JP3488684B2 - Rectifier circuit and compressor drive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifier circuit for converting alternating current into direct current, and a compressor drive device using the rectifier circuit.

[0002]

2. Description of the Related Art FIG. 50 is a circuit block diagram showing a configuration of a conventional rectifier circuit disclosed in Japanese Patent Laid-Open No. 1-259758. This rectifier circuit consists of capacitors 11, 4
Diodes 12, 13, 14, 15, 2 npn
It includes transistors 16 and 17 and a reactor 18.

The cathode of the first diode 12 is connected to the collector of the first npn transistor 16.
The anode of the first diode 12 is connected to the emitter of the first npn transistor 16. Such a connection relationship between a transistor and a diode is called an anti-parallel connection. That is, the first diode 12 is anti-parallel connected to the first npn transistor 16. Similarly, the second
The diode 13 is connected to the second npn transistor 17 in antiparallel. Two npn transistors 16,
17 is connected in series. The connection point between the emitter of the first npn transistor 16 and the collector of the second npn transistor 17 is connected to one end of the reactor 18. The other end of the reactor 18 is connected to one output terminal of the AC power supply 2.

The anode of the third diode 14 is connected to the cathode of the fourth diode 15, and the connection point is connected to the other output terminal of the AC power supply 2. That is, an AC voltage is applied between the connection point of the third and fourth diodes 14 and 15 connected in series and the connection point of the first and second npn transistors 16 and 17 connected in series. To be done. The cathode of the third diode 14 and the collector of the first npn transistor 16 are commonly connected to one electrode of the capacitor 11 and one end of the load. The anode of the fourth diode 15 and the emitter of the second npn transistor 17 are
The other electrode of the capacitor 11 and the other end of the load are commonly connected. First and second npn transistors 16,
Each base of 17 is connected to a control circuit (not shown). The control circuit operates the first npn transistor 16 and the second npn transistor 17 every half cycle of the AC power supply 2. That is, the first n
The pn transistor 16 operates at a high frequency for a half period of one cycle of the AC power supply 2, and the second npn transistor 17 operates at a high frequency for the remaining half period.

Next, the operation of the rectifier circuit shown in FIG. 50 will be described. When the second npn transistor 17 is in the ON state, the AC power supply 2 operates in the reactor 18, the second np
It is short-circuited via the n-transistor 17 and the fourth diode 15. Therefore, the AC power supply 2-reactor 1
A short-circuit current flows through a closed circuit composed of 8-the second npn transistor 17-the fourth diode 15-the AC power supply 2.

When the second npn transistor 17 is turned off, a current flows through a circuit composed of the AC power supply 2-reactor 18-first diode 12-capacitor 11 (or load 3) -fourth diode 15-AC power supply 2. Flows. The capacitor 11 is charged by the current. Therefore, the charging voltage of the capacitor 11 and the reactor 18
The current flowing from the AC power supply 2 to the rectifier circuit decreases in accordance with the inductance value of.

When the first npn transistor 16 is on, the AC power supply 2 is short-circuited via the third diode 14, the first npn transistor 16 and the reactor 18. Therefore, a short circuit current flows in a closed circuit composed of the AC power supply 2-third diode 14, the first npn transistor 16-reactor 18 and the AC power supply 2. When the first npn transistor 16 is turned off, the AC power supply 2-third diode 14-capacitor 1
A current flows in a circuit composed of 1 (or load 3) -second diode 13-reactor 18-AC power supply 2. The capacitor 11 is charged by the current. Therefore, the current flowing from the AC power supply 2 to the rectifier circuit decreases according to the charging voltage of the capacitor 11 and the inductance value of the reactor 18.

Further, Japanese Unexamined Patent Publication No. 10-174442 discloses a rectifying circuit having the structure shown in FIG. This rectifier circuit includes three reactors 101, 102, 10
Three-phase diode full-wave rectification circuit 104 consisting of three or six diodes, two capacitors 10 having the same capacitance
5, 106, three bidirectional switches 107, 108, 1
09 and the control circuit 110. In FIG. 51, reference numeral 111 is a three-phase AC power supply, and reference numeral 112
Is the load. Reactors 101, 102, 103 are
One is connected between each input terminal of the three-phase diode full-wave rectifier circuit 104 and each phase output terminal of the three-phase AC power supply 111. The capacitors 105 and 106 are connected in series between the output terminals of the three-phase diode full-wave rectifier circuit 104. The bidirectional switches 107, 108, and 109 are connected to the input terminals of the three-phase diode full-wave rectifier circuit 104 and the capacitor 10 respectively.
5 and the connection point of the capacitor 106 are connected one by one. The control circuit 110 detects the phase voltage of the three-phase AC power supply 111, and based on the detected phase voltage, the three bidirectional switches 107, 108, 10 at predetermined timing.
A control signal for turning on 9 is generated. By the control signal, each bidirectional switch 107, 108, 109
Are controlled to switch once every half cycle of the power supply voltage.

Conventionally, as a technique for suppressing harmonics in a three-phase power supply, a full-bridge type high power factor converter 115 having the configuration shown in FIG. 52, an active filter 116 having the configuration shown in FIG. 53, etc. are known.

[0010]

In the conventional rectifier circuit shown in FIG. 50, the current flowing from the AC power source 2 to the rectifier circuit is changed by turning on / off the transistor 16 or the transistor 17 at a high frequency during a half cycle of the power supply voltage. Have control. Therefore, there is an advantage that the phase of the current matches the voltage phase of the AC power supply 2, the power factor is improved, and the harmonic current is reduced. However, in this rectifier circuit, since the transistor is turned on / off at high frequency, noise and heat are generated. The generation of noise causes malfunction of peripheral devices. In addition, the heat generation may destroy the transistor of the rectifier circuit. Therefore, noise countermeasures and heat countermeasures are required, which causes a problem that the development period is extended and the cost is increased.

Further, in the conventional rectifier circuit shown in FIG. 51,
By switching the bidirectional switches 107, 108, and 109 only once in each half cycle of the power supply voltage, the waveform of the input voltage becomes a voltage waveform of 12 steps.
Therefore, the waveform of the input current becomes a substantially sinusoidal waveform, the power factor is improved, and a higher harmonic suppression effect than the conventional three-phase 12-pulse rectifier circuit system is obtained. However, in this rectifier circuit, the reactor 10 is provided once every half cycle of the power supply voltage.
Since a current due to switching flows through the coils 1, 102, 103, the magnetic flux of the reactors 101, 102, 103 changes rapidly, and the windings and the iron core vibrate to generate sound.
Since this sound is a sound in a frequency band that is an integral multiple of a power source half cycle and a sound having a natural frequency of the reactors 101, 102, and 103, its noise level is outstanding, and it is a very uncomfortable and uncomfortable sound. .

Further, in the conventional rectifier circuit shown in FIG. 51, a short circuit current flows due to the bidirectional switches 107, 108 and 109, so that the current changes according to the phase of the AC power supply 111. Therefore, in this rectifier circuit, the amount of current increases as the power supply voltage approaches the peak, and the switch 10
Since there is a risk of damaging 7, 108 and 109, it is necessary to add a current protection circuit for preventing damage, which causes a disadvantage of increasing cost. Alternatively, it is conceivable to control the current amount by feedback controlling the current without providing a current protection circuit, but in that case, it is simple and open-loop switching is performed once every half cycle of the power supply voltage. The possible feature may be lost.

The present invention has been made to solve the above problems, and provides a rectifier circuit capable of improving the power factor and reducing the harmonic current as well as reducing the generation of noise and heat. With the goal. Another object of the present invention is to obtain a high-power compressor drive device using a rectifier circuit that generates less noise and heat. Also,
INDUSTRIAL APPLICABILITY The present invention reduces the reactor noise generated by the switching current by suppressing the abrupt change of the current flowing in the reactor, and enables simple and open-loop control without providing a current protection circuit. It is an object of the present invention to provide a rectifier circuit having the above structure and a compressor drive device using the rectifier circuit.

[0014]

In order to solve the problem] was to achieve the above purpose
Therefore, the rectifier circuit according to the present invention uses the AC voltage of the AC power supply.
Rectifying means, which is rectified and connected to the reactor, and a switch
A switching means and a capacitor.
When the trigger means is closed, the reactor and the capacitor
The alternating current power supply in which the switching means is connected in series
Power supply short-circuiting means for short-circuiting
The power supply short-circuit current flowing through the reactor,
The change width between the negative current change rate and the negative current change rate is small
Charge the capacitor and store the
The accumulated charge is transferred to the switching means or the rectifier.
Discharge to the output side of the rectifying means via any of the means
It is characterized by doing. Charging of capacitors according to the present invention
Noise generated from the reactor is reduced by controlling the electric current.
Power factor improvement by controlling the input current and
And the effect of suppressing harmonics is obtained. In addition, zero current
It can realize switching and reduce switching noise.
Thus reducing noise and reactor noise
Cost reduction and small size
Can be realized.

A rectifying circuit according to the present invention is defined in claim 1.
The resonance frequency of the reactor and the capacitor
The number is greater than the power supply frequency of the AC power supply.
Characterize.

The rectifying circuit according to the present invention is defined in claim 1.
The power supply short-circuit means are connected in series and
Alternating every half cycle of the AC voltage according to the polarity of the flow voltage
And the first switching element that switches from the off state to the on state
A switching means including a second switching element, and the serial connection
The midpoint of the connected first and second switching elements and the rectifying means
The capacitor connected between one of the input terminals,
The switching means is provided with respect to the rectifying means.
And are connected in parallel.

The rectifying circuit according to the present invention is defined in claim 1.
At this time, the power supply short-circuit means responds to the polarity of the AC voltage.
Then, the AC voltage is alternately turned off every half cycle of the AC voltage.
The first switching element and the second switching element that switch to the ON state
Switching means and discharge and charge when the power supply is short-circuited.
To switch the electric power alternately to configure the first capacitor
A capacitor and a second capacitor are provided and connected in series.
The connected first capacitor and first switching element are
One input end of the rectifying means and one output end of the rectifying means
A second capacitor and a second capacitor connected in series between
The switching element 2 is connected to the other input end of the rectifying means and the rectifier.
Characterized in that it is connected between one output end of the means
And

The rectifying circuit according to the present invention is defined in claim 1.
The power supply short-circuit means short-circuits the AC power supply.
At this time, the reactor is connected to the reactor through the rectifying means.
A capacitor and the switching means are connected in series,
In addition, the reactor is connected to the reactor without using a rectifying means.
Sensor and the switching means are connected in series,
It is characterized by having some connection state.

The rectifier circuit according to the present invention is characterized in that it has the structure of claim 3.
Or 4, the first switching element and the second switching element
The switching means composed of
Alternating ON state every half cycle of the AC voltage according to the
It is characterized by comprising a control circuit for switching to.

A rectifying circuit according to the present invention is defined in claim 6.
Detects the polarity of the AC voltage and the zero-cross point
And a polarity detection unit that controls the polarity of the polarity.
Zero crossing point of the AC voltage detected by the property detecting section
From, the discharge of the capacitor of the power supply short-circuiting means ends.
The timing is delayed by any time between
Switching composed of a first switching element and a second switching element
The means is alternately turned on.

The rectifying circuit according to the present invention is defined by claim 1.
4 any of the above, connected in series, and
A pair of smoothing capacitors connected to the output side of the rectifying means
And between the pair of smoothing capacitors and the rectifying means
A reverse flow of charge from the pair of smoothing capacitors provided
And a backflow prevention diode for preventing
A smoothing capacitor is connected in parallel to the rectifying means,
The middle point of connection of the pair of smoothing capacitors and the rectifying means
Of the relay connected between the input terminal of the
And a relay switching unit for controlling ON / OFF.
And are characterized.

A rectifying circuit according to the present invention is defined in claim 8.
In the above, the relay switching unit is a voltage of the AC voltage.
Characterized by switching control of the relay according to the value
And

A rectifying circuit according to the present invention is defined in claim 8.
The load voltage to which the output voltage of the rectifier circuit is supplied.
It is equipped with a load detection unit that detects the load and switches the relay.
The load section detects the negative load of the load detected by the load detection section.
A special feature is that the relay switching control is performed according to the load.
To collect.

The rectifying circuit according to the present invention is characterized in that
Or 2, one of the connection sides of the power supply short-circuit means is
Connected to the input side of the rectifying means, of the power supply short circuit means
The other connecting side is connected to the output side of the rectifying means,
The switching means forming the power supply short-circuit means is
Switching once every half cycle of AC voltage
Characterize.

The rectifying circuit according to the present invention is defined in claim 1.
The switching means or the rectifying means.
Instead of going through the gap, one end of the capacitor and the front
The output side of the rectifying means is connected to the output side of the rectifying means.
It is characterized by discharging to.

The rectifier circuit according to the present invention is an AC power supply.
Rectifying means for rectifying AC voltage and connected to reactor
And a switching means and a capacitor,
When the switching means is closed, the reactor and the
The capacitor and the switching means are connected in series
A power supply short-circuit means for short-circuiting the AC power supply, and the power supply short-circuit
A capacitor connected in parallel to said capacitor forming a means
Capacitor parallel switching means, and the capacitor
By connecting and disconnecting the parallel switching means,
AC by said switching means forming a source short circuit means
When the power supply is short-circuited, the power supply short-circuit means is formed.
Power supply short circuit that flows to the reactor through a capacitor
The change width between the positive current change rate and the negative current change rate of the current is small
Charge the capacitor so that it is low, or
By the switching means forming the power supply short-circuit means
When the AC power supply is short-circuited, the power supply short-circuit means is formed.
2 in the half cycle of the AC voltage without passing through the capacitor
Power supply that flows to the reactor after switching more than once
Smooth the short-circuit current, either of the rectifying means
Switching according to the load amount of the load connected between the output terminals
It is characterized by

The rectifying circuit according to the present invention is characterized in that
12 or 13, the capacitor has a capacitance
Is formed so that it can be switched.

The rectifying circuit according to the present invention is characterized in that
12, 13, or 14, the power supply short circuit means
Form a time longer than the charging time of the capacitor, before
Turning on the switching means forming the power supply short-circuit means
It is characterized by keeping the state.

The rectifying circuit according to the present invention is characterized in that
12, 13, or 14, each half of the alternating voltage
A time delay from the zero-cross point in the cycle
Switching to form the power supply short circuit means
It is characterized in that the ON operation of the means is started.

A compression drive according to the invention is claimed
A rectifying circuit according to item 1, 12, 13, or 14 is provided.
An inverter to which the output voltage of the rectifier circuit is applied,
And a motor driven by the inverter
And a compressor.

