CN107276388B - PFC circuit and variable frequency air conditioner - Google Patents
PFC circuit and variable frequency air conditioner Download PDFInfo
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- CN107276388B CN107276388B CN201710535265.5A CN201710535265A CN107276388B CN 107276388 B CN107276388 B CN 107276388B CN 201710535265 A CN201710535265 A CN 201710535265A CN 107276388 B CN107276388 B CN 107276388B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4233—Arrangements for improving power factor of AC input using a bridge converter comprising active switches
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4283—Arrangements for improving power factor of AC input by adding a controlled rectifier in parallel to a first rectifier feeding a smoothing capacitor
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The invention provides a PFC circuit and a variable-frequency air conditioner, wherein a first switch module and a second switch module are added in PFC current, the first switch module is connected in series in an alternating current loop formed by a reactor and a rectifying module, the alternating current input end of a power factor correcting module is connected with the alternating current input end of the rectifying module in parallel, one end of the second switch module is connected in the alternating current loop, and the other end of the second switch module is connected to the common joint of two capacitors in a filter circuit formed by a first capacitor and a second capacitor. The PFC circuit of the invention realizes the switching of the rectifying and filtering circuit in the PFC circuit between the full-bridge rectifying module and the voltage-multiplying rectifying mode through the second switch module so as to realize that the PFC circuit can still realize high conversion efficiency when a load is in low-power operation.
Description
Technical Field
The invention relates to the field of PFC control, in particular to a PFC circuit and a variable frequency air conditioner.
Background
The conventional PFC (Power Factor Correction) circuit for driving a variable frequency compressor or a DC motor under low voltage such as 100VAC (variable frequency Power supply) Power supply voltage generally adopts voltage-multiplying rectification and then outputs Power supply, and because the voltage-multiplying rectification mode has the problem of low conversion efficiency under the low-Power working state when a load works, the waste of electric energy is caused.
Disclosure of Invention
The invention mainly aims to provide a PFC circuit and a variable frequency air conditioner, and aims to solve the problem that the conversion efficiency of the conventional PFC circuit is low when the PFC circuit works in a voltage-multiplying rectification mode.
In order to achieve the above object, the present invention provides a PFC circuit, which includes a reactor, a power factor correction module, a rectification module, a first switch module, a second switch module, a first capacitor, a second capacitor, and a driving module;
the reactor is connected with the input end of an alternating current power supply, and the reactor, the rectifying module and the first switch module are connected in series in an alternating current power supply loop;
the control end of the first switch module is connected with the controller, and the controller controls the on-off of the first switch module so as to control the on-off of the alternating current input loop;
the first capacitor and the second capacitor are connected in series and then connected in parallel at the output end of the rectifying module;
the driving module is connected with the output end of the rectifying module in parallel, the alternating current power supply is rectified by the rectifying module to output direct current so as to provide power for the driving module to work, the control end of the driving module is connected with the controller, and the controller controls the driving module to drive a load to operate;
the alternating current input end of the power factor correction module is connected with the alternating current input end of the rectification module in parallel, the control end of the power factor correction module is connected with the controller, and the power factor correction module performs switching under the control of the controller so as to perform power factor correction on the direct current voltage and the direct current output by the rectification module;
one end of the second switch module is connected with the alternating current loop, the other end of the second switch module is connected with a common contact of the first capacitor and the second capacitor, a control end of the second switch module is connected with the controller, and the controller controls the on-off of the second switch module to control the rectification filter circuit consisting of the rectification module, the first capacitor and the second capacitor to realize the switching of a full-bridge rectification mode and a voltage-multiplying rectification mode.
Preferably, one end of the first switch module and one end of the second switch module are connected to the input end of the zero line of the alternating current power supply, the other end of the second switch module is connected to the common junction of the first capacitor and the second capacitor, and the other end of the first switch module is connected to the common junction of the power factor correction module and an alternating current input end of the rectification module.
Preferably, one end of the second switch module is connected with the input end of the zero line of the alternating-current power supply, and the other end of the second switch module is connected with the common junction of the first capacitor and the second capacitor;
one end of the first switch module is connected with the input end of the live wire of the alternating current power supply, and the other end of the first switch module is connected with a common junction point of the power factor correction module and an alternating current input end of the rectification module.
