WO2015111517A1 - Power conversion apparatus, equipment, and equipment system - Google Patents

Abstract

This power conversion apparatus is provided with: a converter, which increases and converts into a direct current an alternating current power supply voltage; and an inverter that converts the direct current output of the converter into an alternating current voltage at a predetermined frequency. The power conversion apparatus controls the output voltage of the converter corresponding to a limit value of a harmonic current.

Description

Power conversion device, equipment, and equipment system

The present invention relates to a power conversion device that converts the voltage of an AC power source into DC and converts the DC voltage into an AC voltage of a predetermined frequency, equipment equipped with the power conversion device, and equipment equipment system equipped with the power conversion device About.

Equipment with high power consumption (equipment) is connected to power receiving equipment (cubicle). A restriction value for restricting the outflow amount of the harmonic current to the commercial AC power source is set in the power receiving facility. The size of the regulation value is proportional to the power capacity of the power receiving facility. The harmonic current is generated in equipment so-called inverter-equipped equipment equipped with an inverter, and is not generated in an AC motor (induction motor) directly connected to a commercial AC power supply.

Various equipment such as air conditioners, lighting equipment, and elevators are connected to the power receiving equipment. Among these connected devices, when the ratio of inverter-equipped devices is high, the amount of harmonic current generated may exceed the regulation value.

To prevent the amount of harmonic current generated from exceeding the above regulation value, change the power receiving equipment to one with a large power capacity, or suppress harmonics in the power line between the inverter-equipped equipment and the power receiving equipment. It is necessary to arrange the device. There is also a method in which a step-up PWM converter is incorporated as a DC converter in an inverter-mounted device, and the harmonic current is reduced by switching the PWM converter.

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

However, power receiving equipment with large power capacity is expensive, and harmonic suppression devices are 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 purpose of this embodiment is a power conversion device that can reliably reduce the harmonic current regardless of its harmonic order without requiring expensive power receiving equipment and harmonic suppression devices and without reducing the efficiency of the equipment. And provide equipment and equipment systems.

The power conversion device according to claim 1 is a converter that boosts and converts a voltage of an AC power supply, an inverter that converts an output voltage of the converter into an AC voltage, and an output voltage of the converter according to a limit value of a harmonic current. And a controller for controlling.

The facility equipment according to claim 6 includes a plurality of the power conversion devices according to claim 5, and includes a comprehensive controller that comprehensively controls each of the power conversion devices. The integrated controller sets a limit value for the power converter within a limit value range for the facility device based on a “regulation value of harmonic current” set for a power receiving facility to which the facility device is connected. Then, the limit values for these power conversion devices are notified to the controllers of the power conversion devices.

The facility equipment system according to claim 8 is a facility equipment system including a plurality of the facility equipment according to claim 6, and includes a center controller for controlling each of the equipment devices. This center controller is a limit value for each facility device 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 the facility device is connected. And the limit values for these equipment devices are notified to the respective integrated controllers of the respective equipment devices.

The block diagram which shows the structure of 1st and 2nd embodiment. The figure which shows the PWM signal production | generation for converters of each embodiment. The figure which shows the limiting value of the harmonic current in each embodiment as a parameter with an inverter ratio and a harmonic order. The figure which shows the relationship between the output voltage of the converter in each embodiment, and a 5th harmonic current. The figure which shows the value of the harmonic current which generate | occur | produces in each embodiment as a parameter the output voltage and harmonic order of a converter. The figure which shows the relationship between the output voltage and efficiency of the converter in each embodiment. The figure which shows the data for control memorize | stored in the limit value setting part of 1st Embodiment. The flowchart which shows the control of each embodiment. The figure which shows the change of the output voltage of the converter according to the calculated value of the harmonic current in 2nd 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 between 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 heat pump heat source device such as an air conditioner, which is a specific equipment device, and drives a compressor in the heat pump heat source device.

As shown in FIG. 1, a power receiving facility (cubicle) 10 is connected to phase lines R, S, and T of a commercial three-phase AC power source 1, and the power converter 100 of the present embodiment is connected to the power receiving facility 10. . The power conversion device 100 is incorporated in a specific equipment such as a heat pump heat source machine for air conditioning, and outputs drive power to a drive motor of a compressor in the heat pump heat source machine, and is connected to the power receiving equipment 10. Converter 2 (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. The phase winding Lu. Of the above-mentioned compressor motor such as the brushless DC motor 6 is connected to the output terminal of the inverter 5. Lv. Lw is connected.

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

Note that the converter 2 performs full-wave rectification of the three-phase AC voltage supplied from the power receiving facility 10 by the diodes 31a to 36a when the IGBTs 31 to 36 are turned off and on.

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 source 1 through the power receiving facility 10, and the interconnection point of the diodes 33a and 34a is the S phase of the three-phase AC power source 1 through the power receiving facility 10. The interconnection point of the diodes 35 a and 36 a is connected to the T phase of the three-phase AC power source 1 through the power receiving facility 10. The diodes 31a to 36a are regenerative diodes for the IGBTs 31 to 36.

