JP4218173B2 - DC power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a smoothing circuit used for an inverter device such as an air conditioner, a refrigerator, and a washing machine, and a direct current power supply device that obtains direct current from a commercial power source.
[0002]
[Prior art]
  A circuit diagram of an inverter device having a DC power supply device using a conventional smoothing circuit is shown in FIG.
[0003]
  In FIG. 7, the DC power supply device 1 has a commercial power supply 2 of 100 V at 50 Hz or 60 Hz, a full-wave rectifier circuit 3 connected to the commercial power supply 2, and a smoothing circuit 4 connected to the output of the full-wave rectifier circuit 3. ing.
[0004]
  The full-wave rectifier circuit 3 is composed of diodes 5, 6, 7, and 8. The smoothing circuit 4 is composed of a choke coil 9 and an electrolytic capacitor 10.
[0005]
  The load 11 operates by receiving a DC voltage and consumes 1 kW of power.
[0006]
  In the above configuration, the conventional DC power supply device 1 reduces the voltage pulsation (ripple) included in the output of the full-wave rectifier circuit 3 by the choke coil 9 and the capacitor 10 and outputs it to the load 11. A DC voltage with a small ripple voltage is supplied.
[0007]
  Here, the choke coil 9 is formed by winding a copper wire around an iron core in which silicon steel plates are laminated and provided with a gap. The choke coil 9 has an inductance of L = 3 mH, and the capacitor 10 has C = 4700 microfarads. It has a capacitance.
[0008]
  The choke coil 9 stores energy calculated by half the value obtained by multiplying the L value by the square of the current (ampere), and the capacitor 10 calculates by half the value obtained by multiplying the C value by the square of the voltage (volt). The smoothing circuit 4 outputs the instantaneous power supplied from the input and the load by alternately performing the energy storing action and the discharging action of the stored energy. As a result, the ripple included in the full-wave rectified voltage waveform, which is the output of the full-wave rectifier circuit 3, is considerably absorbed, and the peak-to-peak of the ripple voltage is absorbed. A smoothing action that suppresses the voltage to 10 volts or less is realized.
[0009]
[Problems to be solved by the invention]
  In such a conventional technique, the choke coil 9 and the capacitor 10 constituting the smoothing circuit 4 are considerably large in weight, volume and cost.
[0010]
  That is, for the choke coil 9, the energy storage amount per gram is 0.0004 joules, 0.002 joules per cc, 0.0005 joules per circle, and the capacitor 10 is also an electrolytic type. The energy storage amount per gram was as low as 0.5 joule, 0.8 joule per cc, and 0.1 joule per circle.
[0011]
  In addition, both the input current of the smoothing circuit 4 and the current waveform supplied to the device from the commercial power source 2 have a problem that the power factor becomes low by shifting from a shape similar to the voltage waveform. there were.
[0012]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention has an input terminal to which alternating electric power is supplied from a commercial power source, an output terminal, a flywheel, an electric machine connected to the flywheel, and a switching element. And an inverter circuit connected to the electric machine, and a control circuit having the switching element and turning on / off, receiving electric power including a ripple having a frequency twice the output frequency of the commercial power supply from the input terminal, FlywheelWithin the commercial power cycle,Accelerated by the electric machine in a state where the instantaneous power input from the input terminal is greater than the instantaneous power output from the output terminal.PeriodThe electric machine is decelerated by the electric machine in a state where the instantaneous power input from the input terminal is smaller than the instantaneous power output from the output terminal.Have a period,Output DC voltage from the output terminalBy,A DC power supply device having a high input power factor while reducing weight, volume, and cost is realized.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is connected to an input terminal to which AC electric power is supplied from a commercial power supply, an output terminal, a flywheel, and the flywheel. An electric machine, an inverter circuit having a switching element and connected to the electric machine, a control circuit having the switching element and turning on and off, and having a frequency twice the output frequency of the commercial power supply from the input terminal Receiving power including ripple, the flywheel isWithin the commercial power cycle,Accelerated by the electric machine in a state where the instantaneous power input from the input terminal is greater than the instantaneous power output from the output terminal.PeriodThe electric machine is decelerated by the electric machine in a state where the instantaneous power input from the input terminal is smaller than the instantaneous power output from the output terminal.Have a period,Output DC voltage from the output terminalBy,DC power supply with high input power factor by increasing the stored energy per unit weight, unit volume and unit cost, reducing circuit weight, volume and cost with the same capacity (watt), and by switching on / off the switching element Realize equipmentIn addition, the DC power supply can be smoothed with a configuration that is smaller, lighter, and lower in cost than a capacitor or a reactor (choke coil?).
