JP6501942B2 - Power converter, equipment, and equipment system - Google Patents

Description

  The present invention converts a voltage of an alternating current power supply into a direct current and converts the direct current voltage into an alternating current voltage of a predetermined frequency, an equipment including the power conversion apparatus, and an equipment system including the power conversion apparatus About.

  Equipment that consumes a large amount of power is connected to a power receiving equipment (cubicle). In this power reception facility, a regulation value for regulating the amount of outflow of harmonic current to the commercial AC power supply side is set. The magnitude of this regulation value is proportional to the power capacity of the power reception facility. In addition, harmonic current is generated by facility equipment equipped with an inverter, so-called inverter mounted equipment, and is not generated by an AC motor (induction motor) directly connected to a commercial AC power supply.

  Various equipment such as an air conditioner, a lighting fixture, and an elevator are connected to the power reception equipment. Among the connected devices, when the ratio of the device equipped with the inverter is high, the amount of generation of the harmonic current may exceed the regulation value.

  In order to ensure that the amount of harmonic current generation does not exceed the above regulation value, either change the power reception facility to one with a large power capacity, or reduce harmonics in the power supply line between the inverter mounted device and the power reception facility. The device needs to be deployed. There is also a method of incorporating a step-up type PWM converter as a DC converter into an inverter mounted device and reducing harmonic current by switching the PWM converter.

JP 2004-120878 A Japanese Patent Application Laid-Open No. 2004-263887

  However, a power receiving facility with a large power capacity is expensive, and a harmonic suppression device is also expensive. Further, since the switching element of the PWM converter has a large power loss, there is a problem that the reduction of the harmonic current due to the switching of the PWM converter causes the efficiency of the equipment to be reduced.

  The object of the present embodiment is to provide a power converter capable of reliably reducing harmonic currents regardless of their harmonic order without requiring expensive power receiving equipment and harmonic suppression devices, and without causing deterioration in the efficiency of the equipment. And equipment equipment and equipment equipment system.

The power converter according to claim 1 includes a reactor, a diode connected to an AC power supply via the reactor, and a switching element connected in parallel to the diode, and boosts and DC converts the voltage of the AC power supply. A converter, an inverter for converting an output voltage of the converter into an AC voltage, an input unit for inputting a limiting value of harmonic current, and a harmonic current generated on an input side of the converter are input to the input unit The minimum value of the output voltage of the converter which can fall within the limit value is stored in advance in association with the load of the inverter, and the minimum value of the output voltage corresponding to the actual load size of the inverter is read out from the storage content and a controller output voltage of said converter to control the switching of the converter such that the read-out minimum, the Obtain.

The equipment apparatus of Claim 4 is provided with two or more power conversion devices of Claim 3 , Comprising: The integrated controller which comprehensively controls each said power conversion device is provided. The integrated controller sets the limit value for the power conversion device within the range of the limit value for the facility device based on the “regulation value of harmonic current” set in the power receiving facility to which the respective facility device is connected. And determining the limit value for the power converter to the controllers of the power converter.

An installation device system according to claim 6 is an installation device system including a plurality of the installation devices according to claim 4, and includes a center controller that controls each of the installation devices. The center controller is a limit value for each of the facility devices within the range of the limit value for the facility device system based on the “regulation value of harmonic current” set in the power receiving facility to which each of the facility devices is connected. And notify the integrated controllers of the installation devices of the limit value for the installation devices.

FIG. 2 is a block diagram showing the configuration of the first and second embodiments. The figure which shows PWM signal generation for the converter of each embodiment. The figure which shows the limiting value of the harmonic current in each embodiment by making an inverter ratio and a harmonic order into a parameter. The figure which shows the relationship between the output voltage of the converter and 5th harmonic current in each embodiment. The figure which shows the value of the harmonic current which generate | occur | produces in each embodiment as a parameter of the output voltage of a converter, and a harmonic order. The figure which shows the relationship of the output voltage of a converter and efficiency in each embodiment. FIG. 5 is a view showing control data stored in a limit value setting unit of the first embodiment. The flowchart which shows control of each embodiment. FIG. 13 is a graph showing a change in output voltage of the converter according to the calculated value of harmonic current in the second embodiment. The block diagram which shows the structure of 3rd Embodiment. The figure which shows the control conditions of 3rd Embodiment. The figure which shows the relationship of the load and efficiency in 4th Embodiment. The figure which shows the relationship between the load and harmonic current in 4th Embodiment. The block diagram which shows the structure of the principal part of 5th Embodiment.

[1] First Embodiment
A first embodiment of the present invention will be described with reference to the drawings. The power conversion device according to the first embodiment is incorporated in a specific equipment such as a heat pump type heat source machine such as an air conditioner, and drives a compressor in the heat pump type heat source machine.

  As shown in FIG. 1, a power reception facility (cubicle) 10 is connected to phase lines R, S, T of a commercial three-phase AC power supply 1, and the power conversion device 100 of the present embodiment is connected to the power reception facility 10. . The power conversion apparatus 100 is incorporated in a specific equipment, for example, a heat pump type heat source machine for air conditioning, and outputs driving power to a drive motor of a compressor in the heat pump type heat source machine, and is connected to the power receiving equipment 10 Converter (also referred to as a PWM converter) 2, a smoothing capacitor 4 connected to the output terminal of the converter 2, and an inverter 5 connected to the smoothing capacitor 4. At the output end of the inverter 5, for example, a phase winding Lu. Lv. Lw is connected.

  Converter 2 includes reactors 21, 22, and 23, a bridge circuit of diodes 31a to 36a connected to three-phase AC power supply 1 via reactors 21, 22, and 23, and switching elements connected in parallel to these diodes 31a to 36a. For example, IGBTs (Insulated Gate Bipolar Transistors) 31 to 36 are provided, and three-phase AC voltage supplied from the power receiving facility 10 is boosted and DC-converted by on and off switching of the IGBTs 31 to 36. For example, converter 2 converts an AC voltage of 200 V into a DC voltage of approximately 300 V. The output voltage Vc of the converter 2 is applied to the smoothing capacitor 4.

  In addition, the converter 2 full-wave rectifies the three-phase alternating current voltage supplied from the call | power receiving installation 10 by diode 31a-36a by stop of on-off switching of IGBT31-36.

  The bridge circuit of the diodes 31a to 36a includes a series circuit of diodes 31a and 32a, a series circuit of diodes 33a and 34a, and a series circuit of diodes 35a and 36a. The interconnection point of the diodes 31a and 32a is connected to the R phase of the three-phase AC power supply 1 through the power reception facility 10, and the interconnection point of the diodes 33a and 34a is the S phase of the three phase AC power supply 1 through the power reception facility 10. The interconnection point between the diodes 35 a and 36 a is connected to the T phase of the three-phase alternating current power supply 1 through the power receiving facility 10. The diodes 31 a to 36 a are regenerative diodes of the IGBTs 31 to 36.

