JP5045687B2 - Power supply, air conditioner - Google Patents

Description

  The present invention belongs to the technical field of a power supply device that supplies power to a driving load such as a compressor motor using a rectifier circuit and a smoothing unit.

  An air conditioner that performs an air conditioning operation such as cooling and heating indoor air includes a compressor that compresses a refrigerant and a fan that blows air that has been cooled or heated, and also drives such a compressor and fan. A power supply device that supplies power to the motor is provided.

  The power supply device includes, for example, a rectifier circuit that rectifies AC power, a capacitor that smoothes the output of the rectifier circuit, a main relay that conducts and cuts off a current path between the rectifier circuit and the capacitor, and the like. Is done. Also, in order to prevent the occurrence of so-called inrush current immediately after the start of power supply to the capacitor, a bypass circuit that bypasses the main relay is provided, and a resistor element for preventing the inrush current is provided in the bypass circuit, thereby supplying power A technique for limiting the supply current by turning off the main relay immediately after the start so that the supply current to the capacitor flows through the resistance element is generally known (see Patent Document 1 below).

  Further, in order to be able to arbitrarily set the timing of flowing a current to the inrush current preventing resistance element, techniques for providing an inrush current preventing relay separately from the main relay are disclosed in Patent Documents 2 to 4 below. Yes.

  Patent Document 2 listed below includes an inverter main circuit, a capacitor connected between a pair of DC power supply lines extending from the DC power supply to the inverter main circuit, and a rush intervening in the DC power supply line extending from the DC power supply to the capacitor. A current suppressing resistor; a first switch means connected in parallel to the inrush current suppressing resistor; and a shunt resistor and a second switch means connected in parallel to the first switch means. An inverter device including the series circuit is disclosed.

  Patent Document 3 below discloses a circuit in which a parallel circuit of a relay and a resistor is provided as an inrush current suppression circuit, and a main power supply relay is provided between the parallel circuit and the main power supply.

  Further, in Patent Document 4 below, a configuration in which a parallel circuit of a series circuit of a rush current prevention resistor element and a rush current prevention relay and a main relay is installed in a direct current section (between the rectifier circuit and the smoothing section), The structure installed in an alternating current part (between a commercial power supply and a rectifier circuit) is disclosed.

JP 2003-348869 A JP 2008-104276 A JP 2006-238602 A JP 2005-261040 A

  When the parallel circuit of the series circuit of the inrush current preventing resistance element and the inrush current preventing relay and the main relay is to be installed in the DC part (between the rectifier circuit and the smoothing part) as in Patent Document 4, the inrush current The prevention relay is applied with a DC voltage larger than the power supply voltage of the commercial power supply. For example, when the commercial power source is 200 (V), a DC voltage of about 300 (V) is applied to the inrush current prevention relay. Thus, since a large DC voltage is applied to the inrush current prevention relay, a DC voltage relay that can be maintained at a high voltage is required as the inrush current prevention relay.

  However, since the current flowing through the inrush current prevention relay is limited by the inrush current prevention resistance element, the current value is not so large (for example, a current of about several amperes), and the current does not prevent the inrush current. The time which flows through the relay for a certain time is a certain short time after the supply of electric power from the commercial power supply to the smoothing unit is started.

  Therefore, if a relay having a DC voltage contact capacity is used as an inrush current prevention relay, a relay that is over-special with respect to the current value of the current flowing through the relay will be used, and in terms of cost and circuit scale. It becomes a problem.

  On the other hand, when the main relay, the inrush current preventing resistance element, and the inrush current preventing relay are to be installed in an alternating current section (between the commercial power supply and the rectifier circuit), a direct current voltage relay that can be maintained at a high voltage. However, it is necessary to provide the parallel circuit (a parallel circuit of a main circuit and a series circuit of an inrush current preventing resistor element and an inrush current preventing relay) for each AC power line. is there. For this reason, the number of parts increases, which causes a problem in terms of cost and circuit scale.

  The present invention has been made to solve the above-described problems, and proposes a power supply device capable of preventing the occurrence of an inrush current while preventing or suppressing an increase in cost and an increase in circuit scale. Objective.