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

Further, the rectifier circuit according to the present invention includes a reactor, a rectifier unit for rectifying an AC voltage applied via the reactor, and a pair of serially connected output terminals of the rectifier unit. A capacitor, a first switching means connected to the input terminal of the rectifying means,
Between the resonance capacitor connected between the first switching means and the connection point between the pair of capacitors, the second switching means connected in parallel with the resonance capacitor, and the output terminal of the rectifying means. Depending on the load amount of the connected load, the second switching means is turned off to switch the first switching means once every half cycle of the AC voltage, or the second switching means is switched.
Control means for turning on the switching means of 2) and switching the first switching means twice or more in a half cycle of the AC voltage.

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a rectifier circuit and a compressor drive device according to the present invention will be described below in detail with reference to the drawings.

Embodiment 1. FIG. 1 is a diagram showing the principle of the rectifier circuit according to the first embodiment of the present invention. This rectifying circuit includes a rectifying unit 4, a power supply short-circuiting unit 5, a charge discharging unit 6, a reactor 18, and a smoothing capacitor 11. The rectifying means 4 rectifies the AC voltage applied by the AC power supply 2 via the reactor 18. The output voltage of the rectifying means 4 is smoothed by the smoothing capacitor 11 and supplied to the load 3. The power supply short-circuit means 5 includes a capacitor (not shown). The power supply short-circuit means 5 uses the charging and discharging of the capacitor to control the current flowing through the rectifier circuit with an AC voltage. The charge discharging means 6 is the power supply short-circuit means 5.
The electric charge accumulated in the capacitor is discharged to the output side of the rectifying means 4 after the polarity of the alternating voltage changes.

FIG. 2 is a circuit block diagram showing the structure of the rectifier circuit according to the first embodiment of the present invention. This rectifier circuit has eight diodes 41, 42, 43, 44, 6
1, 62, 63, 64, three capacitors 51, 65,
66, transistors 52 and 53 which are two switching elements,
The polarity detector 71, the control circuit 72, the reactor 18, and the smoothing capacitor 11 are provided.

First, the connection relationship of each component will be described. The cathode of the diode 41 is the cathode of the diode 43, the collector of the transistor 52, the diode 6
1 and the anode of the diode 63. The anode of the diode 41 is the diode 42
Connected to the cathode. The anode of the diode 43 is connected to the cathode of the diode 44. The anode of the diode 42 is the anode of the diode 44,
It is connected to the emitter of the transistor 53, the anode of the diode 62 and the cathode of the diode 64.

Anode of diode 41 and diode 4
The connection point between the second cathode and the second cathode is connected to one end of the reactor 18. The other end of the reactor 18 is connected to one output end of the AC power supply 2. The other output end of the AC power supply 2 is
It is connected to the connection point between the anode of the diode 43 and the cathode of the diode 44 via the polarity detection unit 71. The polarity detector 71 is connected to the control circuit 72. The control circuit 72 is connected to the base of the transistor 52 and the base of the transistor 53, respectively. The emitter of the transistor 52 is connected to the collector of the transistor 53, the anode of the diode 61 and the cathode of the diode 62.

The capacitor 51 is connected between the connection point between the anode of the diode 41 and the cathode of the diode 42 and the connection point between the emitter of the transistor 52 and the collector of the transistor 53. The cathode of the diode 63 is connected to the positive electrode of the capacitor 65 and the positive electrode of the smoothing capacitor 11. The positive electrode of the capacitor 65 and the positive electrode of the smoothing capacitor 11 are commonly connected to the positive input terminal of the load 3.
The negative electrode of the capacitor 65 is the positive electrode of the capacitor 66, and the anode of the diode 43 and the diode 4
4 is connected to the connection point with the cathode. The negative electrode of the capacitor 66 and the negative electrode of the smoothing capacitor 11 are commonly connected to the anode of the diode 64. The negative electrode of the capacitor 66 and the negative electrode of the smoothing capacitor 11 are connected to the negative input terminal of the load 3.

Next, the function of each component will be described. The polarity detector 71 detects the polarity of the AC power supply 2 and the zero-cross point. The control circuit 72, based on the detection signal sent from the polarity detection unit 71, the transistors 52,
The on / off operation of 53 is controlled.

Specifically, the transistor 52 is turned on only when the output end of the AC power supply 2 on the reactor 18 side has a negative polarity (hereinafter, this polarity is a negative polarity).
On the other hand, the transistor 53 is the reactor 1 of the AC power supply 2.
Only when the output end on the 8th side has a positive polarity (hereinafter, this polarity is a positive polarity) is the ON state. The capacitor 65 is
This is a voltage doubler capacitor for smoothing the positive voltage of the AC power supply 2. The capacitor 66 is a voltage doubler capacitor for smoothing the negative voltage of the AC power supply 2. The diode 63 prevents current from flowing backward from the capacitor 65 when the transistor 52 is turned on. Similarly, diode 64 prevents current from flowing back into capacitor 66 when transistor 53 turns on.

Four diodes 41, 42, 43, 44
Has a function as a rectifying means 4 (see FIG. 1).
Also, a capacitor 51, two transistors 52, 5
3, the polarity detection unit 71 and the control circuit 72 have a function as the power supply short-circuit means 5 (see FIG. 1). Also, the diodes 61, 62, 63, 64, the voltage doubler capacitor 6
5, 66, the polarity detection unit 71, and the control circuit 72 have a function as the charge discharging unit 6 (see FIG. 1).

Next, the operation of the rectifier circuit shown in FIG. 2 will be described. 3 to 8 are diagrams for explaining current paths in the circuit shown in FIG. In these figures, the path indicated by the dashed arrow is the path through which the current flows. First, the case where the output end of the AC power supply 2 on the reactor 18 side has a positive polarity, that is, the positive polarity is described. When the transistor 53 is turned on when the AC power source 2 has a positive polarity, a current flows from the AC power source 2 through the reactor 18, the capacitor 51, the transistor 53, and the diode 44 in this order, and finally, as shown in FIG. AC power supply 2
Return to.

That is, the current path at this time is AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2. The AC power supply 2 is short-circuited by this current path. Therefore, a steep current flows as an input current from the AC power supply 2 to the rectifier circuit. When this current flows, the capacitor 51
Is charged.

When the charging of the capacitor 51 is completed, no more current flows through the capacitor 51. That is, no current automatically flows in the current path of AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2. Therefore, it is not necessary to control the off timing of the transistor 53.
Here, the control circuit 72 (see FIG. 2) turns the transistor 53 from the ON state to the OFF state after the current stops flowing in the current path of the AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2. Control to switch to. This causes the transistor 53 to operate with zero current switching, which switches off when the current is zero. Therefore, the noise when the transistor 53 is switched off by the control circuit 72 is zero. That is, no noise is generated.

When the load amount of the load 3 is light, the time until the charging of the capacitor 51 is completed, that is, the AC power supply 2-reactor 18-capacitor 51-transistor 5
3-The diode 44-the time during which the short-circuit current flows in the current path of the AC power supply 2 becomes long, and the output voltage across the smoothing capacitor 11 may become too high. In that case, the control circuit 72 may switch the transistor 53 off before the charging of the capacitor 51 is completed, thereby forcibly interrupting the short-circuit current. In that case, the operation of the transistor 53 does not result in zero current switching, but there is an advantage that the failure of the load 3 due to the application of the overvoltage to the load 3 can be avoided and the reliability of the rectifier circuit can be improved.

The reactor 18 has the property of trying to keep the current flowing. Therefore, when the short-circuit current does not flow in the current path of the AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2, instead of the AC power supply 2, the reactor 18, as shown in FIG. A current flows so as to return to the AC power supply 2 via the diode 41, the diode 63, and the capacitor 65 in order. The capacitor 65 is charged by the current flowing through the path of this AC power supply 2-reactor 18-diode 41-diode 63-capacitor 65-AC power supply 2. That is, when the charging of the capacitor 51 is completed and the diode 41 is further turned on, the rectifier circuit of the first embodiment operates as a normal half-wave rectifier circuit. Therefore, the voltage doubler capacitor 65 and the smoothing capacitor 11 are charged.

When the charging of the voltage doubling capacitor 65 and the smoothing capacitor 11 is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed. Here, the control circuit 72 (see FIG. 2) controls to switch the transistor 52 from the off state to the on state after the timing of the zero cross at which the polarity of the AC power supply 2 is inverted. That is, even if the polarity of the AC power supply 2 is reversed from the positive polarity to the negative polarity, the transistor 52 does not turn on immediately.

Therefore, the capacitor 51 starts to discharge. The discharge current is, as shown in FIG. 5, from the AC power supply 2 to the capacitor 66, the diode 64, the diode 62,
It flows through the condenser 51 and the reactor 18 in order, and finally returns to the AC power supply 2. That is, the current path at this time is the AC power supply 2-capacitor 66-diode 64-diode 62-capacitor 51-reactor 1
8-The AC power supply 2 is used. Therefore, the transistor 52
Even if is not turned on, the input current flows from the AC power supply 2 to the rectifier circuit by the discharge current of the capacitor 51. That is, since the input current can be passed through the rectifier circuit without operating the transistor 52, the power factor is improved. Further, since there is no operation loss caused by the operation of the transistor 52, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on timing of the transistor 52 according to the load 3, the rectifier circuit can be controlled to the maximum power factor.

The input current flowing in the rectifier circuit due to the discharge of the capacitor 51 changes with the amount of discharge of the charge charged in the capacitor 51. The input current stops flowing when all the charges stored in the capacitor 51 are exhausted, but before that, the control circuit 72 (see FIG. 2) controls the transistor 52 to turn on. When the transistor 52 is turned on, a current flows from the AC power supply 2 through the diode 43, the transistor 52, the capacitor 51, and the reactor 18 in this order, and finally returns to the AC power supply 2, as shown in FIG. That is, the current path at this time is the AC power supply 2-diode 43-transistor 52-capacitor 5
1-Reactor 18-AC power supply 2.

Since the AC power supply 2 is short-circuited by this current path, a steep current flows as an input current from the AC power supply 2 to the rectifier circuit. This current causes the capacitor 5
1 is charged again. When the charging of the capacitor 51 is completed, the AC power supply 2-diode 43-transistor 52-
No current automatically flows in the current path of the capacitor 51-reactor 18-AC power supply 2. Therefore, it is not necessary to control the off timing of the transistor 52. AC power supply 2-Diode 43-Transistor 52-
When the short-circuit current stops flowing in the current path of the capacitor 51-reactor 18-AC power supply 2, the control circuit 72 (see FIG. 2) switches the transistor 52 from the on state to the off state. Thereby, the transistor 52 will operate with zero current switching. Therefore, no noise is generated when the transistor 52 is switched off by the control circuit 72.

When the load of the load 3 is light, the transistor 52 is turned off before the capacitor 51 is completely charged, as in the case of the transistor 53.
The short circuit current may be forcibly cut off. In that case as well, like the transistor 53, the operation of the transistor 52 does not result in zero current switching, but there is an advantage that the rectifier circuit can easily respond to changes in the load amount of the load 3.

AC power supply 2-diode 43-transistor 52-capacitor 51-reactor 18-AC power supply 2
When the short-circuit current stops flowing in the current path of, the AC power supply 2 causes the capacitor 66, the diode 64, and the
A current flows so as to return to the AC power supply 2 via the diode 42 and the reactor 18 in order. This AC power supply 2-
The capacitor 66 is charged by the current flowing through the path of the capacitor 66-diode 64-diode 42-reactor 18-AC power supply 2. That is, when charging of the capacitor 51 is completed and the diode 42 is turned on,
The rectifier circuit of the first embodiment operates as a normal half-wave rectifier circuit. Therefore, the voltage doubler capacitor 66
And the smoothing capacitor 11 is charged.

When the charging of the voltage doubling capacitor 66 and the smoothing capacitor 11 is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed to the positive polarity. The control circuit 72 (see FIG. 2) does not immediately turn on the transistor 53 at the zero-cross timing of the AC power supply 2. That is, the transistor 53
Is switched from the OFF state to the ON state by the control circuit 72 with a delay from the zero-cross timing of the AC power supply 2. Therefore, after the polarity is inverted, the capacitor 51 is discharged until the transistor 53 is turned on. As shown in FIG. 8, the discharge current flows from the AC power supply 2 through the reactor 18, the capacitor 51, the diode 61, the diode 63, and the capacitor 65 sequentially, and finally returns to the AC power supply 2. That is, a current path of AC power supply 2-reactor 18-capacitor 51-diode 61-diode 63-capacitor 65-AC power supply 2 is formed.

Therefore, even if the transistor 53 is not turned on, the AC power supply 2 is generated by the discharge current of the capacitor 51.
Input current flows from the rectifier circuit. That is, since the input current can be passed through the rectifier circuit without operating the transistor 53, the power factor is improved. Also, the transistor 5
Since there is no operation loss caused by the operation of No. 3, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on timing of the transistor 53 according to the load 3, the rectifier circuit can be controlled to the maximum power factor. The control circuit 72 (see FIG. 2) turns on the transistor 53 before all the charge stored in the capacitor 51 is discharged and the input current stops flowing. As a result, the state shown in FIG. 3 is restored, and the AC power supply 2-reactor 18-capacitor 51
-Transistor 53-Diode 44-Charging current for the capacitor 51 flows through the path of the AC power supply 2. Embodiment 1
The rectifier circuit repeats the above operation.

FIG. 9 is a waveform diagram showing the input current of the rectifier circuit of the first embodiment. By controlling and operating the rectifier circuit as described above, an input current as shown in FIG. 9 is obtained. The drive signal for the transistor 53 is the power supply 1
One pulse per cycle is emitted when the AC power supply 2 has a positive polarity. The drive signal of the transistor 52 is one pulse per one cycle of the power supply, and is generated when the AC power supply 2 has a negative polarity.

Transistor 52 or transistor 53
The drive signal of 1 is controlled only by the timing of the rising edge for turning on the transistor 52 or the transistor 53, respectively. The transistor 52 or the transistor 53 may be turned off at any timing before the charging current to the voltage doubler capacitors 65 and 66 and the smoothing capacitor 11 stops flowing and the input current to the rectifying circuit becomes zero. That is, the transistor 5
2 or the timing of the falling edge of the drive signal of the transistor 53 does not require fine control.

FIG. 10 is an enlarged view showing a part of the waveform of the input current shown in FIG. In FIG. 10, the solid line shows the waveform when the capacitor 51 is provided, and the dotted line shows the waveform when the capacitor 51 is not provided for comparison.

When the AC power supply 2 is short-circuited (FIG. 3,
6), when the capacitor 51 is present, the input current flowing through the reactor 18 becomes close to zero immediately before the short circuit is released, that is, immediately before the charging of the capacitor 51 ends. Therefore, the reactor 1 when the short circuit is released
The amount of change in current of No. 8 approaches zero, and the noise generated in the reactor 18 is little or small. On the other hand, when the capacitor 51 is not provided, the current when the AC power supply 2 is short-circuited increases with time.
Then, the current flowing through the reactor 18 sharply decreases due to the release of the short circuit. Therefore, since the amount of change in current due to the release of the short circuit is large, noise is generated in the reactor 18.