  Inverter 5 connects IGBTs 51 and 52 in series, and a U-phase series circuit in which the connection point of IGBTs 51 and 52 is connected to phase winding Lu of brushless DC motor 6, IGBTs 53 and 54 are connected in series, IGBTs 53 and 54 V-phase series circuit in which the interconnection points are connected to the phase winding Lv of the brushless DC motor 6, IGBTs 55, 56 are connected in series, and the interconnection points of the IGBTs 55, 56 are phase windings Lw of the brushless DC motor 6 It includes a series circuit for W phase to be connected, and converts the voltage of the smoothing capacitor 4 into a three-phase AC voltage of a predetermined frequency by switching of each IGBT and outputs it from an interconnection point of each IGBT. Note that regenerative diodes (free wheel diodes) 51a to 56a are connected in reverse parallel to the IGBTs 51 to 56, respectively. It is desirable to use a fast recovery diode as the regenerative diodes 51a to 56a in order to reduce the loss.

  The brushless DC motor 6 is constituted by a stator having three phase windings Lu, Lv, Lw connected in a star shape, and a rotor having a permanent magnet. The rotor rotates due to the interaction between the magnetic field generated by the flow of current through the phase windings Lu, Lv and Lw and the magnetic field produced by the permanent magnet.

  The current sensor (current detection means) 71, 72, 73 for detecting the input current is disposed in the current path between the power receiving facility 10 and the converter 2. Current sensors 81, 82, and 83 for detecting an output current (phase winding current) are disposed in a current passage between the output terminal of the inverter 5 and the brushless DC motor 6. The detection results of the current sensors 71 to 83 are supplied to the controller 90. The controller 90 drives the brushless DC motor 6 by sensorless-vector control of the inverter 5 based on the detected current values of the current sensors 81, 82, 83. Further, a voltage detection unit 60 is connected to both ends of the smoothing capacitor 4. Voltage detection unit 60 detects an output voltage (an input voltage to inverter 5) Vc of converter 2. The detection result is supplied to the controller 90.

  The controller 90 includes a first control unit 91, a second control unit 92, a third control unit 93, a limit value setting unit (memory) 94, an input unit 95, and a communication unit 96 as main functions.

  As shown in FIG. 2, the first control unit 91 performs pulse width modulation (PWM; carrier signal Eo and sine wave signals Er, Es) of carrier signal (triangular wave signal) Eo of a predetermined frequency with sine wave signals Er, Es, Et. , And Et to generate PWM signals Dr, Ds, Dt, and drive the IGBTs 31 to 36 of the converter 2 on and off by the generated PWM signals Dr, Ds, Dt. The sine wave signals Er, Es, Et are generated based on the target value of the output voltage Vc and the detection results of the current sensors 71, 72, 73, etc., and R phase voltage, S phase voltage, T phase of the three phase AC power supply 1 Synchronize with the cycle of voltage (current).

  The second control unit 92 pulse-width modulates a carrier signal (triangular wave signal) Eio of a predetermined frequency with sine wave signals Eu, Ev, Ew (PWM; voltage comparison between the carrier signal Eio and the sine wave signals Eu, Ev, Ew) Thus, the PWM signals Du, Dv, Dw are generated, and the IGBTs 51 to 56 of the inverter 5 are turned on and off by the generated PWM signals Du, Dv, Dw. The sine wave signals Eu, Ev, Ew are generated based on the detection results of the current sensors 81, 82, 83, and are synchronized with the period of the voltage induced in the phase windings Lu, Lv, Lw of the brushless DC motor 6.

  Third control unit 93 sets limit value setting unit 94 such that harmonic current In generated at the input side of converter 2 (input side of power conversion device 100) falls within predetermined limit value Ins for the power conversion device. The output voltage Vc of the converter 2 is controlled in accordance with the control data stored in the memory 2 via the first control unit 91. The limit value Ins is set individually for each facility connected to the power receiving facility 10 within the range of “the regulation value Ino of the harmonic current In” set for the power receiving facility 10. The control data is determined by associating the minimum value (target value) Vcmin of the output voltage Vc of the converter 2 where the harmonic current In generated at the input side of the converter 2 can be contained within the limit value Ins. It is stored in the limit value setting unit 94 by manual operation of the input unit 95 or data input from the communication unit 96. The input unit 95 may be any device that can input data, such as a keyboard and a changeover switch. The communication unit 96 receives control data transmitted from the external system controller 101 and inputs it to the limit value setting unit 94.

  Specifically, the third control unit 93 reads the minimum value Vcmin corresponding to the actual load size of the inverter 5 from the limit value setting unit 94, and the output voltage Vc of the converter 2 is the read minimum value The voltage levels of the sine wave signals Er, Es, Et in the first control unit 91 are adjusted (the on / off duty of the PWM signals Dr, Ds, Dt is adjusted) so as to be Vcmin. That is, the minimum value Vcmin is the target value of the output voltage Vc of the converter 2.

  Here, the size of the actual load of the inverter 5 is the power consumption of the brushless DC motor 6. The power consumption of the brushless DC motor 6 may be calculated using the detection result of the voltage detection unit 60 and the detection results of the current sensors 81, 82, 83, or the detection results of the current sensors 71, 72, 73 on the input side. It may be calculated using

  The basic operation of converter 2 will be described.

  In the phase where the R-phase voltage of the three-phase AC power supply 1 becomes a positive level, a current flows from the three-phase AC power supply 1 through the reactor 21 and the positive side diode 31a to the smoothing capacitor 4 and the current through the smoothing capacitor 4 The negative side diode 34a and the reactor 22 return to the S phase of the three phase AC power supply 1, and then, as the phase of the R phase voltage advances, the negative side diode 36a and the reactor 23 pass the T phase of the three phase AC power supply 1 A path back to is formed. Then, in addition to this operation, the IGBT 32 repeatedly turns on and off according to the PWM signal Dr generated by the controller 90. When the IGBT 32 is turned on, the connection point between the diodes 31a and 32a conducts with the negative output terminal of the converter 2, and a short circuit path via the reactor 21, IGBT 32, negative diode 34a and reactor 22 with respect to the three-phase AC power supply 1. Is formed. By the formation of the short circuit, energy (charge) is stored in the reactors 21 and 22. The energy stored in the reactors 21 and 22 is supplied to the smoothing capacitor 4 when the IGBT 32 is off. By this energy supply, boosting is performed.

  In the phase where the S-phase voltage of the three-phase AC power supply 1 becomes a positive level, a current flows from the three-phase AC power supply 1 through the reactor 22 and the positive side diode 33a to the smoothing capacitor 4 and the current through the smoothing capacitor 4 The negative side diode 36a and the reactor 23 return to the T phase of the three-phase alternating current power supply 1, and then, as the phase of the S phase voltage advances, the negative side diode 32a and the reactor 21 pass the R phase of the three-phase alternating current power supply 1 A path back to is formed. Then, in addition to this operation, the IGBT 34 is repeatedly turned on and off according to the PWM signal Ds generated by the controller 90. When the IGBT 34 is turned on, the connection point between the diodes 33 a and 34 a conducts with the negative output terminal of the converter 2, and a short circuit via the reactor 22, the IGBT 34, the negative diode 36 a and the reactor 23 with respect to the three-phase AC power supply 1. Is formed. Due to the formation of the short circuit, energy (charge) is stored in the reactors 22 and 23. The energy stored in the reactors 22 and 23 is supplied to the smoothing capacitor 4 when the IGBT 34 is off. By this energy supply, boosting is performed.