Preferably, one end of the second switch module is connected to the input end of the live wire of the alternating-current power supply, and the other end of the second switch module is connected to the common junction point of the first capacitor and the second capacitor;
one end of the first switch module is connected with the input end of the zero line of the alternating current power supply, and the other end of the first switch module is connected with a common joint of the power factor correction module and an alternating current input end of the rectification module.
Preferably, one end of the first switch module is connected to the live wire input end of the alternating current power supply, the other end of the first switch module and one end of the second switch module are connected, an alternating current input end of the power factor correction module and an alternating current input end of the rectification module are connected in common, and the other end of the second switch module is connected to a common junction point of the first capacitor and the second capacitor.
Preferably, the device also comprises a current detection module,
the current detection module is connected in series with the alternating current loop, and the output end of the current detection module is connected with the controller to detect the value of the alternating current input by the alternating current power supply.
Preferably, the device also comprises a zero-crossing detection module,
the zero-crossing detection module is connected with the input end of the alternating current power supply in parallel, the output end of the zero-crossing detection module is connected with the controller to detect a voltage zero-crossing signal of the alternating current power supply, and the controller controls the switching state of the power factor correction module to switch according to the voltage zero-crossing signal.
Preferably, when the load is a compressor, the controller is further configured to:
judging the current frequency for controlling the operation of the compressor, and when the operation frequency is greater than a preset value, controlling the second switch module to be conducted by the controller so as to control the rectification filter circuit to work in a voltage-multiplying rectification mode; when the operating frequency is smaller than the preset value, the controller controls the second switch module to be switched off so as to control the rectifying and filtering circuit to work in a full-bridge rectifying mode.
Preferably, the power factor correction module comprises a rectifying unit, a switching unit and a driving unit;
two input ends of the rectifying unit are two alternating current input ends of the power factor correction module, and two output ends of the rectifying unit are connected with the switch unit in parallel;
the control end of the switch unit is connected with the driving unit, and the input end of the driving unit is connected with the control end of the power factor correction circuit.
In order to achieve the above object, the present invention further provides an inverter air conditioner, which includes the power factor correction circuit.
According to the PFC circuit provided by the invention, the first switch module and the second switch module are added in the PFC current, the first switch module is connected in series in an alternating current loop formed by a reactor and a rectifying module, the alternating current input end of a power factor correcting module is connected with the alternating current input end of the rectifying module in parallel, one end of the second switch module is connected in the alternating current loop, and the other end of the second switch module is connected to the common joint of two capacitors in a filter circuit formed by a first capacitor and a second capacitor. The PFC circuit of the invention realizes the switching of the rectification filter circuit in the PFC circuit between the full-bridge rectification module and the voltage-multiplying rectification mode through the second switch module so as to realize that the PFC circuit can still realize high conversion efficiency when a load is in low-power operation, and the first switch module realizes that the whole PFC and the load can be disconnected when the PFC circuit is in abnormal work protection, thereby realizing the safety protection of the whole PFC circuit.
Drawings
Fig. 1 is a schematic circuit diagram of a PFC circuit according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of a current loop of the first embodiment operating in the voltage-doubler rectification mode;
FIG. 3 is a schematic diagram of a current loop of the first embodiment operating in the voltage-doubler rectification mode;
fig. 4 is a schematic circuit diagram of a PFC circuit according to a second embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a PFC circuit according to a third embodiment of the present invention;
FIG. 6 is a schematic diagram of a current loop of the third embodiment operating in the voltage-doubler rectification mode;
FIG. 7 is a schematic diagram of a current loop of the third embodiment operating in the voltage-doubler rectification mode;
fig. 8 is a schematic circuit diagram of a PFC circuit according to a fourth embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
Referring to fig. 1, fig. 1 is a structural diagram of a PFC circuit according to a first embodiment of the present invention, and for convenience of description, only the parts related to the embodiment of the present invention are shown, and detailed descriptions are as follows:
the PFC circuit provided in the embodiment of the present invention includes a reactor L, a power factor correction module 10, a rectification module 40, a first switch module 20, a second switch module 30, a first capacitor E1, a second capacitor E2, a controller 60, and a driving module 50;
