Is applied to the load 16 in series.
[0046]
In this state, a high voltage is supplied to the load 16, but the supplied current is small.
[0047]
In the power supply device 1 of the present invention, each transformer 21₁, 21₂Inside, primary winding 31₁, 31₂And secondary winding 32₁, 32₂The turn ratios of the primary windings 31 are equal to each other.₁, 31₂The magnitudes of the alternating voltages applied to the secondary windings 32 are therefore equal.₁, 32₂The magnitudes of the alternating voltages induced in are equal.
[0048]
Each secondary winding 32₁, 32₂In the period S, each secondary winding 32 is represented by the magnitude E of the voltage induced in₁, 32₂The voltage generated between the end points “a” of the series connection circuit of FIG.₁, 32₂The size is multiplied by the number of. If there are n secondary windings, n × E.
[0049]
In the power supply device 1, each rectifier element 36 is₁, 36₂The cathode side of the secondary winding 32₁, 32₂Is connected to the secondary winding 32.₁, 32₂Among the end points a of the series connection circuit, the rectifying element 36 connected to the end point a on which the positive voltage is induced.₁Or 36_ThreeIs reverse biased and shuts off. On the other hand, the rectifying element 36 connected to the end point a on which the negative voltage is induced.₁Or 36_ThreeAre forward-biased.
[0050]
As a result, the secondary winding 32₁, 32₂The choke coil 35 connected to the end point a where the positive voltage is induced by the n × E voltage generated in the series connection circuit of₁Or 35_ThreeAnd the rectifying element 36 connected to the end point a where the negative voltage is induced.₁, 36₂A current flows through the first output terminal 38 and is supplied to the load 16.
[0051]
Primary winding 31₁, 31₂When the polarity of the AC voltage applied to is reversed, the secondary winding 32₁, 32₂The polarity of the voltage induced in the series connection circuit is also reversed, but is supplied from the first output terminal 38 to the load 16 as before the inversion.
[0052]
As shown in the timing chart of FIG.₁, 31₂When the phases of the voltages applied to the secondary windings 32 match,₁, 32₂There is a period in which a positive voltage is induced and a period in which a negative voltage is induced.
[0053]
FIG. 2 shows a current flowing during a period in which a positive voltage is induced, and FIG. 3 shows a current flowing in a period in which a negative voltage is induced.
[0054]
Symbol I in FIG.₁₁And symbol I in FIG._{twenty one}The secondary winding 32₁, 32₂The current flowing by the voltage n × E (n = 2) generated at both ends of the serial connection circuit and its direction are shown.
[0055]
These currents i₁₁, I_{twenty one}Is a choke coil 35₁, 35_ThreeAnd supplied to the load 16. At this time, the secondary winding 32₁, 32₂In the series connection circuit, n × E voltage is generated, and the first output terminal 38 has an output voltage V of magnitude n × E / 2._OAppears. At this time, the choke coil 35₁, 35_ThreeAt both ends of the secondary winding 32₁, 32₂The voltage drops by a voltage n × E / 2 which is half the voltage generated in the series connection circuit.
[0056]
Their current i₁₁, I_{twenty one}The primary winding 31₁, 31_ThreeWhen the polarity of the AC voltage applied to is reversed, the current i₁₁And current i_{twenty one}Switch between each other.
[0057]
Each current i₁₁, I_{twenty one}The choke coil 35₁, 35_ThreeAre supplied to the load 16 but the current i₁₁And current i_{twenty one}Are switched to each other, each choke coil 35₁, 35_ThreeThe current that flows through is temporarily stopped.
[0058]
Each choke coil 35₁, 35_ThreeIs the current i₁₁, I_{twenty one}Are respectively charged by magnetic energy and the current i₁₁, I_{twenty one}When the choke coil 35 stops₁, 35_ThreeAn electromotive force is generated in FIG.₁₂And symbol i in FIG._{twenty two}Is generated and supplied from the first output terminal 38 to the load 16.
[0059]
Choke coil 35₁, 35_ThreeCurrent I due to discharge₁₂, I_{twenty two}The choke coil 35₁, 35_ThreeCurrent i charged₁₁, I_{twenty one}Is the same size. Choke coil 35₁, 35_ThreeCurrent i charged₁₁, I_{twenty one}Are equal to each other, so eventually each current i₁₁, I_{twenty one}, I₁₂, I_{twenty two} Are approximately equal in size.