  In the phase where the T-phase voltage of the three-phase AC power supply 1 becomes a positive level, a current flows from the three-phase AC power supply 1 through the reactor 23 and the positive side diode 35a to the smoothing capacitor 4 and the current through the smoothing capacitor 4 The negative side diode 32a and the reactor 21 return to the R phase of the three-phase AC power supply 1, and then, as the phase of the T phase voltage advances, the negative side diode 34a and the reactor 22 pass the S phase of the three-phase AC power supply 1 A path back to is formed. Then, in addition to this operation, the IGBT 36 repeatedly turns on and off according to the PWM signal Dt generated by the controller 90. When the IGBT 36 is on, the connection point between the diodes 35 a and 36 a conducts with the negative output terminal of the converter 2, and a short circuit via the reactor 23, the IGBT 36, the negative diode 32 a and the reactor 21 with respect to the three-phase AC power supply 1. Is formed. Due to the formation of the short circuit, energy (charge) is stored in the reactors 23 and 21. The energy stored in the reactors 23 and 21 is supplied to the smoothing capacitor 4 when the IGBT 36 is off. By this energy supply, boosting is performed.

  In the phase where each of R phase input voltage, S phase input voltage, and T phase input voltage becomes a negative level, IGBT31, 33, 35 parallelly connected with positive side diode 31a, 33a, 35a repeats ON and OFF. The operation accompanying the on / off of these IGBTs 31, 33, 35 is basically the same operation pattern as the positive level period, except that the positive / negative is opposite. Therefore, the detailed description is omitted.

  Next, harmonic current In generated on the input side of converter 2 along with operation of inverter 5 and limit value Ins for limiting harmonic current In will be described.

  A regulation value Ino for regulating the amount of outflow of the harmonic current In from the power reception facility 10 to the three-phase AC power source 1 side is determined according to the total rated power consumption of each inverter-equipped device connected to the power reception facility 10 Be From this regulation value Ino, a limit value Ins for limiting the harmonic current In generated from each inverter-mounted device connected to the power receiving facility 10 is determined. The limit value Ins is the value of the upper limit of the harmonic current In that may be generated by one inverter-mounted device, and is determined by calculation from the limit value Ino.

  An example of the limit value Ins is shown in FIG. 3 with the inverter ratio (50%, 75%, 100%) and the harmonic order (5th, 7th, 11th, 13th) as parameters. Generally, the subject of regulation is the harmonic current In whose order is up to the 40th order, but the harmonic current In whose order exceeds the 13th order is not shown in FIG. The inverter ratio is a ratio (%) of the total rated power consumption of one or more inverter-mounted devices connected to the power reception facility 10 to the power capacity (also referred to as the power reception capacity) of the power reception facility 10.

  When the inverter ratio is 50%, the ratio of the total rated power consumption of the inverter mounted device to the power capacity of the power receiving facility 10 is 50%, and the ratio of the total rated power consumption of the non-inverter mounted device to the power capacity of the power receiving facility 10 is It is up to 50%. When the inverter ratio is 75%, the ratio of the total rated power consumption of the inverter mounted device to the power capacity of the power receiving facility 10 is 75%, and the ratio of the total rated power consumption of the non-inverter mounted device to the power capacity of the power receiving facility 10 is It is up to 25%. When the inverter ratio is 100%, all of the facility devices connected to the power receiving facility 10 are inverter-mounted devices, and the ratio of the total rated power consumption of the inverter-mounted devices to the power capacity of the power receiving facility 10 is 100%.

  The limit value Ins shown in FIG. 3 decreases as the inverter ratio increases and decreases as the harmonic order increases. In practice, the limit value Ins of each harmonic order has a correlation, and if the limit value Ins in any harmonic order is determined, the limit value Ins in the other harmonic order can be calculated.

  Here, a simulation result of the fifth harmonic current In generated when the IGBTs 31 to 36 of the converter 2 are switched is shown in FIG. The fifth harmonic current In generated when switching the IGBTs 31 to 36 of the converter 2 becomes smaller as the output voltage Vc of the converter 2 is higher in a boost region higher than a predetermined value (for example, 290 V) of the converter 2. The seventh harmonic current In exhibits the same tendency according to the simulation and the experimental results in a real machine.

  The harmonic current In of the order higher than the fifth order or the seventh order repeats slight increase and decrease without uniformly decreasing with the rise of the output voltage Vc of the converter 2. The high-order harmonic current In does not have to be considered in the boost region of the converter 2 because the regulation value Ino itself is originally small.

  The output voltage Vc of the converter 2 is the value of the 5th, 7th, 11th, 13th harmonic current In generated when the input voltage to the converter 2 is, for example, 200 V and the rated load of the inverter 5 is, for example, 6.7 kW. The results obtained by simulation using the parameters as parameters are shown in FIG. “No boosting” in FIG. 5 indicates a case where the IGBTs 31 to 36 of the converter 2 are not switched on and off, and the converter 2 is full-wave rectified by only the diodes 31 a to 36 a (non-switching operation).

  Moreover, the relationship between the output voltage Vc of the converter 2 and the efficiency (power conversion efficiency) of the power conversion device 100 is shown in FIG. The higher the output voltage Vc, the lower the efficiency. This is due to the influence that the switching on time of the IGBTs 31 to 36 in the converter 2 increases and the power loss due to the on resistances of the IGBTs 31 to 36 increases.

  From the above, in order to reduce the efficiency as much as possible while keeping the harmonic current In within the limit value Ins, the output voltage Vc of the converter 2 is as low as possible within the range where the harmonic current In falls within the limit value Ins. It turns out that it is preferable to control to a value. In order to realize this control, the minimum value Vcmin, which is as low as possible among the output voltage Vc of the converter 2 that the harmonic current In generated at the input side of the converter 2 can fall within the limit value Ins, sets the load of the inverter 5 as a parameter. As control data to be used, it is stored in the limit value setting unit 94 of the controller 90. The reduction of the harmonic current due to the switching of the conventional PWM converter is only to switch the PWM converter with a constant PWM signal for uniformly outputting a predetermined large voltage from the PWM converter.

  The third control unit 93 of the controller 90 reads the minimum value Vcmin corresponding to the actual load size of the inverter 5 from the limit value setting unit 94 so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin. Then, the IGBTs 31 to 36 of the converter 2 are turned on and off (PWM switching control).

  For example, as shown in FIG. 7, the control data in limit value setting unit 94 includes inverter ratios (50%, 75%, 100%) and fifth harmonics, which have different minimum values Vcmin different according to the load of inverter 5. It corresponds to the limit value (4A, 3A, 2A) Ins of the wave current In.