[0014]
  Further, according to claim 2, the current waveform supplied from the input terminal of the DC power supply device according to claim 1 is made substantially the same as the voltage waveform supplied to the input terminal, so that the weight, volume, and cost are also reduced. To reduce the input power and keep the output voltage more stable.
[0015]
【Example】
  Next, specific examples of the present invention will be described.
[0016]
  Example 1
  FIG. 1 is a circuit diagram of a DC power supply device according to the first embodiment.
[0017]
  In FIG. 1, the DC power supply device 20 includes a 100 V 50 Hz or 60 Hz commercial power source 21, a full-wave rectifier circuit 22 connected to the commercial power source 21, and a smoothing circuit 23 connected to the output of the full-wave rectifier circuit 22. A load 24 is connected to.
[0018]
  The full-wave rectifier circuit 22 uses a bridge type constituted by diodes 25, 26, 27, and 28.
[0019]
  The smoothing circuit 23 has input terminals 30a and 30b and output terminals 31a and 31b. Further, a disk-shaped iron plate having a diameter of 2 inches and a thickness of 5.5 mm can be freely rotated by, for example, a ball bearing (not shown). A flywheel 32 having a supported mass of 88 grams, and an electric machine 33 directly connected to the shaft of the flywheel 32 are provided.
[0020]
  An inverter circuit 34 is connected to the electric machine 33. In the first embodiment, the inverter circuit 34 is configured by a first switching element 35, a second switching element 36, and diodes 37, 38, 39, and 40. The first switching element 35 and the second switching element 36 are both configured using insulated gate bipolar transistors (IGBTs).
[0021]
  In the first embodiment, the first switching element 35 has a collector terminal connected to the input terminal 30a, the second switching element 36 has an emitter terminal connected to the output terminal 31b, and the gate terminal of any switching element is the control circuit 41. The on / off state is controlled by switching the presence or absence of a voltage applied between the gate and the emitter.
[0022]
  Furthermore, in Example 1, the input voltage detection means 50 which detects the voltage Vin supplied between the input terminals 30a and 30b, the input current detection means 51 which detects the current Iin supplied from the input terminal 30a, and the output terminal 31a , 31b, an output voltage detection means 52 for detecting the output voltage Vout, and an output current detection means 53 for detecting the current Iout output from the output terminal 31a.
[0023]
  In this embodiment, the input voltage detection means 50 is composed of resistors 54 and 55, the output voltage detection means 52 is composed of resistors 56 and 57, and the input current detection means 51 and the input current detection means 53 are In either case, a resistor is used to detect a voltage drop that occurs when a current flows.
[0024]
  The control circuit 41 receives signals from the input voltage detection means 50, the input current detection means 51, the output voltage detection means 52, and the output current detection means 53, and the current waveform of the input current Iin supplied from the input terminal 30a is input. The ON / OFF conduction ratio of the first switching element 35 and the second switching element 36 is controlled so that the voltage waveform of the voltage Vin supplied between the terminals 30a and 30b is substantially the same.
[0025]
  The smoothing circuit 23 receives power including periodic pulsations of 100 Hz from the input terminals 30a and 30b when the frequency of the commercial power supply 21 is 50 Hz, and the flywheel 32 is input from the input terminals 30a and 30b. In a state where the instantaneous power that is generated, that is, the product of Iin and Vin, is greater than the instantaneous power that is output from the output terminals 31a and 31b, that is, the product of Iout and Vout, the electric machine 33 operates as a motor and accelerates (rotates). The electric energy corresponding to the difference between the input and the output is stored as kinetic energy in the flywheel 32.
[0026]
  Conversely, in the state where the instantaneous power input from the input terminals 30a and 30b is smaller than the instantaneous power output from the output terminals 31a and 31b, the electric machine 33 operates as a generator and decelerates (rotation speed). The kinetic energy stored in the flywheel 32 is converted into electrical energy, and as a result, DC power with almost no pulsation is output from the output terminals 31a and 31b.
[0027]
  Specifically, the load 24 is connected to, for example, an inverter for driving a motor having a three-phase, six-stone structure, and is supplied with a small DC voltage corresponding to a ripple, so that vibration is reduced and speed / torque is reduced. Fluctuation is small and highly efficient motor driving is performed.
