Power quality management system and air conditioning device

Abstract

The power conversion device (3) is supplied with power from an AC power source (1). The active filter device (2) as a power quality improvement unit improves the quality of the AC power source (1). The controller (37) limits the operation of the power conversion device (3) so that any one of the power supply power, power supply current and power supply harmonics when the fault detection unit (4) detects that the active filter device (2) has a fault is less than the maximum value of the power supply power, power supply current and power supply harmonics when the active filter device (2) is not faulty.

Description

Technical Field

[0001] The present disclosure relates to a power quality management system and an air conditioning device. Background Art

[0002] In air conditioners and the like, power quality improvement devices (harmonic suppression devices) such as active filters are provided to suppress the outflow of power supply harmonic currents to the power system (e.g., a power system including commercial power supplies). The power quality improvement device improves the power factor of the power supply by making the waveform of the power supply current from the power supply approximately sinusoidal. This enables the miniaturization and reduction of the capacity of power receiving equipment such as power transformers, wiring, circuit breakers, and fuses.

[0003] Patent Document 1 discloses a technique related to the power quality improvement device, that is, when a power quality improvement device (active filter) in an air conditioner fails, the compressor is kept running.

[0004] Patent Document 1: Japanese Patent No. 5342528 Summary of the invention

[0005] -Technical problem to be solved by the invention-

[0006] As described above, if a power quality improvement device is provided in an air conditioner, the capacity of the power receiving device will be reduced. In the above-mentioned Patent Document 1, when the power quality improvement device fails, if the compressor is allowed to continue to operate at maximum power, for example, as in the case where the power quality improvement device is not failed, the power supply power will exceed the capacity of the power receiving device. Therefore, there is a possibility that the power receiving device may be damaged or burned.

[0007] The present disclosure aims to reduce the possibility of damage and burning of power receiving equipment even if a power quality improvement device fails.

[0008] -Technical solutions for solving technical problems-

[0009] A first aspect of the present disclosure relates to a power quality management system, which includes: load devices 70A, 70B, 7, 70, 9A, 9B, which are supplied with power from a power source 1 to operate; power quality improvement units 2, 8, which are connected to the power source 1 and improve the quality of the power source 1; fault judgment units 4, 41, which judge whether the power quality improvement units 2, 8 are faulty; and operation restriction units 37A, 37B, 37, 75, 95A, 95B, which, when the fault judgment units 4, 41 judge that the power quality improvement units 2, 8 are faulty, restrict the operation of the load devices 70A, 70B, 7, 70, 9A, 9B so that any one of the power supply power, power supply current and power supply harmonics is less than the respective maximum values ​​of the power supply power, the power supply current and the power supply harmonics when the power quality improvement units 2, 8 are not faulty.

[0010] In this way, since the power supply power etc. when the power quality improvement unit 2, 8 fails does not exceed the maximum value of the power supply power etc. when the power quality improvement unit 2, 8 is normal, it is possible to suppress the power supply power etc. from exceeding the capacity of the power receiving device. Therefore, when the power quality improvement unit 2, 8 fails, it is possible to reduce the damage and burning of the power receiving device.

[0011] A second aspect of the present disclosure is based on the first aspect and is characterized in that the power quality improvement unit 2 , 8 is any one of a PWM conversion device, an active filter device 2 and a phase modulation device 8 .

[0012] The third aspect of the present disclosure is based on the first aspect or the second aspect and is characterized in that the load devices 70A, 70B, 7, 70, 9A, 9B are any one of the air conditioning devices 70A, 70B, 70, the elevators 9A, 9B and the lighting equipment 7.

[0013] The fourth aspect of the present disclosure is based on any one of the first to third aspects and is characterized in that the fault judgment unit 41 judges that the power quality improvement unit 8 has a fault based on the power factor of the power supply 1 being lower than a first specified value.

[0014] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 8 .

[0015] The fifth aspect of the present disclosure is based on any one of the first to third aspects and is characterized in that the fault judgment unit 4, 41 judges that the power quality improvement unit 2 has a fault based on the fact that the power supply higher harmonics exceed a second specified value.

[0016] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 2 .

[0017] The sixth aspect of the present disclosure is based on any one of the first to third aspects and is characterized in that the fault judgment unit 4, 41 judges that the power quality improvement unit 2 has a fault when the waveform of the power current Is from the power supply 1 is different from the waveform of the power current Is when the power quality improvement unit 2 is not faulty.

[0018] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 2 .

[0019] A seventh aspect of the present disclosure is based on the first aspect, and is characterized in that the power quality improvement unit 2 is incorporated into the load device 70A, 70B, 7, 70, 9A, 9B.