  For example, when the input voltage to the converter 2 is 200 V, the rated load of the inverter 5 is 6.7 kW, and the inverter ratio is 50%, the limit value Ins for each inverter mounted device is 4 A with respect to the fifth harmonic current In It becomes. In this case, the third control unit 93 reads "Vca1" as the minimum value Vcmin if the actual load of the inverter 5 is 25% of the rated load of the inverter 5, and the actual load of the inverter 5 If Vcmin is 50% of the rated load, "Vcb1" is read as the minimum value Vcmin. If the actual load of the inverter 5 is 75% of the rated load of the inverter 5, "Vcc1" is read as the minimum value Vcmin. If the actual load is 100% of the rated load of the inverter 5, "Vcd1" is read as the minimum value Vcmin. The relationship between the minimum values Vca1 to Vcd1 is Vca1 <Vcb1 <Vcc1 <Vcd1. Then, the third control unit 93 performs on / off control of the IGBTs 31 to 36 of the converter 2 (PWM switching control) so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin (one of Vca1 to Vc1). Do. Thus, the fifth harmonic current In generated from the power conversion device 100 can be contained within the limit value Ins of 4 A without decreasing the efficiency of the power conversion device 100 as much as possible.

  For example, when the input voltage to the converter 2 is 200 V, the rated load of the inverter 5 is 6.7 kW, and the inverter ratio is 75%, the limit value Ins per device of each inverter mounted device is 3 A with respect to the fifth harmonic current Become. In this case, the third control unit 93 reads “Vca2” as the minimum value Vcmin if the actual load of the inverter 5 is 25% of the rated load of the inverter 5, and the actual load of the inverter 5 is that of the inverter 5. If 50% of the rated load, “Vcb2” is read as the minimum value Vcmin, and if the actual load of the inverter 5 is 75% of the rated load of the inverter 5, “Vcc2” is read as the minimum value Vcmin. If the actual load is 100% of the rated load, "Vcd2" is read as the minimum value Vcmin. The relationship between the minimum values Vca2 and Vcd2 is Vca2 <Vcb2 <Vcc2 <Vcd2. Then, the third control unit 93 performs on / off control (PWM switching control) on the IGBTs 31 to 36 of the converter 2 so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin (one of Vca2 to Vcd2). ). Thus, the fifth harmonic current In generated from the power conversion device 100 can be suppressed to within the limit value Ins of 3 A without lowering the efficiency of the power conversion device 100 as much as possible.

  For example, when the input voltage to converter 2 is 200 V, the rated load of inverter 5 is 6.7 kW, and the inverter ratio is 100%, the limit value Ins for each inverter-equipped device is 2.0 A with respect to the fifth harmonic current It becomes. In this case, the third control unit 93 reads “Vca3” as the minimum value Vcmin if the actual load of the inverter 5 is 25% of the rated load of the inverter 5, and the actual load of the inverter 5 is If 50% of the rated load, "Vcb3" is read as the minimum value Vcmin, and if the actual load of the inverter 5 is 75% of the rated load of the inverter 5, "Vcc3" is read as the minimum value Vcmin. If the actual load is 100% of the rated load of the inverter 5, "Vcd3" is read as the minimum value Vcmin. The relationship between the minimum values Vca2 and Vcd2 is Vca3 <Vcb3 <Vcc3 <Vcd3. Then, the third control unit 93 turns on and off the IGBTs 31 to 36 of the converter 2 so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin (one of Vca3 to Vcd3) (PWM switching control ). As a result, the fifth harmonic current In generated from the power conversion device 100 can be suppressed within 2 A, which is the limit value Ins, without lowering the efficiency of the power conversion device 100 as much as possible.

  As shown in FIG. 4, the higher the output voltage Vc, the more the harmonic current In can be reduced. Therefore, the minimum value Vcmin of the output voltage Vc must be increased as the inverter ratio is higher (as the limit value Ins is lower). In consideration of this point, the relationships Vca1 <Vca2 <Vca3, Vcb1 <Vcb2 <Vcb3, Vcc1 <Vcc2 <Vcc3, and Vcd1 <Vcd2 <Vcd3 are established.

  These minimum values Vcmin are determined by a test performed at the time of manufacture of a heat pump type heat source machine which is an inverter mounted device in which the power conversion device 100 is mounted. A limit value Ins based on these minimum values Vcmin is determined according to the power capacity of the power receiving facility 10, the inverter ratio, and the rated load of the inverter 5. Therefore, when the installation destination of the heat pump type heat source unit is determined in advance, control data adapted to the situation of the installation position is determined at the time of manufacturing the heat pump type heat source unit. The control data may be stored in the limit value setting unit 94 at the time of manufacture of the heat pump type heat source machine, or when the heat pump type heat source machine is installed, a worker creates it at the installation site and sets limit values from the input unit 95 The unit 94 may be sequentially input and stored.

  The “regulation value Ino of the harmonic current In” set in the power reception facility 10 differs depending on the harmonic order. The regulation value Ino in each harmonic order has a correlation, and if the regulation value Ino in any harmonic order is determined, the regulation value Ino in another harmonic order can be calculated. For this reason, if the limit value Ins in a specific harmonic order is set, the limit value Ins in other harmonic orders is uniquely determined by the same formula as the calculation of the control value Ino.

  In the above description, the fifth harmonic current In is described to be contained within the limit value Ins for easy understanding, but in practice, the minimum value Vcmin included in the control data of FIG. The harmonic current In in all harmonic orders that are subject to the restriction of is set to a value that falls within the range of the respective limit value Ins.

  The actual control will be described according to the flowchart of FIG.

  The controller 90 detects the size of the refrigeration load of the heat pump type heat source unit in which the power conversion device 100 is mounted (step S1), and causes the inverter 5 to output an AC voltage of the frequency F corresponding to the detection result (step S2). The output of the inverter 5 drives the brushless DC motor 6 at variable speed. The refrigeration load of the heat pump type heat source unit is an air conditioning load, a cooling load, a heating load, and the like.

  For the power conversion device 100, as described above, control data for storing the harmonic current In within the limit value Ins is stored in the limit value setting unit 94. The controller 90 detects the size of the load of the inverter 5 from the value of the output voltage Vc detected by the voltage detection unit 60 and the output current value of the inverter 5 detected by the current sensors 81, 82, 83 (step S3) ). Then, the controller 90 reads the minimum value Vcmin corresponding to the detected load size from the limit value setting unit 94, and the IGBTs 31 to 33 of the converter 2 so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin. 36 performs PWM switching control. Thus, harmonic current In generated from power conversion device 100 can be reliably suppressed within limit value Ins regardless of the harmonic order, without lowering the efficiency of power conversion device 100 as much as possible. Therefore, it is not necessary to change the power reception facility 10 to a large-capacity expensive one, and it is not necessary to install an expensive harmonic suppression device between the power reception facility 10 and the power conversion device 100.

  Moreover, since the output voltage Vc of the converter 2 is as low as possible in the range where the harmonic current In falls within the limit value Ins, the power loss due to the converter 2 can be minimized, and the efficiency of the power conversion device 100 can be minimized. Improve.

The first control unit 91 of the controller 90 feeds back the voltage levels of the sine wave signals Er, Es, Et for PWM signal generation so that the output voltage Vc detected by the voltage detection unit 60 becomes the minimum value Vcmin. Control. Specifically, in the feedback control, when the output voltage Vc is equal to or more than the minimum value Vcmin-α (α is a small margin value), the sine wave signals Er, Es, Et for PWM signal generation are used. Lower the output voltage Vc, and lower the voltage levels of the sine wave signals Er, Es, Et for generating the PWM signal when the output voltage Vc is less than the minimum value Vcmin-α. To raise the output voltage Vc. Thus, the output voltage Vc is approximately kept at a value near the minimum value Vcmin. Note that vector control using detected current values of the current sensors 71, 72, 73 is used to adjust the voltage levels of the sine wave signals Er, Es, Et.
[2] Second embodiment
A second embodiment of the present invention will be described.