[0028]
  In the present embodiment, the electric machine 33 is a synchronous machine having a rotor 58 using a permanent magnet magnetized with 48 poles and a stator winding, and further, the position of the rotor 58 by a Hall IC ( The position detection means 60 which detects an angle) is provided.
[0029]
  The Hall IC outputs a high signal when the opposing rotor 58 is at the N-pole position, and outputs a low signal when the opposing rotor 58 is at the S-pole, but the rotor 58 always rotates in one direction. Therefore, the polarity of the induced electromotive force Ve in the Fleming right-hand rule generated in the stator winding 59 by the rotation of the rotor 58 having a permanent magnet is positive during the period when the output of the position detection means 60 is high. And is negative when the output of the position detection means 60 is low.
[0030]
  In the present embodiment, capacitors 61 and 62 are connected to the input side and the output side of the smoothing circuit 23, respectively, but these are both plastics having a capacitance of 0.1 micro F to 1 micro F. It is composed of a film capacitor and acts to remove the AC component of the on / off frequency components (the carrier frequency and the fundamental frequency due to the rotation of the flywheel) of the first switching element 35 and the second switching element 36. It has become.
[0031]
  In the present embodiment, the control circuit 41 first inputs signals from the input voltage detection means 50 and the output current detection means 53, the output of the input current detection means 51 is proportional to the value of the output current Iout, and the input voltage Vin. The power factor of the input of the smoothing circuit 23 is controlled by controlling on / off of the first switching element 35 so that the same full-wave rectified waveform is obtained, and by controlling the output voltage Vout to a constant value of approximately 200V. The power factor of the device viewed from the commercial power source 21 is close to 100%, and the loss in terms of power transmission and distribution can be kept as low as possible.
[0032]
  In addition, since the capacitors 61 and 62 used in this embodiment only need to remove only a high-frequency component much higher than the frequency of the commercial power supply 21, it is extremely in comparison with the conventional capacitor 10. Small, light, and inexpensive ones are sufficient.
[0033]
  FIG. 2 shows an operation waveform diagram when the smoothing circuit 23 of the first embodiment is operated under the conditions of power consumption 1 kW and the commercial power supply 21 at 100 V 50 Hz.
[0034]
  2A shows the input voltage Vin of the smoothing circuit 23 by a solid line, the output voltage Vac of the commercial power supply 21 by a broken line, and FIG. 3A shows the input current Iin of the smoothing circuit 23 by a solid line. The output current voltage Iac of 21 is indicated by a broken line.
[0035]
  FIG. 3C shows the input power Pin of the smoothing circuit 23 by a solid line and the output power Pout by a broken line, which are calculated by Pin = Vin × Iin and Pout = Vout × Iout, respectively.
[0036]
  3 (D) shows the output logic P of the position detection means 33, FIG. 3 (O) shows the drive waveform Q1 of the first switching element 35, and FIG. 3 (F) shows the drive waveform Q2 of the second switching element 36. ing.
[0037]
  Since the commercial power supply 21 has a peak value of Vin and Vac of 141 V, and the power of Example 1 is 1 kW, the peak value of Iin and Iac is 14.1 A, and Pin is centered on an average value of 1 kW. Therefore, the maximum of the instantaneous value is 2 kW and the minimum is zero.
[0038]
  Therefore, the smoothing circuit 23 stores the electric energy corresponding to the portion A in FIG. 3C as the kinetic energy of the flywheel 32, and conversely, the portion B stores the kinetic energy stored as electric energy. The action will be performed.
[0039]
  In addition, the energy of the part of A and B of FIG.3 (c) is calculated | required by an area, and all become 3.2 joules.
[0040]
  FIG. 3 (d) shows a waveform when rotating at a constant speed of 5000 revolutions per minute for the sake of simplicity. In this embodiment, since the electric machine 33 has 48 poles, the period of the P signal is shown. Is 500 microseconds, and both the high period and the low period are 250 microseconds.
[0041]
  However, in actuality, the rotation speed reaches about 5000 rotations per minute near t1 where the kinetic energy is maximum, but the above period is around t0 and t2 where the kinetic energy is minimum. It will be long.
