JP6121290B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus such as an air conditioner or a refrigerator.

  Conventionally, in a refrigeration apparatus and an inverter apparatus used therefor, an inverter is configured using a semiconductor element such as IPM (Intelligent Power Module), and an electric motor is driven. It is necessary to set it below the current at which the magnet of the electric motor (for example, DC brushless motor) does not demagnetize. It is known to have a function that can change the output of the overcurrent detection level creation, adjust the reference signal so that it becomes the overcurrent level set compared with the input signal, and change the overcurrent level. 1. As a result, the types of inverter boards are reduced and shared.

JP 2012-70531 A

  In the above prior art, since the level of the reference signal can be freely adjusted, the overcurrent protection can be controlled by the current setting value, and the overcurrent detection circuit and the substrate can be shared. For example, a semiconductor element such as an IPM As for new inverter devices due to the discontinuation of production, noise tests and the like to be commercialized must be performed on each board that requires each inverter current rating and overcurrent protection level.

  An object of the present invention is to omit a test on the entire substrate when replacing a semiconductor element such as an IPM, and to reduce the types of inverter devices.

  In order to solve the above problems, the present invention provides a compressor that compresses a refrigerant, a motor that drives the compressor, a heat exchanger that exchanges heat between the refrigerant and air, and a fan that blows air to the heat exchanger. In a refrigeration apparatus that forms a refrigeration cycle by providing a fan motor that drives the fan, a converter circuit that converts AC power from an AC power source into DC power, and DC power generated by the converter circuit is AC An inverter circuit for converting the electric power to output to the motor; a first board provided with a driver circuit for controlling the inverter circuit; and a second board provided with a microcomputer for controlling the driver circuit, The first substrate and the second substrate are separate bodies and are electrically connected.

  In addition to the above configuration, a fan inverter circuit that converts the DC power generated by the converter circuit into AC power and outputs the AC power to the fan motor, and a fan driver circuit that controls the fan inverter circuit; And a microcomputer for controlling the driver circuit for the fan. The third board is provided separately from the fan motor, and the second board and the third board are electrically connected. Good to be connected to.

  According to the present invention, when a semiconductor element such as an IPM is replaced, a test on the entire substrate can be omitted, and the types of inverter devices can be reduced.

Air conditioner refrigeration cycle diagram The block diagram of the inverter apparatus and outdoor fan control apparatus which concern on embodiment of this invention The perspective view which shows the inverter converter board | substrate which concerns on embodiment of this invention. The perspective view which shows the microcomputer board which concerns on embodiment of this invention The perspective view which shows the fan control board which concerns on embodiment of this invention. The perspective view which shows the state which wired and assembled the inverter converter board, microcomputer board, and fan control board which concern on embodiment of this invention Sectional drawing of the inverter apparatus which concerns on embodiment of this invention The perspective view which shows the assembled state of the inverter apparatus which concerns on embodiment of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to FIGS.

  FIG. 1 is a refrigeration cycle diagram of an air conditioner according to an embodiment of the present invention. The air conditioner 110 includes a compressor 101, an outdoor four-way valve 112, an indoor heat exchanger 102, an indoor expansion valve 104, and outdoor heat. It has a refrigerating cycle in which the exchanger 105, the accumulator 107, and the suction side of the compressor 101 are sequentially connected to each other. When the room is cooled, the refrigerant compressed by the compressor 101 is condensed and liquefied by the outdoor heat exchanger 105, then depressurized by the indoor expansion valve 104, and evaporated by the indoor heat exchanger 102. It returns to 101. The indoor heat exchanger 102 and the indoor expansion valve 104 are provided in the indoor unit 109, and the indoor unit 109 is provided with an indoor blower 103 for promoting heat exchange.

  The compressor 101, the outdoor heat exchanger 105, the accumulator 107, and the like are provided in the outdoor unit 108, and the outdoor unit 108 is provided with an outdoor blower 106 for promoting heat exchange. The compressor 101 is driven by a permanent magnet synchronous motor 111, and the rotation speed (operation frequency) of the motor 111 is variably controlled by an inverter device 210.