  In the first embodiment, the minimum value Vcmin of the output voltage Vc where the harmonic current In can fall within the limit value Ins is set as a limit value setting unit 94 using the load (25%, 50%, 75%, 100%) of the inverter 5 as a parameter. Because it is configured to store in, it is necessary to store in the limit value setting unit 94 a large number of minimum values Vcmin corresponding to the size of the load of the inverter 5.

  Also, normally, the size of the load of the inverter 5 does not change stepwise. For this reason, in order to correspond successively to the size of the load of the inverter 5, a plurality of minimum values Vcmin are prepared, or the minimum values Vcmin existing between the respective minimum values Vcmin determined to be discrete are linearly interpolated. It is necessary to calculate by calculation of etc. Furthermore, in the first embodiment, the minimum value Vcmin of the output voltage Vc at which the harmonic current In can fall within the limit value Ins is determined by a test, but the external environment other than the load of the inverter 5 (temperature, humidity, etc.) It is difficult to conduct tests under all conditions, taking into account that the effect on the harmonic current value. For this reason, the minimum value Vcmin has to be determined in a state where a certain margin is given to the limit value Ins. Depending on the actual operating conditions, this margin may unnecessarily reduce the efficiency of the power converter 100.

  In consideration of these points, in the second embodiment, the harmonic current In generated from the power conversion device 100 is detected, and the detected value In is fed back to the control of the output voltage Vc of the converter 2. Thus, the efficiency of power conversion device 100 can be enhanced while the harmonic current In generated from power conversion device 100 is reliably contained within limit value Ins.

  The limit value setting unit 94 of the controller 90 stores in advance the limit value Ins itself for the power converter for the harmonic current In of the specific order as control data. The data of the minimum value Vcmin is not stored in the limit value setting unit 94. Furthermore, the controller 90 includes a harmonic calculation unit 97 shown by a broken line in FIG. The harmonic calculation unit 97 calculates the harmonic current In of the order that needs to be suppressed by Fourier transforming the detection results of the current sensors 71, 72, 73 for detecting the input current.

  The third control unit 93 of the controller 90 compares the calculated value In of the harmonic calculation unit 97 with the limit value Ins in the limit value setting unit 94, and in the range of the converter 2 within the range where the calculated value In falls within the limit value Ins. The output voltage Vc of the converter 2 is controlled so that the output voltage Vc becomes the lowest.

  Specifically, as shown in FIG. 9, the third control unit 93 sets the calculated value In of the harmonic calculation unit 97, the limit value Ins, and the set value “Ins−ΔI1” determined for the limit value Ins. Compare with “Ins−ΔI2”. The set value “Ins−ΔI1” is a value lower than the limit value Ins by a predetermined value ΔI1. The set value “Ins−ΔI2” is a value lower than the limit value Ins by a predetermined value ΔI2 (> ΔI1).

  When the calculated value In of the harmonic calculation unit 97 rises and reaches the set value “Ins−ΔI2” (point A in the figure), the controller 90 raises the output voltage Vc of the converter 2 by a fixed value. Despite this increase, when the calculated value In of the harmonic calculation unit 97 further increases and reaches the limit value Ins (point B in the figure), the controller 90 further increases the output voltage Vc of the converter 2 by a fixed value. Raise it. Here, the rise of the output voltage Vc is executed by raising the on / off duty of the PWM signal to the converter 2. Conversely, the reduction of the output voltage Vc is performed by reducing the on / off duty of the PWM signal to the converter 2.

  When the calculated value In decreases to the set value “Ins−ΔI1” due to the increase of the output voltage Vc (point C in the drawing), the controller 90 decreases the output voltage Vc of the converter 2 by a fixed value. When the calculated value In rises again and reaches the limit value Ins due to the drop of the output voltage Vc (point D in the drawing), the controller 90 further raises the output voltage Vc of the converter 2 by a fixed value.

  In summary, the controller 90 raises the output voltage Vc when the calculated value In reaches the set value “Ins−ΔI2” from a low value. The controller 90 raises the output voltage Vc when the calculated value In reaches the limit value Ins in a state where the set value “Ins−ΔI2” or more, and outputs it when the calculated value In falls to “Ins−ΔI1”. Decrease the voltage Vc.

  As a result, as in the first embodiment, highly efficient operation of the power conversion device 100 is possible. There is no need to store a large number of data in the limit value setting unit 94, and it is not necessary to perform calculations such as linear interpolation for obtaining the minimum value Vcmin. In the second embodiment, once the limit value Ins is determined, the harmonic current In is calculated using the current sensors 71, 72, 73, and feedback control of the output voltage Vc of the converter 2 is performed according to the calculated value In. It is only. Further, since the current sensors 71, 72, 73 used when generating the switching PWM signal for the converter 2 are also used to calculate the harmonic current In, the circuit configuration of the power conversion device 100 can be simplified.

  Further, in the second embodiment, since the output voltage Vc of the converter 2 is feedback-controlled in accordance with the calculated value In of the harmonic calculation unit 97, the power receiving facility 10 is changed to a large-capacity expensive one. There is no need to install an expensive harmonic suppression device between the power receiving equipment 10 and the power conversion device 100, and the harmonic current In can be reliably reduced regardless of its order. Moreover, because the output voltage Vc is not unnecessarily increased, highly efficient operation of the power conversion device 100 is possible.

  Further, in a large-scale facility provided with a plurality of heat pump-type heat source machines to which power is supplied from the power reception facility 10 together, the plurality of heat pump-type heat source machines may be comprehensively controlled by the upper system controller 101 . In this case, the controller 90 of each heat pump type heat source machine sends the calculated value In of the harmonic calculation unit 97 to the system controller 101. The system controller 101 receives the calculated value In sent from the controller 90 of each heat pump type heat source unit, and compares the sum of these calculated values In with the “regulation value Ino of the harmonic current In” in the power receiving facility 10 The limit value Ins for each heat pump heat source unit is set according to the comparison result. Then, the system controller 101 sends the set limit value Ins to the controller 90 of each heat pump type heat source unit. The controller 90 of each heat pump type heat source machine receives the limit value Ins sent from the system controller 101 at the communication unit 96, and stores the received limit value Ins in the limit value setting unit 94. Thus, even in a large-scale facility provided with a plurality of heat pump type heat source devices to which power is supplied from power reception facility 10, harmonic current In generated from power conversion device 100 of each heat pump type heat source device is limited by Ins. While being housed inside, highly efficient operation of each power conversion device 100 is possible.

  Here, the system controller 101 is not only the calculated value In of the harmonic current generated from the power conversion device 100 during the switching operation (during operation) of the converter 2 but also the power conversion device during which the switching operation of the converter 2 is stopped. The calculated values In of harmonic currents generated from 100 must also be collected and summed. Therefore, at least the controller 90 of the power conversion device 100 in operation of the inverter 5 sends the calculated value In of the harmonic calculation unit 97 to the system controller 101 even when the converter 2 is stopped (full-wave rectification). send.