[0060]
Each secondary winding 32₁, 32₂When the induced current is applied in series to the load 16 and the current flowing through the load 16 fluctuates, the secondary winding 32₁, 32₂Current I generated by₁₁, I_{twenty one}Automatically follows the output voltage V_OIs maintained at a constant value (here, voltage E).
[0061]
That is, when the current flowing through the load 16 decreases, the current supplied from the first output terminal 38 decreases accordingly, and when the current flowing through the load 16 increases, the current supplied from the first output terminal 38 increases accordingly. Grows according to.
[0062]
In the power supply device 1, the current sensor 15 is provided at one or both of the first output terminal 38 and the second output terminal 39, and the magnitude of the output current supplied from the power supply device 1 to the load 16. Is measured by the current sensor 15.
[0063]
The measurement result of the current sensor 15 is input to the control circuit 24. A first upper limit value is set in advance in the control circuit 24, and the output current I supplied to the load 16 is set._OExceeds the first upper limit value, the primary winding 31₁, 31₂The state is shifted from the state in which the phases of the AC voltages applied to are matched.
[0064]
FIG. 11 shows the primary winding 31 by the control circuit 24.₁, 31₂The state of the phase of the alternating voltage applied to is shifted by an angle F. In the timing chart of FIG. 10, one period T is entirely occupied by the period S, but in the timing chart of FIG. 11, the period S and the period P are mixed.
[0065]
The period S in FIG.₁, T_ThreeStarts at time t₂, T_FourThe period P ends at the time t when the period S ends.₂, T_FourStarting at time t when period S starts_Three(And time t₁).
[0066]
The operation of the power supply device 1 when the period S and the period P coexist will be described along the timing chart of FIG.
[0067]
First, time t₁~ T₂During each secondary winding 32₁, 32₂When a positive voltage is induced in each secondary winding 32, as shown in FIG.₁, 32₂The voltage E induced by the load 16 and the choke coil 35 are connected in series.₁Applied to the series connection circuit. Symbol I₃₃The secondary winding 32₁, 32₂The current supplied to the load 16 by the voltage 2 · E at both ends of the serial connection circuit is shown.
[0068]
At this time, one secondary winding 32₂Due to the voltage E induced in the current I₃₂Is supplied to the load 16.
[0069]
These secondary windings 32₁, 32₂The current I generated by₃₃, I₃₂Is the same rectifying element 36_ThreeAnd a different choke coil 35₁, 35₂Flowing. At that time choke coil 35₁, 35₂To charge.
[0070]
Time t₁Immediately before the secondary winding 32₁, 32₂The voltage induced in the choke coil 35₂Current is flowing through the time t₁~ T₂During that time, the choke coil 35₂Is discharged, and symbol I in FIG.₃₃Is supplied to the load 16.
[0071]
Next, time t₂Is passed, the two primary windings 31₁, 31₂One of the primary windings 31₂The current flowing through the primary winding 31 is reversed.₂Secondary winding 32 magnetically coupled to₂A negative voltage is induced.
[0072]
The other primary winding 31₁A positive voltage is applied to the primary winding 31 thereof.₁Secondary winding 32 magnetically coupled to₁In this case, a positive voltage is induced.
[0073]
FIG. 5 shows a current flowing through the power supply device 1 in such a state, and a secondary winding 32 in which a positive voltage and a negative voltage are induced, respectively.₁, 32₂Thus, the positive current I₄₁And negative current I₄₂Are respectively generated and supplied from the first output terminal 38 to the load 16.
[0074]
In the state shown in FIG.₁, 32₂Induced voltage is applied in parallel to the load 16 and the positive current I₄₁And negative current I₄₂Is supplied to the load 16 in parallel.
[0075]
This current I₄₁, I₄₂Is the same rectifying element 36₂Through another choke coil 35₁, 35_ThreeThe choke coil 35₁, 35_ThreeAre each charged with magnetic energy.
[0076]
Current I₄₁, I₄₂Choke coil 35 that does not flow₂At time t₂Just before the secondary winding 32₂Current I supplied from₃₂Flows and is charged by the time t₂And its current I₃₂When the choke coil 35 stops₂An electromotive force is generated in the current I₄₃Is generated.
[0077]
Its current I₄₃The secondary winding 32₁, 32₂Generated current I₄₁, I₄₂Same rectifier element 36₂And is supplied to the load 16 from the first output terminal 38.