  Thereby, it respond | corresponds to the capability required for a refrigerating cycle. In addition to the rotation speed of the compressor 101, the opening degree of the indoor expansion valve 104 or the outdoor expansion valve (not shown) for adjusting the refrigerant flow rate, the rotation speed of the indoor blower 103 and the outdoor blower 106, and the cooling / heating operation mode are set. The outdoor four-way valve 112 and the like to be controlled are controlled, and as such information, the operation command signal by the remote controller that performs operation mode, temperature setting, etc., the temperature of each part (compressor discharge gas temperature, outside air temperature, heat exchanger temperature, evaporation temperature, A signal that detects a suction temperature, a suction temperature, a freezing temperature, a gas pipe temperature, and the like is input to the outdoor control board 227 shown in FIG.

  Further, the inverter request frequency output from the outdoor control board 227 is input via the interface connector 240, and the operating frequency and the compressor motor 111 operating current are output from the inverter device 210 to the outdoor control board 227.

  The detection signal and the command signal input to the outdoor control board 227 are input to the microcomputer 231 via the interface connector 240, whereby the refrigeration cycle control is performed by the inverter device 210, and various control mechanisms ( The outdoor expansion valve, the outdoor blower 106, and the outdoor four-way valve 112) for switching the cooling / heating operation mode are controlled.

  FIG. 2 is a block diagram showing the configuration of the inverter device 210. Hereinafter, FIG. 2 will be described in detail with reference to FIGS. First, the circuit configuration will be described, and detailed control will be described later.

  The inverter device 210 converts the AC power from the three-phase AC power supply 273 into DC power, and generates AC power from the DC power generated by the converter circuit 225 to operate the compressor motor 111 at an operating frequency. An inverter circuit 221 that drives the inverter circuit 221, an inverter driver circuit 232 that switches the inverter circuit 221, a protection circuit B 275 that takes in a voltage generated in the shunt resistor 224 and protects the switching element 222, and a shunt resistor 224. An inverter / converter board 201 having a current detection circuit 233 for detecting a direct current flowing through the inverter circuit 221 and a protection circuit A274 for performing soft protection so as not to operate exceeding the rated current of the inverter circuit 221; Communication with the substrate 227 The communication circuit 239, the microcomputer 231 that controls the inverter circuit 221, and the power source that supplies the high voltage generated by the converter circuit 225 to the microcomputer 231 and the driver circuit 232, for example, a control power supply of about 5V or 15V The microcomputer board 204 includes a circuit 235 and a DC voltage detection circuit 234 that checks whether the DC voltage is an insufficient voltage.

  Conventionally, in the inverter device 210, the IPM composed of the inverter circuit 221 and the driver circuit 232 and the microcomputer 231 that controls the IPM are mounted on the same substrate and integrally configured, whereas in the circuit configuration shown in FIG. The inverter / converter board 201 on which the IPM is arranged and the microcomputer board on which the microcomputer 231 is arranged are separately formed as separate boards. By dividing the board in this manner, for example, a noise test in units of boards required for IPM or microcomputer 231 replacement work accompanying production stoppage can be performed on the inverter / converter board 201 or the microcomputer board 204 alone. Therefore, the test on the entire substrate of the inverter device 210 can be omitted, and the test man-hour and time can be reduced. Further, even if the replacement work of each board occurs, it can be replaced for each inverter / converter board 201 or microcomputer board 204.

  The inverter / converter board 201 constituting the inverter device 210 has both an IPM constituted by the inverter circuit 221 and the driver circuit 232 and a converter circuit 225 which is a DM (Diode Module). When it is necessary to replace the IPM or DM semiconductor element 203, the IPM ratings 25A, 30A, 50A, and 75A exist, and the DM also includes 20A, 30A, 40A, 50A, 60A, and 100A. Select one that has the same external dimensions as the DM and the pin spacing of the controller. Thereby, the old and new alternatives of the semiconductor element 203 are performed without changing the combination of the interfaces.

