WO2022149214A1 - 電力変換装置、空気調和機、及び冷凍サイクル適用機器 - Google Patents

電力変換装置、空気調和機、及び冷凍サイクル適用機器 Download PDF

Info

Publication number
WO2022149214A1
WO2022149214A1 PCT/JP2021/000206 JP2021000206W WO2022149214A1 WO 2022149214 A1 WO2022149214 A1 WO 2022149214A1 JP 2021000206 W JP2021000206 W JP 2021000206W WO 2022149214 A1 WO2022149214 A1 WO 2022149214A1
Authority
WO
WIPO (PCT)
Prior art keywords
converter
power
current
conversion device
power conversion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2021/000206
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
厚司 土谷
和徳 畠山
啓介 植村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP2022573840A priority Critical patent/JP7490089B2/ja
Priority to PCT/JP2021/000206 priority patent/WO2022149214A1/ja
Priority to US18/254,777 priority patent/US20240007012A1/en
Priority to CN202180087890.2A priority patent/CN116711202A/zh
Publication of WO2022149214A1 publication Critical patent/WO2022149214A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • 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
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0009—Devices or circuits for detecting current in a converter
    • 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
    • H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
    • H02M5/46—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by dynamic converters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/88—Electrical aspects, e.g. circuits
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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
    • 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
    • H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
    • H02M5/42—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters
    • H02M5/44—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC
    • H02M5/453—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M5/458—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only