The inverter 5 includes IGBTs 51 and 52 connected in series, and U-phase series circuits, IGBTs 53 and 54, in which the interconnection points of the IGBTs 51 and 52 are connected to the phase winding Lu of the brushless DC motor 6. Are connected in series to the phase winding Lv of the brushless DC motor 6, and the IGBTs 55 and 56 are connected in series. The interconnection point of the IGBTs 55 and 56 is connected to the phase winding Lw of the brushless DC motor 6. Including a series circuit for W phase to be connected, the voltage of the smoothing capacitor 4 is converted into a three-phase AC voltage of a predetermined frequency by switching of each IGBT, and output from an interconnection point of each IGBT. The IGBTs 51 to 56 are connected to regenerative diodes (free wheel diodes) 51a to 56a in antiparallel. It is desirable to use fast recovery diodes for the regenerative diodes 51a to 56a in order to reduce loss.

The brushless DC motor 6 includes a stator having three phase windings Lu, Lv, and 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 current flowing through the phase windings Lu, Lv, and Lw and the magnetic field created by the permanent magnet.

Current sensors (current detection means) 71, 72, 73 for detecting input current are disposed in the energization path between the power receiving facility 10 and the converter 2. Current sensors 81, 82, 83 for detecting an output current (phase winding current) are disposed in a current path between the output end of the inverter 5 and the brushless DC motor 6. The detection results of these current sensors 71 to 83 are supplied to the controller 90. The controller 90 drives the brushless DC motor 6 by performing sensorless vector control of the inverter 5 based on the detected current values of the current sensors 81, 82, and 83. Further, the voltage detector 60 is connected to both ends of the smoothing capacitor 4. Voltage detector 60 detects an output voltage (input voltage to inverter 5) Vc of converter 2. This 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 controller 91 performs pulse width modulation (PWM; carrier signal Eo and sine wave signals Er, Es) on a carrier signal (triangular wave signal) Eo having a predetermined frequency with sine wave signals Er, Es, Et. , Et are voltage-combined) to generate PWM signals Dr, Ds, Dt, and the generated PWM signals Dr, Ds, Dt drive the IGBTs 31 to 36 of the converter 2 on and off. 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, and the like, and the R-phase voltage, S-phase voltage, and T-phase of the three-phase AC power supply 1 are generated. Synchronized with the period of voltage (current).

The second control unit 92 performs pulse width modulation of a carrier signal (triangular wave signal) Eio having 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). As a result, PWM signals Du, Dv, and 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, and 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.

The third control unit 93 limits the limit value setting unit 94 so that the harmonic current In generated on the input side of the converter 2 (input side of the power conversion device 100) falls within a predetermined limit value Ins for the power conversion device. The output voltage Vc of the converter 2 is controlled through the first control unit 91 according to the control data stored in. The limit value Ins is set individually for each facility device connected to the power receiving facility 10 within the range of the “restriction 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 with which the harmonic current In generated on the input side of the converter 2 can be within the limit value Ins with the load of the inverter 5. Therefore, the limit value setting unit 94 stores the value 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 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 (adjustment of on / off duty of the PWM signals Dr, Ds, Dt) 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 actual load size 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 results of the voltage detection unit 60 and the detection results of the current sensors 81, 82, 83, or the detection results of the input-side current sensors 71, 72, 73. You may calculate using.

A basic operation of the converter 2 will be described.
In the phase where the R-phase voltage of the three-phase AC power supply 1 is at a positive level, a current flows from the three-phase AC power supply 1 through the reactor 21 and the positive diode 31a to the smoothing capacitor 4, and the current passing through the smoothing capacitor 4 is first It returns to the S phase of the three-phase AC power source 1 through the negative side diode 34a and the reactor 22, and then the T phase of the three-phase AC power source 1 passes through the negative side diode 36a and the reactor 23 as the phase of the R phase voltage advances. A path back to is formed. In addition to this operation, the IGBT 32 is repeatedly turned on and off in accordance with the PWM signal Dr generated by the controller 90. When the IGBT 32 is turned on, the interconnection point of the diodes 31 a and 32 a is electrically connected to the negative output terminal of the converter 2, and is a short circuit via the reactor 21, IGBT 32, negative diode 34 a, and reactor 22 with respect to the three-phase AC power supply 1. Is formed. By forming this 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 turned off. By this energy supply, the voltage is boosted.

In the phase where the S-phase voltage of the three-phase AC power source 1 is at a positive level, current flows from the three-phase AC power source 1 through the reactor 22 and the positive diode 33a to the smoothing capacitor 4, and the current passing through the smoothing capacitor 4 is first The phase returns to the T phase of the three-phase AC power source 1 through the negative side diode 36a and the reactor 23. Next, as the phase of the S phase voltage advances, the R phase of the three-phase AC power source 1 passes through the negative side diode 32a and the reactor 21. A path back to is formed. 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 interconnection point of the diodes 33 a and 34 a is electrically connected to the negative output terminal of the converter 2, and is a short circuit via the reactor 22, IGBT 34, negative diode 36 a, and reactor 23 with respect to the three-phase AC power supply 1. Is formed. By forming this 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 turned off. By this energy supply, the voltage is boosted.

In the phase where the T-phase voltage of the three-phase AC power supply 1 is at a positive level, a current flows from the three-phase AC power supply 1 through the reactor 23 and the positive diode 35a to the smoothing capacitor 4, and the current passing through the smoothing capacitor 4 is It returns to the R phase of the three-phase AC power source 1 through the negative side diode 32a and the reactor 21, and then the S phase of the three-phase AC power source 1 passes through the negative side diode 34a and the reactor 22 as the phase of the T phase voltage advances. A path back to is formed. In addition to this operation, the IGBT 36 is repeatedly turned on and off in accordance with the PWM signal Dt generated by the controller 90. When the IGBT 36 is on, the interconnection point of the diodes 35 a and 36 a is electrically connected to the negative output terminal of the converter 2, and is a short circuit via the reactor 23, IGBT 36, negative diode 32 a, and reactor 21 with respect to the three-phase AC power supply 1. Is formed. By forming this 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 turned off. By this energy supply, the voltage is boosted.