According to the first embodiment described above, the input current flowing from the AC power supply 2 to the rectifier circuit is controlled by charging / discharging the capacitor 51, and the on-timing of the transistors 52 and 53 is controlled, so that the power of the rectifier circuit is increased. The rate can be improved. Further, since the OFF timing of the transistors 52 and 53 does not require fine control, the power factor can be improved by a simple control process. Furthermore, by controlling the input current, the power supply harmonic current contained in the input current can be reduced.

Further, according to the first embodiment described above, since the transistor 52 and the transistor 53 are alternately turned on every half cycle of the AC voltage, the switching element is turned on / off at a frequency much higher than the AC voltage cycle. Compared to a rectifier circuit that is turned off, the amount of noise generated is reduced and the amount of heat generation is extremely reduced. Further, since the loss associated with the on / off operation of the transistor is significantly reduced, the efficiency of the rectifier circuit is improved.

Further, according to the above-described first embodiment, when the currents flowing through the transistors 52 and 53 are zero, the transistors 52 and 53 are switched from the on state to the off state, so that the off timing of the transistors 52 and 53 is changed. The amount of noise generated is theoretically zero. Moreover, since the current flowing through the reactor 18 becomes zero when the short circuit is released by utilizing the charge and discharge of the capacitor, the reactor 18 is
The noise generated from is reduced.

Further, according to the first embodiment described above, when the transistors 52 and 53 are in the ON state, the capacitor 5
The electric charge stored in 1 is discharged to the load 3 side. Since the amount of discharge at that time is controlled by the on timing of the transistors 52 and 53, the DC voltage supplied to the load 3 can be changed.

Further, according to the above-described first embodiment, since the self-extinguishing type element is used, the transistors 52 and 53 can be forcibly turned off. Therefore,
Even if the change in the load amount of the load 3 is large, the rectifier circuit can be used. In this case, the transistors 52, 5
No. 3 does not achieve zero current switching, but the amount of noise is small because the load is small.

In the first embodiment described above,
Although the voltage doubler capacitors 65 and 66 and the smoothing capacitor 11 are provided, the present invention is not limited to this, and the smoothing capacitor 11 may be omitted as shown in FIG. 11. In this case, the smoothing capacitor 11 can be regarded as a capacitor in which the voltage doubling capacitors 65 and 66 are connected in series. Therefore, FIG.
It goes without saying that the rectifier circuit having the structure shown in (1) operates in the same manner as the rectifier circuit having the structure shown in FIG.

Embodiment 2. FIG. 12 is a circuit block diagram showing the configuration of the rectifier circuit according to the second embodiment of the present invention. The rectifier circuit according to the second embodiment has a configuration in which a relay 54, a relay switching unit 73 and a load detection unit 74 are added to the rectifier circuit according to the first embodiment shown in FIG. Since other configurations are the same as those of the circuit shown in FIG. 2, the same configurations are denoted by the same reference numerals and the description thereof will be omitted.

The relay 54 is provided for switching the half-wave rectification method and the full-wave rectification method. Relay 54
The midpoint of the connection of the diodes 43 and 44 connected to DC,
It is connected between the midpoint of the connection of the capacitors 65 and 66, which are DC-connected. When the relay 54 is in the ON state, that is, when it is closed, the rectifier circuit shown in FIG. 12 is a half-wave rectifier circuit having the same configuration as the rectifier circuit shown in FIG. When the relay 54 is in the off state (when it is open), the state shown in FIG.
The rectifier circuit shown in 2 operates as a full-wave rectifier circuit.

The load detector 74 detects the load amount of the load 3. For example, the load detection unit 74 is configured with a current sensor or the like that detects a current flowing through the load 3. Alternatively, when the load 3 is composed of an inverter or the like that operates a motor load, the load detection unit 74 is composed of a sensor that detects the inverter frequency and the motor rotation speed. The detection signal of the load detector 74 is sent to the control circuit 72. The control circuit 72 outputs a control signal to the relay switching unit 73 based on the detection result of the load amount. The relay switching unit 73 switches ON / OFF operation of the relay 54 based on the control signal.

When the relay 54 is in the ON state, the operation of the rectifier circuit is the same as that in the first embodiment, and the description thereof will be omitted to avoid duplication. When the relay 54 is in the OFF state, the midpoint of the connection of the diodes 43 and 44 connected to the direct current and the midpoint of the connection of the capacitors 65 and 66 connected to the direct current are insulated. Therefore, the capacitors 65 and 66 are regarded as one capacitor.

Since the capacitor regarded as one and the smoothing capacitor 11 are connected in parallel, they are also regarded as one capacitor. In this way, the three capacitors 65, 66, and 11 are regarded as one capacitor, and the relay 54, the relay switching unit 73, the load detection unit 74, and the two diodes 63 and 6 are included.
If 4 is omitted, the full-wave rectifier circuit shown in FIG. 13 is obtained. That is, FIG. 13 is a circuit block diagram showing the configuration of the full-wave rectifier circuit corresponding to the case where the relay is open in the rectifier circuit of FIG. In FIG. 13, the capacitor 11
a is the three capacitors 65, 66, 11 shown in FIG.
Equivalent to.

In the case of the full-wave rectifier circuit shown in FIG.
The relay 54, the relay switching unit 73, and the load detection unit 74 shown in (3) may be omitted because the relay 54 is open. In the case of the full-wave rectifier circuit shown in FIG. 13, the diodes 63 and 64 shown in FIG. 12 may be omitted because these diodes 63 and 64 are turned on when the transistors 52 and 53 are turned on in FIG. This is because the charge is prevented from flowing back from the capacitors 65 and 66. That is, in the case of the full-wave rectifier circuit shown in FIG. 13, there is no need for the double voltage capacitors 65 and 66 shown in FIG.

As described above, in the rectifier circuit shown in FIG. 12, the circuit configuration when the relay 54 is in the OFF state is as shown in FIG.
The configuration is the same as that of the full-wave rectifier circuit shown in FIG. Therefore, the operation when the relay 54 is in the off state will be described based on the circuit of FIG. 14 to 19 are diagrams for explaining current paths in the circuit shown in FIG.
In these figures, the path indicated by the dashed arrow is the path through which the current flows.

First, the case where the output end of the AC power supply 2 on the side of the reactor 18 has a positive polarity, that is, the positive polarity is described. When the transistor 53 is turned on when the AC power supply 2 has a positive polarity, the current becomes as shown in FIG.
It flows from the AC power supply 2 through the reactor 18, the capacitor 51, the transistor 53, and the diode 44 in order, and finally returns to the AC power supply 2.

That is, the current path at this time is AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2. Due to this current path, the AC power supply 2 is short-circuited, and a steep input current flows from the AC power supply 2 to the rectifier circuit. The capacitor 51 is charged by this input current. When the charging of the capacitor 51 is completed, no more current flows in the capacitor 51. That is, the AC power supply 2-reactor 18-
Capacitor 51-Transistor 53-Diode 44-
No current automatically flows through the current path of the AC power supply 2. Therefore, it is not necessary to control the off timing of the transistor 53.

Here, the control circuit 72 (see FIG. 13) is
AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC 53 is switched from the ON state to the OFF state after no current flows in the current path of AC power supply 2. As a result, the transistor 53 operates with zero current switching, and the noise during the switching becomes zero.

As in the first embodiment, the control circuit 72 may switch off the transistor 53 before the charging of the capacitor 51 is completed, depending on the load amount of the load 3. In that case, the operation of the transistor 53 does not result in zero current switching, but there is an advantage in that the rectifier circuit can easily respond to changes in the load amount of the load 3.

AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2
When the short-circuit current no longer flows in the current path of, as shown in FIG. 15, from the AC power supply 2 to the reactor 18 and the diode 4
A current flows so as to return to the AC power supply 2 via the capacitor 1, the capacitor 11a and the diode 44 in sequence.
The capacitor 11a is charged by the current flowing through the path of this AC power supply 2-reactor 18-diode 41-capacitor 11a-diode 44-AC power supply 2.
That is, when the capacitor 51 is completely charged and the diode 41 is turned on, the rectifier circuit according to the second embodiment operates as a normal full-wave rectifier circuit.

When the charging of the capacitor 11a is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed. The control circuit 72 (see FIG. 13) switches the transistor 52 from the off state to the on state with a delay from the zero cross timing at which the polarity of the AC power supply 2 is inverted.

Therefore, since the transistor 52 does not turn on immediately after the polarity of the AC power supply 2 is reversed from the positive polarity to the negative polarity, the capacitor 51 starts discharging as shown in FIG. The discharge current flows from the AC power supply 2 through the diode 43, the capacitor 11a, the diode 62, the capacitor 51, and the reactor 18 sequentially, and finally returns to the AC power supply 2. That is, the current path at this time is the AC power supply 2-diode 43-capacitor 11a-
It becomes the diode 62-capacitor 51-reactor 18-AC power supply 2.

Therefore, even if the transistor 52 is not turned on, the discharge current of the capacitor 51 causes the AC power supply 2 to flow.
Input current flows from the rectifier circuit. That is, since the input current can be passed through the rectifier circuit without operating the transistor 52, the power factor is improved. Also, the transistor 5
Since there is no operation loss caused by the operation of No. 2, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on timing of the transistor 52 according to the load 3, the rectifier circuit can be controlled to the maximum power factor.

The control circuit 72 (see FIG. 13) turns on the transistor 52 before all the charges charged in the capacitor 51 are discharged. When the transistor 52 is turned on, a current flows from the AC power supply 2 through the diode 43, the transistor 52, the capacitor 51, and the reactor 18 in this order, and finally returns to the AC power supply 2, as shown in FIG. That is, the current path at this time is the AC power supply 2-diode 43-transistor 52-capacitor 51-reactor 18-AC power supply 2.

Since the AC power supply 2 is short-circuited by this current path, a steep input current flows from the AC power supply 2 to the rectifier circuit, and the capacitor 51 is charged again. Capacitor 5
When the charging of 1 is completed, the AC power supply 2-diode 43-
Transistor 52-Capacitor 51-Reactor 18-
No current automatically flows through the current path of the AC power supply 2. Therefore, it is not necessary to control the off timing of the transistor 52. AC power supply 2-diode 43
-Transistor 52-Capacitor 51-Reactor 18
-When the short-circuit current stops flowing in the current path of the AC power supply 2,
The control circuit 72 (see FIG. 13) causes the transistor 52
Switches from the on state to the off state. That is, since the transistor 52 operates with zero current switching, noise during the switching operation becomes zero. As in the case of the transistor 53, the transistor 52 may be forcibly turned off before the capacitor 51 is completely charged, depending on the load amount of the load 3.

AC power supply 2-diode 43-transistor 52-capacitor 51-reactor 18-AC power supply 2
When the short-circuit current stops flowing in the current path of, as shown in FIG. 18, from the AC power source 2 to the diode 43 and the capacitor 1
A current flows so as to return to the AC power supply 2 via the 1a, the diode 42, and the reactor 18 in order. The capacitor 11a is charged by the current flowing through the path of this AC power supply 2-diode 43-capacitor 11a-diode 42-reactor 18-AC power supply 2. That is,
When the charging of the capacitor 51 is completed and the diode 43 is turned on, the rectifier circuit according to the second embodiment operates as a normal full-wave rectifier circuit.

When the charging of the capacitor 11a is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed to the positive polarity. The transistor 53 is switched from the off state to the on state by the control circuit 72 with a delay from the zero-cross timing of the AC power supply 2. Therefore, after polarity inversion, the transistor 5
The discharge of the capacitor 51 occurs until 3 is turned on. The discharge current is, as shown in FIG.
To reactor 18, capacitor 51, diode 6
1, the condenser 11a, and the condenser 44, and then returns to the AC power source 2. That is, AC power supply 2-reactor 18-capacitor 51-diode 61-capacitor 11a-diode 44-AC power supply 2
Is formed.

Therefore, even if the transistor 53 is not turned on, the discharge current of the capacitor 51 causes the AC power supply 2 to flow.
Input current flows from the rectifier circuit. That is, since the input current can be passed through the rectifier circuit without operating the transistor 53, the power factor is improved. Also, the transistor 5
Since there is no operation loss caused by the operation of No. 3, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on timing of the transistor 53 according to the load 3, the rectifier circuit can be controlled to the maximum power factor.

The transistor 53 is turned on by the control circuit 72 (see FIG. 13) before all the charges stored in the capacitor 51 are discharged. As a result, the state shown in FIG. 14 is restored, and the AC power supply 2-reactor 18-capacitor 5
The charging current of the capacitor 51 flows through the path of 1-transistor 53-diode 44-AC power supply 2. The rectifier circuit according to the second embodiment repeats the above operation.

According to the second embodiment described above, in addition to the same effect as the first embodiment, by controlling the ON / OFF of the relay 54, the rectifier circuit can be operated as a half-wave rectifier circuit or a full-wave rectifier circuit. It can be operated as a rectifier circuit. For example, in case of switching on / off of the relay 54 in accordance with the AC voltage, AC voltage when the 100V can be used as a half-wave rectification circuit rectifying circuit by turning on the relay 54. Further, the AC voltage at the time of 200V can be used rectifier circuit by turning off the relay 54 as a full-wave rectifier circuit.

Alternatively, when the relay 54 is switched on / off according to the load amount of the load 3, the rectifier circuit may be used as a half-wave rectifier circuit by turning on the relay 54 when the load amount is heavy. it can. Further, when the load is light it can be used rectifier circuit as a full-wave rectifier circuit by turning off the relay 54. For example, when the load 3 is composed of an inverter and a motor, if a voltage higher than the voltage required for the inverter and the motor is applied, the efficiency will decrease. In Embodiment 2 described above, the efficiency of the inverter or the motor that is the load 3 can be improved by turning off the relay 54 when the load amount of the inverter or the motor is light and the voltage is not required.

Third embodiment. FIG. 20 is a circuit block diagram showing the configuration of the rectifier circuit according to the third embodiment of the present invention. The rectifier circuit according to the third embodiment does not include the transistor 52, the diodes 61, 63 and 64 and the capacitors 65 and 66 in the rectifier circuit according to the first embodiment shown in FIG. 2, but includes the capacitor 55, the transistor 56 and the diode 67. It has been configured. Other configurations are shown in FIG.
Since it is the same as the circuit shown in FIG. 6, the same components are given the same reference numerals and the description thereof is omitted.