Definitions

  • This disclosure relates to power converters, air conditioners, and refrigeration cycle applicable equipment.
  • the present disclosure particularly relates to a power conversion device that receives AC power from an AC power source and outputs AC power having a variable frequency and a variable voltage value, and an air conditioner and refrigerating cycle applicable device provided with the power conversion device.
  • the above power conversion device is used, for example, to supply electric power to a motor for driving a compressor of a refrigeration cycle application device, for example, an air conditioner.
  • a refrigeration cycle application device for example, an air conditioner.
  • the power supply to the power converter is supplied by the operation of the circuit breaker for wiring. It may be blocked. In such a situation, it is inconvenient because the refrigeration cycle applicable equipment cannot be operated.
  • the load can be reduced, for example, by reducing the rotational speed of the motor that drives the compressor.
  • Patent Document 1 describes that a current transformer is used to detect the effective value of the current flowing through the bridge circuit of the power conversion device (paragraph 0025).
  • the current transformer has a problem that the detection accuracy is not sufficiently high and the detection error is particularly large for low frequency components.
  • An object of the present disclosure is to improve the detection accuracy of the input current to the power converter, thereby preventing the input current to the power converter from becoming excessive and continuing to supply power to the load. It is to make the upper limit of the input current that can be made larger.
  • the power converter of the present disclosure is A converter that converts AC power from AC power to DC power and outputs it.
  • An inverter that converts DC power output from the converter into AC power with variable frequency and variable voltage value and supplies it to the load.
  • a shunt resistor that detects the output current of the converter,
  • a control device that controls the inverter based on the output current detected by the shunt resistor is provided. The control device calculates the input current of the converter from the output current detected by the shunt resistance, and when the calculated input current becomes larger than a predetermined threshold value, the input current of the converter is small. The mode of operation of the inverter is changed so as to be.
  • the input current to the power converter can be detected with high accuracy, and as a result, the input current to the power converter can be prevented from becoming excessive and the power can be supplied to the load.
  • the upper limit of the input current that can be continued can be increased.
  • FIG. It is a figure which shows the power conversion apparatus of Embodiment 1.
  • FIG. It is a block diagram which shows an example of the control device of FIG. It is a wiring diagram which shows an example of the level shift circuit of FIG.
  • (A) and (b) are diagrams showing the relationship between the input signal and the output signal of the level shift circuit of FIG. It is a figure which shows the path of the current which flows through a converter in a positive half cycle in a diode rectification mode. It is a figure which shows the path of the current which flows through a converter in a negative half cycle in a diode rectification mode.
  • (A) to (d) are diagrams showing the operation of the converter in the diode rectification mode.
  • FIG. 1 shows the power conversion device 1 of the first embodiment together with a motor which is a load thereof.
  • the motor is a motor of a compressor of an air conditioner.
  • the motor may be a motor used in a refrigeration cycle applicable device other than the air conditioner, or may be a motor used in other devices.
  • the illustrated power conversion device 1 has a converter 20, an inverter 40, a control device 50, a reactor 110, a smoothing capacitor 120, and a shunt resistor 130.
  • the converter 20 has its first and second AC side terminals 201 and 202 connected to the AC power supply 10 by the first and second AC wirings 111 and 112. Specifically, the first AC side terminal 201 is connected to the first output terminal 101 of the AC power supply 10 by the AC wiring 111, and the second AC side terminal 202 is connected to the second AC power supply 10 by the AC wiring 112. It is connected to the output terminal 102.
  • the AC power source 10 may be, for example, a commercial power source or a power source generated by a private power generation facility.
  • the AC power source 10 is a household commercial power source
  • the AC power source is supplied via a household outlet.
  • a circuit breaker is provided in the wiring connected to the outlet, and when the current supplied to the voltage converter via the outlet becomes excessive, the circuit breaker operates and the current supply is cut off.
  • a reactor 110 is provided in the middle of the first AC wiring 111.
  • the reactor 110 stores the electric power supplied from the AC power source 10 as magnetic energy and releases this energy to boost the voltage and improve the power factor.
  • the converter 20 converts the AC power into DC power.
  • the first DC side terminal of the converter 20, that is, the positive terminal 203, and the second DC side terminal, that is, the negative terminal 204 are connected to the first and second DC bus lines 121 and 122, respectively, in the converter 20.
  • the generated DC power is supplied to the inverter 40 via the first and second DC bus 121 and 122.
  • the smoothing capacitor 120 smoothes the output voltage of the converter 20.
  • the smoothing capacitor 120 has a positive electrode connected to the first DC bus 121 and a negative electrode connected to the second DC bus 122.
  • the inverter 40 converts the DC power output from the converter 20 into three-phase AC power having a variable frequency and a variable voltage value and supplies the DC power to the motor 60 to rotate the motor 60.