The invention described in claim 1 includes a rectifier circuit (RC) that rectifies AC power supplied from an external power source (E), a smoothing section (C) that smoothes the output of the rectifier circuit (RC), and A main relay (RL1) provided on a current path between the rectifier circuit (RC) and the smoothing unit (C), an inrush current preventing resistance element (R1), and an inrush current preventing relay (RL2). , An inrush current prevention circuit for preventing the occurrence of an inrush current to the smoothing section (C), and a driving power generation section for generating driving power to be supplied to a driving object using the output of the smoothing section (C). 3 and 23), and a control unit (2) for controlling the on / off operation of the main relay (RL1) and the inrush current prevention relay (RL2) and for controlling the operation of the drive power generation unit (3, 23); The inrush current prevention circuit comprises the In the state where it is branched from the AC power line connected to the power source (E) and upstream of the rectifier circuit (RC) and is connected in parallel to the rectifier circuit (RC) and the main relay (RL1). Connected to the smoothing section (C), half of the AC power transmitted through the AC power supply line and the series circuit of the inrush current preventing resistance element (R1) and the inrush current preventing relay (RL2). A half-wave rectification circuit (D) that rectifies the wave and outputs the same to the smoothing unit (C). The control unit (2) turns off the main relay (RL1) and the inrush current prevention relay (RL2). ) Is periodically turned on by the half-wave rectification by the half-wave rectifier circuit (D) during the inrush current prevention period in which power is supplied to the smoothing unit (C) via the inrush current prevention circuit. On the inrush current prevention circuit By turning on the main relay (RL1) and turning off the inrush current prevention relay (RL2) during a period (Tw) when the current becomes zero, the smoothing unit (C) is connected via the main relay (RL1). It is a power supply device which transfers to the normal electric power supply period which supplies electric power to .

  According to the present invention, an inrush current prevention circuit having an inrush current prevention resistance element and an inrush current prevention relay is branched from an AC power line connected to the external power source and upstream of the rectifier circuit, and Since the rectifier circuit (RC) and the main relay (RL1) are connected in parallel to the smoothing unit, AC power can be supplied to the smoothing unit via an inrush current prevention circuit.

  In addition, since the inrush current prevention circuit includes a half wave rectification circuit that half-wave rectifies AC power transmitted through the AC power line and outputs the half-wave rectification circuit to the smoothing unit, an inrush current prevention relay (inrush current prevention relay) is provided. A period in which the current flowing in the circuit) is 0 (zero) can be provided.

  Therefore, when the state where power is supplied to the smoothing section via the inrush current prevention circuit is shifted to the state where power is supplied via the main relay, the current flows to the inrush current prevention relay (inrush current prevention circuit). By turning off the inrush current prevention relay during a period when the current becomes 0 (zero), it is possible to prevent the occurrence of inrush current while preventing the occurrence of welding in the inrush current prevention relay.

  Furthermore, according to the present invention, an inrush current prevention circuit is branched from an AC power supply line connected to the external power supply and upstream of the rectifier circuit, and is connected to the rectifier circuit (RC) and the main relay (RL1). On the other hand, since it is connected to the smoothing unit in a parallel connection state and power is supplied to the smoothing unit via the inrush current prevention circuit, power is supplied to the smoothing unit via the inrush current prevention circuit. Sometimes, the smoothing unit can be supplied with the AC voltage that is smaller than the output voltage of the rectifier circuit.

  Therefore, it is not necessary to use a relay that can withstand a relatively large voltage as the main relay, the inrush current prevention relay, and the inrush current prevention resistance element on the DC side, and the inrush current prevention relay is not required. The main relay, the inrush current prevention relay, and the inrush current prevention resistance element are connected to the AC power supply line of each phase connected to the external power source as in the case of providing the current prevention relay and the inrush current prevention resistance element on the AC side. It is no longer necessary to provide As a result, an increase in cost and an increase in circuit scale can be prevented or suppressed.

According to the present invention, the control unit turns on the main relay and turns off the inrush current prevention relay during a period in which the current on the inrush current prevention circuit is zero in the inrush current prevention period, Since the transition to the normal power supply period for supplying power to the smoothing unit via the main relay is made, when the transition from the inrush current prevention period to the normal supply period, current flows to the inrush current prevention relay. It is possible to avoid a situation where the relay is switched from on to off in a state where the relay is on.

  Therefore, the two terminals are welded by the discharge between the terminals of the inrush current preventing relay that can be generated by switching the inrush current preventing relay from on to off in the state where the current flows through the inrush current preventing relay. Can be avoided.