the reactor L is connected with the input end of the alternating current power supply, and the reactor L, the rectifying module 40 and the first switching module 20 are connected in series in an alternating current power supply loop;
the control end of the first switch module 20 is connected with the controller 60, and the controller 60 controls the on-off of the first switch module 20 to control the on-off of the alternating current input loop;
the first capacitor E1 and the second capacitor E2 are connected in series and then connected in parallel at the output end of the rectifying module 40;
the driving module 50 is connected in parallel to the output end of the rectifying module 40, the alternating current power supply is rectified by the rectifying module 40 to output direct current power to provide power for the driving module 50 to work, the control end of the driving module 50 is connected with the controller 60, and the controller 60 controls the driving module 50 to drive the load to operate;
the alternating current input end of the power factor correction module 10 is connected in parallel with the alternating current input end of the rectification module 40; the power factor correction module 10 and the reactor L form a PFC circuit, a control end of the power factor correction module 10 is connected to the controller 60, and the power factor correction module 10 performs switching under the control of the controller 60 to perform power factor correction on the dc voltage and the dc current output by the rectification module 40;
one end of the second switch module 30 is connected to the ac loop, the other end of the second switch module 30 is connected to the common junction of the first capacitor E1 and the second capacitor E2, the control end of the second switch module 30 is connected to the controller 60, and the controller 60 controls the on/off of the second switch module 30 to control the rectifier filter circuit composed of the rectifier module 40, the first capacitor E1 and the second capacitor E2 to realize the switching between the full-bridge rectification mode and the voltage-multiplying rectification mode.
Specifically, the first switch module 20 includes a switch K1 and a switch driving unit 1 for driving the switch K1, where the switch K1 is generally a relay, the switch driving unit 1 is a corresponding circuit for driving the relay, and has a driving circuit formed by a triode, a control stage of the triode, i.e., a base, is a control end of the first switch module 20, two switch ends of the relay are two ends of the first switch module 20, and the controller 60, i.e., a control port of the MCU, controls on/off of the switch K1 through the switch driving unit 1 by outputting a signal. Here, since the relay and the switch driving unit 1 for driving the relay are related to the prior art, detailed description of the circuit thereof is omitted.
The circuit structure of the second switch module 30 is the same as that of the first switch module 20, the second switch module 30 includes a switch K2 and a switch driving unit 2 for driving the switch K2, and a control port of the controller 60 outputs a control signal to control the on/off of the switch K2 through the switch driving unit 2.
The power factor correction module 10 includes a rectification unit 11, a switching unit 12 and a driving unit 13;
two input ends of the rectifying unit 11 are two alternating current input ends of the power factor correction module, and two output ends of the rectifying unit 11 are connected in parallel with the switching unit 12;
the control end of the switch unit 12 is connected to the driving unit 13, and the input end of the driving unit 13 is connected to the control end of the PFC circuit.
Here, the rectifying unit 11 includes a full-bridge rectifying module BR1 for rectifying the input ac power into dc power, the switching unit includes a switching tube Q1 formed by an IGBT (Insulated Gate Bipolar Transistor), the PFC driving unit 12 is a driving circuit for driving the switching tube Q1 to operate, a control terminal of the PFC driving unit 12 is connected to the controller 60, and the controller 60 controls the switching of the switching tube Q1 through the PFC driving unit 12, so as to control the operation of the power factor correction module 10.
The rectifier module 40 is also composed of a full-bridge rectifier module BR2, which is the same as the circuit structure of the rectifier unit 11 of the power factor correction module 10, and rectifies the input ac power into dc power.
In this embodiment, one end of the first switch module 20 and one end of the second switch module 30 are connected to the input end of the zero line of the ac power source, the other end of the second switch module 30 is connected to the common node of the first capacitor E1 and the second capacitor E2, and the other end of the first switch module 20 is connected to the common node of the power factor correction module 10 and an ac input end of the rectifier module 40.
The PFC circuit of this embodiment further includes a current detection module 70, two detection terminals of the current detection module 70 are connected in series to the ac loop, and an output terminal of the current detection module 70 is connected to the controller 60 to detect an ac current value input by the ac power supply. The current detection module 70 comprises a current transformer T1 and an additional detection circuit, the output end of the current detection module 70 is connected with the controller 60, and the controller can obtain the detected current value of the ac loop. The specific circuit of the current detecting module 70 can refer to the prior art, and is not described herein again.