The electrode of the capacitor 51 on the side not connected to the reactor 18 is connected only to the collector of the transistor 53. The capacitor 55 is connected between the polarity detection unit 71 and the collector of the transistor 56. The emitter of the transistor 56 is the transistor 53
Connected to the emitter. A drive signal is supplied from the control circuit 72 to the base of the transistor 56. That is, the transistor 56 is driven by the control circuit 72.

The diode 67 is connected in antiparallel to the transistor 56. That is, the anode and cathode of the diode 67 are connected to the emitter and collector of the transistor 56, respectively. Transistor 53
The drive signal of is one pulse per one cycle of the power supply, and is generated when the AC power supply 2 has a positive polarity. The drive signal of the transistor 56 is one pulse per one cycle of the power supply, and is generated when the AC power supply 2 has a negative polarity.

21 to 28 are diagrams for explaining current paths in the circuit shown in FIG. In these figures, the path indicated by the dashed arrow is the path through which the current flows.
First, the case where the output end of the AC power supply 2 on the reactor 18 side has a positive polarity, that is, the positive polarity is described. When the transistor 53 is turned on with the electric charge remaining in the capacitor 55 when the AC power supply 2 has a positive polarity, current flows from the AC power supply 2 to the reactor 18, the capacitor 51, the transistor 53, and the diode 67 as shown in FIG. Then, the electric current flows through the capacitor 55 and the condenser 55, and finally returns to the AC power supply 2.

That is, the current path at this time is AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 67-capacitor 55-AC power supply 2. The AC power supply 2 is short-circuited by this current path.
Capacitor 51 is charged while capacitor 55 is discharged.

When all the charges accumulated in the capacitor 55 have been discharged, a current flows from the AC power source 2 through the reactor 18, the capacitor 51, the transistor 53 and the diode 44 in this order, as shown in FIG.
Finally, return to the AC power supply 2. That is, the current path at this time is the AC power supply 2-reactor 18-capacitor 51.
-Transistor 53-Diode 44-AC power supply 2. The capacitor 51 continues to be charged. Capacitor 51
When the charging of is completed, no current automatically flows in the current path of the AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2.
Therefore, it is not necessary to control the off timing of the transistor 53.

Here, the control circuit 72 (see FIG. 20) is
AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC 53 is switched from the ON state to the OFF state after no current flows in the current path of AC power supply 2. As a result, the transistor 53 operates with zero current switching, and the noise during the switching becomes zero.

As in the first embodiment, the transistor 53 may be turned off by the control circuit 72 before the charging of the capacitor 51 is completed, depending on the load amount of the load 3. In that case, the operation of the transistor 53 does not result in zero current switching, but there is an advantage in that the rectifier circuit can easily respond to changes in the load amount of the load 3.

AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 44-AC power supply 2
When the short-circuit current stops flowing in the current path of, as shown in FIG. 23, from the AC power supply 2 to the reactor 18 to the diode 4
A current flows so as to return to the AC power supply 2 through the capacitor 1, the capacitor 11 and the diode 44 in order. The capacitor 11 is charged by the current flowing through the path of this AC power supply 2-reactor 18-diode 41-capacitor 11-diode 44-AC power supply 2. That is, when the charging of the capacitor 51 is completed and the diode 41 is further turned on, the rectifier circuit of the third embodiment operates as a normal full-wave rectifier circuit.

When the charging of the capacitor 11 is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed. Control circuit 7
2 (see FIG. 20) switches the transistor 56 from the off state to the on state after the timing of the zero-cross when the polarity of the AC power supply 2 is inverted. Therefore, after the polarity of the AC voltage is inverted, while the transistor 56 is in the OFF state, the capacitor 51 starts discharging, as shown in FIG. The discharge current is from the AC power supply 2 to the diode 43 and the capacitor 1.
1, the diode 62, the capacitor 51, and the reactor 18, and then finally returns to the AC power supply 2.
That is, the current path at this time is AC power supply 2-diode 43-capacitor 11-diode 62-capacitor 51-reactor 18-AC power supply 2.

Therefore, the AC power supply 2 is operated by the discharge current of the capacitor 51 without operating the transistor 56.
Since the input current can flow from the rectifier circuit, the power factor is improved. Further, since there is no operation loss caused by the operation of the transistor 56, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on-timing of the transistor 56 according to the load 3, the rectifier circuit can be controlled to the maximum power factor. Before the charge of the capacitor 51 is completely discharged, that is, the capacitor 5
In the state where the electric charge remains at 1, the control circuit 72 (see FIG. 20) turns on the transistor 56. When the transistor 56 is turned on, as shown in FIG.
The discharging of 1 and the charging of the capacitor 55 occur simultaneously.

The current at that time flows from the AC power supply 2 through the capacitor 55, the transistor 56, the diode 62, the capacitor 51 and the reactor 18 in this order, and finally returns to the AC power supply 2. That is, the current path at this time is the AC power supply 2-capacitor 55-transistor 56.
-Diode 62-Capacitor 51-Reactor 18-
It becomes the AC power supply 2. The AC power supply 2 is short-circuited by this current path.

When all the charges accumulated in the capacitor 51 have been discharged, a current flows from the AC power supply 2 through the capacitor 55, the transistor 56, the diode 42 and the reactor 18 in this order, as shown in FIG.
Finally, return to the AC power supply 2. That is, the current path at this time is the AC power supply 2-capacitor 55-transistor 5
6-Diode 42-Reactor 18-AC power supply 2. The capacitor 55 continues to be charged. Capacitor 55
When the charging is completed, no current automatically flows in the current path of the AC power supply 2-capacitor 55-transistor 56-diode 42-reactor 18-AC power supply 2.
Therefore, it is not necessary to control the off timing of the transistor 56.

The control circuit 72 (see FIG. 20) controls the transistor 5 after the current stops flowing through the transistor 56.
Switch 6 from on to off. That is, the transistor 53 operates with zero current switching, and noise during the switching is zero. In addition,
Similar to the case of the transistor 53, the transistor 56 may be forcibly turned off before the capacitor 55 is completely charged, depending on the load amount of the load 3. In that case,
The operation of the transistor 56 does not result in zero current switching, but there is an advantage that the rectifier circuit can easily respond to changes in the load amount of the load 3.

AC power supply 2-capacitor 55-transistor 56-diode 42-reactor 18-AC power supply 2
When the short-circuit current no longer flows in the current path of, as shown in FIG.
A current flows so as to return to the AC power supply 2 via the diode 1, the diode 42, and the reactor 18 in order. The capacitor 11 is charged by the current flowing through the path of this AC power supply 2-diode 43-capacitor 11-diode 42-reactor 18-AC power supply 2. At this time, the rectifier circuit of the third embodiment operates as a normal full-wave rectifier circuit.

When the charging of the capacitor 11 is completed, the input current from the AC power supply 2 to the rectifier circuit stops flowing. After that, the polarity of the AC power supply 2 is reversed. Control circuit 7
2 (see FIG. 20) switches the transistor 53 from the off state to the on state after the timing of the zero cross when the polarity of the AC power supply 2 is inverted.

Therefore, after the polarity of the AC voltage is inverted, while the transistor 53 is in the off state, the capacitor 55 starts to discharge, as shown in FIG. The discharge current is AC power supply 2
To reactor 18, diode 41, capacitor 1
1, the diode 67, and the capacitor 55 in order, and finally returns to the AC power supply 2. That is, the current path at this time is AC power supply 2-reactor 18-diode 41-capacitor 11-diode 67-capacitor 55-AC power supply 2.

Therefore, the AC power supply 2 is operated by the discharge current of the capacitor 55 without operating the transistor 53.
Since the input current can flow from the rectifier circuit, the power factor is improved. Further, since there is no operation loss caused by the operation of the transistor 53, the efficiency of the rectifier circuit is increased. Further, by optimally controlling the on timing of the transistor 53 according to the load 3, the rectifier circuit can be controlled to the maximum power factor. The transistor 53 is turned on by the control circuit 72 (see FIG. 20) before all the charges stored in the capacitor 55 are discharged. As a result, the state returns to the state shown in FIG. 21, and the charging current of the capacitor 51 flows through the route of AC power supply 2-reactor 18-capacitor 51-transistor 53-diode 67-capacitor 55-AC power supply 2. The rectifier circuit according to the third embodiment is
The above operation is repeated.

According to the third embodiment described above, in addition to the effect similar to that of the first embodiment, two capacitors 51 and 55 are provided as capacitors for controlling the current flowing by the AC voltage by charging and discharging. , The condenser is 1
In contrast to the embodiment 1 or the embodiment 2 which has only one,
Since the number of times of charging / discharging each capacitor 51, 55 is halved, the effect of extending the life of the capacitors 51, 55 is obtained.

Fourth Embodiment FIG. 29 is a circuit block diagram showing the configuration of the rectifier circuit according to the fourth embodiment of the present invention. The rectifier circuit of the fourth embodiment differs from the rectifier circuit of the first embodiment shown in FIG. 2 in the following points.

That is, in the fourth embodiment, instead of the rectifying means 4 including the four diodes 41, 42, 43 and 44, the rectifying means 4 including the two diodes 45 and 46.
a is provided. Further, a capacitor 57 is provided instead of the capacitor 51. Transistors 52 and 5
A switch element 58 is provided in place of 3. There are no diodes 61, 62, 63, 64. Since other configurations are the same as those of the circuit shown in FIG. 2, the same configurations are denoted by the same reference numerals and the description thereof will be omitted.

The capacitor 57 and the switch element 58 are connected in series. One end of the series connection body composed of the capacitor 57 and the switch element 58 is connected to the reactor 18
Is connected to one end on the side not connected to the AC power supply 2. In addition, the other end of this series connection body has a polarity detection unit 71.
It is connected to the. The switch element 58 is a control circuit 72.
The AC power supply 2 is controlled by the ON / OFF operation every half cycle. That is, the control circuit 72 controls to turn on / off the switch element 58 every half cycle of the AC power supply 2. The capacitor 57 is charged and discharged when the switch element 58 is turned on. The capacitor 57 and the switch element 58 have a function as the power supply short-circuit means 5.

The anode of the diode 45 and the cathode of the diode 46 are commonly connected to one end of the reactor 18 on the side not connected to the AC power supply 2. The cathode of the diode 45 is connected to one end of a series connection body composed of two voltage doubler capacitors 65 and 66 connected in series, one end of the smoothing capacitor 11 and one input end of the load 3.

Further, the anode of the diode 46 is connected to the other end of the series connection body composed of the voltage doubler capacitors 65 and 66, the other end of the smoothing capacitor 11 and the other input end of the load 3. The midpoint of the connection between the voltage doubler capacitors 65 and 66 is connected to the polarity detector 71. Therefore,
The rectifier circuit shown in FIG. 29 is a general half-wave rectifier circuit in which a series connection body including a capacitor 57 and a switch element 58 is connected to the AC power supply 2 side.

FIG. 30 is a circuit diagram showing an embodiment of the switch element 58. The switch element 58 is a self-turn-off type bidirectional element. The switch element 58 shown in FIG.
Is composed of a diode bridge 58a and a transistor 58b which is a switching element. The switch element 58 is arranged on the alternating current side, but is a self-extinguishing type switching element 58.
Since b is a unidirectional flow element, it cannot be used on the AC side. Therefore, the diode bridge 58a is used for rectification.
Make up eight. If the open / close element 58b is a bidirectional flow element, rectification by the diode bridge 58a is unnecessary.

According to the fourth embodiment described above, the switching element 58 can be switched to zero current by utilizing the charging / discharging of the capacitor 57.
The same effect as that of the first embodiment can be obtained. Further, according to the fourth embodiment described above, the use of the self-arc-extinguishing type element as the switch element 58 brings about the following effects. That is, the ON time of the switch element 58 is determined by the charging time of the capacitor 57. Capacitor 57
The charging time of the switch element 58 is almost determined by the capacitor capacity and 1/4 of the resonance frequency of the reactor 18.
The ON time of is almost constant regardless of the load amount. But,
When the load 3 changes to a light load amount, the switch element 58
The on-time of may become too long. In that case, the switch element 58 is forcibly turned off. Thereby, the supply voltage to the load 3 can be changed. In this case, even if the zero current switching is not used, the amount of noise is small because the load is small.

As shown in FIG. 31, when the switch element 58 is in the off state, a charge discharging means 6a for discharging the charge accumulated in the capacitor 57 to the output side of the rectifying means 4a is further provided. It may be. For example, the charge discharging means 6a is composed of two diodes 68 and 69. In that case, the anode of the diode 68 is connected to the cathode of the diode 69 and the midpoint of the connection between the capacitor 57 and the switch element 58. The cathode of the diode 68 is connected to the cathode of the diode 45. The anode of the diode 69 is the diode 4
6 connected to the anode.

According to the rectifier circuit shown in FIG. 31, the capacitor 57 is discharged when the switch element 58 is in the OFF state by starting the operation of the switch element 58 with a delay from the zero-cross timing of the AC voltage. .
Therefore, the energy stored in the capacitor 57 can be used for the load 3, and the efficiency of the rectifier circuit is further improved. Further, since the capacitor 57 can be discharged even when the rectifier circuit is not energized,
The voltage across the capacitor 57 decreases over time,
Improves reliability. In the rectifier circuit shown in FIG. 29, even if a resistor is connected in parallel with the capacitor 57, the same effect as that of the rectifier circuit shown in FIG. 31 can be obtained.

Embodiment 5. FIG. 32 is a circuit block diagram showing the configuration of the compressor drive device according to the fifth embodiment of the present invention. In the compressor drive device of the fifth embodiment, the load 3 of the rectifier circuit of the first embodiment shown in FIG. 2 is composed of, for example, a three-phase inverter 8 and a compressor 9. Also,
This compressor drive device includes an inverter control circuit 80. Since the configuration and operation of the rectifier circuit portion are the same as those of the circuit shown in FIG. 2, the same components are designated by the same reference numerals and description thereof will be omitted.

The inverter 8 has a structure in which two transistors are connected in series and a series connection body 81, 82, 83 in which a diode is connected in antiparallel to each transistor is connected in parallel in three columns. There is. Each series connection 8
The three-phase input terminals of the compressor 9 are connected to the middle points of the connections of the two transistors at 1, 82, and 83, respectively. The inverter control circuit 80 supplies a drive signal to the bases of the six transistors of the inverter 8 to control the rotating operation of the compressor 9. Further, the inverter control circuit 80 controls the rotation speed of the compressor 9. The inverter control circuit 80 supplies information about the rotation speed of the compressor 9 to the control circuit 72.

The control circuit 72 changes the delay time from the zero-cross timing of the AC voltage to the operation start timing of the transistors 52 and 53 based on the information on the rotation speed of the compressor 9 received from the inverter control circuit 80. The higher the number of revolutions of the compressor 9, the heavier the load,
The lower the rotation speed, the lighter the load. Therefore, the delay time of the operation start timing of the transistors 52 and 53 changes according to the load amount. Here, the household electric appliance is connected to the breaker installed in the house in the house. If the current capacity of this breaker is exceeded, the breaker will shut off the power. Therefore, the operation of all electric appliances in the home is stopped.
To avoid this, household appliances are generally restricted to operate at ampacities such that the breaker does not operate.