According to a second aspect of the invention, in the power supply device according to claim 1, at a predetermined timing of the inrush current prevention period, a voltage detection unit (VDC for detecting an output voltage of the smoothing section (C) ), And the control unit (2) compares the output voltage of the smoothing unit (C) detected by the voltage detection unit (VDC) with a predetermined threshold, and the smoothing unit (C) When the output voltage is greater than the threshold value, the power supply device is determined to be normal, and when the output voltage of the smoothing unit (C) is equal to or lower than the threshold value, an abnormality has occurred in the power supply device (1) When the power supply device (1) is determined to be normal, the transition from the inrush current prevention period to the normal power supply period is performed.

  According to this invention, the output voltage of the smoothing unit detected at a predetermined timing in the inrush current prevention period is compared with a predetermined threshold value, and the output voltage of the smoothing unit is larger than the threshold value. The power supply device is determined to be normal, and when the output voltage of the smoothing unit is less than or equal to the threshold value, it is determined that an abnormality has occurred in the power supply device. In the method, it is possible to detect whether or not the power supply device is normal.

  Further, when the power supply device is normal, the normal power supply period is shifted from the inrush current prevention period to the normal power supply period, so that the normal power supply operation is performed in a state where an abnormality has occurred in the power supply device. Can be prevented.

The invention described in claim 3 is the power supply device according to claim 2, wherein the control unit (2) has determined that an abnormality has occurred in the power supply device (1), notifies the fact Is.

  According to this invention, a user or a service person can recognize that an abnormality has occurred in the power supply device.

The invention according to claim 4 includes a compressor, a motor (M) as the drive target that drives the compressor, and the power supply device (1) according to any one of claims 1 to 3. It is an air conditioner.

According to this invention, in the air conditioner, the effect of the invention according to any one of claims 1 to 3 can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of an inrush current can be prevented, preventing or suppressing the generation | occurrence | production of the welding in an inrush current prevention relay, the cost increase, and the increase in a circuit scale.

It is a circuit diagram which shows an example of the power supply device which concerns on this invention. It is a figure which shows the rush current prevention period which supplies an electric current to a capacitor | condenser, preventing generation | occurrence | production of the rush current to a capacitor | condenser, and the normal supply period which supplies an electric current to a capacitor | condenser without performing the electric current restriction | limiting to a capacitor | condenser. It is a figure which shows the waveform of the electric current which flows into an inrush current prevention circuit, when the inrush current prevention relay is turned ON. It is the graph showing the time change of the voltage of a capacitor | condenser when abnormality has not generate | occur | produced in the power supply device. It is a flowchart which shows the abnormality determination process by the said determination part.

  Hereinafter, embodiments of a power supply device according to the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing an example of a power supply device according to the present invention.

  As shown in FIG. 1, the power supply device 1 is suitable as a power supply device for driving a motor M of a compressor provided in an air conditioner (not shown), for example, a rectifier circuit RC, a main relay RL1, a coil L, capacitor C, voltage detection circuit VDC, inverter circuit 3, switching unit 4, inrush current preventing resistance element R1 (hereinafter simply referred to as resistance element R1), inrush current preventing relay RL2, and diode D and the control unit 2 are provided.

  The rectifier circuit RC is connected to output terminals T1 to T3 of an external power source E such as a commercial power source, and rectifies AC power output from the external power source E. The rectifier circuit RC is composed of, for example, a diode bridge circuit.

  The capacitor C, the main relay RL1 and the coil L are connected in series. Both terminals of this series circuit are connected to the respective output terminals of the rectifier circuit RC. The capacitor C constitutes a smoothing circuit and smoothes the output of the rectifier circuit RC. The coil L is an element provided for improving the power factor of the inverter circuit 3.

  The main relay RL1 turns on and off the current path from the rectifier circuit RC to the capacitor C and the inverter circuit 3. That is, when the main relay RL1 is turned on, the current path from the rectifier circuit RC to the capacitor C and the inverter circuit 3 becomes conductive, and the output of the rectifier circuit RC is supplied to the capacitor C and the inverter circuit 3, while the operation is performed. When the main relay RL1 is turned off by stopping or detecting an abnormality, the current path from the rectifier circuit RC to the capacitor C and the inverter circuit 3 is interrupted, and the output of the rectifier circuit RC is converted to the capacitor C and the inverter circuit. 3 is not supplied.