Other configurations and operations are the same as in the first embodiment. Therefore, the description is omitted.
[3] Third Embodiment
In the third embodiment, a heat pump type heat source machine which is one equipment connected to one refrigeration load (air conditioning load, cooling load, heating load, etc.) includes a plurality of, for example, four compressors. This heat pump type heat source machine is, as shown in FIG. 10, four brushless DC motors 6 for driving the four compressors respectively, and four power converters for outputting driving power to the brushless DC motors 6. 100, one integrated controller 150 that comprehensively controls each controller 90 of the power conversion apparatus 100. The configuration of each power conversion device 100 is the same as that of the first embodiment.

  The four compressors are connected in parallel to one another as components of one refrigeration cycle for cooling or heating air or medium (water or the like). This one refrigeration cycle includes one use side heat exchanger or a plurality of use side heat exchangers connected in parallel with each other.

  The total rated power consumption of each power conversion device 100 corresponds to four times the rated power consumption of one power conversion device 100 of the first embodiment. Therefore, the limit value Ins 'for the controller (for the heat source unit) with respect to the total value In' of the fifth harmonic currents In generated from each power conversion device 100 when the inverter ratio is 50% is the power conversion shown in FIG. It becomes 16A (= 4.0A × 4) four times the limiting value Ins = 4.0A for the apparatus.

  Since one refrigeration load is driven by four compressors (brushless DC motor 6), the output frequency F of the inverter 5 in each power conversion device 100 is set to the same value. That is, the brushless DC motors 6 are driven at the same rotational speed.

  During the switching operation of converter 2, power loss associated with switching occurs, so the efficiency of power converter 100 is lower than when converter 2 performs only full-wave rectification without switching operation (see FIG. 12). Therefore, in order to obtain the high efficiency of each power conversion device 100 while keeping the total value In 'of the harmonic current In generated from each power conversion device 100 within the above limit value Ins', the number of switching operations of each converter 2 is As much as possible.

  The limit value Ins' (= 16A) for the equipment described above is input and stored in the memory 151 of the general controller 150 at the time of manufacture or installation of the heat pump type heat source machine. As described above, for example, the limit value Ins' for equipment for the total value of the fifth harmonic currents In generated from the power conversion devices 100 when the inverter ratio is 50% is 16A. Note that, as described above, if the limit value Ins 'for installation equipment with respect to the total value of the fifth harmonic current In is determined, the limit value Ins' for installation equipment with respect to the total value of harmonic currents In of other orders is Calculated by calculation.

  Further, in the memory 151 in the general controller 150, control conditions shown in FIG. 11 are stored. This control condition is a value (a non-boost mode value) Iny of the harmonic current In flowing out of the converter 2 in the non-boost mode where only one full-wave rectification is performed by one converter 2 without switching operation, and the converter 2 When the switching operation (boost operation) is carried out to bring the output voltage Vc of the converter 2 to the maximum level, the value Inx of the harmonic current In flowing out of the converter 2 (referred to as boost mode minimum value) It corresponds to the load of the inverter 5.

  That is, when the load of one inverter 5 is 25% of the rated load of the inverter 5, the non-boosting mode value Iny is Iny1, and the boosting mode minimum value Inx is Inx1 (Iny1> Inx1). When the load of one inverter 5 is 50% of the rated load of the inverter 5, the non-boosting mode value Iny is Iny2, and the boosting mode minimum value Inx is Inx2 (Iny2> Inx2). When the load of one inverter 5 is 75% of the rated load of the inverter 5, the non-boosting mode value Iny is Iny3 and the boosting mode minimum value Inx is Inx3 (Iny3> Inx3). When the load of one inverter 5 is 100% of the rated load of the inverter 5, the non-boosting mode value Iny is Iny4, and the boosting mode minimum value Inx is Inx4 (Iny4> Inx4).

  The general controller 150 detects the load of each inverter 5 through each controller 90, and based on the non-boost mode value Iny and the boost mode minimum value Inx corresponding to each detected load, the four power electronics devices 100 The number of switching operations of each converter 2 that can bring the total value of the generated harmonic currents In into the limit value Ins' for equipment is determined.

  Hereinafter, although a calculation example for suppressing the fifth harmonic current In will be described, in fact, the general controller 150 performs the same calculation for all the order harmonic currents In that need to be suppressed. Based on this calculation, the general controller 150 sets the number of switching operations of each converter 2 such that the total value of the harmonic current values In of all the orders that require suppression falls within the limit value Ins' for equipment. decide.

  For example, when the non-boost mode value Iny1 at 25% load is 6.0 A and the minimum value Inx1 is 0.3 A, the general controller 150 stops the switching operation of the two converters 2 and switches the remaining two converters 2 Make it work. Thereby, the total value of harmonic current In generated from each power conversion device 100 is “6.0 A + 6.0 A + 0.3 A + 0.3 A = 12.6 A”, and falls within the limit value Ins ′ (= 16 A) for equipment . Moreover, in this case, since the two converters 2 do not perform the switching operation, the efficiency of the two power electronics devices 100 in which the two converters 2 exist is improved.

  Furthermore, in this case, a margin of 3.4 A is generated between the limit value Ins' (= 16 A) for the facility device and the total value 12.6 A of the harmonic current In generated from each power conversion device 100. On the other hand, to reduce the harmonic current In, the output voltage Vc of the converter 2 may be increased. However, as shown in FIG. 6 of the first embodiment, the efficiency of the power conversion device 100 decreases as the output voltage Vc increases. Do. Therefore, if the output voltage Vc of the converter 2 which performs switching operation is lowered by the margin of 3.4 A, the efficiency can be further improved.

  In order to realize this, the general controller 150 performs switching operation of the value “= 16A− (6.0A + 6.0A) = 4A” of the harmonic current In that can flow out from the two converters 2 operating switching. It is selected as the allowable value ΔIn for the two converters 2.

  The general controller 150 divides the selected tolerance value ΔIn (= 4 A) by the two converters 2 performing switching operation. Then, the general controller 150 sets the divided allowance value ΔIn (= 2 A) as the limit value Insz for the power conversion device with respect to the controller 90 of each power conversion device 100 including the two converters 2 performing switching operation. Allocate and notify. At the same time, the general controller 150 stops the switching operation of the two converters 2 which may stop the switching operation.

  Each controller 90 for controlling the two converters 2 performing switching operation controls the PWM signal for obtaining the minimum value Vcmin of the output voltage Vc corresponding to the notified limit value Insz (= 2 A) as shown in FIG. The converter 2 is PWM-switched by the PWM signal generated from the data and generated. The operation of converter 2 at this time is the same as that of the first embodiment. As a result, the harmonic currents In flowing out of the two converters 2 performing switching operation can be contained in the limit value Insz (= 2 A) for the power conversion device. As a result, the output voltages Vc of the two converters 2 performing switching operation can be reduced, and the efficiency can be further improved.

  The control of each controller 90 for keeping the harmonic current In flowing out from the two converters 2 performing switching operation within the limit value Insz (= 2 A) for the power conversion device has been described in the second embodiment. Configuration and control may be used.