[0042]
  As to the on / off driving method of each switching element, as shown in FIGS. 3A and 3F, the period A is a period during which the P signal is high, that is, the stator winding of the electric machine 33. The first switching element 35 and the second switching element 36 are turned on only during a period in which the induced electromotive force Ve generated on the line 59 is positive, and control is performed to turn off both when the P signal is low. Yes.
[0043]
  On the other hand, during the period B, the first switching element 35 and the second switching element 36 are turned on only when the P signal is low, and both are off when the P signal is high.
[0044]
  In any switching element, the P signal is not kept on for 250 microseconds during which the P signal is high or low, and the conduction ratio is controlled by PWM control at a carrier frequency of 30 kHz during that period. It has become.
[0045]
  For the control of the PWM conduction ratio, for the first switching element 35, the value of the input current Iin detected by the input current detecting means 51 is always set to the value of the input voltage Vin detected by the input voltage detecting means 55. By performing feedback control so as to be multiplied, an input current waveform having the same waveform as the input voltage waveform is obtained, and the power factor at the input of the smoothing circuit 23 or the power of the apparatus as viewed from the commercial power source 21 is obtained. The rate is extremely high, and thus it is possible to ensure good performance with the loss in transmission and distribution as much as possible.
[0046]
  In the present embodiment, the predetermined value multiplied by Vin is a value updated every 20 ms so as to be proportional to the value of the output current Iout detected by the output current detecting means 53.
[0047]
  In the present embodiment, the second switching element 36 feedback-controls the PWM conduction ratio so that the value of the output voltage Vout detected by the output voltage detection means 52 becomes a constant value of approximately 200V.
[0048]
  During the period A, when the first switching element 35 and the second switching element 36 are turned on in a state where Ve> 0, the current supplied to the stator winding 59 of the electric machine 33 and the rotor Since a force is generated between the 58 permanent magnets according to Fleming's left-hand rule, torque in the direction of accelerating the flywheel 32 is generated in the rotor 58, and a part of the input power Pin is converted into kinetic energy. The energy is stored.
[0049]
  During the period B, when the second switching element is turned on in a state of Ve <0, an operation similar to an operation generally called a boost chopper is performed by the action of the inductance of the stator winding 59, Power is supplied to the output through the diode 40.
[0050]
  Here, the input of the step-up chopper is the induced electromotive force Ve generated in the stator winding 59 when the first switching element 35 is completely turned off. Kinetic energy is extracted and converted into electric power.
[0051]
  In the present embodiment, the first switching element 35 is also PWM-controlled to control the input current Iin during the period B, so that the flywheel kinetic energy and the input power Pin are in the period B. The operation is performed so that the synthesized one is output.
[0052]
  As described above, the smoothing circuit 23 according to the first embodiment includes the flywheel 32 and the electric machine 33, and the difference between the input power input from the input terminals 30a and 30b and the output power output from the output terminals 31a and 31b. Can be stored and released as kinetic energy, so that the weight, volume, and price can be extremely suppressed.
[0053]
  Inventor's experiments and calculations show that the energy storage performance of flywheel is 25 joules per gram, 50 joules per cc, 15-20 joules per circle, and these values are similar to those of the aforementioned choke coils and electrolytic capacitors. Since the value is much larger than that of the same, the weight, volume, and price can be suppressed when the capacity is the same (wattage).
[0054]
  In the first embodiment, the pulsation of the voltage applied between the input terminals 30a and 30b of the smoothing circuit 23 (particularly by supplying AC electric power from the commercial power supply 21 and outputting a DC voltage). The ripple) frequency can be fixed to twice the output frequency of the commercial power source 21, the upper limit design value of the instantaneous torque required for the electric machine 33 is clarified, and the necessary and sufficient operation as the smoothing circuit 23 is performed. Will be able to.
[0055]
  Further, the output voltage Vout can be varied to some extent. For example, when a motor driving inverter is connected as the load 24, the motor speed can be varied within a certain range. Thus, the operation speed range can be expanded.
[0056]
  (Example 2)
  FIG. 3 shows a circuit diagram of a main part of the smoothing circuit according to the second embodiment.
[0057]
  In FIG. 3, the smoothing circuit 70 has input terminals 71 a and 71 b and output terminals 72 a and 72 b, and includes a first switching element 73, a second switching element 74, and diodes 75, 76, 77, 78. It has become what.
[0058]
  (Example 3)
  FIG. 4 is a circuit diagram showing the principal part of the smoothing circuit according to the third embodiment.