In the phase in which each of the R-phase input voltage, the S-phase input voltage, and the T-phase input voltage is at a negative level, the IGBTs 31, 33, and 35 connected in parallel with the positive diodes 31a, 33a, and 35a are repeatedly turned on and off. About the operation | movement accompanying ON / OFF of these IGBT31,33,35, it becomes an operation pattern fundamentally the same as a positive level period only by positive / negative being reversed. Therefore, the detailed description is abbreviate | omitted.

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

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

An example of the limit value Ins is shown in Fig. 3 using the inverter ratio (50%, 75%, 100%) and the harmonic order (5th, 7th, 11th, 13th) as parameters. In general, the harmonic current In having an order up to the 40th order is subject to regulation, but the harmonic current In exceeding the 13th order is not shown in FIG. The inverter ratio is the ratio (%) of the total rated power consumption of one or a plurality of inverter-equipped devices connected to the power receiving facility 10 to the power capacity (also referred to as the power receiving capacity) of the power receiving facility 10.

When the inverter ratio is 50%, the ratio of the total rated power consumption of the inverter-equipped 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-equipped device to the power capacity of the power receiving facility 10 is 50%. The maximum is 50%. When the inverter ratio is 75%, the ratio of the total rated power consumption of the inverter-equipped equipment to the power capacity of the power receiving equipment 10 is 75%, and the ratio of the total rated power consumption of the non-inverter-equipped equipment to the power capacity of the power receiving equipment 10 is Up to 25%. When the inverter ratio is 100%, all of the equipment 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 in the power capacity of the power receiving facility 10 is 100%.

The limit value Ins shown in FIG. 3 is smaller as the inverter ratio is larger and smaller as the harmonic order is higher. Actually, there is a correlation between the limit value Ins of each harmonic order, and if the limit value Ins at any harmonic order is determined, the limit value Ins at other harmonic orders can be obtained by calculation.

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 the IGBTs 31 to 36 of the converter 2 are switched decreases as the output voltage Vc of the converter 2 increases in the boost region of the converter 2 at a predetermined value (for example, 290 V) or more. In addition, according to the simulation and the experimental result with an actual machine, the seventh harmonic current In also shows the same tendency.

The harmonic current In having a higher order than the fifth and seventh orders does not decrease uniformly with respect to the increase of the output voltage Vc of the converter 2, and slightly increases and decreases. Such a high-order harmonic current In does not need to be considered in the boosting region of the converter 2 because the regulation value Ino itself is originally small.
For example, when the input voltage to the converter 2 is 200 V and the rated load of the inverter 5 is 6.7 kW, for example, the fifth, seventh, eleventh and thirteenth harmonic currents In are expressed as the output voltage Vc of the converter 2. FIG. 5 shows the result obtained by simulation using as a parameter. “No boost” in FIG. 5 indicates the case where the IGBTs 31 to 36 of the converter 2 are not switched on / off, and the converter 2 is full-wave rectified only by the diodes 31a to 36a (non-switching operation).

Further, the relationship between the output voltage Vc of the converter 2 and the efficiency (power conversion efficiency) of the power converter 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 is increased and the power loss due to the on resistance of the IGBTs 31 to 36 is increased.

From the above, in order to suppress the efficiency as much as possible while suppressing the harmonic current In within the limit value Ins, the output voltage Vc of the converter 2 is as low as possible within a range where the harmonic current In is within the limit value Ins. It turns out that it is suitable to control to a value. In order to realize this control, the minimum value Vcmin, which is as low as possible, of the output voltage Vc of the converter 2 in which the harmonic current In generated on the input side of the converter 2 can fall within the limit value Ins, determines the load of the inverter 5 as a parameter. Is stored in the limit value setting unit 94 of the controller 90. Note that the harmonic current can be reduced by switching the conventional PWM converter only by switching 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 / off (PWM switching control).

For example, as shown in FIG. 7, the control data in the limit value setting unit 94 includes a plurality of minimum values Vcmin that differ depending on the load of the inverter 5, an inverter ratio (50%, 75%, 100%) and a fifth harmonic. This is associated with the limit value (4A, 3A, 2A) Ins of the wave current In.

For example, when the input voltage to the converter 2 is 200V, the rated load of the inverter 5 is 6.7 kW, and the inverter ratio is 50%, the limit value Ins for each inverter-equipped device is 4A for 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 50% of the rated load, “Vcb1” 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, “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 (PWM switching control) of 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 (any one of Vca1 to). To do. As a result, the fifth harmonic current In generated from the power conversion device 100 can be contained within 4A that is the limit value Ins without reducing the efficiency of the power conversion device 100 as much as possible.

For example, when the input voltage to the converter 2 is 200V, the rated load of the inverter 5 is 6.7kW, and the inverter ratio is 75%, the limit value Ins for each inverter-equipped device is 3A for the 5th 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 If the load is 50% of the rated load, “Vcb2” 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, “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 to Vcd2 is Vca2 <Vcb2 <Vcc2 <Vcd2. Then, the third control unit 93 performs on / off control (PWM switching control) of 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 (any one of Vca2 to Vcd2). ) Thus, the fifth harmonic current In generated from the power conversion device 100 can be suppressed within 3A which is the limit value Ins without reducing the efficiency of the power conversion device 100 as much as possible.