The PFC circuit of this embodiment further includes a zero-crossing detection module 80, where the zero-crossing detection module 80 is configured to detect a voltage zero-crossing signal of the ac power source, and the controller 60 switches the switching state of the power factor correction module 10 according to the voltage zero-crossing signal. The specific circuit of the zero-crossing detection module 80 can refer to the prior art, and is not described herein again.
The circuit shown in this embodiment operates as follows: when the K1 of the first switch module 20 is closed and the K2 of the second switch module 30 is open, the rectifying and filtering circuit composed of the rectifying module 40, the first capacitor E1 and the second capacitor E2 operates in the full-bridge rectifying mode. At the moment, a live wire, namely an L wire, of the alternating current power supply is loaded on an alternating current input end of the full-bridge rectification module BR2 through the first FUSE1, the differential mode filter inductor L2, the current transformer T1 and the reactor L. The live wire, i.e. the L wire, of the ac power supply passes through the differential-mode filter inductor L2, and when the K1 of the first switch module 20 is loaded at the other ac input end of the full-bridge rectifier module BR 2. The alternating current power supply outputs direct current after being rectified by the full-bridge rectification module BR2, and stable direct current is obtained after being filtered by a filter circuit formed by connecting the first capacitor E1 and the second capacitor E2 in series and is loaded on the driving module 50, so that the rectification module BR2 works in a full-bridge rectification mode at the moment. Meanwhile, a PFC circuit composed of the full-bridge rectifier module BR1, the switching tube Q1, the PFC driving unit 12 and the reactor L performs PFC correction under the control of the controller 60, namely the MCU, and since the PFC circuit is connected to an alternating current side, an alternating current signal needs to be rectified into direct current through the full-bridge rectifier module BR1 and loaded at two ends of a source electrode and a drain electrode of the IGBT switching tube Q1, and a grid electrode is controlled by a switching pulse signal output by the MCU through the PFC driving unit. When the switch tube Q1 is switched on, the alternating current power supply forms a loop through the reactor L, the full-bridge rectifier module BR1, the switch tube Q1 and the K1 of the first switch module 20, the reactor L stores energy, when the switch tube Q1 is switched off, induced electromotive force is generated on the reactor L, the current direction of the current corresponding to the induced electromotive force flowing through the reactor L is consistent with that before the switch tube Q1 is switched off, and the current corresponding to the induced electromotive force charges the first capacitor E1 and the second capacitor E2 through the full-bridge rectifier module BR2, so that PFC correction is realized.
When the K1 of the first switch module 20 is closed and the K2 of the second switch module 30 is closed, the rectifying and filtering circuit composed of the rectifying module 40, the first capacitor E1 and the second capacitor E2 operates in the voltage-doubling rectifying mode. As shown in fig. 2, when the alternating current of the alternating current power supply starts from the line L, the alternating current flows through the reactor L, the full-bridge rectifier module BR2, the first capacitor E1 and the switch K2 to return to the line N of the alternating current as shown by the dotted line in the figure; as shown in fig. 3, when the ac current of the ac power supply starts from the N line, the ac current flows through the switch K2, the second capacitor E2, the full-bridge rectifier module BR2, and the reactor L, and returns to the ac current from the L line, as shown by the dotted line in the figure. Since the alternating current starts from the L line and the N line, the first capacitor E1 and the second capacitor E2 are respectively charged, the voltage loaded at the two ends of the first capacitor E1 and the second capacitor E2 after being connected in series is twice of the alternating current charging voltage, that is, the double-voltage rectification mode is operated at this time. Meanwhile, the operation of the PFC circuit is substantially the same as that when the switch K2 is turned off, that is, when the switching tube Q1 is turned on, the current loop is the same as that described above, and when the switching tube Q1 is turned off, the current direction corresponding to the induced electromotive force generated in the reactor L is the same as that before the switching tube Q1 is turned off, and at this time, the current charges the first capacitor E1 or the second capacitor E2 in the directions of the dotted lines in fig. 2 and 3, respectively, thereby implementing PFC correction.