[0078]
FIG. 14 shows the secondary winding 32 as described above.₁, 32₂This is a simulation result showing waveforms of current and voltage flowing in the power supply device 1 when a period S in which the induced voltage is applied in series to the load 16 and a period P in which the induced voltage is applied in parallel are mixed.
[0079]
Reference V31 in FIG.₁, V31₂Is the primary winding 31₁, 31₂The waveform of the alternating voltage applied to is shown, I32₁, I32₂Is the secondary winding 32₁, 32₂The current waveform which flows in is shown.
[0080]
I36₁~ I36_ThreeIs the rectifying element 36₁~ 36_ThreeShows the waveform of the current flowing through V36.₁~ V36_ThreeIndicates the potential of the cathode terminal (positive and negative are reversed).
[0081]
Next, time t_ThreeElapses and each primary winding 31₁, 31₂When all the voltages applied to are negative, the secondary winding 32₁, 32₂The polarity of the voltage induced by the negative polarity also becomes negative, and each secondary winding 32₁, 32₂The induced voltage is applied to the load 16 in series.
[0082]
FIG. 6 shows the current flowing at this time, and the secondary winding 32 is shown.₁, 32₂Current I by the voltage 2 × E generated at both ends of the series connection circuit₅₁And one secondary winding 32 is generated.₁Due to the voltage E induced in the current I₅₂Is generated.
[0083]
Also, time t_ThreeBefore the choke coil 35₁Current I supplied to_{twenty two}Is stopped and the choke coil 35 is stopped.₁An electromotive force is generated in the current I₅₃Has been generated.
These currents I₅₁, I₅₂, I₅₃Is supplied to a load 16.
[0084]
Next, time t_FourElapses, one of the secondary windings 32₂Of the secondary winding 32 is changed from the negative polarity to the positive polarity.₁, 32₂The induced voltage generated in the step is applied to the load 16 in parallel. Therefore, as shown in FIG.₁, 32₂Current I due to the induced voltage of₆₁, I₆₂Is generated and supplied to the load 16 in parallel. Its current I₆₁, I₆₂Are different rectifier elements 36.₁, 36₂And the same choke coil 35₂And is supplied to the load 16. Other choke coils 35₁, 35_ThreeHas an electromotive force, and the electromotive force causes a current I₆₃, I₆₄Are generated and supplied to the load 16 respectively.
[0085]
The above is the primary winding 31.₁, 31₂The phase shift amount F of the AC voltage applied to the coil is 180 ° or less. However, when the slip amount F increases to 180 ° as shown in FIG.₁, 32₂The voltages induced by the two have opposite polarities, the series period S disappears, the entire period T becomes the parallel period P, and the current is supplied to the load 16 in parallel.
[0086]
At this time, the load 16 has a current I shown in FIG.₇₁~ I₇₃And the current I shown in FIG.₈₁~₈₄And are supplied alternately.
[0087]
Each secondary winding 32₁, 32₂Current I generated by the induced voltage of₇₁, I₇₂, I₈₁, I₈₂Are equal to each other, and each choke coil 35 is₁~ 35_ThreeCurrent I generated by the electromotive force of₇₃, I₈₃, I₈₄The choke coil 35₁~ 35_ThreeCurrent I charged₇₁, I₇₂, I₈₁+ I₈₂Is equal to
I₇₁= I₇₂= I₈₁= I₈₂= I₇₃/ 2 = I₈₃= I₈₄
It is.
[0088]
As described above, the entire one period T is the parallel period P, and each secondary winding 32₁, 32₂Current I due to induced voltage₇₁, I₇₂, I₈₁, I₈₂Is the choke coil 35₁~ 35_ThreeThe output voltage V_OBecomes a voltage E / 2 that is half the induced voltage E.
[0089]
At this time, each choke coil 35₁~ 35_ThreeThen, the voltage drops by E / 2, and the choke coil 35₁~ 35_ThreeCurrent I₇₁, I₇₂, I₈₁, I₈₂By each choke coil 35,₁~ 35_ThreeIs charged with magnetic energy.
[0090]
On the other hand, when the period S of series connection and the period P of parallel connection coexist in one cycle T as in the timing chart of FIG._OIs a size between n × E / 2 and E / 2, and is a size corresponding to the ratio of the period S and the period P included in one period T. For example, when the period S and the period P are 1: 1, the output voltage V_OBecomes E · 3/4.