For example, if the input voltage to the converter 2 is 200V, the rated load of the inverter 5 is 6.7kW, and the inverter ratio is 100%, the limit value Ins for each inverter-equipped device is 2.0A for the 5th harmonic current. It becomes. In this case, if the actual load of the inverter 5 is 25% of the rated load of the inverter 5, the third control unit 93 reads “Vca3” as the minimum value Vcmin, and the actual load of the inverter 5 If the load is 50% of the rated load, “Vcb3” 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, “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 to Vcd2 is Vca3 <Vcb3 <Vcc3 <Vcd3. Then, the third control unit 93 performs on / off control (PWM switching control) of 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 (any one of Vca3 to Vcd3). ) Thus, the fifth harmonic current In generated from the power conversion device 100 can be suppressed within 2A that is the limit value Ins without reducing 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 higher the inverter ratio (the lower the limit value Ins), the higher the minimum value Vcmin of the output voltage Vc must be. Considering this point, the relations of 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 manufacturing a heat pump heat source machine that is an inverter-mounted device in which the power conversion device 100 is mounted. The limit value Ins on which these minimum values Vcmin are based 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 heat source machine is determined in advance, the control data according to the situation of the installation place is determined at the time of manufacturing the heat pump heat source machine. This control data may be stored in the limit value setting unit 94 at the time of manufacturing the heat pump type heat source device, or created by an operator at the installation site at the time of installation of the heat pump type heat source device, and the limit value set from the input unit 95 The data may be input and stored in the unit 94 sequentially.

It should be noted that the “regulation value Ino of the harmonic current In” set in the power receiving facility 10 differs depending on the harmonic order. The regulation value Ino at each harmonic order has a correlation, and if the regulation value Ino at any of the harmonic orders is determined, the regulation value Ino at other harmonic orders can be obtained by calculation. 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 calculation formula as the calculation of the regulation value Ino.

In the above description, it has been described that the fifth harmonic current In is included in the limit value Ins for easy understanding. However, actually, the minimum value Vcmin included in the control data in FIG. The harmonic current In at all harmonic orders that are subject to the above regulation is set to a value that falls within the range of the respective limit values Ins.

Actual control will be described with reference to the flowchart of FIG.
The controller 90 detects the size of the refrigeration load of the heat pump heat source machine on which the power conversion device 100 is mounted (step S1), and outputs an AC voltage having a frequency F corresponding to the detection result from the inverter 5 (step S1). S2). The brushless DC motor 6 is driven at a variable speed by the output of the inverter 5. The refrigeration load of the heat pump heat source machine is an air conditioning load, a cooling load, a heating load, or the like.

As described above, control data for storing the harmonic current In in the limit value Ins is stored in the limit value setting unit 94 for the power converter 100. The controller 90 detects the magnitude of the load of the inverter 5 from the value of the output voltage Vc detected by the voltage detector 60, the output current value of the inverter 5 detected by the current sensors 81, 82, 83, and the like (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 31 of the converter 2 so that the output voltage Vc of the converter 2 becomes the read minimum value Vcmin. 36 is subjected to PWM switching control. Thus, the harmonic current In generated from the power conversion device 100 can be reliably suppressed within the limit value Ins regardless of the harmonic order without reducing the efficiency of the power conversion device 100 as much as possible. Therefore, it is not necessary to change the power receiving facility 10 to a large-capacity and expensive one, and it is not necessary to install a high-priced harmonic suppression device between the power receiving facility 10 and the power converter 100.

In addition, since the output voltage Vc of the converter 2 is as low as possible within a range where the harmonic current In falls within the limit value Ins, power loss due to the converter 2 can be minimized, and as a result, the efficiency of the power converter 100 is improved. Will improve.

The first control unit 91 of the controller 90 feeds back the voltage levels of the sine wave signals Er, Es, and Et for generating the PWM signal so that the output voltage Vc detected by the voltage detection unit 60 becomes the minimum value Vcmin. Control. More specifically, this food back control is performed when the output voltage Vc is equal to or greater than the minimum value Vcmin−α (α is a margin value and a small value), and the PWM signal generation sine wave signals Er, Es, Et When the output voltage Vc is lower than the minimum value Vcmin-α, the voltage level of the sine wave signals Er, Es, Et for generating the PWM signal is decreased. To increase the output voltage Vc. Thereby, the output voltage Vc is generally maintained at a value near the minimum value Vcmin. Note that vector control using the 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 at which the harmonic current In can fall within the limit value Ins is used as a limit value setting unit 94 with the load (25%, 50%, 75%, 100%) of the inverter 5 as a parameter. Therefore, it is necessary to store a large number of minimum values Vcmin corresponding to the load of the inverter 5 in the limit value setting unit 94.

In general, the load of the inverter 5 does not change stepwise. For this reason, in order to sequentially cope with the load size of the inverter 5, a larger number of minimum values Vcmin are prepared, or the minimum value Vcmin existing between the minimum values Vcmin determined to be skipped is linearly complemented. It is necessary to obtain by calculation such as. Further, 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 checking the test, but the external environment other than the load of the inverter 5 (temperature and humidity, etc.) It is difficult to perform the test under all conditions in consideration of the fact that affects the harmonic current value. For this reason, the minimum value Vcmin must be determined in a state where a certain margin is provided for the limit value Ins. This margin may unnecessarily reduce the efficiency of the power conversion device 100 depending on the actual driving situation.