  The voltage detection circuit VDC detects a voltage between both poles of the capacitor C. Although not shown, for example, two voltage dividing resistance elements are connected in series, and the voltage at the connection point of these voltage dividing resistance elements is calculated. An output configuration is assumed. The voltage detection circuit VDC outputs the detected voltage to the control unit 2 as a voltage signal.

  The inverter circuit 3 generates a predetermined AC voltage from the voltage across the capacitor C and the motor drive signal output from the control unit 2, and outputs the current or voltage to the motor M. The switching unit 4 includes a switching element made of, for example, an npn type bipolar transistor, and the switching element is turned on / off in response to a PWM signal output from the control unit 2.

  The resistor element R1, the inrush current preventing relay RL2, and the diode D are connected in series. That is, one terminal of the resistor element R1 and one terminal of the inrush current prevention relay RL2 are connected, and the other terminal of the inrush current prevention relay RL2 and the anode of the diode D are connected. This series circuit functions as an inrush current prevention circuit for preventing an inrush current to the capacitor C.

  The inrush current prevention circuit is connected to the external power supply E and branched from an AC power supply line on the upstream side of the rectifier circuit RC, and is connected in parallel to the rectifier circuit RC and the main relay RL1. The other terminal of the resistance element R1 functions as an input terminal of the inrush current prevention circuit, and the cathode of the diode D functions as an output terminal of the inrush current prevention circuit.

  Here, in the present embodiment, the input terminal of the inrush current prevention circuit (the other terminal of the resistance element R1) is connected to one AC power supply line among the AC power supply lines connected to the external power supply E. The output terminal of the inrush current prevention circuit (the cathode of the diode D) is connected to one electrode plate of the capacitor C.

  As a result, in addition to the main path for supplying the power supplied from the external power source E to the capacitor C via the rectifier circuit RC, the main relay RL1 and the coil L, the power supplied from the external power source E is used for the inrush current prevention circuit. Thus, a sub-path for supplying to the capacitor C is provided. And the power supply device 1 of this embodiment charges the capacitor C using the said sub path | route about the period when an inrush current may generate | occur | produce when the capacitor | condenser C is charged using a main path | route, and this period After that, the capacitor C is charged using the main path except when no abnormality has occurred in the power supply device 1.

  As described above, since the diode D is provided on the sub path, the capacitor C is charged by the half-wave rectified AC power using the sub path (via the inrush current prevention circuit). . Due to the half-wave rectification action of the diode D, a period in which the current supplied to the capacitor C, that is, the current flowing through the inrush current prevention relay RL2 is 0 (zero) appears periodically.

  In the present embodiment, the inrush current prevention relay RL2 is turned off during a period (period Tw shown in FIG. 3) in which the current flowing through the inrush current prevention relay is 0 (zero). Thus, the inrush current prevention relay RL2 is turned off when a current is flowing through the inrush current prevention relay RL2, so that the inrush current prevention relay is caused by discharge between the terminals of the inrush current prevention relay RL2. Prevents welding of RL2.

  Further, when comparing the maximum value of the AC voltage of each phase output from the external power supply E with the output voltage of the rectifier circuit RC, the output voltage of the rectifier circuit RC is the AC voltage output from the external power supply E. It is larger than the maximum value.

  Here, if the resistor element R1, the inrush current preventing relay RL2, and the main relay RL1 are provided on the capacitor C side (DC side) from the rectifier circuit RC, the capacitor is connected via the inrush current preventing resistor element and the inrush current preventing relay. When charging C, since the current flowing through the inrush current prevention relay becomes relatively large, the inrush current prevention relay RL2 must be able to withstand a relatively large voltage, which increases the cost and circuit scale. Incurs an increase.

  In addition, a parallel circuit of the series circuit of the resistor element R1 and the inrush current prevention relay RL2 and the main relay RL1 is provided on the external power supply E side (AC side) from the rectifier circuit RC, that is, the main relay RL1 is provided on the AC power supply line. And providing a series circuit of the resistor element R1 and the inrush current prevention relay RL2 connected in parallel to the main relay RL1, the AC power lines of the respective phases connected to the external power source E In addition, the resistor element R1, the inrush current preventing relay RL2, and the main relay RL1 are required, which leads to an increase in cost and an increase in circuit scale.