When the voltage input from the AC power supply 2 is constant and the current capacity is limited to a constant value by the breaker, active power is represented by the product of voltage, current and power factor. Therefore, since the power factor can be improved by applying the rectifier circuit according to the present invention to a compressor driving application,
The active power is increased and the output can be increased.

According to the fifth embodiment described above, the compressor 9
Output can be increased, and noise can be suppressed by performing zero current switching as in the first embodiment. Therefore, when a television or a radio is placed near a household electric appliance to which this compressor driving device is applied, it is possible to suppress the occurrence of flicker and noise in the image and sound. Therefore, the fifth embodiment
For household appliances that apply the compressor drive device of, and other household appliances affected by noise,
Since it is not necessary to take measures against noise, it is possible to reduce the size and cost of these household electric appliances. That is, it can be easily applied to a refrigerator or a dehumidifier arranged indoors, or an outdoor unit of an air conditioner.

According to each of the above-described embodiments, the power factor can be improved, so that the amount of reactive power can be reduced and the amount of reactive power of the total amount of power generated at the power plant can be reduced. Therefore, since the power generation efficiency of the power plant can be improved, the carbon dioxide emission amount can be reduced.

In the fifth embodiment, the control circuit 72 of the rectifying circuit and the inverter control circuit 80 are described separately, but the control circuit 72 and the inverter control circuit 80 are constituted by a single control means such as a microcomputer. You may.

Further, although the case where the compressor 9 is driven has been described in the fifth embodiment, the present invention is not limited to this, and the invention can be applied to driving a motor. In that case, for example, it can be applied to household electric appliances such as a washing machine and a vacuum cleaner. Further, although the application example of the rectifier circuit shown in FIG. 2 is described in the fifth embodiment, the rectifier circuit shown in each of FIGS. 11, 12, 13, 20, 29 or 31 may be applied. . At this time, the same effect can be obtained even if the smoothing capacitor 11 is replaced by the voltage doubler capacitors 65 and 66. In addition to household electric appliances, it is necessary to improve the power factor, but in areas where power factor improvement is postponed due to noise countermeasures and cost problems, systems not related to motor drive, and substation related It is also applicable to the technical field of.

Sixth Embodiment FIG. 33 is a circuit block diagram showing the configuration of the rectifier circuit according to the sixth embodiment of the present invention. This rectifier circuit has six diodes 121, 12
2, 123, 124, 125, 126 rectifying means, two smoothing capacitors 127, 128 having the same capacity,
One resonance capacitor 129, three switching elements 13
The switching means composed of 0, 131 and 132, the three reactors 133, 134 and 135 having the same capacity, the zero cross detection means 136 and the control means 137 are provided. In FIG. 33, reference numeral 138 is a three-phase AC power supply, and reference numeral 139 is a load.

The cathode of the diode 121 is connected to the cathode of the diode 123 and the cathode of the diode 125. The anode of the diode 121 is connected to the cathode of the diode 122. The anode of the diode 123 is connected to the cathode of the diode 124. The anode of the diode 125 is connected to the cathode of the diode 126. Diode 122
Is connected to the anode of the diode 124 and the anode of the diode 126. Connection point between the diode 121 and the diode 122, the diode 12
3 and the diode 124 and the diode 12
5 and the diode 126, that is, between the input terminals of the rectifying means and the output terminals of the respective phases of the three-phase AC power supply 138, the reactors 133, 134, 135, respectively.
Are connected one by one.

The smoothing capacitor 127 and the smoothing capacitor 128 are composed of three diodes 121, 123, 125.
Each cathode and three diodes 122, 124, 12
6 is connected in series with each anode, that is, between the output terminals of the rectifying means. One electrode of the resonance capacitor 129 has a smoothing capacitor 127 and a smoothing capacitor 128.
It is connected to the connection point with. Each input terminal of the rectifying means is commonly connected to the other electrode of the resonance capacitor 129 via the switch elements 130, 131 and 132, respectively. The zero-cross detector 136 detects the voltage zero-cross point of each phase of the three-phase AC power supply 138. Control means 137
On the basis of the detection signal supplied from the zero-cross detection means 136, the three switch elements 130, 131, 13
2 ON / OFF operation is controlled. A load 139 is connected between the output terminals of the rectifying means.

In the rectifier circuit shown in FIG. 33, as shown in FIG. 34, the resonance capacitor 129, the three switch elements 130, 131, 132, the zero-cross detecting means 136 and the control means 137 (not shown) are the same as in the first embodiment. The power supply short-circuiting unit 140 having the same function as the power supply short-circuiting unit described in 1. is configured. Further, the two smoothing capacitors 127 and 128, the zero-cross detecting means 136 and the control means 137, which are not shown in FIG. 34, constitute the charge discharging means 141 having the same function as the charge discharging means described in the first embodiment. ing. In the sixth embodiment, the two smoothing capacitors 127 and 128 have a function as a capacitor that constitutes the charge discharging means 141 in addition to a function as a smoothing capacitor that smoothes the bus DC voltage. It also serves as a capacitor constituting 141. 6 diodes 121, 122, 12
3,124,125,126 have a function as the rectification means 142. In FIG. 34, reference numeral 143 is a reactor.

Next, the operation of the rectifier circuit shown in FIG. 33 will be described. 35 to 39 are diagrams for explaining the current path of the circuit shown in FIG. 33, and the current path is shown by a dashed arrow in these figures. In the description of this current path, the rectifier circuit shown in FIG. 33 is a general full-wave rectifier circuit, and for convenience, the AC power supply 13 is shown in FIGS.
The R phase, the S phase, and the T phase are selected from the top of No. 8. The operation when the phase voltage of the R phase is from 0 (zero) degree to about 2 / 3π will be described.
After that, the same operation as that of the R phase is performed for the S phase and the T phase, and thus the description of the operation of the S phase and the T phase is omitted.

FIG. 35 shows a current path when the phase voltage of the R phase is 0 (zero). At this time, T of the power source 138
Power supply 138 from the phase terminal via reactor 135, diode 125, smoothing capacitor 127, smoothing capacitor 128, diode 124 and reactor 134.
A current flows to the S-phase terminal. No current flows in the R phase. After that, when a preset delay time elapses, R
The switch element 130 connected to the phase is turned on. As a result, as shown in FIG. 36, in addition to the current flowing from the T phase to the S phase, the current is also supplied from the R phase terminal of the power source 138 to the reactor 133, the switch element 130, the resonance capacitor 129, the smoothing capacitor 128, the diode 124. And flows through the reactor 134 to the S-phase terminal of the power supply 138. Therefore, the non-flow section in the three-phase rectification is eliminated, and the current can be passed through each phase.

As the angle of the R phase voltage increases, the phase current flowing from the T phase to the S phase starts to flow from the R phase to the S phase. The resonance capacitor 129 is set so that the charging of the resonance capacitor 129 is completed at about that time.
The capacity of is properly selected. Resonance capacitor 129
When the charging is completed, no current flows through the resonance capacitor 129, so that no current flows through the switch element 130 as shown in FIG. That is, it is equivalent to turning off the switch element 130 connected to the R phase.
After that, the switch element 130 is turned off. FIG. 37
At the time point indicated by, the T-phase becomes the non-flow section.

When a voltage zero cross of the T phase is detected after a certain time has elapsed and a preset delay time has elapsed, the switch element 132 connected to the T phase is turned on. As a result, as shown in FIG. 38, in addition to the current flowing from the R phase to the S phase, the current flowing in the R phase passes through the smoothing capacitor 127, the resonance capacitor 129, the switch element 132, and the reactor 135, and the power source 13
It also flows to the T-phase terminal of No. 8. Therefore, in this case as well,
The non-flow section in the three-phase rectification is eliminated, and the current can be passed through each phase. Here, in the current path shown in FIG. 36 and the current path shown in FIG. 38, the directions of the currents flowing through the resonance capacitors 129 are opposite to each other.
9 will be charged and discharged.

When the angle of the R-phase voltage increases with the lapse of time, the charging of the resonance capacitor 129 is completed, and as shown in FIG.
As shown in FIG. 9, no current flows through the resonance capacitor 129. Therefore, it is equivalent to turning off the switch element 132 connected to the T phase. At this point, S
The current flowing into the phase decreases, and the current flowing from the R phase to the S phase changes so as to flow from the R phase to the T phase. afterwards,
The switch element 132 is turned off. At the time point shown in FIG. 39, the S phase is the non-flow section. The operation up to this point is R
This is an operation while the phase voltage of the phase changes from 0 (zero) degree to about 2 / 3π.

Subsequently, the switching operation of the switch element 131 connected to the S phase in the non-flow section is shifted to the ON operation. Then, while the phase voltage of the S phase changes from 0 (zero) degree to about 2 / 3π, the same operation as that of the R phase is performed for the S phase, and the T phase becomes the non-flow section. Following that,
While the phase voltage of the T phase changes from 0 (zero) degree to about 2 / 3π, the same operation is performed for the T phase as for the R phase. Then, the R phase again becomes a non-flow section, and FIG.
Return to the state shown in 5. In this way, one cycle of the power supply is constructed. After that, the above-described operation is alternately repeated in three phases.

In the above description, the resonance capacitor 129
It is assumed that the capacity of 1 is such that charging is completed from the start of operation of the switch element 130 to the commutation time of the phase current. Similarly, the capacitance of the resonance capacitor 129 is such a capacitance that charging is completed from the start of operation of the switch elements 131 and 132 to the commutation time of the phase current. Here, the charging time of the resonance capacitor 129 depends on the reactors 133, 134, 135 and the resonance capacitor 129.
It depends on the combination of the capacitance values of. This corresponds to each of the reactors 133, 134, 135 and the resonance capacitor 129.
This is because the LC resonance is used, and the ON frequency of the switch elements 130, 131 and 132 is determined by the resonance frequency.

FIG. 40 is a circuit diagram of the rectifier circuit shown in FIG.
2 each switching signal, and the resonance capacitor 129
It is a waveform diagram showing each waveform of the current flowing through. In this figure, regarding the current flowing through the resonance capacitor 129,
The direction shown in FIG. 36, that is, the direction of the current flowing from the three-phase AC power source 138 to the smoothing capacitors 127 and 128 is the positive direction.

As described above, by operating the rectifier circuit shown in FIG. 33, a phase current as shown in FIG. 41 flows. Further, by controlling the current in this manner, it is possible to improve the power factor and suppress harmonics. In particular, harmonics can be suppressed to a level satisfying the regulations currently considered for three-phase power sources in Japan. A list of the regulation values is shown in FIG.

Here, according to the load amount of the load 139, the reactor 1 required to satisfy the regulation shown in FIG.
There is a suitable capacity of 33,134,135. Therefore, the capacities of the reactors 133, 134, 135 are determined according to the load amount of the load 139. The capacity of the resonance capacitor 129 is determined by the capacity values of the reactors 133, 134 and 135. However, even if the resonance frequencies in the LC resonance are the same, the amounts of the harmonics included in the input current do not completely match, so the reactors 133, 134, and 13 due to the capacitance of the resonance capacitor 129 are the same.
It is desirable to fine-tune the capacity of 5.

Further, as described above, the LC resonance frequency determines the on-time of the switch elements 130, 131 and 132, and the switching operation is performed once every half cycle of the power supply. Therefore, the LC resonance frequency fr and the power supply frequency fs are set.
The following equation (1) holds between and. And FIG.
In the case of a three-phase rectifier circuit such as that shown in (5), since the fifth harmonic component is large, it is preferable to set the LC resonance frequency fr so as to satisfy equation (2). Considering this, set it slightly smaller. Therefore, the set value of the resonance frequency fr is in the range represented by the following equation (3). fr ≧ 2fs ... (1) fr = 2fs × 5 (2) 2fs ≦ fr ≦ 10fs (3)

Here, the values of the reactors 133, 134 and 135 inserted in the R, S and T phases are set to L (unit:
H (Henry)) and the capacitance of the resonance capacitor 129 is C (unit: F (Farad)). In the rectifier circuit shown in FIG. 33, the input current passes through two of the three reactors 133, 134 and 135 before returning from the AC power source 138 to the AC power source 138 via the rectifier circuit.
Therefore, the resonance frequency fr is expressed by the following equation (4). fr = 1 / (2π) × (√1 / 2LC) (4)

In the rectifier circuit shown in FIG. 33, the reactor 13 is based on the equation (3) and the equation (4).
The input current can be controlled by setting the capacitances of the capacitors 3,134,135 and the resonance capacitor 129 and operating them as shown in FIGS. 35 to 39. As a result, the power factor can be improved, and the harmonics can be suppressed to a level satisfying the regulation (see FIG. 42) currently under consideration. Further, by setting the capacities of the reactors 133, 134, 135 and the resonance capacitor 129 as described above, the cost is lower than that of the conventional full-bridge type high power factor converter shown in FIG. 52 and the conventional active filter shown in FIG. Thus, it is possible to obtain a harmonic suppression circuit that satisfies the regulation shown in FIG.

However, the load amount of the load 139 is not generally determined by the product or application to which the rectifier circuit is applied, but when the load 139 is a variable load type, the load amount depends on the operating conditions. different. Therefore, the reactors 133, 134, 135 and the resonance capacitor 129 are
However, in general, there is no variable capacitance type passive component. Therefore, the capacitances of the reactors 133, 134, 135 and the resonance capacitor 129 are actually set values under certain load conditions. For example, the reactors 133, 134, 135 and the resonance capacitor 1
It is considered that the capacity of 29 is generally set based on the load amount in the rated condition of the product to which the rectifier circuit is applied, but the capacity is not limited to this.

In addition, the switch elements 130, 131, 13
The delay time until the ON operation of No. 2 starts is set in advance, but this delay time may be changed according to the load amount. By doing so, it becomes possible to select the capacitance of the passive component that is somewhat independent of the amount of load.
Further, in this case, since only the delay time is changed, the input current can be controlled in an open loop. Therefore, even if the load amount changes, a rectifier circuit that improves power factor and suppresses harmonics. Can be manufactured with a minimum cost increase.