Considering these points, in the second embodiment, the harmonic current In itself generated from the power converter 100 is detected, and the detected value In is fed back to the control of the output voltage Vc of the converter 2. As a result, the efficiency of the power conversion device 100 can be increased while the harmonic current In generated from the power conversion device 100 is reliably kept within the limit value Ins.

The limit value setting unit 94 of the controller 90 stores in advance, as control data, the limit value Ins for the power converter for the harmonic current In of a specific order. 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 indicated 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 performing a Fourier transform on the detection results of the current sensors 71, 72, and 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 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 calculates 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. “Ins−ΔI2” is compared. 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 increases and reaches the set value “Ins−ΔI2” (point A in the figure), the controller 90 increases the output voltage Vc of the converter 2 by a certain 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 certain value. Raise. Here, the output voltage Vc is increased by increasing the on / off duty of the PWM signal for the converter 2. Conversely, the output voltage Vc is lowered by reducing the on / off duty of the PWM signal for the converter 2.

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

In summary, the controller 90 increases the output voltage Vc when the calculated value In reaches the set value “Ins−ΔI2” from a low value. In a state where the set value is “Ins−ΔI2” or more, the controller 90 increases the output voltage Vc when the calculated value In reaches the limit value Ins, and outputs when the calculated value In decreases to “Ins−ΔI1”. The voltage Vc is lowered.

As a result, as in the first embodiment, the power conversion apparatus 100 can be operated with high efficiency. It is not necessary to store a large amount of data in the limit value setting unit 94, and calculation such as linear interpolation for obtaining the minimum value Vcmin is also unnecessary. In the second embodiment, when the limit value Ins is determined, the harmonic current In is calculated using the current sensors 71, 72, and 73, and the output voltage Vc of the converter 2 is feedback-controlled according to the calculated value In. Only. Moreover, since the current sensors 71, 72, 73 used when generating the switching PWM signal for the converter 2 are also used for the calculation of the harmonic current In, the circuit configuration of the power conversion device 100 can be simplified.

Moreover, in this 2nd Embodiment, since it is the structure which feedback-controls the output voltage Vc of the converter 2 according to the calculated value In of the harmonic calculation part 97, the power receiving installation 10 is changed into an expensive thing with a large capacity. There is no need to install an expensive harmonic suppression device between the power receiving facility 10 and the power converter 100, and the harmonic current In can be reliably reduced regardless of its order. Moreover, since the output voltage Vc is not increased unnecessarily, the power conversion device 100 can be operated with high efficiency.

Further, in a large-scale facility provided with a plurality of heat pump heat source devices to which electric power is supplied from the power receiving facility 10, the plurality of heat pump heat source devices may be comprehensively controlled by the host system controller 101. . In this case, the controller 90 of each heat pump heat source apparatus 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 heat source machine, compares the total value of these calculated values In and the “regulated value Ino of the harmonic current In” in the power receiving facility 10, The limit value Ins for each heat pump heat source 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 heat source machine. The controller 90 of each heat pump heat source apparatus receives the limit value Ins sent from the system controller 101 by the communication unit 96 and stores the received limit value Ins in the limit value setting unit 94. Thereby, even in a large-scale facility including a plurality of heat pump heat source devices to which power is supplied from the power receiving facility 10, the harmonic current In generated from the power conversion device 100 of each heat pump heat source device is limited to the limit value Ins. It is possible to operate each power conversion device 100 with high efficiency while being housed inside.

Here, the system controller 101 includes not only the calculated value In of the harmonic current generated from the power conversion device 100 in which the converter 2 is switching (operating) but also the power conversion device in which the switching operation of the converter 2 is stopped. The calculated value In of the harmonic current generated from 100 must also be collected and summed. For this reason, at least the controller 90 of the power conversion device 100 in which the inverter 5 is in operation 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 those in the first embodiment. Therefore, the description is omitted.

[3] Third embodiment
In the third embodiment, a heat pump heat source machine, which is one equipment connected to one refrigeration load (air conditioning load, cooling load, heating load, etc.), includes a plurality of units, for example, four compressors. As shown in FIG. 10, this heat pump type heat source machine includes four brushless DC motors 6 that respectively drive the four compressors, and four power converters that output driving power to the brushless DC motors 6. 100, and one integrated controller 150 that comprehensively controls each controller 90 of these power converters 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 as components of one refrigeration cycle for cooling or heating air or a 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 to 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 device) with respect to the total value In ′ of the fifth harmonic current In generated from each power conversion device 100 when the inverter ratio is 50% is the power conversion shown in FIG. The limit value Ins for the apparatus is 16A (= 4.0A × 4), which is four times the 4.0A.

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

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

The limit value Ins ′ (= 16 A) for the equipment is input and stored in the memory 151 in the integrated controller 150 when the heat pump heat source is manufactured or installed. As described above, for example, the limit value Ins ′ for facility equipment with respect to the total value of the fifth harmonic current In generated from each power converter 100 when the inverter ratio is 50% is 16A. Note that, as described above, if the limit value Ins ′ for equipment for the total value of the fifth harmonic current In is determined, the limit value Ins ′ for equipment for the total value of the harmonic current In of other orders is determined. It is obtained by calculation.