  As described above, in the third embodiment, in the heat pump type heat source apparatus including the plurality of power conversion devices 100, the total value of the harmonic currents In generated from the respective power conversion devices 100 is the limit value Ins' for equipment. High efficiency operation of each power conversion device 100 is possible while being contained in (= 16 A).

  An example of an algorithm of the process of the third embodiment is as follows.

  Limit value Ins' (= 16 A) for the total value of harmonic current In generated from each power conversion device 100 is divided by the value 6.0 A of harmonic current In flowing out of one converter 2 without switching operation, and the division Result The integer "2" of 2.66 A is multiplied by the value 6.0 A of the harmonic current flowing out of one converter 2 without switching operation, and the multiplication result 12 A is subtracted from the limit value Ins' (= 16 A). The subtraction result 4.0A is an allowable value ΔTn of the harmonic current In that can flow out from the remaining converter 2 that performs switching operation. Then, the integer "2" of the division result 2.66A is subtracted from the number "4" of all the converters 2, and the subtraction result "2" (corresponding to the number N of the converters 2 performing switching operation) is reduced to the minimum value Inx. The multiplication result “N × Inx” is compared with the tolerance ΔTn (= 4.0 A), and if the condition “N × Inx ≦≦ Tn is satisfied, the tolerance ΔTn (= 4.0 A) is It divides by the number N of the converter 2 which carries out switching operation, and assigns this division result as the limit value Insz per converter.

  On the other hand, when the number N of converters 2 performing switching operation is “2”, and the relationship between the multiplication result “N × Inx” and the allowable value ΔTn (= 4.0 A) is “N × Inx”> ΔTn, the converter performing switching operation Increase the number N of 2 by 1 unit. Thus, the number of switching operations N of converter 2 is increased until the condition of “(N + 1) × Inx” ≦ ΔTn is satisfied, and the number N of switching operations when this condition is satisfied allows ΔTn (= 4.0 A). And the controller 90 is notified of this division result as the limit value Insz per converter to be switched. The controller 90 that has received the notification of the limit value Insz stores the limit value Insz in the limit value setting unit 94, controls its own PWM switching based on the first embodiment or the second embodiment, and sets the respective limit values. An operation is performed in which the output voltage Vc is as low as possible in Insz.

Therefore, it is not necessary to change power reception equipment 10 to a large-capacity expensive one, and it is not necessary to install an expensive harmonic suppression device between power reception equipment 10 and each power conversion device 100. High-efficient operation of each power conversion device 100 can be performed while reliably reducing the generated harmonic current In regardless of the order thereof.
[4] Fourth Embodiment
In the third embodiment, the control of the heat pump type heat source unit in which the output frequencies F of the inverters 5 in the plurality of power conversion devices 100 are set to the same value has been described, but in the fourth embodiment, the inverters in the plurality of power conversion devices 100 The control of the heat pump type heat source machine in which the output frequency F of 5 is set to mutually different values will be described. The configuration other than this control is the same as that of FIG. 10 of the third embodiment.

  FIG. 12 shows the relationship between the load of one inverter 5 and the efficiency of the power conversion device 100 including the inverter 5. The broken line in FIG. 12 indicates the efficiency in the non-boosting mode in which the converter 2 is only subjected to full-wave rectification without switching operation, and the solid line in FIG. 12 indicates the efficiency in the boosting mode in which the converter 2 is switched.

  In the step-up mode in which the converter 2 performs switching operation, the efficiency of the power conversion device 100 is lower than in the non-step-up mode in which the converter 2 is only subjected to full-wave rectification without switching operation. Furthermore, the reduction degree of the efficiency of the power conversion device 100 in the boost mode in which the converter 2 performs switching operation is large when the load of the inverter 5 is small (power consumption is small), and small when the load of the inverter 5 is large. It is in.

  On the other hand, FIG. 13 shows the relationship between the harmonic current value In generated from the power conversion device 100 and the load of the inverter 5 in the power conversion device 100 in the non-boost mode where only full wave rectification is performed. . That is, as the load of the inverter 5 is larger (the power consumption of the inverter 5 is larger and the input current to the converter 2 is larger), the harmonic current In becomes larger. This relationship tends to be the same for any harmonic order.

  From the above, when the inverters 5 operate independently of one another, the converter 2 corresponding to the inverter 5 corresponding to the large load has a switching operation corresponding to the inverter 5 corresponding to the small load. The overall efficiency will be higher than switching operation of 2.

  The limit value Ins ′ for facility equipment with respect to the total value In ′ of the harmonic current In generated from each power conversion device 100 corresponds to “the regulation value Ino of harmonic current In in the power reception facility 10 and the inverter ratio in the power reception facility 10 It depends on you. The general controller 150 calculates the number of converters 2 that can not be switched as in the third embodiment. In this calculation, as the converter 2 capable of not performing the switching operation, the converter 2 corresponding to the inverter 5 with a small load is selected in the order of the small load.

  For example, the general controller 150 can operate four inverters 5 at 25% load, 50% load, 75% load and 100% load, respectively, and cause any two converters 2 not to perform switching operation In the case, two converter 2 corresponding to 25% load and 50% load are not switched. Then, the general controller 150 causes the converter 2 corresponding to the 100% load with the largest load among the two converters 2 to be switched to perform switching operation so that the generation value of the harmonic current In is minimized. Then, each controller 90 is notified of the “margin of generated value of harmonic current In” generated by the switching operation as the limit value Insz for the power converter on the converter 2 side corresponding to the 75% load (limit value setting (limit value setting) Store in section 94). The limit value Insz is calculated by the following equation.

Insz = Ins'-In1-In2-Inx
As described above, Ins ′ is a limit value for facility equipment with respect to the total value In ′ of the harmonic current In generated from each power conversion device 100. Iny1 is the value (non-boost mode value) of the harmonic current In in the non-boost mode of the converter 2 corresponding to the 25% -load inverter 5. Iny2 is the value (non-boosting mode value) of the harmonic current In in the non-boosting mode of the converter 2 corresponding to the 50% load inverter 5. Inx 4 switches (boosts) converter 2 corresponding to 100% load inverter 5 to bring output voltage Vc to the maximum level, and the minimum value of harmonic current In flowing out from converter 2 ( Boost mode minimum value). These Iny1, Iny2 and Inx4 are the same as those shown in FIG.

  The general controller 150 receives each load data from the controller 90 of the four power conversion devices 100, and based on the load data and the limit value Ins' for the equipment, the switching operation and the non-switching operation of the converter 2 are performed. , And assigns a limit value Inz for the power conversion device to the converter 2 to be switched and notifies each controller 90 of it. Each controller 90 performs PWM switching control of each converter 2 in accordance with the limit value Inz notified from the general controller 150. The operation and control of the specific individual converter 2 are the same as in the first embodiment or the second embodiment.