  FIG. 3 shows the mounting state of the inverter / converter substrate 201 and the semiconductor element 203. In order to generate heat, the semiconductor element 203 is arranged on the solder surface side where the components on the back side of the mounting surface on which the circuit components are mounted are soldered, and the heat radiation fins 236 are attached to radiate heat. It is preferable to provide a fixing screw hole for the radiation fin 236 attached to the semiconductor element 203 different from the semiconductor element 203 to be mounted so that the fixing screw hole to the radiation fin 236 can also correspond to the plurality of semiconductor elements 203.

  FIG. 4 shows a mounting state of the microcomputer board 204. It is necessary to supply 5V to the microcomputer 202 as a power source. This voltage generates 5 V from the DC voltage input from the high voltage section by the switching transformer 4.

  The outdoor control board 227 includes an outside temperature detection circuit 262 that detects the outside temperature using the outside temperature thermistor 261, a discharge temperature detection circuit 264 that detects the discharge temperature of the compressor 101 using the discharge temperature thermistor 263, and a discharge pressure. A discharge pressure detection circuit 266 that detects the discharge pressure of the compressor 101 using the sensor 265 is provided.

  The fan control board 228 includes a fan inverter circuit 221, a microcomputer 231 that controls the fan inverter circuit 221, an inverter driver circuit 232 that switches the fan inverter circuit 221, and a current detection circuit 233. The communication circuit 239 and the fan motor separation jumper wire 113 are included.

  Further, the DC voltage generated from the converter circuit 225 of the inverter device 210 is input to the fan control board 228. The inverter device 210 and the outdoor control board 227 are connected. The fan control board 228 drives the fan of the outdoor fan 106.

  Although the fan control board 228 is conventionally configured integrally with the fan motor 114, the fan motor 114 and the fan control board 228 that is a control board of the fan motor 114 are separated and configured as separate bodies. Even in the case of failure, only the fan motor 114 can be replaced. Therefore, the cost for replacing the fan control board 228 does not occur, and the cost for replacing the fan motor 114 can be reduced.

  In addition, the input voltage to the fan inverter circuit 221 uses the DC voltage generated from the converter circuit 225 of the inverter device 210, so that it is not necessary to provide a separate converter circuit 225 on the fan control board 228 as in the prior art. , Space saving of electric box, circuit configuration can be simplified and cost can be reduced.

  Further, on the fan control board, a part of the wiring for electrically connecting the fan inverter circuit 221 and the fan motor 114 is configured by the fan motor separation jumper wire 113, so that the fan motor 114 is caused by overcurrent or overvoltage. Since the fan motor separation jumper wire 113 can be cut when a failure occurs, it is possible to prevent the overcurrent or overvoltage from being reapplied to the fan motor 114.

  FIG. 5 shows a mounting state of the fan control board 228. A smoothing capacitor 5 is mounted to smooth the input DC voltage. The semiconductor element 203 is mounted on the solder surface side in order to generate heat, and a radiation fin 236 is attached. Two semiconductor elements 203 are mounted on the fan control board 228 when there are two fans and one when there is one fan. A connector 202 connected by a lead wire is attached for transmission with the microcomputer board 204.

  FIG. 6 shows a state where the inverter / converter board 201, the microcomputer board 204, and the fan control board 228 are actually connected by wiring. A connector 202 is mounted on each board for wiring. Through these connectors 202, the microcomputer board 204 and the fan control board 228 are electrically connected by the first wiring 206, and the microcomputer board 204 and the inverter / converter board 201 are electrically connected by the second wiring 207. Connected. When the fan control board 228 and the inverter / converter board 201 are stopped due to a problem error, error information is sent to the microcomputer 231.

  FIG. 7 is a cross-sectional view of the inverter device 210 and shows a mounting state of the substrate and the semiconductor element 203. As shown in the figure, the semiconductor element 203 is radiated by providing heat radiation fins 236 on the back side of the semiconductor element 203 mounted on the solder surface of the substrate. Since the heat dissipating fins 236 may come into contact with and interfere with other mounted circuit components, and a large area fin is required for heat dissipation, it is usually mounted on the solder surface.