Furthermore, the memory 151 in the integrated controller 150 stores the control conditions shown in FIG. This control condition is that a single converter 2 performs a full-wave rectification without a switching operation, and a harmonic current In value (referred to as a non-boosting mode value) Iny flowing out of the converter 2 in a non-boosting mode and a converter 2 When the switching operation (boost operation) is performed and the output voltage Vc of the converter 2 reaches the maximum level, the value of the harmonic current In flowing out from the converter 2 (referred to as the boost mode minimum value) Inx is This 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-boost mode value Iny is Iny3, and the boost 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 integrated controller 150 detects the load of each inverter 5 via each controller 90, and from the four power converters 100 based on the non-boost mode value Iny and the boost mode minimum value Inx corresponding to each detected load. The number of switching operations of each converter 2 that can accommodate the total value of the generated harmonic current In within the limit value Ins ′ for equipment is determined.

Hereinafter, although a calculation example for suppressing the fifth harmonic current In will be described, in practice, the integrated controller 150 performs the same calculation for all the harmonic currents In that need to be suppressed. Based on this calculation, the total controller 150 determines the number of switching operations of each converter 2 so that the total value of the harmonic current values In of all orders that need to be controlled falls within the limit value Ins ′ for each facility device. decide.

For example, when the non-boosting mode value Iny1 at 25% load is 6.0A and the minimum value Inx1 is 0.3A, the integrated controller 150 stops the switching operation of the two converters 2 and switches the remaining two converters 2 Make it work. As a result, the total value of the 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”, which is within the limit value Ins ′ (= 16 A) for equipment. . In addition, in this case, since the two converters 2 do not perform the switching operation, the efficiency of the two power conversion devices 100 including the two converters 2 is improved.

Furthermore, in this case, a margin of 3.4 A is generated between the limit value Ins ′ (= 16 A) for equipment and the total value 12.6 A of the harmonic current In generated from each power converter 100. On the other hand, in order 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. To do. Therefore, if the output voltage Vc of the converter 2 that performs the 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 the switching operation of the value “= 16 A− (6.0 A + 6.0 A) = 4 A” of the harmonic current In that can flow out of the two converters 2 that perform the switching operation. The allowable value ΔIn for the two converters 2 is selected.

The total controller 150 distributes the selected allowable value ΔIn (= 4 A) by the two converters 2 that perform the switching operation. Then, the integrated controller 150 uses the apportioned allowable value ΔIn (= 2A) as the limit value Insz for the power converter for each controller 90 of each power converter 100 including the two converters 2 that perform switching operation. Assign and notify. At the same time, the general controller 150 stops the switching operation of the two converters 2 that may stop the switching operation.

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

Note that the control of each controller 90 for keeping the harmonic current In flowing out of the two converters 2 that perform the switching operation within the limit value Insz (= 2A) for the power converter is described in the second embodiment. Configuration and control may be used.

As described above, in the third embodiment, in the heat pump heat source apparatus including the plurality of power conversion devices 100, the total value of the harmonic current In generated from each power conversion device 100 is calculated as the limit value Ins ′ for equipment. While being within (= 16A), each power converter 100 can be operated with high efficiency.

An example of the processing algorithm of the third embodiment is as follows.
The limit value Ins ′ (= 16 A) for the total value of the harmonic current In generated from each power converter 100 is divided by the value 6.0 A of the harmonic current In flowing out from one converter 2 without switching operation, and the division The integer “2” of the result 2.66A is multiplied by the harmonic current value 6.0A flowing out from one converter 2 without the switching operation, and the multiplication result 12A is subtracted from the limit value Ins ′ (= 16A). The subtraction result 4.0A is the allowable value ΔTn of the harmonic current In that can flow out of the remaining converter 2 that performs the switching operation. Then, the integer “2” of the division result 2.66A is subtracted from the number “4” of all converters 2 and the subtraction result “2” (corresponding to the number N of converters 2 that perform switching operation) is subtracted from the minimum value Inx. And the multiplication result “N × Inx” and the allowable value ΔTn (= 4.0 A) are compared. If the condition “N × Inx” ≦ ΔTn is satisfied, the allowable value ΔTn (= 4.0 A) is calculated. Dividing by the number N of converters 2 that perform the switching operation, the division result is assigned as a limit value Insz per converter.

On the other hand, when the number N of the converters 2 that perform the 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 that performs the switching operation Increase the number N of 2 by 1. In this way, the number N of switching operations of the converter 2 is increased until the condition of “(N + 1) × Inx” ≦ ΔTn is satisfied, and the allowable value ΔTn (= 4.0 A) with the number of switching operations N when this condition is satisfied. ) And notifies the controller 90 of the result of the division as a limit value Insz per converter to be switched. Upon receiving the notification of the limit value Insz, the controller 90 stores the limit value Insz in the limit value setting unit 94 and controls its own PWM switching based on the first embodiment or the second embodiment. An operation is performed in which the output voltage Vc is as low as possible in Insz.

Therefore, it is not necessary to change the power receiving facility 10 to a large-capacity expensive one, and it is not necessary to install a high-order harmonic suppression device between the power receiving facility 10 and each power conversion device 100. Highly efficient operation of each power conversion device 100 can be performed while reliably reducing the generated harmonic current In regardless of the order.