Next, the noise suppressing effect of the reactors 133, 134 and 135 realized by the resonance capacitor 129 will be described. In FIG. 43, the resonance capacitor 12
The switch element 13 with and without 9
The main part of the phase current (the part surrounded by the dotted line in FIG. 41) when 0, 131, and 132 are switched is schematically shown. As shown in FIG. 43 (a), when the resonance capacitor 129 is not provided, the current flowing when the switch elements 130, 131, 132 are turned on is the difference between the voltage between the AC power supply 138 and the smoothing capacitor 127, or the AC voltage. The current flows in an amount corresponding to the difference between the voltage across the power source 138 and the voltage across the smoothing capacitor 128. On the other hand, when the resonance capacitor 129 is provided as shown in FIG. 33, the switching element 130,
The current flowing when 131 and 132 turn on becomes less likely to flow as the resonance capacitor 129 is charged, and therefore changes smoothly as shown in FIG. 43 (b).

Now, the mechanism of noise generation will be considered. When the switch elements 130, 131 and 132 are turned on, a power supply short circuit current flows and the current increases. The current increase rate at this time is not constant without the resonance capacitor 129, and the current increase rate also increases as the power supply voltage increases. Then, the resonance capacitor 12
If there is no 9, switch elements 130, 131, 13
The current flowing through 2 is the switching elements 130, 131, 13
When 2 is turned off, it becomes zero. On the other hand, when the resonance capacitor 129 is provided, the current increase rate is not the increase rate of the power supply voltage but the resonance capacitor 129.
It depends on the charging voltage of. Therefore, when the resonance capacitor 129 is completely charged, the current increase rate di /
dt becomes zero. Then, when the charging of the resonance capacitor 129 is completed, the switch elements 130, 131, 132
Since the current flowing through the switch element becomes zero, the switch element 130,
This is synonymous with switching off 131 and 132.
The power supply short-circuit current, which has been flowing from the reactors 133, 134, 135 via the switch elements 130, 131, 132 from this time point, changes its flow to the rectifying means side.

As for this current, the power supply short-circuit current is the reactor 1
The energy stored by flowing through 33, 134, and 135 flows, so that the current also decreases as the energy decreases. Current change rate di at this time
/ Dt has a negative value, and its absolute value becomes maximum at the moment when the flow changes. Reactor 133,134,135
Magnetic flux is generated in the reactors 133, 134, 135
Electromagnetic force is generated by the flow of current in the. The magnetic flux changes according to the current change rate, and the change in magnetic flux causes a change in electromagnetic force. Therefore, the reactors 133, 134, 135
Vibrates and generates noise. Therefore, the smaller the magnetic flux change, that is, the smaller the current change rate, the reactor 1 is.
The noise generated at 33, 134 and 135 is small. Here, the current change rate is the degree of protrusion at the protrusion of the phase current shown in FIG. Reactors 133, 134, 1 have a larger change width when changing from the positive current change rate di / dt to the negative current change rate −di / dt.
The vibration of 35 becomes large and the noise becomes large. As shown in FIG. 43, when the resonance capacitor 129 is provided, the change width at the time of changing from the positive current change rate di / dt to the negative current change rate −di / dt is smaller than that without the resonance capacitor 129. The vibration of 133,134,135 becomes smaller, and the noise becomes smaller.

According to the sixth embodiment described above, since the resonance capacitor 129 is provided, the switching elements 130 and 13 are provided.
The amount of change in current when the current flowing through 1,132 changes from zero to a negative current change rate is minimized. Thereby, the reactors 133, 134, 135
Since the abrupt change of the magnetic flux generated at is suppressed, the vibrations of the windings and the iron core forming the reactors 133, 134 and 135 are reduced, and the noise can be suppressed. Also,
According to the sixth embodiment, a current flows through switching elements 130, 131 and 132 via resonance capacitor 129, so that the current automatically becomes zero when resonance capacitor 129 is completely charged. Zero current switching can be achieved by switching off the switch elements 130, 131, 132 when the current is zero.
As a result, noise is reduced and switching loss at turn-off can be reduced, so that circuit efficiency is improved and energy can be saved. Further, since the control relating to the turn-off of the switch elements 130, 131, 132 is not required, the control processing is very small and an inexpensive CPU can be used.

In the above-described sixth embodiment, the preset delay time setting value and resonance capacitor 129 are set.
Depending on the capacity of the switch, the switching element 130 connected to the R phase in the state shown in FIG. 37 may be turned on during the transition from the state shown in FIG. 36 to the state shown in FIG. Further, in the middle of the transition from the state shown in FIG. 38 to the state shown in FIG. 39, the switch element 132 connected to the T-phase may be turned on in the state shown in FIG. 39. Even in such a case, the sixth embodiment
The same effect as can be obtained.

In the sixth embodiment described above, the AC power source 138 and the rectifying means 142 are three-phase, but they may be single-phase or multi-phase. The configuration of the rectifier circuit in the case of a single phase is shown in FIG. 44. In FIG. 44, reference numerals 151, 152, 153 and 154 are diodes constituting rectification means, and reference numerals 157, 158 and 15 are used.
Reference numeral 0 is a smoothing capacitor, reference numeral 159 is a resonance capacitor, reference numerals 160 and 161 are switch elements constituting switching means, and reference numerals 163 and 16 are provided.
4 is a reactor. Further, reference numeral 168 is a single-phase AC power supply, and reference numeral 169 is a load. The reason that the smoothing capacitor 150 is connected in parallel to the smoothing capacitors 157 and 158 connected in series is that the single phase and the three phases have different capacities for smoothing. If the pulsation of the DC voltage is not taken into consideration, the smoothing capacitor 150
Even without it, there is no change in operation. The detailed connection relationship and operation of this single-phase case are the same as those of the three-phase case described in detail in the sixth embodiment, and a description thereof will be omitted.

Seventh Embodiment FIG. 45 is a circuit block diagram showing the structure of the rectifier circuit according to the seventh embodiment of the present invention. This rectifier circuit differs from the sixth embodiment shown in FIG. 33 in that the resonance capacitor 129 is not provided, the control means 177 is provided instead of the control means 137, and the load amount of the load 139 is detected. That is, the load amount detection means 170 is provided. Other configurations are the same as those in the sixth embodiment, and therefore, the sixth embodiment.
The same components as those in FIG. The operation of the rectifier circuit shown in FIG. 45 is almost the same as the operation described in the sixth embodiment except for the resonance capacitor 129. However, in the seventh embodiment, the switch elements 130, 131, 132 are not operated only once in a power supply half cycle, but as shown in FIG. Work more than. As a result, di / dt, which is the current change in the steep protrusion of the phase current, is suppressed, and the reactor 13
Vibrations at 3,134,135 are reduced to reduce noise generated from the reactors 133,134,135.

As shown in FIG. 46, the reactors 133, 134, 13 are, for example, three times (FIG. (B)) than when the number of times of switching is once every half cycle of the power supply (FIG. (A)).
The current flowing through 5 becomes smooth, and the current change (di / d
It can be seen that there are few suddenly changing protrusions in t). In addition, when the number of times of switching is three times in a half cycle of the power supply ((b) in the same figure)
The current flowing through the reactors 133, 134, 135 becomes smoother and the number of projections with abrupt changes in current (di / dt) is smaller than that in a large number of four or more times ((c) in the figure). Recognize.

The zero-cross detecting means 136 supplies the control means 177 with a signal giving a reference point for a preset delay time. The control means 177 operates so as to turn on the switches of the switch elements 130, 131, 132 according to the phase of the voltage detected by the zero-cross detection means 136. If the reference point for this delay time is unknown, at what time the switch elements 130, 131,
It became unclear whether 132 should be operated,
The operation becomes unstable. In addition, the expected harmonic suppression capability may not be exhibited, and conversely the harmonics may be promoted. Here, since the reference point of the delay time is set by the zero-cross detection means 136, sufficient harmonic wave suppression capability is exhibited. Further, it becomes possible to control the current in an open loop without causing an imbalance in the phase current.

The load amount detecting means 170 uses the load 139.
Is detected and supplied to the control means 177.
The control means 177 controls the ON operation of the switch elements 130, 131, 132 with a delay time according to the state of the load 139. Thereby, the delay time is changed according to the load amount, and the current is controlled. In this way, the delay time changes according to the load 139, so that the harmonic suppression capability according to the load state is exhibited. Further, the input current can be controlled also by the load without the harmonic component of a certain specific order protruding. Even if the delay time is always constant, there is no problem in operation.

According to the seventh embodiment described above, the reactor can be secured while maintaining the harmonic suppression capability equivalent to the case where each switching element 130, 131, 132 is operated once in the half cycle of the power supply as in the sixth embodiment. The inductance value of 133,134,135 can be made small. That is, the ability to suppress harmonics is
It is determined by the amount of energy stored by the currents flowing through 33, 134 and 135. Further, if the reactor has the same inductance value, the energy storage amount increases as the number of switching times per power source half cycle increases. Therefore, in order to set the harmonic suppression capability to the same level when the number of times of switching is large and when the number of times of switching is 1, that is, in order to store the same amount of energy, the reactors 133, 134, 135 having a larger number of times of switching are required. It means that the inductance value of can be small. As a result, the sixth embodiment is possible without providing the resonance capacitor 129.
The same effect as the above, that is, an effect equivalent to suppressing noise by the resonance capacitor 129 is obtained. Further, since the capacities of the reactors 133, 134 and 135 can be reduced, it contributes to downsizing and cost reduction. Also,
Since heat generation can be suppressed by reducing those capacities, loss is reduced and an energy saving effect is obtained.

In the above-described seventh embodiment, the number of times of switching of each switching element 130, 131, 132 per half power source cycle is not limited to 3 times, but may be 2 times or 4 times. May be more than. However, if the number of times of switching is increased too much, it is no different from high-frequency switching, which causes inconveniences such as generation of noise and increase of control load. Therefore, the period for turning on / off the switch elements 130, 131, 132 is not particularly limited, but may be, for example, 1 to 3 kHz.
It is desirable to set z or less. As described above, by appropriately increasing the number of switchings, it is possible to obtain a circuit that can easily take measures against noise without increasing the amount of noise generation.

Eighth Embodiment FIG. 47 is a circuit block diagram showing the structure of the rectifier circuit according to the eighth embodiment of the present invention. This rectifier circuit differs from the sixth embodiment shown in FIG. 33 in that the relay 180, which is the second switching means, is connected in parallel to the resonance capacitor 129.
The control means 187 is provided instead of the control means 137, and the load amount detection means 170 for detecting the load amount of the load 139 is provided. Since other configurations are the same as those of the sixth embodiment, the same configurations as those of the sixth embodiment are designated by the same reference numerals and the description thereof will be omitted. Regarding the load amount detecting means 170,
Since it has been described in the seventh embodiment, the description thereof is omitted here. The operation of the rectifier circuit shown in FIG.
Is the same as that of the sixth embodiment when it is in the off state, and is the same as that of the seventh embodiment when the relay 180 is in the on state.

The control means 187 is the load amount detection means 170.
On / off of the relay 180 and the switch elements 130, 131, based on the load amount of the load 139 detected by
The on / off of 132 is controlled. When the load amount is larger than the predetermined value, the control means 187 turns off the relay 180 and performs the same control as in the sixth embodiment. That is, the control means 187 controls the switch elements 130, 131, 132 at the timing described in the sixth embodiment.
Is operated once every half cycle of the power supply. As a result, when the load is heavy, the resonance capacitor 129 becomes effective and the reactor sound is suppressed. On the other hand, when the load amount is smaller than the predetermined value, the control means 187 turns on the relay 180, and similarly to the seventh embodiment, each switch element 13 is turned on.
0, 131, and 132 are operated twice or more in a power supply half cycle. Thereby, the reactor sound is suppressed as described in the seventh embodiment. In the case of a light load, since the current flowing through the reactors 133, 134, 135 is small, the noise level generated from the reactors 133, 134, 135 is lower than that in the case of a heavy load. Therefore, in the case of a light load, each switch element 130, 131, 132 may be operated once every half cycle of the power supply. Then, it is possible to avoid an increase in control processing load.

According to the eighth embodiment described above, in the case of a heavy load, the resonance capacitor 129 suppresses the reactor sound. Therefore, as in the sixth embodiment, the effect of suppressing the reactor sound and the noise due to zero current switching are reduced. The effect of reduction and energy saving can be obtained. Further, when the load is light, similar to the seventh embodiment, the effect of suppressing the reactor sound, the size reduction, the cost reduction, and the energy saving can be obtained. Also, when the load is light, the resonance capacitor 1
In order to invalidate 29, when the switching elements 130, 131, 132 are turned on until the resonance capacitor 129 is completely charged, too much current flows and the smoothing capacitor 127
It is possible to avoid the disadvantage that the voltage value appearing at both ends of the series circuit of the smoothing capacitor 128 becomes high and the voltage input to the load 139 becomes too high. Therefore, a more reliable rectifier circuit can be obtained.

Ninth Embodiment FIG. 48 is a circuit block diagram showing the structure of the rectifier circuit according to the ninth embodiment of the present invention. This rectifier circuit is different from that of the sixth embodiment shown in FIG. 33 in that a relay 180 which is a second switching means and a second resonance capacitor 190 are connected in series to each other in parallel with the resonance capacitor 129. Is connected to the control means 137, the control means 197 is provided instead of the control means 137, and the load amount detection means 170 for detecting the load amount of the load 139 is provided. Since other configurations are the same as those of the sixth embodiment, the same configurations as those of the sixth embodiment are designated by the same reference numerals and the description thereof will be omitted. Since the load amount detecting means 170 has been described in the seventh embodiment, the description thereof will be omitted here. In the rectifier circuit shown in FIG. 48, when the relay 180 is turned on / off, the resonance capacitors 129, 1
The operation is the same as that of the sixth embodiment except that the capacity of 90 is changed.

The control means 197 has a load amount detecting means 170.
On / off of the relay 180 and the switch elements 130, 131, based on the load amount of the load 139 detected by
The on / off of 132 is controlled. When the load amount is smaller than the predetermined value, the control means 197 turns off the relay 180, and similarly to the sixth embodiment, each switching element 1
30, 131, 132 are operated once every half cycle of the power supply.
As a result, only one resonance capacitor 129 is effective in the case of a light load, and the load 1 in the case of the above-described light load is effective.
The inconvenience that the voltage input to 39 becomes too high is avoided. On the other hand, when the load amount is larger than the predetermined value, the control means 197 turns on the relay 180, and similarly to the sixth embodiment, each switch element 130, 131, 1 is connected.
32 is operated once every half cycle of the power supply. Thereby, in the case of heavy load, the two resonant capacitors 129, 190
Is effective and the capacitance is increased to prolong the ON time of the switch elements 130, 131 and 132 and prevent the harmonic suppression capability from being lowered.

According to the ninth embodiment described above, only the resonance capacitor 129 can be made effective or the two resonance capacitors 129 and 190 can be made effective in accordance with the load amount, so the load amount at the time of light load Even when the appropriate capacitor capacity is different from the appropriate capacitor capacity for the heavy load, it is possible to appropriately control the current by switching the capacitors. Therefore, since the effect of suppressing the reactor sound by the resonance capacitors 129 and 190 can be obtained over a wide range of load amounts, a more reliable rectifier circuit can be obtained.