[0091]
In the power supply device 1, the first upper limit value I is supplied to the control circuit 24.₁Is preset and the output current I_OIs the first upper limit I₁Is shorter than the parallel period P, the entire period T is operated in the serial period S, and the output current I_OIs the first upper limit I₁Exceeding the period, a period S is generated according to the amount exceeding the output current I_OWhile increasing the output voltage V_OReduce.
[0092]
FIG. 13 shows the output current I_OAnd output voltage V_OIt is the graph which showed this relationship. Output current I_OIs the first upper limit I₁Between the smaller points A to B, the output voltage V_oIs a constant value of the voltage E, and the output current I_OIs the first upper limit I₁Exceeds the output current I_OOutput voltage V while increasing_OIs lowered.
[0093]
The control circuit 24 outputs the output voltage V appearing between the first output terminal 38 and the second output terminal 39._OIs input and the output current I_OAnd output voltage V_OBoth have been measured. In the present embodiment, the output current I is controlled by the control circuit 24._OIs the first upper limit I₁Is exceeded, the phase shift amount F is increased, and the output power (output current I_OAnd output voltage V_OProduct) so that the output current I_OWhile increasing the output voltage V_OReduce.
[0094]
However, the output voltage V of the present invention_OIs not limited to this. For example, the output current I_OOutput voltage V while linearly increasing_OVarious control methods are included such as reducing the linearity.
[0095]
As described above, the phase shift amount F increases, reaches 180 °, and at the point C in which one period T becomes the parallel period P, the output voltage V_OBecomes E / 2.
[0096]
Symbol I₂Is the output voltage V_OOutput current I when becomes E / 2_OOutput current I_OIs a second upper limit value.
[0097]
In this power supply device 1, the output current I_OIs the second upper limit I₂The control circuit 24 causes the transistor Q to₁~ Q_FourThe conduction period of the primary winding 31 is shortened.₁, 31₂The effective value of the AC voltage supplied to is reduced.
[0098]
As a result, the secondary winding 32₁, 32₂The period D during which no voltage is induced becomes longer than negligible, and the output voltage V depends on the length of the period D._ODecreases further from E / 2.
[0099]
The point D is a state where the first output terminal 38 and the ground terminal 39 are short-circuited, that is, the output voltage V_OIs zero and the output current I_OIs the output voltage V_OUntil the value exceeds E / 2 and becomes zero, the second upper limit value I₂Maintain the value of.
[0100]
Next, FIG. 15 is a circuit diagram of the power supply device 2 of the second example of the present invention.
In the power supply device 2 of the second example, a transformer 21 is added to the power supply device 1 of the first example._Three, 21_FourAnd the rectifier circuit 22_Four, 22_FiveAnd switch circuit 26_Three, 26_FourHas been added. Each switch circuit 26₁~ 26_FourThe internal structure is as shown in FIG.
[0101]
In the power supply device 1 of the first example, two transformers 21₁, 21₂And its transformer 21₁, 21₂Secondary winding 32 in₁, 32₂Are connected in series, but in the power supply device 2 of the second example, each transformer 21₁~ 21_Four4 secondary windings 32 in total₁~ 32_FourAre connected in series.
[0102]
Secondary winding 32₁~ 32_FourThe end point a of the series connection circuit and the secondary winding 32₁~ 32_FourThe connection point b between the rectifier circuits 22₁~ 22_FiveInner choke coil 35₁~ 35_FiveTo the first output terminal 38, and the rectifying element 36₁~ 36_FiveTo the ground terminal 39.
[0103]
Rectifier element 36₁~ 36_FiveThe anode side is connected to the second output terminal 39 having the ground potential, and the cathode side is connected to the end point a or the connection point b.
[0104]
Each transformer 21₁~ 21_FourPrimary winding 31 in₁~ 31_FourAre each separately switched circuit 26₁~ 26_FourThe control circuit 24 is connected to each switch circuit 26.₁~ 26_FourEach primary winding 31₁~ 31_FourWhen the phase of the AC voltage applied to the secondary winding 32 is changed,₁~ 32_FourThe polarity of the induced voltage is controlled. Thereby, an induced voltage is applied to the load 16 in series and in parallel.