[4] Fourth embodiment
In the third embodiment, the control of the heat pump heat source machine 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 heat source machine in which the output frequency F of 5 is set to a different value will be described. The configuration other than this control is the same as 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 performs only 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 performs switching operation.

In the boost mode in which the converter 2 is switched, the efficiency of the power conversion device 100 is lower than in the non-boost mode in which the converter 2 performs only full-wave rectification without switching operation. Furthermore, the degree of reduction in efficiency of power conversion device 100 in the boost mode in which converter 2 is switched is large when the load on inverter 5 is small (power consumption is small) and small when the load on 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 converter 100 and the load of the inverter 5 in the power converter 100 in the non-boosting mode in which the converter 2 performs only full-wave rectification without switching operation. . That is, the higher the load of the inverter 5 (the higher the power consumption of the inverter 5 and the greater the input current to the converter 2), the higher the harmonic current In. This relationship has the same tendency at any harmonic order.

From the above, when the inverters 5 operate independently from each other, the converter corresponding to the inverter 5 on the smaller load side is switched by switching the converter 2 corresponding to the inverter 5 on the larger load side. As a result, the overall efficiency is higher than the 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 converter 100 is set to the “regulation value Ino of the harmonic current In” in the power receiving facility 10 and the inverter ratio in the power receiving facility 10. It depends on it. The overall controller 150 calculates the number of converters 2 that can be prevented from switching operation, as in the third embodiment. In this calculation, the converter 2 corresponding to the inverter 5 having a small load is selected as the converter 2 that cannot be switched.

For example, the integrated controller 150 can operate the four inverters 5 at 25% load, 50% load, 75% load, and 100% load, respectively, so that any two converters 2 are not switched. In this case, the two converters 2 corresponding to the 25% load and 50% load are not switched. Then, the general controller 150 switches the converter 2 corresponding to the 100% load having the largest load among the two converters 2 to be switched so that the generated value of the harmonic current In is minimized. Then, “the margin of the generated value of the harmonic current In” generated by the switching operation is assigned as the limit value Insz for the power converter on the converter 2 side corresponding to the 75% load and notified to each controller 90 (limit value setting) Stored in the unit 94). The limit value Insz is calculated by the following equation.
Insz = Ins'-In1-In2-Inx
Ins ′ is a limit value for facility equipment with respect to the total value In ′ of the harmonic current In generated from each power converter 100 as described above. Iny1 is the value of the harmonic current In (non-boosting mode value) when the converter 2 corresponding to the inverter 5 with 25% load is in the non-boosting mode. Iny2 is the value of the harmonic current In (non-boosting mode value) when the converter 2 corresponding to the 50% load inverter 5 is in the non-boosting mode. Inx4 is the minimum value of the harmonic current In that flows out of the converter 2 when the converter 2 corresponding to the inverter 5 with 100% load is switched (boost operation) to bring the output voltage Vc to the maximum level. Boost mode minimum value). These Iny1, Iny2, and Inx4 are the same as those shown in FIG.

The general controller 150 receives the load data from the controllers 90 of the four power conversion devices 100, and the switching operation and non-switching operation of the converter 2 based on the load data and the limit value Ins ′ for the equipment. And a limit value Inz for the power converter for the converter 2 to be switched is assigned and notified to each controller 90. Each controller 90 performs PWM switching control of each converter 2 according to the limit value Inz notified from the integrated controller 150. The specific operation and control of each converter 2 are the same as those in the first embodiment or the second embodiment.

By the above control, it is necessary to install an expensive harmonic suppression device between the power receiving facility 10 and the heat pump heat source device (each power conversion device 100) without having to change the power receiving facility 10 to a large-capacity expensive one. The high-efficiency operation of each power converter 100 can be executed while reliably reducing the harmonic current In generated from the heat pump heat source machine (each power converter 100) regardless of the order.

[5] Fifth embodiment
As shown in FIG. 14, a facility equipment system 200 including a number of heat pump heat source devices 200 a, 200 b... 200 n and a center controller 201 is connected to the power receiving facility 10. 200n is connected to, for example, a hot water storage tank of one or a plurality of 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 to the heat pump type heat source devices 200a, 200b,... 200n by the water pipe 202b and heated, and the water heated by the heat pump type heat source devices 200a, 200b,. Supplied to hot water storage tank.

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

The center controller 201 controls the general controllers 150 of the heat pump heat source devices 200a, 200b,. Further, the center controller 201 stores in advance in the internal memory the limit value Inms for the equipment device system with respect to the total value Inm of the harmonic current In generated from the heat pump heat source devices 200a, 200b. The limit value Inms is determined according to the “regulation value Ino of the harmonic current In” set in the power receiving facility 10 and the inverter ratio in the power receiving facility 10.

The center controller 201 distributes the limit value Ins ′ for the facility device for each of the heat pump heat source devices 200a, 200b... 200n within the limit value Inms for the facility device system, and sets each limit value Ins ′ as a heat pump type. It notifies to the controller 90 of heat source machine 200a, 200b ... 200n, respectively. Specific control of the center controller 201 will be described.

First, the center controller 201 selects the number of heat pump heat source units including the converter 2 that can be prevented from switching operation, similar to the integrated controller 150 of the fourth embodiment. In this selection, the heat pump heat source device including the inverter 5 having a small load is assigned in order of increasing load as the heat pump heat source device including the converter 2 that cannot be switched. The general controller 150 of the heat pump heat source apparatus that has received this assignment stops the switching operation of all the converters 2 in the heat pump heat source apparatus.