In the PFC circuit of the present embodiment, the second switch module 30 performs switching between the full-bridge rectification mode and the voltage-doubling rectification mode, and the first switch module 20 is connected in series in the ac loop, so that when the first switch module 20 is turned off, the ac loop is turned off, and when the ac loop is turned off, the rectifier module 40 and the power factor correction module 10 are connected in series in the ac loop, and power supply to the two modules is also turned off, thereby realizing power supply to the whole PFC circuit and the rear-stage driving module 50 and the load of the rectifier module 20. In a specific application, the load includes a compressor or a motor, the driving Module 50 corresponds to a driving circuit for driving the compressor or the motor, the compressor or the motor is a permanent magnet synchronous motor, the driving Module 50 includes an IPM Module (Intelligent Power Module), and the driving Module is configured to invert a direct current loaded on the IPM Module into an alternating current to drive the compressor or the motor under the control of the controller 60. When the PFC circuit of this embodiment is in operation, because the input of the PFC circuit is an alternating current, it is necessary to ensure that a current is maintained when the switching tube Q1 is in operation to store energy in the reactor L, and therefore the controller needs to detect a zero-crossing signal of the alternating current through the zero detection module 80, and control the switching tube Q1 to be turned on after the zero-crossing to ensure that the switching tube Q1 can store energy in the reactor L through a continuous current. In addition, during the operation of the PFC circuit, the controller 60 needs to obtain the current working current of the circuit through the current detection module 70, if the working current of the load is found to be too high, which causes the working current of the PFC circuit to be too high, the controller 60 needs to control the operating frequency of the switching tube Q1 to be reduced to reduce the working current, and when the working current is detected to exceed the limit value, the first switching module 20 needs to be controlled to be turned off to turn off the entire PFC circuit and the load, so as to achieve the safety protection of the PFC circuit and the load. Since the entire PFC circuit and load are powered off when the first switch module 20 is turned off, and the control module 60 still needs to operate, a dc power supply needs to be added to supply power to the control module 60, as shown in fig. 1.
The rectifying and filtering circuit shown in this embodiment is suitable for increasing the output dc voltage through voltage-doubling rectification when the input ac voltage is low, such as the input ac voltage is 100V, taking the load as an example of a compressor, when the compressor operates in a high power environment, reducing half of the output dc voltage in relation to the full-bridge mode can reduce the working current of the load, so that the load operates more safely and the conversion efficiency of the PFC module is also higher, and when the compressor operates in a low-power load, such as when the operating frequency of the compressor is less than a preset value of 20Hz, the working current of the circuit is low, the conversion efficiency of the PFC circuit in the voltage-doubling rectification mode is low, and at this time, the controller 60 controls the second switch module 30 to be turned off, so that the rectifying and filtering circuit operates in the full-bridge rectification mode, the conversion efficiency of the PFC circuit is improved, although the working current is improved in the voltage-doubling rectification mode, the working current value of the compressor is still within a safe range due to the low working frequency of the compressor. Therefore, for a load with a wide working current range, such as a variable frequency compressor, at this time, the controller needs to acquire the frequency of the current compressor, and if the frequency of the compressor is smaller than the preset value, that is, the working current of the current compressor is low, the second switch module 30 is controlled to be switched off so that the rectifying and filtering circuit works in a full-bridge rectifying mode to improve the conversion efficiency of the PFC circuit; if the frequency of the compressor is greater than the preset value, that is, the current working current of the compressor increases, the second switch module 30 is controlled to be turned on to make the rectifying and filtering circuit work in the voltage-multiplying rectifying mode to reduce the supply current of the load, so that the load can work more safely without causing overcurrent protection.
According to the PFC circuit provided in the embodiment of the present invention, the first switch module 20 and the second switch module 30 are added to the PFC current, the first switch module 20 is connected in series to an ac loop including the reactor L and the rectifier module 40, the ac input terminal of the power factor correction module 10 is connected in parallel to the ac input terminal of the rectifier module 40, one end of the second switch module 30 is connected to the ac loop, and the other end is connected to a common node of two capacitors in a filter circuit including the first capacitor E1 and the second capacitor E2. The PFC circuit according to the embodiment of the present invention implements switching of the rectifying and filtering circuit in the PFC circuit between the full-bridge rectifying module and the voltage-doubler rectifying mode through the second switch module 30, so as to implement that the PFC circuit can still implement a high conversion rate when the load works in a low power state, and the first switch module 30 implements that the power supply of the whole PFC circuit can be cut off when the PFC circuit is protected from working abnormality, thereby implementing safety protection of the whole PFC circuit.