[0059]
  In FIG. 4, the smoothing circuit 80 has input terminals 81 a and 81 b and output terminals 82 a and 82 b, and includes a first switching element 83, a second switching element 84, and diodes 85, 86, 87, 88. In this embodiment, the switching elements 83 and 84 are connected to the input terminal 81a and the output terminal 82b via the diodes 85 and 86, respectively. However, this is insufficient for each switching element in terms of withstand voltage in the reverse direction. The diodes 85 and 86 are connected in series to the collector terminal or emitter terminal of the IGBT for the purpose of sufficiently ensuring the reverse breakdown voltage.
[0060]
  (Example 4)
  FIG. 5 is a circuit diagram showing the principal part of the smoothing circuit according to the fourth embodiment.
[0061]
  In FIG. 5, the smoothing circuit 90 has input terminals 91a and 91b and output terminals 92a and 92b, and includes a first switching element 93, a second switching element 94, and diodes 95, 96, 97, and 98. It has become what.
[0062]
  In each of the second embodiment, the third embodiment, and the fourth embodiment, a smoothing circuit is configured by using two switching elements, and when the kinetic energy is stored in the flywheel 32, the first switching elements 73, 83, 93 and the second switching elements 74, 84, 94 are turned on, so that power is supplied between the input terminals via the first switching element, the second switching element, and the stator winding of the electric machine 33. The
[0063]
  The release of kinetic energy is controlled by the conduction ratio of the second switching element.
[0064]
  As a result, in the second to fourth embodiments, the smoothing operation is performed by the same operation.
[0065]
  In addition to the circuit diagrams shown in these embodiments, at least two switching elements are provided, one terminal of the first switching element is connected to the input terminal, and the second switching element Other circuit configurations may be used as long as one terminal is connected to the output terminal.
[0066]
  In each embodiment, only one stator winding 59 is used and the simplest configuration is a single-phase coil. Therefore, the number of parts is small, but in the case of a device with high power. May be an electric machine having a plurality of stator windings, such as one having a three-phase stator winding.
[0067]
  In addition, the electric machine is not particularly limited to those using permanent magnets. For example, the inductance of the stator winding changes according to the rotation of the rotor, which is generally called a reluctance motor. In this case, for example, the position detecting means detects the period in which the inductance increases and the period in which the inductance decreases with respect to the rotation of the rotor, and supplies current to the stator winding during the increasing period. By acting as a motor, the electric energy is converted into kinetic energy and stored in the flywheel. Conversely, during the period when the inductance decreases, the current is supplied to the stator winding to act as a generator and the flywheel Kinetic energy can be converted into electrical energy and output.
[0068]
  Furthermore, various electric machines such as induction machines (induction motors), hysteresis motors, commutator motors, and magnet motors can be used.
[0069]
  In each embodiment, the choke coil used in the prior art is completely eliminated, so that a choke coil with less accumulated energy with respect to weight, volume, and cost is unnecessary as compared with an electrolytic capacitor. The effect by this has become very large.
[0070]
  However, for example, in order to remove a high-frequency component such as several times the frequency of the commercial power supply 21, a configuration using a choke coil may be used. The specification, that is, the energy storage amount is sufficiently small compared with the conventional technology, and the merit in at least one of the weight, volume, and cost of the apparatus still occurs.
[0071]
  (Example 5)
  FIG. 6 illustrates a configuration diagram of a smoothing circuit flywheel and an electric machine according to the fifth embodiment.
[0072]
  In FIG. 6, each of the flywheels 100 and 101 is formed of an iron plate having a diameter of 2 inches and a thickness of 3 mm, and the electric machines 102 and 103 are connected to each of them.
[0073]
  Here, the flywheels 100 and 101 have exactly the same specifications, and the electric machines 102 and 103 have exactly the same specifications, but the rotational direction during operation is indicated by arrows in FIG. As shown in the reverse direction.
[0074]
  Although the flywheels 100 and 101 are accelerated or decelerated at the same time, the rotational torques are opposite to each other. Therefore, the reaction torque generated during acceleration and deceleration is the same motion with one flywheel. Compared to the case of storing energy, each of them will be half and cancel in the opposite direction. For example, when a rectifier circuit is soldered on a printed circuit board, for example, A stress such as a shock applied to the soldered portion can be made extremely small, and a highly reliable device with less noise and vibration can be realized.