[0020] The eighth aspect of the present disclosure relates to an air conditioning device, which includes: a higher harmonic generating unit 3, 6, which is connected to a power supply 1 and is supplied with power from the power supply 1, and is a source of power supply higher harmonics; a power quality improvement unit 2, 5, which is connected in parallel with the higher harmonic generating unit 3, 6 relative to the power supply 1 and improves the quality of the power supply 1; a fault judgment unit 4, 42, 48, 48a, which judges whether the power quality improvement unit 2, 5 has a fault; and an operation limiting unit 37, which, when the fault judgment unit 4, 42, 48, 48a judges that the power quality improvement unit 2, 5 has a fault, limits the operation of the higher harmonic generating unit 3, 6, so that any one of the power supply power, the power supply current and the power supply higher harmonics is less than the respective maximum values ​​of the power supply power, the power supply current and the power supply higher harmonics when the power quality improvement unit 2, 5 has not failed.

[0021] In this way, since the power supply power etc. when the power quality improvement unit 2, 5 fails does not exceed the maximum value of the power supply power etc. when the power quality improvement unit 2, 5 is normal, it is possible to suppress the power supply power etc. from exceeding the capacity of the power receiving device. Therefore, when the power quality improvement unit 2, 5 fails, it is possible to reduce the damage and burning of the power receiving device.

[0022] A ninth aspect of the present disclosure is based on the eighth aspect and is characterized in that the power quality improvement unit 2 , 5 is any one of an active filter 2 and a PWM converter 5 .

[0023] The tenth aspect of the present disclosure is based on the eighth aspect or the ninth aspect, and is characterized in that: the fault judgment unit 42 judges that the power quality improvement unit 2 has a fault based on the power factor of the power supply 1 being lower than a third specified value.

[0024] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 2 .

[0025] The eleventh aspect of the present disclosure is based on the eighth aspect or the ninth aspect, and is characterized in that the fault judgment unit 48 judges that the power quality improvement unit 2 has a fault based on the fact that the power supply higher harmonics exceed a fourth specified value.

[0026] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 2 .

[0027] The twelfth aspect of the present disclosure is based on the eighth aspect or the ninth aspect, and is characterized in that: the fault judgment unit 48a judges that the power quality improvement unit 2 has a fault when the waveform of the power supply current Is from the power supply 1 is different from the waveform of the power supply current Is when the power quality improvement unit 2 is not faulty.

[0028] In this way, it is possible to easily understand whether or not a failure has occurred in the power quality improving unit 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a block diagram showing the structure of an air conditioning device according to the first embodiment;

[0030] Figure 2 is a block diagram showing the structure of an air conditioning device according to a second embodiment;

[0031] Figure 3 is a block diagram showing the structure of a power quality management system according to a third embodiment;

[0032] Figure 4 is a block diagram showing the structure of a power quality management system according to a fourth embodiment;

[0033] Figure 5 is a block diagram showing the structure of a power quality management system according to a fifth embodiment;

[0034] Figure 6 is a block diagram showing the structure of an air conditioning device according to a sixth embodiment;

[0035] Figure 7 is a block diagram showing the structure of an air conditioning device according to a seventh embodiment;

[0036] Figure 8 It is a block diagram showing the configuration of an air conditioning apparatus according to the eighth embodiment. DETAILED DESCRIPTION

[0037] 《First Implementation Mode》

[0038] <summary>

[0039] Figure 1 This is a block diagram showing the configuration of an air conditioning device 70 according to the first embodiment. The air conditioning device 70 is installed in an apartment, a factory, a building, a single-family house (hereinafter referred to as a building, etc.), and performs indoor air conditioning (cooling and heating).

[0040] Power as AC power is supplied from a power system including the AC power source 1 to the air conditioner 70 via the wiring 11. The air conditioner 70 operates by receiving the power.

[0041] Here, a case where the AC power source 1 is a three-phase AC power source (for example, a three-phase commercial power source) is exemplified.

[0042] In the building or the like, a switchboard (not shown) is provided which is connected to the AC power source 1 and receives power from the AC power source 1. The switchboard includes a circuit breaker and distributes the power from the AC power source 1 to the air conditioner 70 via the circuit breaker.

[0043] The capacity of each circuit breaker, AC power source 1, and wiring 11 depends on the power factor of the power supply. In the first embodiment, since the air conditioner 70 has the active filter device 2 as the power quality improvement unit, the power factor of the AC power supply 1 becomes higher. Therefore, compared with the case where the active filter device 2 is not provided, the capacity of each circuit breaker, AC power source 1, and wiring 11 is set lower.