Further, based on the first embodiment of the PFC circuit of the present invention, as shown in fig. 4, a second embodiment of the PFC circuit of the present invention is different from the first embodiment in the circuit connection manner of the first switch module 20 and the second switch module 30.
One end of the second switch module 30 is connected with the input end of the zero line of the alternating current power supply, and the other end of the second switch module 30 is connected with the common junction of the first capacitor E1 and the second capacitor E2;
one end of the first switch module 20 is connected to the input end of the live wire of the ac power source, and the other end of the first switch module 20 is connected to a common point of the ac input ends of the power factor correction module 10 and the rectification module 40.
In the present embodiment, the first switch module 20 is instead connected in parallel to the live line, i.e. the L-terminal, of the near ac power source, specifically, connected in parallel between the reactor L and an ac input terminal of the rectifier module, and since the first switch module 20 is still connected in series in the ac loop, when the first switch module is disconnected, the power supply to the entire PFC circuit is disconnected. The connection relationship of the second switch module 30 is the same as that of the first embodiment.
The operation principle of the first switch module 20 and the second switch module 30 of this embodiment is the same as that of the first embodiment, and will not be described herein again.
Further, based on the first embodiment of the PFC circuit of the present invention, a PFC circuit according to a third embodiment of the present invention is shown in fig. 5, and is different from the first embodiment in the circuit connection manner of the first switch module 20 and the second switch module 30.
One end of the second switch module 30 is connected with the input end of the live wire of the alternating current power supply, and the other end of the second switch module 30 is connected with the common junction of the first capacitor E1 and the second capacitor E2;
one end of the first switch module 20 is connected to the input end of the zero line of the ac power source, and the other end of the first switch module 20 is connected to a common point of the ac input ends of the power factor correction module 10 and the rectifier module 40.
In this embodiment, the second switch module 30 is instead connected in parallel to the L terminal, which is the live line of the near ac power source, specifically, one end thereof is connected in parallel with the reactor L, and the other end thereof is connected in the same manner as the first embodiment.
In this embodiment, when the K1 of the first switch module 20 is closed and the K2 of the second switch module 30 is opened, the rectifying and filtering circuit composed of the rectifying module 40, the first capacitor E1 and the second capacitor E2 operates in the full-bridge rectifying mode, and the operating principle thereof is the same as that of the first embodiment, and is not described herein again.
When the K1 of the first switch module 20 is closed and the K2 of the second switch module 30 is closed, the rectifying and filtering circuit composed of the rectifying module 40, the first capacitor E1 and the second capacitor E2 operates in the voltage-doubling rectifying mode. As shown in fig. 6, when the alternating current of the alternating current power supply starts from the N line, as shown by the dotted line in the figure, the alternating current flows through the switch K1, the full-bridge rectifier module BR2, the first capacitor E1, the switch K2, and the reactor L, and returns to the alternating current from the L line; as shown in fig. 7, when the ac current of the ac power supply starts from the L line, the ac current flows through the reactor L, the switch K2, the second capacitor E2, and the full-bridge rectifier module BR2 to return to the N line of the ac current, as shown by the dotted line in the figure. Therefore, when the alternating current starts from the L line and the N line, the second capacitor E2 and the first capacitor E1 are respectively charged, which is different from the charging circuit of the first embodiment, and the voltage-doubling rectification is also realized. The working mode of the PFC circuit is the same as that of the first embodiment, when the switching tube Q1 is turned off, the direction of the current generated by the reactor L corresponding to the induced electromotive force is the same as that before the switching tube Q1 is turned off, and at this time, the current charges the first capacitor E1 or the second capacitor E2 in the directions of the dotted lines in fig. 6 and fig. 7, respectively, thereby realizing PFC correction.
The working principle of other modules in this embodiment is the same as that in the first embodiment, and will not be described herein again.
Further, based on the first embodiment of the PFC circuit of the present invention, as shown in fig. 8, a PFC circuit according to a fourth embodiment of the present invention is different from the first embodiment in the circuit connection manner of the first switch module 20 and the second switch module 30.
One end of the first switch module 20 is connected to the live wire input end of the ac power supply, the other end of the first switch module 20 and one end of the second switch module 30 are connected, an ac input end of the power factor correction module 10 and an ac input end of the rectifier module 40 are connected in common, and the other end of the second switch module 30 is connected to the common junction of the first capacitor E1 and the second capacitor E2.