  On the other hand, in this embodiment, as described above, the inrush current is prevented by connecting the input terminal of the inrush current prevention circuit to one AC power supply line among the AC power supply lines connected to the external power supply E. When charging the capacitor C through the prevention circuit, the capacitor C is charged with the AC voltage smaller than the output voltage of the rectifier circuit RC. Therefore, the inrush current prevention relay RL2 can be used for direct current that can withstand a relatively large voltage. It is possible to eliminate the need to employ a relay or to provide the resistive element R1, the inrush current preventing relay RL2, and the main relay RL1 on each phase of the AC power supply line.

  Returning to FIG. 1, the control unit 2 includes a ROM (Read Only Memory) for storing various control programs, a RAM (Random Access Memory) having a function for temporarily storing data and a function as a work area, and the control program. And the like. The main relay control unit 21, the inrush current prevention relay control unit 22, the motor drive signal generation unit 23, the time measurement unit 24, the determination unit 25, and the notification A function as the unit 26 is provided. The control unit 2 operates upon receiving power supply from the external power source E.

  The main relay control unit 21 controls the on / off operation of the inrush current prevention relay RL2. The inrush current prevention relay control unit 22 controls the on / off operation of the main relay RL1.

  In the power supply device 1 of the present embodiment, as shown in FIG. 2, when charging the capacitor C and driving the motor M, current is supplied to the capacitor C while preventing the inrush current from flowing into the capacitor C. An inrush current prevention period and a normal supply period in which current is supplied to the capacitor C without limiting the current to the capacitor C as in the inrush current prevention period are provided.

  In the inrush current prevention period, the main relay control unit 21 turns off the main relay RL1, and the inrush current prevention relay control unit 22 turns on the inrush current prevention relay RL2. As a result, the power supplied from the external power source E is supplied to the capacitor C through the inrush current prevention circuit. As a result, in the inrush current prevention period, the current is limited by the presence of the inrush current prevention resistance element R1, so that the capacitor C is charged with a current smaller than the normal supply period, and the occurrence of the inrush current is prevented.

  Here, as shown in FIG. 3, a period during which the supply current of the capacitor C, that is, the current flowing through the inrush current prevention relay RL2 is 0 (zero) during the inrush current prevention period due to the half-wave rectification action by the diode D. As described above that Tw appears periodically, the inrush current prevention relay control unit 22 performs the normal supply period from the inrush current prevention period in the period Tw in which the current flowing through the inrush current prevention relay RL2 becomes 0 (zero). The inrush current prevention relay RL2 is turned off so as to make a transition to (1).

  On the other hand, in the normal supply period, the main relay control unit 21 turns on the main relay RL1, and the inrush current prevention relay control unit 22 turns off the inrush current prevention relay RL2. At this time, the power supplied from the external power source E is supplied to the capacitor C via the rectifier circuit RC and the main relay RL1. Thereby, the capacitor C can be charged more efficiently than the inrush current prevention period because there is no power loss in the resistance element R1 in the inrush current prevention circuit.

  The switching from the inrush current prevention period to the normal supply period is performed when the power supply device 1 is operating normally. In the power supply device 1 of the present embodiment, it is determined whether or not the power supply device 1 is operating normally for a predetermined time after power supply from the external power supply E to the control unit 2 is started in the inrush current prevention period. The inrush current prevention period when the capacitor C is charged to a predetermined voltage Vth or more, based on whether or not the capacitor C has been charged to a predetermined voltage Vth or more. Is switched to the normal supply period. As shown in FIG. 4, the predetermined time Tth is the time when the voltage Vc of the capacitor C is assumed to reach the threshold value Vth or more when no abnormality has occurred in the power supply device 1. It is.

  The time measurement unit 24 and the determination unit 25 are provided to confirm whether or not the power supply device 1 is operating normally. The time measurement unit 24 is configured such that a breaker (not shown) is turned on. When the power supply from the external power source E to the control unit 2 is started, time measurement is started.