  • the motor 60 is, for example, a motor of a compressor of an air conditioner.
  • the shunt resistor 130 is provided in the middle of the second DC bus 122 between the negative electrode of the smoothing capacitor 120 and the negative terminal 204 of the converter 20, and is a current detection for detecting the output current Is of the converter 20. It is used as a means.
  • the voltage between both ends of the shunt resistor 130 is input to the control device 50.
  • the control device 50 detects the current flowing through the shunt resistor 130 based on the voltage between both ends of the shunt resistor 130, that is, the output current of the converter 20, and controls the converter 20 and the inverter 40 based on the value of the detected current. ..
  • the control device 50 includes an AC voltage detection unit 51, a level shift circuit 52, a DC voltage detection unit 53, a polarity determination unit 54, an input current calculation unit 55, and a controller 56.
  • the polarity determination unit 54, the input current calculation unit 55, and the controller 56 are composed of a processing circuit 58.
  • the processing circuit 58 is composed of, for example, a microcomputer.
  • the AC voltage detection unit 51 is connected to the AC wiring 111 closer to the AC power supply than the reactor 110 and to the AC wiring 112, and outputs from the first and second output terminals 101 and 102 of the AC power supply 10.
  • the power supply voltage Va to be generated is detected, and a signal indicating the value of the detected voltage is supplied to the control device 50.
  • the instantaneous value of the power supply voltage Va represents the potential of the first output terminal 101 with reference to the potential of the second output terminal 102.
  • a half cycle in which the potential of the first output terminal 101 with respect to the second output terminal 102 is positive is referred to as a positive half cycle, represented by the symbol Hp, and the first output terminal 101 with respect to the second output terminal 102.
  • a half cycle in which the potential is negative is called a negative half cycle Hn and is represented by the symbol Hn.
  • the polarity determination unit 54 determines the polarity of the voltage Va applied from the AC power supply 10, and supplies a signal Sp indicating the determined polarity to the controller 56.
  • a signal indicating the voltage Vsh between both ends thereof (represented by the same code Vsh) is output from the shunt resistor 130, and the level shift circuit 52 of the control device 50 converts the level of this signal Vsh and the converted signal. Output Vsh_m. It can be said that both the signal Vsh and the signal Vsh_m indicate the current flowing through the DC bus 122.
  • the input current calculation unit 55 calculates the value of the input current of the converter 20 based on the signal Vsh_m, as described later.
  • a chip type resistor As the shunt resistor 130, it is desirable to use a resistor having a small temperature coefficient of resistance such as cement resistance.
  • FIG. 3 shows an example of the level shift circuit 52.
  • the illustrated level shift circuit 52 includes a voltage divider circuit composed of resistors R1 and R2, a first operational amplifier OP1 and a second operational amplifier OP2. These operational amplifiers OP1 and OP2 operate with a single power supply of 5 V.
  • the voltage divider circuit divides the power supply voltage of 5V and outputs a voltage of 2.5V. This voltage of 2.5V is input to the inverting input terminal of the first operational amplifier OP1.
  • the output terminal of the first operational amplifier OP1 is coupled to the non-inverting input terminal.
  • the first operational amplifier OP1 operates as a voltage follower, and the output of the first operational amplifier OP1 is maintained at 2.5V.
  • the output of the first operational amplifier OP1 is input as a bias voltage to the non-inverting input terminal of the second operational amplifier OP2 via the resistor R5.
  • One end of the shunt resistor 130 (the negative electrode side of the smoothing capacitor 120) is grounded, and when a current flows through the shunt resistor 130, the potential Vsh at the other end is lowered by the amount of the voltage drop at the shunt resistor.
  • the potential Vsh at the other end is input to the inverting input terminal of the second operational amplifier via the resistor R4.
  • the output of the second operational amplifier OP2 is coupled to the inverting input terminal via the feedback resistor R6.
  • the output voltage Vsh_m of the second operational amplifier OP2 changes around the bias voltage of 2.5 V.
  • the width of the change is equal to the value obtained by multiplying the absolute value of the potential of the non-inverting input terminal by the amplification factor.
  • Vsh changes in the negative direction with an increase in the instantaneous value of the current Is with reference to 0.
  • Vsh_m is kept at 2.5V, but when Vsh changes in the negative direction, Vsh_m changes from 2.5V to a smaller value, that is, toward zero.
  • the width of the change of Vsh_m is greatly expanded with respect to the change of Vsh.
  • the signal Vsh_m output from the level shift circuit 52 is supplied to the input current calculation unit 55 as a signal representing the current Is.
  • the input current calculation unit 55 calculates the input current Ia of the converter 20 based on the signal Vsh_m supplied from the level shift circuit 52. As the input current Ia, for example, an effective value is calculated. The calculated input current Ia is notified to the controller 56.
  • the DC voltage detection unit 53 detects the bus voltage Vdc.
  • the bus voltage Vdc referred to here is a DC voltage between the first DC bus 121 and the second DC bus 122, that is, a DC voltage between the electrodes of the smoothing capacitor 120.
  • the detected value of the DC voltage detecting unit 53 is used for controlling the inverter 40.
  • the controller 56 controls the converter 20 based on the input current Ia. To control the converter 20, the controller 56 outputs signals Sa to Sd for controlling the on / off of the switching elements 2a to 2d described later in the converter 20.