In this embodiment, the first switch module 20 and the second switch module 30 are instead connected in series at the end near the live line of the ac power source, i.e. the L-terminal, specifically, the first switch module 20 is connected in series between the reactor L and one ac input end of the rectifier module, and one end of the second switch module 30 is connected in parallel with the other end of the first switch module 20 away from the reactor L and one end of the rectifier module 40.
In this embodiment, the PFC circuit operates in the full-bridge rectification and voltage-doubling rectification modes as in the third embodiment, and the other modules operate in the same mode as in the first embodiment, which is not described herein again.
The present invention further provides an inverter air conditioner, which comprises an indoor unit and an outdoor unit, wherein the outdoor unit comprises an inverter compressor, and the outdoor unit control circuit comprises the PFC circuit.
In the description herein, references to the description of the terms "first embodiment," "second embodiment," "example," etc., mean that a particular method, apparatus, or feature described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, methods, apparatuses, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. A power factor correction circuit is characterized by comprising a reactor, a power factor correction module, a rectification module, a first switch module, a second switch module, a first capacitor, a second capacitor, a controller and a driving module;
the reactor is connected with the input end of an alternating current power supply, and the reactor, the rectifying module and the first switch module are connected in series in an alternating current power supply loop;
the control end of the first switch module is connected with the controller, and the controller controls the on-off of the first switch module so as to control the on-off of the alternating current power supply loop;
the first capacitor and the second capacitor are connected in series and then connected in parallel at the output end of the rectifying module;
the driving module is connected with the output end of the rectifying module in parallel, the alternating current power supply is rectified by the rectifying module to output direct current so as to provide power for the driving module to work, the control end of the driving module is connected with the controller, and the controller controls the driving module to drive a load to operate;
the alternating current input end of the power factor correction module is connected with the alternating current input end of the rectification module in parallel, the control end of the power factor correction module is connected with the controller, and the power factor correction module performs switching under the control of the controller so as to perform power factor correction on direct current voltage and direct current output by the rectification module;
one end of the second switch module is connected with the alternating current power supply loop, the other end of the second switch module is connected with a common contact of the first capacitor and the second capacitor, a control end of the second switch module is connected with the controller, and the controller controls on-off of the second switch module to control the rectifier module, the first capacitor and the second capacitor to form a rectifier filter circuit to realize switching of a full-bridge rectification mode and a voltage-multiplying rectification mode.
2. The power factor correction circuit of claim 1,
one end of the first switch module and one end of the second switch module are connected to the input end of the zero line of the alternating current power supply in a sharing mode, the other end of the second switch module is connected to the common junction of the first capacitor and the second capacitor, and the other end of the first switch module is connected to the common junction of the power factor correction module and the alternating current input end of the rectification module.
3. The power factor correction circuit of claim 1,
one end of the second switch module is connected with the input end of the zero line of the alternating current power supply, and the other end of the second switch module is connected with the common contact of the first capacitor and the second capacitor;
one end of the first switch module is connected with the input end of the live wire of the alternating current power supply, and the other end of the first switch module is connected with a common contact point of the alternating current input ends of the power factor correction module and the rectification module.
4. The power factor correction circuit of claim 1,
one end of the second switch module is connected with the input end of the alternating-current power supply live wire, and the other end of the second switch module is connected with the common junction of the first capacitor and the second capacitor;
one end of the first switch module is connected with the input end of the zero line of the alternating current power supply, and the other end of the first switch module is connected with a common joint of the power factor correction module and an alternating current input end of the rectification module.
5. The power factor correction circuit of claim 1,
one end of the first switch module is connected with the live wire input end of the alternating current power supply, the other end of the first switch module and one end of the second switch module are connected, an alternating current input end of the power factor correction module and an alternating current input end of the rectification module are connected in common, and the other end of the second switch module is connected with a common junction of the first capacitor and the second capacitor.
6. The power factor correction circuit of claim 1, further comprising a current detection module,
the current detection module is connected in series with the alternating current power supply loop, and the output end of the current detection module is connected with the controller so as to detect the alternating current value input by the alternating current power supply.