  The determination unit 25 detects the voltage of the capacitor C based on the voltage signal from the voltage detection circuit VDC when the time measured by the time measurement unit 24 reaches a predetermined time in the inrush current prevention period. Then, it is determined whether or not the detected voltage is equal to or higher than a predetermined threshold value Vth. When the detected voltage is equal to or higher than a predetermined threshold value Vth, it is determined that the power supply device 1 is normal. When the detected voltage is less than a predetermined threshold value Vth, it is determined that an abnormality has occurred in the power supply device 1.

  When the determination unit 25 determines that the power supply device 1 is normal, the inrush current prevention relay control unit 22 turns off the inrush current prevention relay RL2, and the main relay control unit 21 turns on the main relay RL1. . Thereby, the power supply device 1 shifts from the inrush current prevention period to the normal supply period.

  When the determination unit 25 determines that an abnormality has occurred in the power supply device 1, the notification unit 26 notifies that fact visually or audibly.

  The motor drive signal generator 23 generates a motor drive signal to be output to the inverter circuit 3 based on the voltage signal output from the voltage detection circuit VDC, and outputs the motor drive signal to the inverter circuit 3. .

  FIG. 5 is a flowchart showing the abnormality determination process by the determination unit 25. It is assumed that the main relay RL1 is turned off in advance and the inrush current prevention relay RL2 is turned on in advance before executing the abnormality determination process shown in FIG.

  As shown in FIG. 5, when the power supply from the external power source E is started by turning on a breaker (not shown) (step # 1), the control unit 2 starts measuring time by the time measuring unit 24. (Step # 2). Then, the determination unit 25 of the control unit 2 determines whether or not the measurement time of the time measurement unit 24 has reached a predetermined time Tth (see FIG. 4) (step # 3), and the measurement time is If it is determined that the predetermined time Tth has been reached (YES in step # 3), the voltage Vc of the capacitor C is detected based on the voltage signal from the voltage detection circuit VDC (step # 4). It is determined whether or not Vc is equal to or greater than a predetermined threshold value Vth (step # 5).

  When the determination unit 25 determines that the voltage Vc of the capacitor C is equal to or higher than the threshold value Vth (YES in step # 5), the determination unit 25 determines that the power supply device 1 is normal and prevents inrush current. In response to this determination, relay control unit 22 turns off inrush current prevention relay RL2 (step # 6), and main relay control unit 34 turns on main relay RL1 (step # 7).

  On the other hand, when the determination unit 25 determines that the voltage Vc of the capacitor C is less than the threshold value Vth (NO in step # 5), the determination unit 25 determines that an abnormality has occurred in the power supply device 1, Upon receiving this determination, the inrush current prevention relay control unit 22 turns off the inrush current prevention relay RL2 (step # 8), and the notification unit 26 notifies that an abnormality has occurred in the power supply device 1. (Step # 9).

  As described above, in this embodiment, the input terminal of the inrush current prevention circuit having the inrush current prevention resistance element R1 and the inrush current prevention relay RL2 is one of the AC power supply lines connected to the external power source E. Since the output terminal of the inrush current prevention circuit (cathode of the diode D) is connected to one electrode plate of the capacitor C, AC power is supplied to the capacitor C through the inrush current prevention circuit. Can be supplied.

  Moreover, since the diode D (an example of a half-wave rectifier circuit) that half-wave rectifies the AC power transmitted through the AC power line and outputs it to the capacitor C is provided in the inrush current prevention circuit, the inrush current prevention circuit is provided. A period in which the current flowing through the relay RL2 is 0 (zero) can be provided.

  Further, since the inrush current prevention relay RL2 is connected in series to the inrush current prevention resistance element R1, the timing for supplying power to the capacitor C via the inrush current prevention resistance element R1 and the timing for stopping the power supply are set. It can be set arbitrarily. Using this, when the state of supplying power to the capacitor C through the inrush current prevention circuit is shifted to the state of supplying power through the main relay RL1, the current flowing through the inrush current prevention relay RL2 Since the inrush current prevention relay RL2 is turned off during the period when the current becomes 0 (zero), it is possible to prevent the occurrence of inrush current while preventing the occurrence of welding in the inrush current prevention relay RL2. .

  Further, the input terminal of the inrush current prevention circuit having the inrush current prevention resistance element R1 and the inrush current prevention relay RL2 is connected to one AC power supply line among the AC power supply lines connected to the external power supply E. Since the output terminal (the cathode of the diode D) of the inrush current prevention circuit is connected to one electrode plate of the capacitor C, an AC voltage smaller than the output voltage of the rectifier circuit RC is supplied when power is supplied to the capacitor C. Thus, power can be supplied to the capacitor C.