  • the controller 56 also controls the inverter 40 based on the input current Ia and the bus voltage Vdc, the operation instruction by the remote controller (not shown), and the detected temperature of the air-conditioned space by the temperature sensor (not shown). To control the inverter 40, the controller 56 outputs signals Sm1 to Sm6 for on / off control of switching elements of six arms (not shown) of the inverter 40.
  • the converter 20 is composed of a bridge type rectifier circuit including a parallel connection of a diode and a switching element in each of a plurality of, specifically four arms.
  • the converter 20 has its input terminals, that is, AC side terminals 201 and 202, connected to AC wiring 111 and 112, and output terminals, that is, positive terminals 203 and negative terminals 204, respectively, connected to DC bus 121 and 122.
  • the first switching element 2a is connected between the first AC side terminal 201 and the positive terminal 203
  • the second switching element 2b has the first AC side terminal 201 and the negative terminal 204
  • the third switching element 2c is connected between the second AC side terminal 202 and the positive terminal 203
  • the fourth switching element 2d is connected to the second AC side terminal 202 and the negative terminal. It is connected to 204.
  • Diodes 3a to 3d are connected in parallel to the switching elements 2a to 2d, respectively, and each switching element and the diode connected in parallel form an arm of a bridge circuit.
  • the switching elements 2a to 2d are composed of, for example, a MOSFET (Metal-Oxide-Semiconductor Ductor Field-Effective Transistor).
  • MOSFET Metal-Oxide-Semiconductor Ductor Field-Effective Transistor
  • the switching elements 2a to 2d are composed of MOSFETs, their parasitic diodes are used as the diodes 3a to 3d.
  • the parasitic diode is formed by a pn junction existing between the source and drain of each MOSFET, and the source side (lower side in FIG. 1) of the MOSFET is the anode and the drain side (upper side in FIG. 1) is the cathode. It has become.
  • the drain of the MOSFET constituting the first switching element 2a and the drain of the MOSFET constituting the third switching element 2c are connected to the positive terminal 203, and the source of the MOSFET constituting the second switching element 2b is used.
  • the source of the MOSFET constituting the fourth switching element 2d is connected to the negative terminal 204.
  • the converter 20 operates in a diode rectification mode, a synchronous rectification mode, or a high power factor mode.
  • the choice of mode is generally determined by the magnitude of the load.
  • the diode rectification mode is selected when the load is relatively light.
  • Synchronous rectification mode is selected when the load is medium.
  • the high power factor mode is selected when the load is relatively high, for example near rated values and overloaded. The operation of the converter in each mode will be described below.
  • the diode rectification mode In the diode rectification mode, full-wave rectification is performed by keeping the switching elements 2a to 2d in the off state and passing a current through the diodes 3a to 3d.
  • the diode rectification mode is also called a passive mode.
  • FIG. 5 and 6 show the path of the current Is flowing through the converter 20 in the diode rectification mode.
  • the current Is flows in the path shown by the broken line F1a with an arrow in FIG. 5, and the smoothing capacitor 120 is charged.
  • the current Is flows in the path shown by the broken line F1b with an arrow in FIG. 6, and the smoothing capacitor 120 is charged.
  • FIG. 7A shows the power supply voltage Va.
  • FIG. 7B shows the input current Ia of the converter 20.
  • the portion indicated by the reference numeral Ca is the current flowing along the path indicated by the broken line F1a
  • the portion indicated by the reference numeral Cb is the current flowing along the path indicated by the broken line F1b.
  • FIG. 7 (c) shows the voltage Vsh appearing across the shunt resistor 130.
  • FIG. 7D shows a voltage signal Vsh_m obtained by level-shifting the voltage Vsh.
  • the change in the vertical axis direction is shown to be smaller than that in FIG. 4 (b). The same applies to FIG. 14 (d) described later.
  • the switching loss in the switching elements 2a to 2d can be eliminated.
  • the switching elements 2a to 2d In the synchronous rectification mode, at least a part of the switching elements 2a to 2d is turned on for at least a part of the period in which the current flows through the diodes connected in parallel, that is, the diodes of the same arm.
  • each of the switching elements 2a and 2c of the arm connected to the positive terminal 203 is turned on for at least a part of the period in which the current flows through the diode connected in parallel, and is connected to the negative terminal 204.
  • Each of the switching elements 2b and 2d of the arm is kept on for half a cycle including the period of current flowing through the parallel-connected diodes and does not include the period of current flowing through the parallel-connected diodes. It remains off for the duration of the cycle.
  • the period in which current flows through each diode is the period in which a forward voltage is applied to the diode.
  • the voltage applied to each diode is determined by the power supply voltage Va, the voltage between both ends of the smoothing capacitor 120, and the electromotive force or voltage drop of the reactor 110.
  • Whether or not a current is flowing through each diode is determined based on the polarity of the power supply voltage Va and the instantaneous value of the output current Is.
  • FIGS. 8 and 9 show the current flow in the synchronous rectification mode
  • FIGS. 10A to 10F show the waveforms of the power supply voltage Va, the output current Is, and the signals Sa to Sd.
  • FIGS. 10 (c) to 10 (f) when each of the signals Sa to Sd is High, the corresponding switching element is turned on, and when Low, the corresponding switching element is turned off.