[0105]
FIG. 22 shows the primary winding 31 of the power supply device 2.₁~ 31_FourThe phases of the AC voltages applied to the secondary windings 32 match each other.₁~ 32_Four6 is a timing chart when the induced voltage is supplied to the load 16 in series.
[0106]
16 and 17 show the current and the direction at this time, and the symbol I in FIG.₁₀₁Each secondary winding 32₁~ 32_Four17 represents a current that flows when the induced voltage of the positive polarity is positive.₁₀₂Shows the current that flows in the case of negative polarity, contrary to FIG. 16 and 17 and later-described FIGS.₁~ 35_FiveThe current generated by the electromotive force is omitted.
[0107]
FIG. 23 shows each primary winding 31.₁~ 31_FourThe phase of the AC voltage applied to is shifted by 180 °, and the secondary windings 32 connected in series₁~ 32_FourOf adjacent secondary windings 32₁~ 32_FourIt is a timing chart when the induced voltage of becomes opposite to each other.
[0108]
18 and 19 are diagrams showing the current and direction flowing at that time.₁₁₁, I₁₁₃Is a current generated by the positive induced voltage, and the symbol I₁₁₂, I₁₁₄Is a current generated by a negative induced voltage. Similarly, reference numeral I in FIG.₁₂₂, I₁₂₄Is a current generated by the positive induced voltage, and the symbol I₁₂₁, I_{one two Three}Is a current generated by a negative induced voltage.
[0109]
One period T is entirely occupied by S, and each secondary winding 32₁~ 32_FourWhen the induced voltage is in series with the load 16, a voltage of 4 × E is applied to the secondary winding 32.₁~ 32_FourA half voltage, that is, a voltage of 2 × E appears between the first and second output terminals 38 and 39. At this time, the current is applied to the choke coil 35.₁Or 35_FiveThe choke coil 35₁, 35_FiveA voltage drop of 2 × E is caused at both ends.
[0110]
When one period T is entirely occupied by P and the induced voltage is in parallel with the load 16, a voltage half of the induced voltage E, that is, a voltage of E / 2 is the first and second output terminals 38, 39. Appear in between. At this time, the choke coil 35₁, 35_Three, 35_FiveOr 35₂, 35_FourThen, the voltage drops by E / 2.
[0111]
Also in this power supply device 2, a preset first upper limit value I₁Until the secondary winding 32 is exceeded.₁~ 32_FourIs induced in series with the load 16.
[0112]
First upper limit I₁Exceeding the phase, a phase P occurs in which the induced voltage is applied in parallel, and the output voltage V corresponding to the ratio of the periods S and P is generated._OIs output. n secondary windings 32₁~ 32_nIf the period S and the period P are mixed, the output voltage V_OIs between n × E / 2 and E / 2, the period S in which the induced voltage is applied in series to the load 16 is s% in one cycle, and the period P in which it is applied in parallel is p In the case of% (s + p = 100%), the size is (n × E × s / 2 + E × p / 2) / 100.
[0113]
In the power supply device 2 of the present invention, when the series period S and the parallel period P are mixed, a plurality of secondary windings 32 are provided.₁~ 32_FourAmong them, the induced voltage of adjacent two or three secondary windings may be applied in series to the load 16 and simultaneously the induced voltage of other secondary windings may be applied in parallel to the load 16. good. That is, in one cycle T, in addition to the serial period S and the parallel period P, a series-parallel period SP may be provided.
[0114]
For example, as shown in FIGS.₁And 32₂Secondary winding set or 32_ThreeAnd 32_FourWhen a voltage of a magnitude of 2 × E is generated by each of the secondary windings, and a voltage of 2 × E is applied to the load 16 in series, two series and two parallel series-parallel periods Can be generated.
[0115]
Symbol I in FIG.₁₃₁And symbol I in FIG.₁₄₁Is the current due to the positive induced voltage in that case, symbol I in FIG.₁₃₂And symbol I in FIG.₁₄₂Is a current due to a negative induced voltage.
[0116]
An example of the control circuit 24 used in the first and second embodiments is shown in FIG.
The control circuit 24 includes an output voltage amplifier 91._VAnd output current amplifier 91_IAnd output power amplifier 91_PAnd an output voltage amplifier 91._VIncludes an output voltage V appearing between the first and second output terminals 38 and 39._O, And an output current amplifier 91_IIncludes the output current I measured by the current sensor 15._OIs converted into voltage and input.