  Therefore, a DC relay that can withstand a relatively large voltage is adopted as the inrush current prevention relay RL2 as in the case where the main relay RL1, the inrush current prevention relay RL2, and the inrush current prevention resistance element R1 are provided on the DC side. No need to do.

  Further, the input terminal of the inrush current prevention circuit having the inrush current prevention resistance element R1 and the inrush current prevention relay RL2 is connected to one AC power supply line among the AC power supply lines connected to the external power supply E. Since the output terminal (the cathode of the diode D) of the inrush current prevention circuit is connected to one electrode plate of the capacitor C, the inrush current prevention relay RL2 and the inrush current prevention resistance element R1 are provided on the AC side. As described above, the necessity of providing the main relay RL1, the inrush current preventing relay RL2, and the inrush current preventing resistance element R1 on the AC power lines of the respective phases connected to the external power source E is also eliminated. As a result, an increase in cost and an increase in circuit scale can be prevented or suppressed.

  Further, the drive target of the power supply apparatus according to the present embodiment is not limited to the motor that drives the compressor, and may be a motor that drives a fan or the like.

2 Control Unit 21 Main Relay Control Unit 22 Inrush Current Prevention Relay Control Unit 23 Motor Drive Signal Generation Unit 24 Time Measurement Unit 25 Determination Unit 26 Notification Unit RC Rectifier Circuit RL1 Main Relay L Coil C Capacitor R1 Inrush Current Prevention Resistance Element RL2 Inrush current prevention relay D Diode

Claims (4)

A rectifier circuit (RC) for rectifying AC power supplied from an external power source (E);
A smoothing section (C) for smoothing the output of the rectifier circuit (RC);
A main relay (RL1) provided on a current path between the rectifier circuit (RC) and the smoothing unit (C);
An inrush current preventing circuit including an inrush current preventing resistance element (R1) and an inrush current preventing relay (RL2) for preventing the occurrence of an inrush current to the smoothing section (C);
A drive power generation unit (3, 23) that generates drive power to be supplied to a drive target using the output of the smoothing unit (C);
A control unit (2) for controlling the on / off operation of the main relay (RL1) and the inrush current prevention relay (RL2) and controlling the operation of the drive power generation unit (3, 23);
The inrush current prevention circuit is connected to the external power source (E) and branched from an AC power line upstream of the rectifier circuit (RC), and is connected to the rectifier circuit (RC) and the main relay (RL1). And connected to the smoothing part (C) in a parallel connection state, through a series circuit of the inrush current preventing resistance element (R1) and the inrush current preventing relay (RL2), and the AC power line. A half-wave rectifier circuit (D) for half-wave rectifying the alternating-current power transmitted and outputting to the smoothing section (C) ,
The control unit (2) supplies power to the smoothing unit (C) via the inrush current prevention circuit by turning off the main relay (RL1) and turning on the inrush current prevention relay (RL2). In the inrush current prevention period, the main relay (RL1) is in a period (Tw) in which the current on the inrush current prevention circuit that appears periodically by the half wave rectification by the half wave rectification circuit (D) becomes zero. The power supply apparatus is shifted to a normal power supply period in which power is supplied to the smoothing section (C) through the main relay (RL1) by turning on the inrush current prevention relay (RL2) . A voltage detection unit (VDC) that detects an output voltage of the smoothing unit (C) at a predetermined timing in the inrush current prevention period;
The control unit (2) compares the output voltage of the smoothing unit (C) detected by the voltage detection unit (VDC) with a predetermined threshold, and the output voltage of the smoothing unit (C) is When larger than the threshold value, it is determined that the power supply device is normal, and when the output voltage of the smoothing unit (C) is equal to or lower than the threshold value, it is determined that an abnormality has occurred in the power supply device (1), If it is determined that the power supply device (1) is normal, the power supply device according to claim 1, the transition from the inrush current prevention period in the normal power supply period. The power supply device according to claim 2 , wherein when the control unit (2) determines that an abnormality has occurred in the power supply device (1), the control unit (2) notifies the fact. A compressor,
A motor (M) as the drive target for driving the compressor;
An air conditioner comprising the power supply device (1) according to any one of claims 1 to 3 .

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