  • the switching elements 2b and 2c are kept off (FIGS. 10 (d) and (e)), the switching elements 2d are kept on (FIG. 10 (f)), and the switching elements 2a. Is turned on for at least a part of the period during which current flows through the diodes 3a connected in parallel (FIG. 10 (c)).
  • the current Is mainly flows in the path shown by the broken line F2a with an arrow in FIG. 8 to charge the smoothing capacitor 120.
  • a current also flows through the diode connected in parallel to the switching element that is turned on, but the current flowing through the diode is smaller than the current flowing through the switching element that is turned on.
  • the switching elements 2a and 2d are kept off (FIGS. 10 (c) and (f)), the switching elements 2b are kept on (FIG. 10 (d)), and the switching elements 2c. Is turned on for at least a part of the period during which current flows through the diodes connected in parallel (FIG. 10 (e)).
  • the current Is mainly flows in the path shown by the broken line F2b with an arrow in FIG. 9 to charge the smoothing capacitor 120.
  • a current also flows through the diode connected in parallel to the switching element that is turned on, but the current flowing through the diode is smaller than the current flowing through the switching element that is turned on.
  • the switching element when the switching element is turned on, the current flowing through the diodes connected in parallel is reduced. This is because the on-resistance of the switching element is smaller than the on-resistance of the diode. In particular, the resistance of the diode increases as the current value increases, so that the ratio of the current flowing through the switching element becomes even larger. By passing most of the current through the switching element, the loss can be reduced and the efficiency of power conversion can be improved.
  • the current Is flowing through the shunt resistor 130 and the operation of the level shift circuit 52 when the converter 20 is operating in the synchronous rectification mode are the same as those described with reference to FIGS. 7 (a) to 7 (d).
  • the short-circuit current referred to here is a current that flows from the first output terminal 101 of the power supply 10 through the reactor 110, through the two switching elements of the converter 20, and back to the second output terminal 102. In this state, almost all of the output voltage of the power supply 10 is applied to the reactor 110.
  • the charging current referred to here is from the first output terminal 101 of the power supply 10, passes through the reactor 110, passes through one switching element of the converter 20, passes through the smoothing capacitor 120, and further passes through another switching element of the converter 20. It is a current flowing in the path passing through and returning to the second output terminal 102.
  • the smoothing capacitor 120 is charged by this charging current.
  • the switching elements of the two arms connected to the AC side terminal of the multiple arms are repeatedly turned on and off alternately in order to alternately flow the short-circuit current and the charging current.
  • the switching elements of the two arms connected to the other AC terminal are repeatedly turned on and off alternately in order to alternately flow the short-circuit current and the charging current.
  • the switching of the two arms connected to the other AC terminal one is kept on and the other is kept off.
  • the switching elements 2a and 2b of the arm connected to the first AC side terminal 201 are controlled to be repeatedly turned on and off alternately. Alternately turning on and off means that when one is on, the other is off.
  • the switching element of the arm connected to the second AC side terminal 202 and the positive terminal 203 is maintained in the ON state and connected to the second AC side terminal 202 and the negative terminal 204.
  • the switching element of the arm is kept off.
  • the switching element of the arm connected to the second AC side terminal 202 and the positive terminal 203 is maintained in the off state and connected to the second AC side terminal 202 and the negative terminal 204.
  • the switching element of the arm is kept on.
  • the switching element 2d is maintained in the on state (FIG. 13 (e)
  • the switching element 2c is maintained in the off state (FIG. 13 (d))
  • the switching element 2a and the switching element 2b are separated from each other. It turns on alternately (FIGS. 13 (b) and 13 (c)).
  • a charging current flows as shown by the broken line F2a with an arrow in FIG.
  • the voltage of the smoothing capacitor 120 gradually increases.
  • the magnetic energy stored in the reactor 110 is also used for charging the smoothing capacitor 120. Therefore, the smoothing capacitor 120 can be charged to a higher voltage. That is, it has a boosting effect.
  • the switching element 2c is maintained in the on state (FIG. 13 (d)), the switching element 2d is maintained in the off state (FIG. 13 (e)), and the switching element 2a and the switching element 2b are brought into contact with each other. It turns on alternately (FIGS. 13 (b) and 13 (c)).
  • a short-circuit current flows as shown by the broken line F3b with an arrow in FIG.
  • This current is a current that increases over time, which causes magnetic energy to be stored in the reactor 110. Further, when this current flows, the distortion of the current waveform becomes small, and the current waveform approaches a sine wave. Therefore, the power factor of the power conversion device is improved, and the harmonic component included in the current can be suppressed.
  • the charging current flows as shown by the broken line F2b with an arrow in FIG.
  • the voltage of the smoothing capacitor 120 gradually increases.
  • the magnetic energy stored in the reactor 110 is also used for charging the smoothing capacitor 120. Therefore, the smoothing capacitor 120 can be charged to a higher voltage. That is, it has a boosting effect.
  • the on / off period of the switching elements 2a and 2b is short as shown in the figure.