[0117]
The output voltage V_OAnd the output current I output from the current sensor 15_OIs input to the multiplier 93, and the output voltage V_OSize and output current I_OThe output power P is calculated from the magnitude of the output voltage, and the output power P is converted into a voltage and output voltage amplifier 91 is converted._VHas been entered.
[0118]
Output voltage amplifier 91_VAnd output current amplifier 91_IAnd output power amplifier 91_POutput voltage reference voltage source 92._VOutput voltage reference voltage source 92_IOutput voltage reference voltage source 92_PAre connected to each amplifier 91._V91_I91_PDepending on the output voltage V_O, Output current I_OOr the magnitude of the output power P and each reference voltage source 92_V, 92_I, 92_PThe difference from the reference voltage output is amplified and output.
[0119]
Each amplifier 91_V91_I91_PThe voltage signal output from the₁~ 94_ThreeAre input to the drive circuit 95 via each of the amplifiers 91._V91_I91_PAmong them, an amplifier (91_VOr 91_IOr 91_P), The drive circuit 95 is controlled.
[0120]
Here, each amplifier 91_V91_I91_POutput signal of the output current I_OIs the first upper limit value I₁Output voltage amplifier 91 while the output voltage is less than_VThe output signal voltage is configured to be maximum.
[0121]
The drive circuit 95 includes n switch circuits 26.₁~ 26_nAre controlled independently, and the output voltage V_OSuddenly changes, the drive circuit 95 causes the output voltage amplifier 91 to_VEach switch circuit 26 based on the output signal of₁~ 26_nThe phase of the output voltage V_OIs maintained constant.
[0122]
Next, the output current I_OIs the first upper limit I₁The output voltage amplifier 91 is reached._VOutput signal voltage and output current amplifier 91_IOutput signal voltage becomes equal, and the output current I_OIncreases and the first upper limit value I₁Exceeds the second upper limit value I₂Each amplifier 91 as long as it is less than_V91_I91_POutput power amplifier 91_PThe output signal voltage is configured to be maximum.
[0123]
Accordingly, each switch circuit 26₁~ 26_nThe phase of the output power amplifier 91_POutput power P (output current I_OAnd output voltage V_OProduct) so that the output current I_OOutput voltage V while increasing_OIs reduced.
[0124]
Next, the second upper limit value I₂, The output current reference voltage source 92_IOutput signal voltage becomes maximum, and the output current I_OIs substantially the second upper limit value I₂Output voltage V while maintaining the current amount of_OReduce.
[0125]
Needless to say, the control circuit 24 of the present invention is not limited to the above-described configuration, and includes various control circuits.
[0126]
【The invention's effect】
As described above, in the power supply device of the present invention, the induced voltage of the plurality of secondary windings can be applied in series, series-parallel, or in parallel, and the output voltage can be lowered while increasing the output current. In this case, since the output voltage can be lowered without controlling the conduction period of the transistor, the use efficiency of the transformer is high.
[Brief description of the drawings]
FIG. 1A is a circuit block diagram of a power supply device of a first example of the present invention. FIG. 1B is a circuit diagram showing an internal configuration of a switch circuit.
FIG. 2 is a diagram (1) showing a path of a current that flows when an induced voltage of a secondary winding is applied in series to a load in the power supply device of the first example.
FIG. 3 is a diagram (2) showing a path of a current that flows when an induced voltage of a secondary winding is applied in series with a load in the power supply device;
FIG. 4 is a diagram (1) showing a path of a current that flows when a period in which an induced voltage of a secondary winding is applied in series to a load and a period in which it is applied in parallel are mixed in the power supply device;
FIG. 5 is a diagram (2) showing a path of a current flowing when a period in which the induced voltage of the secondary winding is applied in series to the load and a period in which the induced voltage is applied in parallel are mixed in the power supply device;
FIG. 6 is a diagram (3) illustrating a path of a current that flows when a period in which the induced voltage of the secondary winding is applied in series to a load and a period in which the induced voltage of the secondary winding is applied in parallel exist in the power supply device;
FIG. 7 is a diagram (4) illustrating a path of a current that flows when a period in which the induced voltage of the secondary winding is applied in series to a load and a period in which the induced voltage is applied in parallel exist in the power supply device;
FIG. 8 is a diagram showing a path of a current that flows when an induced voltage of a secondary winding is applied in parallel to a load (1)
FIG. 9 is a diagram showing a path of a current that flows when the induced voltage of the secondary winding is applied in parallel to the load (2)
FIG. 10 is a timing chart when the induced voltage of the secondary winding is applied in series to the load.