In the ninth embodiment, the resonance capacitors 129 and 190 are connected in parallel, and one of the resonance capacitors 190 is enabled or disabled by turning on / off the relay 180. Not limited to this, any configuration may be used as long as the capacity of the resonance capacitor for LC resonance can be switched by the relay to be small when the load is light and large when the load is heavy.

Embodiment 10. FIG. FIG. 49 is a circuit block diagram showing a configuration of a compressor drive device according to Embodiment 10 of the present invention. In this compressor driving device, a three-phase inverter 201 is connected as a load 139 to the rectifier circuit shown in FIG. 33, and an electric motor 202 is connected to the inverter 201. Therefore, the same components as those of the rectifier circuit shown in FIG. 33 are denoted by the same reference numerals, and duplicate description of the configuration and operation of the rectifier circuit is omitted.

In the tenth embodiment, the R phase, the S phase and the T phase are
Bidirectional switch elements 130, 1 connected to the respective phases
Reference numerals 31 and 132 each include a diode bridge 211 and a self-extinguishing switching element such as an IGBT (insulated gate bipolar transistor) 212. The inverter 201 has a configuration in which two transistors are connected in series, and a series connection body in which a diode is connected in antiparallel to each transistor is connected in three columns in parallel. Inverter control means 221 is connected to the inverter 201, and the inverter control means 221 controls ON / OFF of the six transistors of the inverter 201.

In the tenth embodiment, instead of directly detecting the load amount, the control means 137 is the inverter control means 2
The load amount is estimated on the basis of the control command value supplied from 21. That is, the inverter 201 controls the drive of the electric motor 202, and the output of the electric motor 202 is proportional to the rotation speed.
It can be estimated based on the 01 rotation speed command. And
In the tenth embodiment, similarly to the seventh embodiment, the preset delay time is changed according to the estimated load amount, and thereby the harmonic suppression capability according to the load amount is exerted. It is composed.

Alternatively, instead of estimating the load amount of the inverter 201 based on the rotation speed command to the electric motor 202, a set value inside the inverter control means 221 such as a voltage command value for the voltage applied to the electric motor 202,
The load amount may be estimated based on the phase current value of the electric motor 202 or the like. Alternatively, when the electric motor 202 is a compressor used in an air conditioner, the load torque of the compressor depends on the rotation speed, and therefore the load amount can be estimated only by the rotation speed command. When the electric motor 202 is a compressor, the load amount can be detected by using the discharge temperature, the suction temperature, the temperature of the heat exchanger, or the like. Since these temperatures and the like are detected by the thermistor in the inverter control means 221, the load amount can be easily detected without increasing the cost when these values are used. Further, by adding an element for detecting the circulating coolant speed, the coolant amount, etc., it is possible to detect the load amount using the coolant velocity, the coolant amount, etc.

According to the tenth embodiment described above, when the load 139 of the rectifier circuit is the inverter 201, the load amount can be estimated from the set value such as the operation command value controlled by the inverter 201. By changing the preset delay time according to this command value or the like without providing the load amount detecting means, it is possible to suppress the harmonic generation amount according to the load amount.

In the tenth embodiment described above, the rectifier circuit having the configuration shown in FIG. 33 is used, but the rectifier circuit having the configuration shown in FIG. 45, FIG. 47 or FIG. it can. In particular, in the case of a rectifying circuit using the relay 180 (see FIGS. 47 and 48), the relay 180 may be switched on / off based on the command value of the inverter. Then, a problem such as hunting due to a detection error is less likely to occur, and thus the reliability of the contacts of the relay 180 is improved.

[0181]

As described above, according to the rectifying circuit of the present invention, the rectifying means rectifies the AC voltage applied via the reactor. The power supply short-circuit means includes a capacitor, and the current flowing by the AC voltage is controlled by charging and discharging the capacitor. The charge discharging means is
The electric charge accumulated in the capacitor of the power supply short-circuiting means is discharged to the output side of the rectifying means. This has the effect of reducing the noise generated from the reactor. Further, the effect of improving the power factor and suppressing harmonics can be obtained by controlling the input current. Furthermore, zero current switching can be realized by using a capacitor, and switching noise can be reduced. Therefore, it is not necessary to take measures to reduce noise and reactor noise, and cost and size can be reduced. In addition, efficiency can be improved by effectively using the electric charge by the discharging means.

According to the next invention, the smoothing capacitor smoothes the output voltage of the rectifying means. Therefore, even when the output voltage of the rectifying means is smoothed by the smoothing capacitor, the effect of reducing the noise generated from the reactor can be obtained. In addition, the effect of stabilizing the output voltage can be obtained by using the smoothing capacitor.

According to the next invention, the pair of switching elements are alternately switched from the OFF state to the ON state every half cycle of the AC voltage according to the polarity of the AC voltage. Therefore, the switching frequency of the on / off of the switching element is lower than in the conventional case, and the loss accompanying the on / off operation is significantly reduced, so that the efficiency of the circuit is improved. Further, the switching element is turned on / off to charge / discharge the capacitor of the power supply short-circuit means. Therefore, it is not necessary to accurately control the off timing of the switching element. That is, the power factor of the rectifier circuit can be maximized only by controlling the on-timing of the switching element. Therefore, the power factor can be improved by a simple control process. Further, since the current input from the AC power supply can be controlled by charging and discharging the capacitor, the power supply harmonic current included in the input current can be reduced.

Also, the number of times the switching element is turned on / off is reduced, so that the amount of noise generated is reduced. In addition, by utilizing the charge and discharge of the capacitor, the switching element can be turned off after the current stops flowing through the switching element.
That is, since zero current switching can be realized, the amount of noise generated at the off timing of the switching element can theoretically be zero. Furthermore, since each switching element operates only once per cycle of the AC voltage, the amount of heat generation is significantly reduced. Therefore, deterioration or breakage of the switching element due to heat generation can be suppressed, and a highly reliable rectifier circuit can be obtained.

That is, since the control is performed only for the on timing of the switching element, the control is easy and can be realized with a low-cost control semiconductor. Further, since the two switching elements are alternately used, heat generation can be dispersed, so that the cost and size of the heat radiation countermeasure component can be reduced.
In addition, deterioration due to heat generation can be prevented, and efficiency is higher and less heat is generated than switching at high frequency. In addition, even if the switching element is short-circuited, the product will not be damaged due to the presence of the capacitor, so the reliability is high. Further, the output voltage can be controlled by the capacitor and the discharging means.

According to the next invention, the electric charge accumulated in the capacitor of the power supply short-circuiting means is discharged to the output side of the rectifying means via the diode. Therefore, the electric charge accumulated in the capacitor by the short-circuit current is supplied to the load side, so that the DC voltage supplied to the load can be changed. In addition, if the parasitic diode inside the switching element can be used, it can be configured without increasing the cost, and since it can be configured as one package in the switching element, the number of parts is reduced, the processing cost is reduced, and the work is reduced. The effect of improving the sex is obtained.

According to the next invention, the charge discharging means has a pair of voltage doubler capacitors. The diode prevents charges from flowing back from the voltage doubler capacitor when the switching element is in the ON state. Therefore, a DC output that is approximately twice the AC voltage input to the rectifier circuit can be obtained. Also,
Since it can support doubled voltage, it can be connected to a load that requires a wide range of adjustment. Furthermore, the addition of the pair of diodes eliminates the vertical short circuit of the switching element and improves the reliability.

According to the next invention, the capacitor of the power supply short-circuit means is charged / discharged by switching the transistor on / off. Therefore, the power factor of the rectifier circuit can be improved only by controlling the on-timing of the transistor. Further, since the transistor is a self-extinguishing element, it can be forcibly turned off while flowing current, so damage to the load due to overvoltage output can be prevented, and reliability is improved. further,
It is possible to cope with changes in load.

According to the next invention, by the control circuit,
ON / OFF of each switching element is switched. Therefore, the on-timing of the switching element can be accurately controlled, and the power factor of the rectifier circuit can be improved. Moreover, since the switching elements are alternately operated, it is possible to suppress unnecessary power consumption.

According to the next invention, each switching element is turned on by the control circuit at a timing delayed from the zero cross point of the AC voltage. Therefore, after the polarity of the alternating voltage is reversed, the charged capacitor of the power supply short-circuiting means starts discharging. Due to the discharge, current flows in the rectifier circuit even before the switching element is turned on, so the power factor of the rectifier circuit is improved, and the input current can flow without causing loss due to the ON operation of the switching element. Can be higher. In addition, by controlling the on-timing, it is possible to control the power factor to be optimum. In addition, by controlling the discharge of the charge on the DC side, it is possible to improve the efficiency and control the output voltage by effectively utilizing the charge. Further, it is possible to cope with a change in load.

According to the next invention, when the relay is turned on, the half-wave rectifier circuit is obtained. A full wave rectifier circuit is obtained when the relay is turned off. Therefore, by controlling ON / OFF of the relay according to the voltage value of the AC voltage input to the rectifier circuit, it becomes possible to cope with different AC voltages. Further, by controlling the ON / OFF of the relay according to the load amount, it becomes possible to prevent the load efficiency from decreasing. Further, since full-wave rectification and half-wave rectification can be switched, cost can be reduced by leveling the circuit.

According to the next invention, the relay is turned on / off according to the voltage value of the alternating voltage. Therefore, when an AC voltage is low can be used as a half-wave rectification circuit rectifying circuit by turning on the relay. Also,
When the AC voltage is high can be used rectifier circuit as a full-wave rectifier circuit by turning off the relay.
Further, since the circuit damage can be avoided even if the user makes an input voltage connection error, the reliability is improved.

According to the next invention, the relay is turned on / off according to the load amount. Therefore, when the load is heavy can be used as a half-wave rectification circuit rectifying circuit by turning on the relay. Further, when the load is light it can be used rectifier circuit as a full-wave rectifier circuit by turning off the relay. By switching according to the load amount in this way, it is possible to prevent the efficiency of the motor load from decreasing.

According to the next invention, since there are two capacitors, each capacitor is charged and discharged once per AC voltage cycle. When there is only one capacitor, the capacitor is charged and discharged once every half cycle of the AC voltage. Therefore, the number of times the capacitor is charged and discharged is halved, which extends the life of the capacitor. Further, when each switching element is formed of a transistor, the emitters of the two transistors have the same potential, so that there is an effect that a new gate drive power supply is unnecessary.

According to the next invention, the rectifying means rectifies the AC voltage applied via the reactor. The power supply short-circuit means includes a switch element and a capacitor that operate every half cycle of the AC voltage, and controls the current flowing by the AC voltage by charging and discharging the capacitor. Therefore, the effect of reducing the noise generated from the reactor is obtained. Further, since the switching frequency of the switching element is turned on / off lower than in the conventional case, the loss associated with the on / off operation is significantly reduced, and the efficiency of the circuit is improved.

Further, it is not necessary to precisely control the off timing of the switching element. Therefore, the power factor of the rectifier circuit can be set to the maximum power factor only by controlling the on-timing of the switch element, so that the power factor can be improved by a simple control process. Further, since the current input from the AC power supply can be controlled by charging and discharging the capacitor, the power supply harmonic current included in the input current can be reduced. Further, by using the bidirectional switch element, the effect of reducing the number of parts can be obtained.

According to the next invention, the charge accumulated in the capacitor is discharged to the output side of the rectifying means by the charge discharging means. Therefore, the electric charge accumulated in the capacitor by the short-circuit current is supplied to the load side, so that the DC voltage supplied to the load can be changed. In addition, by controlling the discharge of the charge on the DC side, it is possible to improve the efficiency and control the output voltage by effectively utilizing the charge. Further, it is possible to cope with a change in load. Furthermore, if a self-extinguishing type element is used, the switching element can be forcibly turned off even if zero current switching does not occur, so even if there is a large change in the load, the supply voltage to the load can be correspondingly changed. Can be changed. in this case,
Even if the switching is not zero current switching, the amount of noise is small because the load is small.

Further, according to the compressor drive device of the present invention, the power supply short-circuit means of the rectifier circuit controls the current flowing by the AC voltage by charging and discharging the capacitor, so that the power factor of the rectifier circuit is improved. Therefore, since the noise is reduced and the output of the motor load is increased, it is possible to obtain an electric product that is highly efficient and less affected by external noise. In addition, since it reduces noise, it can be applied to indoor products. By reducing noise and noise, it is possible to reduce the number of countermeasure components, and thus it is possible to reduce the size and cost of electrical products.

According to the next invention, the charges accumulated in the capacitor are discharged to the output side of the rectifying means by the charge discharging means. Therefore, the electric charge accumulated in the capacitor by the short-circuit current is supplied to the load side, so that the DC voltage supplied to the load can be changed. In addition, by controlling the discharge of the charge on the DC side, it is possible to improve the efficiency and control the output voltage by effectively utilizing the charge.

Further, according to the rectifier circuit of the present invention,
A reactor, a rectifying means for rectifying an AC voltage applied via the reactor, a pair of capacitors connected in series between output terminals of the rectifying means, and an input terminal of the rectifying means. Switching means,
The resonance means is connected between the switching means and a connection point between the pair of capacitors, and a control means for switching the switching means once every half cycle of the AC voltage. Since the current flowing by turning on flows through the resonance capacitor, it becomes difficult to flow as the charging of the resonance capacitor progresses. Therefore, the phase current becomes smooth, and abrupt changes in the magnetic flux generated in the reactor are suppressed, so that vibrations in the windings and the iron core can be reduced, and the generation of reactor noise can be suppressed.

In the present invention, if the control means is configured to keep the switching means on for a time longer than the charging time of the resonant capacitor, the switching means is turned off after the charging of the resonant capacitor is completed. Since zero current switching is performed, switching loss at turn-off can be reduced.
Therefore, it is possible to improve circuit efficiency and save energy. In addition, since the control relating to the turn-off of the switching means is unnecessary, the control processing is extremely reduced.

According to the rectifier circuit of the present invention,
Reactor, rectifying means for rectifying the AC voltage applied via the reactor, a pair of capacitors connected in series between the output terminals of the rectifying means, an input terminal of the rectifying means and the pair of capacitors. Since the switching means is connected between the connection points of the capacitors and the control means for switching the switching means at least twice in the half cycle of the AC voltage, the switching means is provided once in the half cycle of the power supply. It is possible to reduce the inductance value of the reactor while ensuring the harmonic suppression capability equivalent to that in the case of operating. Therefore, even if there is no resonance capacitor, the same effect as suppressing noise by the resonance capacitor can be obtained.

In these inventions, the control means is
If the ON operation of the switching means is started at a timing delayed by a predetermined time from the zero-cross point in each half cycle of the AC voltage, the input current can be controlled by an open loop.