  • Each on / off cycle may be constant or variable over the entire half cycle. Further, in each cycle, the ratio (on-duty) occupied by the period in which each of the switching elements 2a and 2b is turned on, that is, the period in which the signal Sa or Sb is high may change during the half cycle period.
  • the on-duty of the signal Sb may be larger when the instantaneous value of the power supply voltage Va shown in FIG. 13A is large, that is, the closer to the middle point of the half-cycle period.
  • the on-duty of the signal Sa may be larger when the instantaneous value of the power supply voltage Va shown in FIG. 13A is large, that is, the closer to the middle point of the half-cycle period. It is desirable that the on-duty of each of the signals Sa and Sb at each time point in each half cycle is set so that the input current Ia approaches a sine wave.
  • the absolute value of the power supply voltage Va becomes small, and the voltage between the AC side terminals 201 and 202 of the converter 20 becomes smaller than the bus voltage Vdc. During that time, it is necessary to control the switching elements 2a to 2d so that the current does not flow back from the smoothing capacitor 120 to the AC power supply 10 via the converter 20. This point is not shown.
  • FIG. 14A shows the power supply voltage Va.
  • FIG. 14B shows the input current Ia of the converter 20.
  • FIG. 14 (c) shows the voltage Vsh appearing across the shunt resistor 130.
  • FIG. 14 (d) shows the voltage signal Vsh_m obtained by level-shifting Vsh.
  • the voltage Vsh is also 0V (FIG. 14 (c)), and the voltage signal Vsh_m is maintained at 2.5V (FIG. 14). 14 (d)).
  • the voltage Vsh becomes a value lower than 0V
  • the voltage signal Vsh_m becomes a value lower than 2.5V.
  • the difference between Vsh_m and 2.5V at each time point is proportional to the absolute value of Vsh.
  • the power factor is improved by the short-circuit current flowing, and the input current Ia (FIG. 14 (b)) of the converter 20 becomes close to a sine wave as a whole.
  • control device 50 controls the converter 20 and the inverter 40.
  • the control device 50 selects an operation mode according to the input current Ia, and when the selected operation mode is the synchronous rectification mode or the high power factor mode, the switching elements 2a to 2d Controls on / off.
  • the control of the converter 20 is performed as follows, for example.
  • the converter 20 When the input current Ia is equal to or less than the first threshold value, the converter 20 is operated in the diode rectification mode.
  • the converter 20 When the input current Ia is larger than the first threshold value and equal to or lower than the second threshold value, the converter 20 is operated in the synchronous rectification mode.
  • the converter 20 When the input current Ia is larger than the second threshold value, the converter 20 is operated in the high power factor mode. As described above, the input current Ia is calculated from the value of the output current Is detected by the shunt resistor 130.
  • the output of the polarity determination unit 54 is used. Whether or not a current is flowing through each diode is determined based on the polarity of the power supply voltage Va and the current flowing through the shunt resistor 130. That is, for each arm connected to the positive terminal 203, the potential of the output terminal (101 or 102) of the AC power supply 10 to which the AC side end of the arm is connected is the other output terminal (102 or 101) of the AC power supply 10. ), If a current is flowing through the shunt resistance 130 in a half cycle higher than the potential of), it is determined that a current is flowing through the diode of the arm.
  • the potential of the output terminal (102 or 101) of the AC power supply 10 to which the AC side end of the arm is connected is the other output terminal (101 or 101) of the AC power supply 10. If a current is flowing through the shunt resistance 130 in a half cycle lower than the potential of 102), it is determined that a current is flowing through the diode of the arm.
  • the control device 50 also controls the inverter 40 as described above.
  • the control of the inverter 40 is usually performed according to the load state of the inverter 40.
  • the motor 60 which is the load of the inverter 40, is the motor of the compressor of the air conditioner as described above.
  • the rotation speed of the motor is determined based on the difference between the detected temperature and the set temperature of the air-conditioned space, the operation mode selected by the user, and the like.
  • the inverter is controlled according to the input current Ia. This is to prevent, for example, a situation in which the input current Ia becomes excessive and the circuit breaker for wiring cuts off. If the input current Ia exceeds a fourth threshold value larger than the above-mentioned third threshold value, it is determined to be excessive.
  • the situation where the input current becomes excessive occurs, for example, when the load of the inverter 40 becomes excessive. It also occurs when the switching element fails during the high power factor operation of the converter 20.
  • the control device 50 lowers the output frequency and output voltage of the inverter 40, for example, when the input current Ia becomes excessive. As a result, the input current of the inverter 40 can be reduced, and the input current of the converter 20 can be reduced accordingly.
  • control device 50 may perform control to reduce the torque command so that the output torque of the motor 60 becomes small when the input current Ia becomes excessive. This also makes it possible to reduce the input current of the inverter 40 and thereby reduce the input current of the converter 20.
  • the output current Is is detected using the shunt resistor 130, and the input current Ia is calculated based on the detection result. Therefore, the input current Ia can be accurately obtained. Therefore, the margin in consideration of the detection accuracy can be reduced.
  • the detection accuracy is low, it is necessary to increase the margin, and as a result, there is a possibility that a protective operation for reducing the input current will be performed even though there is actually a margin.