FIG. 11 is a timing chart when a period in which the induced voltage of the secondary winding is applied in series to the load and a period in which the induced voltage is applied in parallel are mixed.
FIG. 12 is a timing chart when the induced voltage of the secondary winding is applied in parallel to the load.
FIG. 13 is a graph showing the relationship between the output voltage and the output current of the power supply device of the first example of the present invention.
FIG. 14 is a graph showing the internal voltage and current of the power supply device of the first example of the present invention.
FIG. 15 is a block diagram of a power supply device according to a second example of the present invention.
FIG. 16 is a diagram (1) showing a path of a current that flows when the induced voltage of the secondary winding is applied in series with the load in the power supply device;
FIG. 17 is a diagram showing a path of a current that flows when the induced voltage of the secondary winding is applied in series with the load in the power supply device (2)
FIG. 18 is a diagram (1) showing a path of a current that flows when the induced voltage of the secondary winding is applied in parallel to the load in the power supply device;
FIG. 19 is a diagram (2) showing a path of a current that flows when the induced voltage of the secondary winding is applied in parallel to the load in the power supply device;
FIG. 20 is a diagram (1) showing a path of a current that flows when the induced voltage of the secondary winding is applied in series-parallel to the load in the power supply device;
FIG. 21 is a diagram (2) showing a path of a current that flows when the induced voltage of the secondary winding is applied in series and parallel to the load in the power supply device;
FIG. 22 is a timing chart when the induced voltage of the secondary winding is applied in series with the load in the same power supply device;
FIG. 23 is a timing chart when the induced voltage of the secondary winding is applied in parallel to the load in the same power supply device.
FIG. 24 shows an example of a control circuit.
FIG. 25 shows a conventional power supply device.
FIG. 26 is a circuit block diagram when the power supply device is operated in parallel.
[Explanation of symbols]
1, 2 …… Power supply
15 …… Current sensor
16 …… Load
24 …… Control circuit
26₁~ 26_Four...... Switch circuit
31₁~ 31_Four...... Primary winding
32₁~ 32_Four... Secondary winding
35₁~ 35_Five……choke coil
36₁~ 36_Five...... Rectifying element
38 …… First output terminal
39 …… Second output terminal

Claims (4)

A plurality of primary windings;
A switch circuit for supplying an alternating voltage to the primary winding;
A secondary winding magnetically coupled to each of the primary windings;
A plurality of rectifier circuits in which a choke coil and a rectifier element are connected in series;
The secondary winding is connected in series,
The connection point between the secondary windings and the both end points of the series connection circuit of the secondary windings are connected to the connection point of the choke coil of the rectification circuit and the rectification circuit,
The end point on the choke coil side of the rectifier circuit is connected to a first output terminal, the end point on the rectifier element side is connected to a second output terminal,
A capacitor is connected between the first and second output terminals,
When a voltage having the same polarity is induced in the secondary winding, and a series voltage is generated at both ends of the series connection circuit of the secondary windings, the voltage induced in each secondary winding is generated. The power supply apparatus comprised so that the said series voltage may be applied to the load connected to the 2nd terminal . A current sensor provided at one or both of the first and second output terminals;
A control circuit for controlling the phase of the AC voltage applied to the primary winding,
A first upper limit value is set in advance in the control circuit, and when the measured value of the current sensor is equal to or less than the first upper limit value, the phase of the AC voltage applied to the primary winding is aligned and the series voltage is applied to the load. Apply
The power supply device according to claim 1, wherein when the first upper limit value is exceeded, the phase is shifted and the voltage supplied to the load is reduced . A voltage sensor for measuring a voltage between the first and second output terminals;
The power supply device according to claim 2 , wherein the control circuit increases the amount of phase shift so that constant power is supplied to a load from measured values of the current sensor and the voltage sensor . In the control circuit, the output current when the voltage between the first and second output terminals is ½ of the induced voltage of the secondary winding is set as the second upper limit value. ,
The control circuit controls the switch circuit when the output current exceeds the second upper limit value, so that the voltage at the first and second output terminals decreases while a constant current is supplied to the load. The power supply device according to any one of claims 2 and 3 , wherein a period of the alternating voltage applied to the primary winding is shortened .

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