  FIG. 8 shows another example of mounting states of three types of substrates. The same connection as that of FIG. 6 is performed, but the first lead pin 229 and the second lead pin 230 attached to one end of each substrate are electrically connected instead of the wiring.

  The inverter / converter board 201 and the microcomputer board 204 are overlapped with each other so that the microcomputer board 204 is shifted in the plane direction of the board, and is shifted from one end of the inverter / converter board 201 in the direction in which the microcomputer board 204 is shifted. The first lead pin 229 and the second lead pin 230 are electrically connected at a position where one end of the microcomputer board 204 in the direction opposite to the direction overlaps. Similarly, the microcomputer board 204 and the fan control board 228 are connected by shifting the boards in the plane direction. The microcomputer board 204 and the fan control board 228 are stacked so that the fan control board 228 is shifted in the opposite direction to the inverter / converter board 201 and is connected by a first lead pin at a connecting portion provided at the end. . By connecting and fixing with lead pins, unlike the wiring, space saving and malfunction due to noise on the wiring can be prevented.

  Thus, when each board is connected, the board is mounted on the inverter / converter board 201 and the fan control board 228 by shifting the board so as to reduce the area where the boards overlap each other when viewed from above the board plane. It is possible to suppress malfunction due to the influence of inductive noise generated from IPM or the like. In addition, when tall components such as capacitors are placed on the board, if another board is connected in the upward direction of the board plane, the parts mounted on each board or the parts and the board come into contact with each other. Although there is a possibility of interference, by shifting and connecting the respective substrates, the spatial distance between the component existing on the solder surface and the component existing on the mounting surface can be increased, and interference can be prevented.

  The AC voltage from the three-phase AC power supply 273 is converted to DC by the converter circuit 225, and the inverter circuit 221 that is a DC / AC converter is a circuit in which a plurality of switching elements 222 are connected in a three-phase bridge. The converter 225 is provided with a circuit in which a plurality of rectifying elements 226 are bridge-connected.

  Further, an inrush current limiting resistor 254 is provided in parallel with the electromagnetic contactor 253 so that the electromagnetic contactor 253 that is closed when the power is turned on does not weld due to an excessive inrush current flowing through the smoothing capacitor 270. A power factor improving reactor 252 and an electrolytic capacitor 270 are connected between the converter circuit 225 and the inverter circuit 221.

  The inverter circuit 221 is provided with a flywheel element 223 along with the switching element 222 in order to regenerate back electromotive force generated when the switching element 222 is switched. The driver circuit 232 controls a switching operation of the switching element 222 by amplifying a weak signal (a PWM signal described later) from the microcomputer 231. As a result, AC power is generated by the inverter circuit 221 and controlled as an AC frequency, and the compressor motor 111 is driven.

  The microcomputer 231 has a sensorless type vector control function. The rotational speed and phase (magnetic pole position) of the compressor motor 111 are estimated, and a speed sensor and a magnetic pole position sensor are not required. That is, the current supplied to the compressor motor 111 is captured by the microcomputer 231 after the drive current is amplified by the current detection circuit 233, and the drive motor is reproduced. The sine wave alternating current output to 111 is reproduced and monitored.

  Between the microcomputer 231 and the switching element 222, an inverter driver circuit 232 for amplifying the switching element 222 to a level at which the switching element 222 can be driven by a weak signal from the microcomputer 231 is provided.

  The communication circuit 239 includes an interface connector 240 to which a signal from the outdoor control board 227 is input, and a photocoupler 241 that transmits the input signal to the microcomputer 231 by an optical signal, and electrical isolation is obtained. Send and receive with.

  The inverter circuit 221, that is, the IPM converts the input direct current into alternating current, and drives the operating frequency of the compressor motor 111 at a variable speed. Further, the inverter device 210 has a protection function for overcurrent and a protection function for stopping the inverter circuit 221 against a decrease in control power supply voltage. When each protection function is activated, an abnormal signal is output to the microcomputer 231 and the inverter circuit 221 is stopped. Although the inverter circuit 221 is controlled by the driver circuit 232, the inverter circuit 221 is stopped by stopping the pulse signal from the driver circuit 232 to the inverter circuit 221.