  • the capacity of the power converter cannot be fully utilized.
  • the margin can be reduced, the input current Ia becomes larger, and the value closer to the upper limit value (current capacity) is protected. The operation will start. Therefore, the ability of the power conversion device can be fully exerted. For example, when the power converter is used to drive the motor of the compressor of the air conditioner, the influence on the operation of the air conditioner can be further reduced.
  • the shunt resistor 130 is inexpensive, the cost for current detection can be reduced.
  • each of the switching elements 2a and 2c of the arm connected to the positive terminal 203 is turned on for at least a part of the period in which the current flows through the diodes connected in parallel.
  • Each of the switching elements 2b and 2d of the arm connected to the negative terminal 204 is maintained in the ON state and connected in parallel for half a cycle including a period in which a current flows through the diode connected in parallel. Control is performed to keep the diode off for half a cycle, not including the period of current flow through the diode.
  • each of the switching elements 2b and 2d of the arm connected to the negative terminal 204 is turned on and connected to the positive terminal 203 for at least a portion of the period during which current flows through the diodes connected in parallel.
  • Each of the switching elements 2a and 2c of the arm is kept on for half a cycle, including the period of current flow through the parallel-connected diodes, and does not include the period of current flow through the parallel-connected diodes. Controls may be made to remain off for half a cycle.
  • the signals Sa to Sd applied to the gates of the MOSFETs constituting the switching elements 2a to 2d are shown to be output from the control device 50.
  • a drive signal generation circuit may be provided in the converter 20, and the signal output from the control device 50 may be converted by the drive signal generation circuit and then applied to the gate of the MOSFET.
  • the signal applied to the gate of the MOSFET constituting the switching elements 2a and 2c needs to be a signal based on each source.
  • the signal applied to the gate of the MOSFET may be larger than the signal normally generated by the control device 50. Therefore, the drive signal generation circuit described above may convert the signal output from the control device 50 into a signal applied to the gate of the MOSFET.
  • MOSFET is used as the switching element in the above example, a switching element other than the MOSFET may be used.
  • the shunt resistor 130 is inserted into the second DC bus 122 between the negative electrode of the smoothing capacitor 120 and the negative terminal of the converter 20.
  • the insertion position of the shunt resistor 130 is not limited to the above example, and it may be inserted in the path through which the output current of the converter 20 flows.
  • Embodiment 2 In the first embodiment described above, the inverter 40 drives the motor 60 of the compressor of the air conditioner.
  • the power conversion device of the second embodiment also has a function of driving a fan of an air conditioner.
  • FIG. 15 shows the power conversion device of the second embodiment.
  • the power conversion device shown in FIG. 15 is generally the same as the power conversion device shown in FIG. 1, but a drive circuit 70 is added.
  • the drive circuit 70 receives the DC power output from the converter 20 to drive the fan motor 80.
  • the drive circuit 70 may be provided with an inverter similar to that of the inverter 40.
  • control device 50 When the input current Ia becomes excessive, the control device 50 lowers the output frequency and output voltage of the inverter 40, and increases the rotation speed of the motor 80 by the drive circuit 70.
  • the drive circuit 70 drives the motor 80 of the fan, it consumes less power than the inverter that drives the motor 60 of the compressor. That is, even if the rotation speed of the fan motor 80 is increased, the increase in electric power due to the increase is not so large. That is, when the output frequency and the output voltage of the inverter 40 are reduced to reduce the rotation speed of the compressor and the rotation speed of the fan is increased, the power consumption is reduced as a whole.
  • the power conversion device according to the embodiment of the present disclosure has been described above.
  • the power conversion device of the present disclosure can be variously modified.
  • the level shift circuit 52 that converts the voltage signal obtained from the shunt resistor 130 and inputs it to the controller 56 is used, but a circuit other than the illustrated level shift circuit is used. , The voltage signal obtained from the shunt resistor 130 may be converted.
  • the load of the power conversion device includes the motor of the compressor of the air conditioner.
  • the power converter of the present disclosure can also be applied when the load is other than the motor of the compressor of the air conditioner.
  • 2a-2d switching element 3a-3d diode, 10 AC power supply, 20 converter, 40 inverter, 50 control device, 51 AC voltage detector, 52 level shift circuit, 53 DC voltage detector, 54 polarity determination unit, 55 input current Calculation unit, 56 controllers, 60 motors, 70 drive circuits, 80 motors, 110 reactors, 120 smoothing diodes, 130 shunt resistors.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rectifiers (AREA)
  • Inverter Devices (AREA)
PCT/JP2021/000206 2021-01-06 2021-01-06 電力変換装置、空気調和機、及び冷凍サイクル適用機器 Ceased WO2022149214A1 (ja)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2022573840A JP7490089B2 (ja) 2021-01-06 2021-01-06 空気調和機
PCT/JP2021/000206 WO2022149214A1 (ja) 2021-01-06 2021-01-06 電力変換装置、空気調和機、及び冷凍サイクル適用機器
US18/254,777 US20240007012A1 (en) 2021-01-06 2021-01-06 Power converting apparatus, air conditioner, and refrigeration cycle equipment
CN202180087890.2A CN116711202A (zh) 2021-01-06 2021-01-06 电力转换装置、空调机以及制冷循环应用设备