According to the rectifier circuit of the present invention,
A reactor, a rectifying means for rectifying an AC voltage applied via the reactor, a pair of capacitors connected in series between output terminals of the rectifying means, and an input terminal of the rectifying means. A first switching means, a resonance capacitor connected between the first switching means and a connection point between the pair of capacitors, a second switching means connected in parallel with the resonance capacitor; According to the load amount of the load connected between the output terminals of the rectifying means, the second switching means is turned off to switch the first switching means once every half cycle of the AC voltage, or Control for turning on the second switching means to switch the first switching means twice or more in a half cycle of the AC voltage. Because comprising a stage, a second switching means is off state, the current flowing through the first switching means is turned on flows through the resonance capacitor. Therefore, as the charging of the resonant capacitor proceeds, it becomes difficult for the current to flow, and the phase current becomes smooth, so that a sharp change in the magnetic flux generated in the reactor is suppressed. Therefore, it is possible to reduce vibrations in the windings and the iron core, and suppress the generation of reactor noise. On the other hand, when the second switching means is in the ON state, it is possible to reduce the inductance value of the reactor while ensuring the harmonic suppression capability equivalent to the case where the first switching means operates once in a half cycle of the power supply. Therefore, even if the resonance capacitor is invalid, the same effect as suppressing noise by the resonance capacitor can be obtained.

In the present invention, if the control means is configured to keep the first switching means in the ON state for a time longer than the charging time of the resonant capacitor when the second switching means is off. After the charging of the resonance capacitor is completed, the first switching means is turned off, so that the zero current switching is performed. Therefore, the switching loss at the time of turn-off can be reduced, so that the circuit efficiency is improved and the energy can be saved. Further, since the control relating to the turn-off of the first switching means is unnecessary, the control processing is extremely reduced.

According to the rectifying circuit of the present invention,
A reactor, a rectifying means for rectifying an AC voltage applied via the reactor, a pair of capacitors connected in series between output terminals of the rectifying means, and an input terminal of the rectifying means. A first switching means, a first resonance capacitor connected between the first switching means and a connection point between the pair of capacitors, and a second resonance capacitor connected in parallel to the first resonance capacitor. Between the resonance capacitor and both electrodes of the first resonance capacitor, the second switching means connected in series to the second resonance capacitor, and the first switching means for a half cycle of the AC voltage. The second switching means is turned on / off in accordance with the load amount of the load connected between the output terminals of the rectifying means, while switching each time. Since the control means for switching is provided, the capacitor capacity of the LC resonance can be changed according to the load quantity. Therefore, the capacitor capacity appropriate for the load quantity at the light load and the load capacity for the heavy load are suitable. Even when the capacitance is different from that of the capacitor, the current can be appropriately controlled by switching the capacitance. Therefore, the effect of suppressing the reactor sound by the resonance capacitor can be obtained over a wide range of load amounts.

In the present invention, the control means keeps the first switching means on for a time longer than the charging time of the first resonant capacitor when the second switching means is off, or When the second switching means is turned on, the first switching means is turned on for a time longer than a charging time of a resonance capacitor having a longer charging time among the first resonance capacitor and the second resonance capacitor. If the configuration is kept at, the first switching means is turned off after the charging of the resonance capacitor is completed, so that the zero current switching is performed, and therefore, the switching loss at the time of turn-off can be reduced, so that the circuit efficiency is improved. It is possible to improve and save energy. Further, since the control relating to the turn-off of the first switching means is unnecessary, the control processing is extremely reduced.

In the present invention, if the control means is configured to start the ON operation of the first switching means at a timing delayed by a predetermined time from the zero-cross point in each half cycle of the AC voltage, the control circuit is opened. The input current can be controlled by the loop.

Further, since the compressor drive device according to the present invention is provided with the above-mentioned rectifying circuit, the effects of each of the above-mentioned rectifying circuits can be enjoyed.

In each of the above inventions, the rectifying means is 3
It is a phase diode full-wave rectifier circuit and may be connected to a three-phase AC power supply. In this case, a three-phase rectifier circuit can be configured.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of a rectifier circuit according to a first embodiment of the present invention.

FIG. 2 is a circuit block diagram showing a configuration of a rectifier circuit according to the first exemplary embodiment of the present invention.

FIG. 3 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 4 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

5 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 6 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 7 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

8 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

9 is a waveform diagram showing an input current of the rectifier circuit shown in FIG.

10 is an enlarged view showing a part of the waveform of the input current shown in FIG.

FIG. 11 is a circuit block diagram showing another configuration of the rectifier circuit according to the first exemplary embodiment.

FIG. 12 is a circuit block diagram showing a configuration of a rectifier circuit according to a second embodiment of the present invention.

FIG. 13 is a circuit block diagram showing another configuration of the rectifier circuit according to the second embodiment.

FIG. 14 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 15 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

16 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 17 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 18 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 19 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 20 is a circuit block diagram showing a configuration of a rectifier circuit according to a third embodiment of the present invention.

FIG. 21 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

22 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 23 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 20.

FIG. 24 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 25 is a diagram for explaining a current path of the rectifier circuit shown in FIG.

FIG. 26 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 27 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 20.

FIG. 28 is a diagram for explaining current paths in the rectifier circuit shown in FIG.

FIG. 29 is a circuit block diagram showing a configuration of a rectifier circuit according to a fourth embodiment of the present invention.

FIG. 30 is a circuit diagram showing an embodiment of the switch element shown in FIG.

FIG. 31 is a circuit block diagram showing another configuration of the rectifier circuit according to the fourth embodiment.

FIG. 32 is a circuit block diagram showing a configuration of a compressor drive device according to the fifth embodiment of the present invention.

FIG. 33 is a circuit block diagram showing a configuration of a rectifier circuit according to a sixth embodiment of the present invention.

FIG. 34 is a functional block diagram showing a functional configuration of a rectifier circuit according to a sixth embodiment of the present invention.

FIG. 35 is a diagram for explaining a current path of the rectifier circuit shown in FIG. 33.

FIG. 36 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 33.

FIG. 37 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 33.

FIG. 38 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 33.

FIG. 39 is a diagram for explaining current paths in the rectifier circuit shown in FIG. 33.

FIG. 40 is a waveform diagram showing each waveform of an R-phase input voltage, each-phase switching signal, and a current flowing through a resonant capacitor in the rectifier circuit shown in FIG. 33.

41 is a waveform diagram showing a waveform of a current flowing through the rectifier circuit shown in FIG. 33.

FIG. 42 is a chart showing a list of regulation values currently under consideration for three-phase power sources in Japan.

FIG. 43 is a schematic diagram showing an enlarged main part of a phase current at the time of switching in order to explain a difference depending on the presence or absence of a resonance capacitor in the sixth embodiment.

FIG. 44 is a circuit block diagram showing a configuration when a rectifying circuit according to a sixth embodiment of the present invention is applied to a single phase.

FIG. 45 is a circuit block diagram showing a configuration of a rectifier circuit according to a seventh embodiment of the present invention.

FIG. 46 is a schematic diagram showing an example of a current by switching in the seventh embodiment.

FIG. 47 is a circuit block diagram showing a configuration of a rectifier circuit according to an eighth embodiment of the present invention.

FIG. 48 is a circuit block diagram showing a configuration of a rectifier circuit according to a ninth embodiment of the present invention.

FIG. 49 is a circuit block diagram showing a configuration of a compressor drive device according to the tenth embodiment of the present invention.

FIG. 50 is a circuit block diagram showing a configuration of a conventional rectifier circuit.

FIG. 51 is a circuit block diagram showing another configuration of a conventional rectifier circuit.

FIG. 52 is a circuit block diagram showing a configuration of a conventional full-bridge type high power factor converter.

FIG. 53 is a circuit block diagram showing a configuration of a conventional active filter.

[Explanation of symbols]

11, 127, 128, 150, 157, 158 Smoothing capacitors, 18, 133, 134, 135, 163
164 reactor, 2,138,168 AC power supply,
3,139,169 load, 4,4a, 142 rectification means, 5,140 power supply short-circuit means, 51,55,57,12
9, 159, 190 capacitors, 52, 53, 56
Switching element (transistor), 54, 180 relay, 5
8, 130, 131, 132, 160, 161 switch element, 6, 6a, 141 charge discharging means, 61, 6
2, 63, 64, 67 diode, 65, 66 voltage doubler capacitor, 71 polarity detector, 72 control circuit, 7
3 relay switching section, 74 load detecting section, 8 inverter, 9 motor (compressor), 137, 177, 18
7,197 Control means.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunori Sakahirobe 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Mamoru Kawakubo 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Within Mitsubishi Electric Corporation (56) Reference JP-A-9-107681 (JP, A) JP-A-11-164562 (JP, A) JP-A-11-168885 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) H02M 7/12 H02M 7/48

Claims (17)

(57) [Claims] 1. A reactor for rectifying an AC voltage of an AC power supply.
A rectifying means connected to Le, the switching means and the capacitor
And the switching means is closed.
And the reactor and the capacitor and the switching
It includes a power supply short-circuit means for means for short-circuiting the AC power supply are connected in series, and when short-circuiting the AC power supply flows into the reactor
Change between the positive current change rate and the negative current change rate of the power supply short-circuit current
Charge the capacitor so that the
The electric charge accumulated in the capacitor of the
The rectifying device, either through a step or the rectifying means.
Rectifier circuit characterized by discharging to the output side of the stage . 2. A combination of the reactor and the capacitor
The vibration frequency was made higher than the power supply frequency of the AC power supply.
Rectifier circuit according to claim 1, characterized in that. 3. The power supply short-circuit means is connected in series,
A first opening / closing that alternately switches from an off state to an on state every half cycle of the alternating voltage according to the polarity of the alternating voltage.
A switching means comprising an element and a second switching element ; and the capacitor connected between the midpoint of the first and second switching elements connected in series and one input end of the rectifying means. The rectifying circuit according to claim 1 , further comprising: the switching means connected in parallel to the rectifying means. 4. The power supply short-circuit means, in accordance with the polarity of the AC voltage, every half cycle of the AC voltage.
First opening and closing that alternately switches from the off state to the on state
A switching device including an element and a second switching element, and switching between discharging and charging when a power source is short-circuited.
A first capacitor and a second capacitor that form a capacitor
Comprising support and the first capacitor and the first on-off element connected in series
The child is one input end of the rectifying means and one of the rectifying means.
A second capacitor and a second switching element connected in series with the output terminal of the
The child is the other input end of the rectifying means and one of the rectifying means.
Claim that is connected between the output end of
The rectifier circuit according to Item 1 . 5. The power supply short-circuit means, when the AC power supply is short-circuited, is connected via the rectifying means.
The reactor and the switching means
Are connected in series or without the rectification means
The reactor and the switching means in the reactor
Have one of the connection states of being connected in series
The rectifier circuit according to claim 1 , wherein: 6. The first switching element and the second switching element
La configured switching means, the polarity of the alternating voltage
According to the above, the AC voltage is alternately turned on every half cycle.
A switching control circuit is provided , The rectifier circuit of Claim 3 or 4 characterized by the above-mentioned. 7. The polarity of the AC voltage and the zero-cross point
Comprises a polarity detector, for detecting said control circuit is detected by the polarity detection section the
From the zero-cross point of the AC voltage, the power supply short-circuit means
Delay any time between discharging the capacitor
The first switching element and the second switching element at the selected timing.
The rectifying circuit according to claim 6 , wherein the switching means including the children are alternately turned on . 8. A rectifying means connected in series,
A pair of smoothing capacitors connected to the output side, and provided between the pair of smoothing capacitors and the rectifying means.
Are, anti backflow of charges from the pair of the smoothing capacitor
Comprising a tool blocking diode, wherein the pair of the smoothing capacitor in parallel to said rectifying means
And a relay connected between the middle point of connection of the pair of smoothing capacitors and the input end of the rectifying means , and a relay switching unit for controlling ON / OFF of the relay.
Either when, from claim 1, characterized in that it comprises a fourth
Rectifier circuit according to one . 9. The relay switching unit is configured to control the AC voltage.
The switching control of the relay according to the voltage value of
The rectifier circuit according to claim 8 , wherein: 10. The output voltage of the rectifier circuit is supplied.
A load detection unit that detects a load amount of a load, and the relay switching unit is detected by the load detection unit.
The switching control of the relay according to the load amount of the load
Rectifier circuit according to claim 8, wherein the performing control. 11. The power supply short-circuit means has one connection side,
It is connected to the input side of the rectification means, and the other connection side of the power supply short-circuit means is connected to the output side of the rectification means.
The switching means connected to the power side and forming the power supply short-circuit means.
The rectifier circuit according to claim 1 or 2 , wherein the alternating voltage is switched once every half cycle . 12. The switching means or the rectification
Instead of via one of the means
The rectifying means by connecting the end side and the output side of the rectifying means.
Discharge to the output side of the
Rectifier circuit. 13. A rectifier for rectifying an AC voltage of an AC power supply,
A rectifying means connected to the torque converter , a switching means and a capacitor.
When the itching means is closed, the reactor and the controller are closed.
The capacitor and the switching means are connected in series
A power supply short-circuiting means for short-circuiting an AC power supply and a capacitor forming the power supply short-circuiting means are connected in parallel.
Comprising a connection to a capacitor parallel switching means, and to contact and separation of the capacitor parallel switching means
By the switching means forming the power supply short-circuit means,
When the AC power supply is short-circuited, the power supply short-circuit means is formed.
Through the capacitor that flows to the reactor.
Change in positive current change rate and negative current change rate of source short-circuit current
Charge the capacitor so that the width becomes smaller, or
Others, to the switching means for forming the power supply short-circuit means
When the AC power supply is short-circuited, the power supply short-circuit means is formed.
2 in the half cycle of the AC voltage without passing through the capacitor
Power supply that flows to the reactor after switching more than once
Smooth the short-circuit current, either of the rectifying means
Switching according to the load amount of the load connected between the output terminals
Rectifier circuit, characterized in that that. 14. The capacitor switches its capacity.
It is formed so that it can be formed.
The rectifier circuit according to item 13 . 15. The controller forming the power supply short-circuit means.
For a time longer than the charging time of the capacitor,
To keep the switching means forming on
15. The trim according to claim 1, 12, 13 or 14.
Flow circuit . 16. Zero in each half cycle of the alternating voltage.
The power supply is delayed by a predetermined time from the cross point
ON operation of the switching means forming the short-circuit means
14. The method of claim 1, 12, 13 or
Is a rectifier circuit according to 14 . 17. The method according to claim 1, 12, 13 or 14.
Comprising a rectifier circuit of the mounting, the inverter output voltage of the rectifier circuit is applied, Oyo
And a compression with a motor driven by the inverter
Machine, compressor driving apparatus characterized by comprising a.