  It is also possible to monitor the current flowing through the shunt resistor 224 and check whether an overcurrent is flowing. The current flowing through the shunt resistor 224 is monitored, and it can be determined that an overcurrent has flowed when a current greater than the set value flows through the shunt resistor.

In addition, protection circuits A274 and B275 are provided to protect the inverter circuit 221 when an overcurrent occurs in the shunt resistor 224. By providing the protection circuit A274, soft protection is performed so that the inverter circuit 221 is not operated exceeding the rated current. Further, when the switching element 222 that outputs the Fo signal is used, the protection circuit B275 is not mounted. The protection circuit A 274 protects the switching element 222 from an overcurrent that is one time the rated current of the switching element 222. When the switching element 222 that does not output the Fo signal is used, the switching element 222 is protected by mounting the protection circuit B275 instead of the protection circuit A274. The protection circuit B275 protects the switching element 222 from an overcurrent that is 1.3 times the rated current of the switching element 222. When an overcurrent exceeding 1.3 times the power element rating occurs, a signal is sent to the driver circuit 232, and the Fo signal is sent from the driver circuit 232 to the microcomputer 231. When a power element with a built-in overcurrent protection circuit is used for the driver circuit 232, the protection circuit B275 may not be provided.
Then, an overcurrent signal indicating that the inverter device 210 has stopped is transmitted to the microcomputer 231, and the microcomputer 231 transmits a signal indicating that the overcurrent has been received to the outdoor control board 227. The outdoor control board 227 tries to determine whether or not the inverter device 210 has failed. If the protection function is activated even if a predetermined number of retries are attempted, the outdoor control board 227 is considered to have failed. To be judged.

  Further, in Patent Document 1 described above, the output of the overcurrent detection means can be freely varied so that the current of the magnet of the compressor motor 111 (DC brushless motor) when the overcurrent is generated is less than the current value. Therefore, a noise test or the like must be performed on a board basis as in the past because a different overcurrent protection value is set and the board configuration is not the same.

  According to the configuration of the present embodiment, when the replacement is performed due to the production stop of the semiconductor element 203, a noise test is performed on the inverter / converter board 201 to extract anxiety points, and the product development can be performed at an early stage. It becomes possible. Therefore, the test as the whole substrate can be omitted. Unlike the prior art, only the inverter / converter board 201 needs to be tested. The size of the inverter / converter board 201 and the height of the parts are made to be compatible with each other, and the shunt resistor 224 and the protection circuit are manufactured. The inverter device 210 can be driven by adjusting the constant of B275 to the overcurrent protection value of the compressor motor 111 that does not demagnetize.

  On the other hand, when the fan motor 114 fails due to overcurrent or overvoltage, the fan motor isolation jumper wire 113 or the fuse is cut to disconnect the failed fan motor from the board. Since supply can be stopped, re-application of overcurrent or overvoltage is prevented. Therefore, since the failed fan motor 114 can be replaced with a new motor, the replacement of the fan control board 228 can be omitted so that the board replacement cost is not generated.

  Further, when the inverter current is large or the inverter current is small, the inverter / converter board 201 for driving the compressor is replaced with the inverter / converter board 201 suitable for each inverter current to operate the compressor 101. Can do.

  On the other hand, since the manufacturing is subdivided by dividing the microcomputer board 204, the fan control board 228, and the inverter / converter board 201, the manufacturing cost can be reduced. The cost of parts can be reduced by reviewing the cost of parts for each board.