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/000206 WO2022149214A1 (ja) 2021-01-06 2021-01-06 電力変換装置、空気調和機、及び冷凍サイクル適用機器

Publications (1)

Publication Number Publication Date
WO2022149214A1 true WO2022149214A1 (ja) 2022-07-14

Family

ID=82358099

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/000206 Ceased WO2022149214A1 (ja) 2021-01-06 2021-01-06 電力変換装置、空気調和機、及び冷凍サイクル適用機器

Country Status (4)

Country Link
US (1) US20240007012A1 (https=)
JP (1) JP7490089B2 (https=)
CN (1) CN116711202A (https=)
WO (1) WO2022149214A1 (https=)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102024000393A1 (de) 2023-03-06 2024-09-12 Sew-Eurodrive Gmbh & Co Kg Umrichteranordnung und Verfahren zum Betreiben der Umrichteranordnung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007166782A (ja) * 2005-12-14 2007-06-28 Hitachi Ltd 冷凍装置及びそれに用いられるインバータ装置
JP2014124042A (ja) * 2012-12-21 2014-07-03 Hitachi Appliances Inc モータ制御装置及び空気調和機
JP2018068028A (ja) * 2016-10-19 2018-04-26 日立ジョンソンコントロールズ空調株式会社 電力変換装置および空気調和機

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100395954C (zh) * 2003-04-22 2008-06-18 松下电器产业株式会社 电动机控制装置、压缩机、空调机、和冷藏库
KR20160060636A (ko) * 2013-09-25 2016-05-30 타이코 일렉트로닉스 저팬 지.케이. 보호 디바이스
KR102314037B1 (ko) * 2014-06-09 2021-10-15 엘지전자 주식회사 모터 구동장치 및 이를 구비하는 공기조화기
JP6478881B2 (ja) * 2015-09-07 2019-03-06 日立ジョンソンコントロールズ空調株式会社 直流電源装置および空気調和機
KR102843567B1 (ko) * 2020-02-11 2025-08-06 엘지전자 주식회사 전력변환장치, 및 이를 구비하는 공기조화기

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007166782A (ja) * 2005-12-14 2007-06-28 Hitachi Ltd 冷凍装置及びそれに用いられるインバータ装置
JP2014124042A (ja) * 2012-12-21 2014-07-03 Hitachi Appliances Inc モータ制御装置及び空気調和機
JP2018068028A (ja) * 2016-10-19 2018-04-26 日立ジョンソンコントロールズ空調株式会社 電力変換装置および空気調和機

Also Published As

Publication number Publication date
JP7490089B2 (ja) 2024-05-24
CN116711202A (zh) 2023-09-05
US20240007012A1 (en) 2024-01-04
JPWO2022149214A1 (https=) 2022-07-14

Similar Documents

Publication Publication Date Title
JP3740946B2 (ja) 電源装置と、電動機駆動装置および空気調和機
CN104756381B (zh) 功率转换装置
WO2000027019A1 (fr) Procede et appareil de protection d'un cycloconvertisseur mid
KR20150141086A (ko) 모터 구동장치 및 이를 구비하는 공기조화기
JP6802126B2 (ja) インバータ制御装置
KR20160007845A (ko) Bldc fan 모터의 드라이브 제어 시스템
JP4893251B2 (ja) マトリクスコンバータおよびそれを備えた装置
JP4889674B2 (ja) 交流直流変換装置および圧縮機駆動装置並びに空気調和機
JP2008228477A (ja) 電動機制御装置
JP4706349B2 (ja) 直流電源装置および圧縮機駆動装置
JP7490089B2 (ja) 空気調和機
JP2004072806A (ja) 電力変換装置
JP2010142066A (ja) ロボット
KR102160050B1 (ko) 압축기 제어 장치 및 압축기 제어 방법
JP3490600B2 (ja) 電力変換装置のパルス幅変調方法
JP2018007502A (ja) 電力変換装置、空気調和機および電力変換装置の制御方法
JP4487155B2 (ja) Ｐｗｍサイクロコンバータの保護装置
JP4892920B2 (ja) インバータ装置
WO2020183553A1 (ja) 直流電源装置、電力変換装置及び冷凍サイクル装置
JP7278497B2 (ja) 電力変換装置および空気調和機
JP2005045914A (ja) インバータ装置
CN111819781A (zh) 整流电路装置
KR20040034905A (ko) 멀티 에어컨의 인버터 구동장치
JP2008206220A (ja) 電動機制御装置
JP4119761B2 (ja) 空調制御装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21917442

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022573840

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 18254777

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 202180087890.2

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21917442

Country of ref document: EP

Kind code of ref document: A1