7. The power factor correction circuit of claim 1, further comprising a zero crossing detection module,
the zero-crossing detection module is connected with the input end of the alternating current power supply in parallel, the output end of the zero-crossing detection module is connected with the controller so as to detect a voltage zero-crossing signal of the alternating current power supply, and the controller controls the switching state of the power factor correction module to switch according to the voltage zero-crossing signal.
8. The power factor correction circuit of claim 1,
when the load is a compressor, the controller is further configured to:
judging the current frequency for controlling the operation of the compressor, and controlling the second switch module to be conducted by the controller when the operation frequency is greater than a preset value so as to control the rectification filter circuit to work in a voltage-multiplying rectification mode; when the operating frequency is smaller than the preset value, the controller controls the second switch module to be switched off so as to control the rectifying and filtering circuit to work in a full-bridge rectifying mode.
9. The power factor correction circuit as claimed in any one of claims 1 to 8, wherein the power factor correction module comprises a rectifying unit, a switching unit and a driving unit;
two input ends of the rectifying unit are two alternating current input ends of the power factor correction module, and two output ends of the rectifying unit are connected with the switch unit in parallel;
the control end of the switch unit is connected with the driving unit, and the input end of the driving unit is connected with the control end of the power factor correction module.
10. An inverter air conditioner comprising the power factor correction circuit as claimed in any one of claims 1 to 9.
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| CN201710535265.5A CN107276388B (en) | 2017-06-30 | 2017-06-30 | PFC circuit and variable frequency air conditioner |
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| CN201710535265.5A CN107276388B (en) | 2017-06-30 | 2017-06-30 | PFC circuit and variable frequency air conditioner |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110601557A (en) * | 2018-06-13 | 2019-12-20 | 重庆美的制冷设备有限公司 | High-integration intelligent power module and electrical equipment |
| CN109713983A (en) * | 2018-12-29 | 2019-05-03 | 常州朗奇威电器有限公司 | Over Current Protection System, controller and over-current protection method |
| CN109980915A (en) * | 2019-05-17 | 2019-07-05 | 广东美的制冷设备有限公司 | Circuit of power factor correction and air conditioner |
| CN110311547B (en) * | 2019-07-09 | 2021-01-26 | 广东美的制冷设备有限公司 | PFC circuit and air conditioner |
| CN110417251B (en) * | 2019-07-09 | 2021-08-13 | 广东美的制冷设备有限公司 | PFC circuit and air conditioner |
| CN110474527B (en) * | 2019-08-15 | 2020-10-09 | 海信（山东）空调有限公司 | Frequency conversion device for correcting three-phase electric power factor, control method thereof and air conditioner |
| CN111641334B (en) * | 2020-06-05 | 2021-11-23 | 广东美的制冷设备有限公司 | Variable frequency control device and air conditioner |
| CN112432310B (en) * | 2020-10-23 | 2022-08-26 | 珠海格力电器股份有限公司 | Power factor calibration system, method, processor, compressor, air conditioner and medium |
| CN113595412B (en) * | 2021-08-27 | 2023-08-18 | 康佳集团股份有限公司 | LLC circuit and switching power supply |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1933307A (en) * | 2006-08-31 | 2007-03-21 | 上海交通大学 | Active passive mixed single phase power factor correcting circuit |
| CN103973134A (en) * | 2013-01-30 | 2014-08-06 | 广东美的制冷设备有限公司 | Direct-current power device and PWM (pulse width modulation) pulse control method for improving power factor thereof |
| CN104834239A (en) * | 2015-05-12 | 2015-08-12 | 广东美的制冷设备有限公司 | Current loop communication and power supply control circuit of air conditioner and outdoor unit thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2798496A1 (en) * | 2011-12-01 | 2013-06-01 | Rab Lighting, Inc. | Led driver protection circuit |
-
2017
- 2017-06-30 CN CN201710535265.5A patent/CN107276388B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1933307A (en) * | 2006-08-31 | 2007-03-21 | 上海交通大学 | Active passive mixed single phase power factor correcting circuit |
| CN103973134A (en) * | 2013-01-30 | 2014-08-06 | 广东美的制冷设备有限公司 | Direct-current power device and PWM (pulse width modulation) pulse control method for improving power factor thereof |
| CN104834239A (en) * | 2015-05-12 | 2015-08-12 | 广东美的制冷设备有限公司 | Current loop communication and power supply control circuit of air conditioner and outdoor unit thereof |
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