3 Snubber capacitor 4 Switching transformer 5 Smoothing capacitor 6 Inverter output terminal 7 Power supply voltage input terminal 8 IPM PN terminal 9 Converter circuit PN terminal 101 Compressor 102 Indoor heat exchanger 103 Indoor blower 104 Indoor expansion valve 105 Outdoor heat exchanger 106 outdoor fan 107 accumulator 108 outdoor unit 109 indoor unit 110 air conditioner 111 compressor motor 112 outdoor four-way valve 113 fan motor separation jumper wire 114 fan motor 201 inverter / converter board 202 connector 203 semiconductor element 204 microcomputer board 205 inverter for fan 206 First wiring 207 Second wiring 208 MDF connector 210 Inverter device 221 Inverter circuit 222 Switching element 223 Flywheel element 224 Shunt resistor ( Flow detection means)
225 Converter circuit 226 Rectifying element 227 Outdoor control board 228 Fan control board 229 First lead pin 230 Second lead pin 231 Microcomputer (microcomputer)
232 Driver circuit 233 Current detection circuit (current detection means)
234 Power supply voltage detection circuit 235 Power supply circuit 236 Radiation fin 239 Communication circuit 240 Interface connector 241 Photocoupler 252 Power factor improving reactor 253 Magnetic contactor 254 Inrush current limiting resistor 261 Outside temperature thermistor (outside temperature detection means)
262 Outside air temperature detection circuit (outside air temperature detection means)
263 Discharge temperature thermistor (discharge temperature detection means)
264 Discharge temperature detection circuit (Discharge temperature detection means)
265 Discharge pressure sensor (Discharge pressure detection means)
266 Discharge pressure detection circuit (discharge pressure detection means)
267 Inverter control board 270 Electrolytic capacitor 271 Varistor 272 Snubber capacitor 273 Three-phase AC power supply 274 Protection circuit A
275 Protection circuit B

Claims (4)

A compressor for compressing refrigerant, a compressor motor for driving said compressor, a heat exchanger for exchanging heat between the refrigerant and air, and a fan for blowing air to the heat exchanger, a fan motor for driving the fan In a refrigeration apparatus that forms a refrigeration cycle by comprising
A converter circuit for converting an AC power from the AC power supply into DC power, a compressor inverter circuit for converting DC power generated by the converter circuit into AC power to the compressor motor, for the compressor A first board provided with a compressor driver circuit for controlling the inverter circuit;
A compressor microcomputer for controlling the driver circuit for the compressor , and a DC voltage from the converter circuit provided on the first board are stepped down and provided on the compressor microcomputer and the first board. A second substrate provided with a DC power supply circuit for supplying electric power to the compressor driver circuit;
From an inverter circuit for a fan motor that converts DC power generated by the converter circuit provided on the first substrate into AC power and outputs the AC power to the fan motor, and from the DC power supply circuit provided on the second substrate A third board provided with a fan motor driver circuit for controlling the fan motor inverter circuit and a fan motor microcomputer for controlling the fan motor driver circuit, to which power is supplied,
The first substrate, the second substrate, and the third substrate are formed separately from each other, and each of the substrates is electrically connected. Further, the third substrate is separated from the fan motor. refrigerating apparatus characterized by being configured. The refrigeration apparatus according to claim 1,
  The first substrate and the second substrate are stacked in an arrangement in which the second substrate is shifted in the substrate plane direction,
The first substrate and the second substrate are located at a position where one end of the first substrate in the direction in which the second substrate is shifted overlaps with one end of the second substrate in the direction opposite to the shifted direction. A refrigerating apparatus, wherein the refrigerating apparatus is electrically connected by a lead pin. The refrigeration apparatus according to claim 1,
The first substrate and the second substrate are stacked in an arrangement in which the second substrate is shifted in the substrate plane direction,
The first substrate and the second substrate at a position where one end portion of the first substrate in the direction in which the second substrate is shifted and one end portion of the second substrate in the direction opposite to the shifted direction overlap. Are electrically connected by lead pins,
The second substrate and the third substrate are stacked in an arrangement in which the third substrate is shifted in the opposite direction to the first substrate,
The second substrate and the third substrate are located at a position where one end portion of the second substrate in the direction in which the third substrate is shifted overlaps with one end portion of the third substrate in the direction opposite to the shifted direction. A refrigerating apparatus, wherein the refrigerating apparatus is electrically connected by a lead pin. The refrigeration apparatus according to claim 1 or 3,
A part of the wiring for electrically connecting the fan motor inverter circuit and the fan motor on the third substrate is constituted by a jumper wire.