By the above control, it is not necessary to change the power receiving facility 10 to a large-capacity expensive one, and it is necessary to install a high-order harmonic suppression device between the power receiving facility 10 and the heat pump type heat source machine (each power conversion device 100). Therefore, highly efficient operation of each power conversion device 100 can be performed while reliably reducing the harmonic current In generated from the heat pump type heat source machine (each power conversion device 100) regardless of the order thereof.
[5] Fifth Embodiment
As shown in FIG. 14, a facility equipment system 200 including a large number of heat pump type heat source machines 200 a, 200 b... 200 n and a center controller 201 is connected to the power receiving facility 10. The heat pump type heat source machines 200a, 200b... 200n are connected to, for example, a hot water storage tank of one or more refrigeration loads (air conditioning load, cooling load, heating load, etc.) via water pipes 202a, 202b. The water in the hot water storage tank is guided by the water pipe 202b to the heat pump type heat source machine 200a, 200b to 200n and heated, and the water heated by the heat pump type heat source machine 200a, 200b to 200n is heated by the water pipe 202a. It is supplied to the hot water storage tank.

  The heat pump type heat source machine 200 a includes the four power conversion devices 100 and one general controller 150 shown in the third embodiment. The output frequency F of each power conversion device 100 in the heat pump type heat source machine 200a is set to the same value as in the third embodiment. The other heat pump type heat source machines 200b... 200n also have the same configuration as the heat pump type heat source machine 200a.

  The center controller 201 controls the general controllers 150 of the heat pump type heat source machines 200a, 200b. In addition, the center controller 201 stores in advance in the internal memory the limit value Inms for the facility system with respect to the total value Inm of the harmonic currents In generated from the heat pump type heat source machines 200a, 200b. Limit value Inms is determined in accordance with “the regulation value Ino of harmonic current In” set in power reception facility 10 and the inverter ratio in power reception facility 10.

  The center controller 201 distributively defines the limit value Ins 'for equipment for each of the heat pump type heat source machines 200a, 200b, ... 200n within the limit value Inms for equipment system, and heat pump the respective limit value Ins'. The controller 90 of each of the heat source units 200a, 200b. Specific control of the center controller 201 will be described.

  First, the center controller 201 is similar to the general controller 150 of the fourth embodiment, and selects the number of heat pump heat source units including the converter 2 that can not perform switching operation. In this selection, as a heat pump type heat source machine including a converter 2 capable of not performing switching operation, a heat pump type heat source machine including an inverter 5 with a small load is allocated in order of small load. The general controller 150 of the heat pump type heat source unit which has received this allocation stops the switching operation of all the converters 2 in the heat pump type heat source unit.

Subsequently, the center controller 201 instructs the general controller 150 of the heat pump type heat source machine including the inverter 5 with a large load that the harmonic current In generated from the heat pump type heat source machine is the smallest. The general controller 150 that has received this instruction instructs each controller 90 to control the output voltage Vc of all the converters 2 in the heat pump type heat source unit to be at the highest level within the allowable range. Then, the center controller 201 controls the rest of the harmonic current value In with respect to the heat pump type heat source machine including the inverter 5 with the smallest load among the one or more heat pump type heat source machines including the converter 2 to perform switching operation. The margin of is notified as the limit value Ins'. The general controller 150 of the heat pump type heat source unit that has received this notification assigns the limit value Ins for the power conversion device to each of the power conversion devices 100 inside as in the third embodiment. The controller 90 of the power conversion device 100 that has received this allocation stores the received limit value Ins in the limit value setting unit 94 so that the harmonic current In generated from the power conversion device 100 falls within the limit value Ins. The PWM switching control of the converter 2 is performed.
[6] Modification
In each of the above-described embodiments, although the case where the limit value Ins of the harmonic current In is allocated in the range of the “regulation value Ino of the harmonic current In” set in the power receiving facility 10 has been described as an example In the case where a regulation value unrelated to the facility 10 is set individually for each of the power conversion devices 100, the regulation value may be set as the limitation value Ins as it is.

  Although the case where the load of the inverter 5 is the brushless DC motor 6 has been described as an example in each of the above embodiments, the invention is not limited to the brushless DC motor 6, and application to various loads is possible. In addition, although the case where the equipment is a heat pump type heat source machine has been described as an example, it is not limited to the heat pump type heat source machine, but if it is equipment equipped with a converter and an inverter. It is applicable.

  The above embodiments and variations are presented as examples and are not intended to limit the scope of the invention. This novel embodiment and modification can be implemented in other various forms, and various omissions, rewrites and changes can be made without departing from the scope of the invention. These embodiments and modifications are included in the scope of the invention in the scope, and are included in the invention described in the claims and the equivalents thereof.

  The power converter of the present invention can be used for a heat pump type heat source machine and the like.

  DESCRIPTION OF SYMBOLS 1 ... 3 phase AC power supply, 2 ... converter, 4 ... smoothing capacitor, 5 ... inverter, 6 ... brushless DC motor (load) 10 DESCRIPTION OF SYMBOLS 36 ... IGBT (switching element), 51-56 ... IGBT (switching element), 60 ... Voltage detection part, 71, 72, 73 ... Current sensor, 81, 82, 83 ... Current sensor, 90 ... Controller, 91 ... 1st Control unit 92: second control unit 93: third control unit 94: limit value setting unit 95: input unit 96: communication unit 97: harmonic calculation unit 100: power conversion device 101: system Controller, 150: General controller, 200: Equipment system, 200a, 200b: 200n: Heat pump type heat source machine, 201: Center controller

Claims (7)

A converter that includes a reactor, a diode connected to an AC power supply via the reactor, and a switching element connected in parallel to the diode, for boosting and DC converting the voltage of the AC power supply;
An inverter for converting an output voltage of the converter into an AC voltage;
An input for inputting the harmonic current limit value ;
The minimum value of the output voltage of the converter in which the harmonic current generated at the input side of the converter can be contained within the limit value input to the input unit is stored in advance in association with the load of the inverter. A controller for reading out the minimum value of the output voltage corresponding to the size of the load from the storage contents, and controlling switching of the converter such that the output voltage of the converter becomes the read minimum value ;
A power converter comprising: Wherein the controller,
A storage unit that stores the limit value input by the input unit ;
including,
Power converter according to claim 1, wherein a. The controller
A communication unit that receives an input by data communication of the limit value;
A storage unit that stores the limit value received by the communication unit;
including,
The power converter according to claim 1 or 2 characterized by things. An equipment comprising a plurality of power conversion devices according to claim 3 , wherein
A general controller that comprehensively controls each of the power converters;
The integrated controller sets the limit value for the power conversion device within the range of the limit value for the facility device based on the “regulation value of harmonic current” set in the power receiving facility to which the respective facility device is connected. An equipment device, wherein the controller is notified of the limit value for the power conversion device, and the controller for the power conversion device is notified. 5. The equipment according to claim 4 , wherein the integrated controller controls the number of switching operations of each of the converters in each of the power conversion devices. An equipment system comprising a plurality of equipment according to claim 4 , wherein
It has a center controller that controls each of the equipments,
The center controller is a limit value for each of the facility devices within the range of the limit value for the facility device system based on the “regulation value of harmonic current” set in the power receiving facility to which each of the facility devices is connected. An equipment device system characterized in that the integrated controller of each equipment device is notified of the limit value for the equipment device. The said equipment apparatus is a heat source machine provided with the compressor driven by the said inverter, The equipment apparatus of Claim 4 or Claim 5, or the equipment apparatus system of Claim 6 characterized by the above-mentioned.

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