Subsequently, the center controller 201 instructs the general controller 150 of the heat pump heat source apparatus including the inverter 5 having a large load to perform an operation in which the harmonic current In generated from the heat pump heat source apparatus is minimized. Receiving this instruction, the general controller 150 instructs each controller 90 to control the output voltage Vc of all the converters 2 in the heat pump heat source machine to the highest level within the allowable range. Then, the center controller 201 compares the remaining harmonic current value In with respect to the heat pump heat source device including the inverter 5 having the smallest load among one or more heat pump heat source devices including the converter 2 to be switched. Is reported as the limit value Ins ′. Upon receiving this notification, the general controller 150 of the heat pump heat source apparatus assigns a limit value Ins for the power converter to each power converter 100 in the same manner as in the third embodiment. The controller 90 of the power conversion device 100 that has received this assignment 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. PWM switching control of the converter 2 is performed.

[6] Modification
In each of the above-described embodiments, the case where the limit value Ins of the harmonic current In is assigned within the range of the “restriction value Ino of the harmonic current In” set in the power receiving facility 10 has been described as an example. When the regulation value unrelated to the facility 10 is set individually for each power conversion device 100, the regulation value may be set as the limit value Ins as it is.

In the above embodiments, the case where the load of the inverter 5 is the brushless DC motor 6 has been described as an example. However, the present invention is not limited to the brushless DC motor 6 and can be applied to various loads. In addition, the case where the equipment is a heat pump heat source machine has been described as an example. However, the equipment is not limited to a heat pump heat source machine. Applicable.

The above-described embodiments and modifications are presented as examples, and are not intended to limit the scope of the invention. The novel embodiments and modifications can be implemented in various other forms, and various omissions, rewrites, and changes can be made without departing from the spirit of the invention. In these embodiments and modifications, the scope of the invention is included in the gist, and is included in the invention described in the claims and the equivalents thereof.

The power conversion device of the present invention can be used for a heat pump heat source machine or the like.

DESCRIPTION OF SYMBOLS 1 ... Three-phase alternating current power supply, 2 ... Converter, 4 ... Smoothing capacitor, 5 ... Inverter, 6 ... Brushless DC motor (load), 10 ... Power receiving equipment, 21, 22, 23 ... Reactor, 31a-36a ... Diode, 31- 36 ... IGBT (switching element), 51 to 56 ... IGBT (switching element), 60 ... Voltage detector, 71, 72, 73 ... Current sensor, 81, 82, 83 ... Current sensor, 90 ... Controller, 91 ... First 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 heat source machine 201 ... Center controller

Claims (11)

1. A converter that boosts and converts the voltage of the AC power supply; and
   An inverter that converts the output voltage of the converter into an AC voltage;
   A controller for controlling the output voltage of the converter according to a limit value of the harmonic current;
   A power conversion device comprising:
2. The converter includes a reactor, a diode connected to the AC power supply through the reactor, and a switching element connected in parallel to the diode, and boosts and DC converts the voltage of the AC power supply,
   The controller stores in advance a minimum value of the output voltage of the converter that can be accommodated within the limit value so that the harmonic current generated on the input side of the converter is associated with the load of the inverter, and the actual load of the inverter Reading the minimum value of the output voltage corresponding to the magnitude of the storage content, and controlling the switching of the converter so that the output voltage of the converter becomes the read minimum value,
   The power conversion device according to claim 1.
3. The controller calculates a value of the harmonic current from an input current to the converter, and controls the output voltage of the converter so that the calculated value falls within the limit value. Power converter.
4. The controller is
   An input unit for inputting the limit value;
   A storage unit for storing the limit value input by the input unit;
   including,
   The power conversion device according to any one of claims 1 to 3, wherein:
5. The controller is
   A communication unit that receives input by data communication of the limit value;
   A storage unit for storing the limit value received by the communication unit;
   including,
   The power conversion device according to any one of claims 1 to 3, wherein:
6. A facility device comprising a plurality of the power conversion devices according to claim 5,
   A total controller for comprehensively controlling each of the power converters;
   The integrated controller sets the limit value for the power converter within the range of the limit value for the facility device based on the “restriction value of harmonic current” set in the power receiving facility to which the facility device is connected. The facility equipment is characterized in that the limit values for these power conversion devices are notified to the controllers of the power conversion devices.
7. The facility device according to claim 6, wherein the integrated controller controls the number of switching operations of the converters in the power converters.
8. An equipment system comprising a plurality of equipment according to claim 6,
   Comprising a center controller for controlling each facility device;
   The center controller has a limit value for each facility device within a range of limit values for the facility device system based on a “restriction value of harmonic current” set in a power receiving facility to which the facility device is connected. And a limit value for these equipments is notified to each of the integrated controllers of the equipments.
9. The equipment according to claim 6 or claim 7, or the equipment equipment system according to claim 8, wherein the equipment is a heat source machine including a compressor driven by the inverter.
10. The controller includes a current sensor that detects an input current to the converter, controls the output voltage of the converter based on a detection result of the current sensor, and calculates a value of the harmonic current. Item 4. The power conversion device according to Item 3.
11. The power converter according to claim 10, wherein the controller calculates the value of the harmonic current based on a detection result of the current sensor even when the boosting operation of the converter is stopped.

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