[0075]
  In addition, when realized with one flywheel, if the rigidity of the portion supporting the smoothing circuit is low, the instantaneous torque may be insufficient and sufficient performance may not be exhibited. By configuring the electric machines 102 and 103 with members having high rigidity in the rotation direction, almost the same excellent performance can be ensured regardless of the rigidity of the support of the apparatus, and vibration and the like are further reduced. Therefore, even if the outside of the smoothing circuit is supported by rubber or cotton, there is an effect that the expected performance can be secured.
[0076]
  Further, since the rotating flywheels 100 and 101 have moments of inertia having opposite directions, the entire smoothing circuit can cancel the gyro effect, for example, as a portable device. Even when used in equipment where the orientation of the device changes frequently, there is no stress on the support part, and there is no unnatural force when handling by humans. There is also an effect that an excellent device can be obtained.
[0077]
【The invention's effect】
  As described above, the invention according to the first aspect of the present invention particularly includes an input terminal to which AC electric power is supplied from a commercial power supply, an output terminal, a flywheel, and an electric connected to the flywheel. A ripple circuit having a frequency that is twice the output frequency of the commercial power supply from the input terminal, the inverter circuit having a switching element and connected to the electric machine, and the control circuit having the switching element and turning on and off. The flywheel receives power includingWithin the commercial power cycle,Accelerated by the electric machine in a state where the instantaneous power input from the input terminal is greater than the instantaneous power output from the output terminal.PeriodThe electric machine is decelerated by the electric machine in a state where the instantaneous power input from the input terminal is smaller than the instantaneous power output from the output terminal.Have a period,Output DC voltage from the output terminalBy, DC power supply with high input power factor by increasing the stored energy per unit weight, unit volume and unit cost, reducing circuit weight, volume and cost with the same capacity (watt), and by switching on / off the switching element The device can be realized, and the DC power supply can be smoothed with a configuration that is smaller, lighter, and lower in cost than a capacitor or a reactor (choke coil?).
[0078]
  Further, according to claim 2, the current waveform supplied from the input terminal of the DC power supply device according to claim 1 is made substantially the same as the voltage waveform supplied to the input terminal, so that the weight, volume, and cost are also reduced. To reduce the input power and keep the output voltage more stable.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a smoothing circuit and a DC power supply device according to Embodiment 1 of the present invention.
FIG. 2 is an operation waveform diagram of the smoothing circuit and the DC power supply device.
FIG. 3 is a circuit diagram of a smoothing circuit according to a second embodiment of the present invention.
FIG. 4 is a circuit diagram of a smoothing circuit according to a third embodiment of the present invention.
FIG. 5 is a circuit diagram of a smoothing circuit according to a fourth embodiment of the present invention.
FIG. 6 is a configuration diagram of a flywheel and an electric machine according to a fifth embodiment of the present invention.
FIG. 7 is a circuit diagram of a conventional DC power supply device.
[Explanation of symbols]
  30a, 30b, 71a, 71b, 81a, 81b, 91a, 91b Input terminal
  31a, 31b, 72a, 72b, 82a, 82b, 92a, 92b Output terminal
  32 Flywheel
  33 Electric machine
  35, 73, 83, 93 First switching element
  36, 74, 84, 94 Second switching element
  34 Inverter circuit
  41 Control circuit
  50 Input voltage detection means
  51 Input current detection means
  52 Output voltage detection means
  53 Output current detection means
  21 Commercial power supply
  22 Full-wave rectifier circuit
  23, 70, 80, 90 Smoothing circuit

Claims (2)

An input terminal to which AC electric power is supplied from a commercial power source, an output terminal, a flywheel, an electric machine connected to the flywheel, an inverter circuit having a switching element and connected to the electric machine, A control circuit that has the switching element and has an on / off control, receives electric power including a ripple having a frequency twice the output frequency of the commercial power source from the input terminal, and the flywheel is within a cycle of the commercial power source, and duration that will be accelerated by the electrical machine while it is larger than the instantaneous power instantaneous power is output from the output terminal to be inputted from the input terminal, the instantaneous power inputted from the input terminal from the output terminal A DC power supply device that has a period of being decelerated by the electric machine in a state that is smaller than the instantaneous power that is output , and that outputs a DC voltage from the output terminal.   2. The DC power supply device according to claim 1, wherein the current waveform supplied from the input terminal is substantially the same as the voltage waveform supplied to the input terminal.

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