[0044] 〈Structure of air conditioning unit〉

[0045] The air conditioning device 70 includes: a refrigerant circuit (not shown) having a compressor, etc., a power conversion device 3 as a harmonic generating load (equivalent to a harmonic generating unit), an active filter device 2, a fault detection unit 4 equivalent to a fault judgment unit, and a controller 37 as an operation limiting unit.

[0046] In the first embodiment, an example is given in which the controller 37 is incorporated in the power conversion device 3 .

[0047] - Power conversion device -

[0048] The power conversion device 3 is connected to the AC power source 1 via the wiring 11. When the AC power source 1 supplies power to the power conversion device 3, the power conversion device 3 converts the power into AC power with a desired frequency and a desired voltage, and supplies the converted AC power to the compressor (more specifically, the compressor motor 31) as power. In this way, the compressor operates and the refrigerant circuit works, and as a result, the indoor air is conditioned.

[0049] Specifically, the power conversion device 3 includes a rectifier circuit 32 including six diodes 32a to 32f, a smoothing capacitor 33, an inverter circuit 34 including switching elements 35a to 35f and freewheeling diodes 36a to 36f, and a controller 37 including a CPU or the like.

[0050] In the air conditioning device 70, if the power conversion device 3 and the compressor motor 31 are running, higher harmonic currents accompanied by power supply higher harmonics are sometimes generated. That is, the power conversion device 3 can be said to be one of the sources of power supply higher harmonics. The higher harmonic current may flow to the AC power supply 1 via the current path (hereinafter referred to as the power receiving path 11) toward the air conditioning device 70. Usually, the outflow level of such higher harmonic currents flowing to the AC power supply 1 side is limited. Therefore, the air conditioning device 70 involved in the first embodiment seeks to reduce the higher harmonic currents through the active filter device 2 as a power quality improvement unit. From the perspective of equipment capacity, energy saving, etc., it is required to improve the fundamental power factor or the comprehensive power factor including higher harmonics at the power distribution and receiving ends, and the active filter device 2 of the first embodiment also has the function of improving the fundamental power factor and the comprehensive power factor.

[0051] - Controller -

[0052] The controller 37 controls the on and off of each switching element 35a to 35f. In particular, the controller 37 according to the first embodiment functions as an operation limiting unit, and controls the operation of the compressor motor 31 to be limited when a failure occurs in the active filter device 2. This will be described in detail in "About Operation Limitation Control".

[0053] - Active filter device -

[0054] The active filter device 2 is built into the air conditioning device 70 , that is, is assembled into the air conditioning device 70 .

[0055] The active filter device 2 has a function of eliminating the harmonic current that flows out of the power conversion device 3 and appears in the power receiving path 11 of the power conversion device 3. That is, the active filter device 2 flows the compensation current so that the waveform of the power supply current Is flowing in the power receiving path 11 is close to a sine wave. More specifically, the active filter device 2 detects the harmonic current that appears in the power receiving path 11, generates the compensation current that is in reverse phase with the detected harmonic current, and supplies it to the power receiving path 11.

[0056] Then, the active filter device 2 improves the fundamental wave power factor by flowing the compensation current. In this example, the active filter device 2 is configured to flow a compensation current that also compensates for the reactive component of the fundamental wave, thereby improving the fundamental wave power factor or the comprehensive power factor including higher harmonics. Therefore, it can be said that the active filter device 2 has the function of improving the quality of the AC power supply 1.

[0057] Such an active filter device 2 is connected in parallel with a power conversion device 3 with respect to an AC power supply 1. Specifically, the active filter device 2 includes a current source 23 composed of six switching elements 21a to 21f and six freewheeling diodes 22a to 22f, a capacitor 24, and a controller 25 composed of a CPU or the like that controls the on and off of each switching element 21a to 21f.

[0058] When the load of the air conditioner 70 is the largest (for example, when the cooling output is the maximum), it is considered that the harmonic current generated in the air conditioner 70 is the largest. Therefore, it is usually assumed that the harmonic current when the air conditioner 70 reaches the maximum load, so as to set the ability (the amount of power that can be generated), that is, the capacity of the active filter device 2. In other words, the capacity of the AC power supply 1, the capacity of the wiring 11, etc. are designed according to the power supply current Is when the load of the air conditioner 70 is the maximum.

[0059] - Fault Detection Unit -

[0060] The fault detection unit 4 is connected to the controller 25 of the active filter device 2 and the controller 37 of the power conversion device 3 .

[0061] The fault detection unit 4 is a microcomputer composed of, for example, a CPU or a memory, and receives a fault status signal from the controller 25 of the active filter device 2. This signal is used when the fault detection unit 4 determines whether a fault has occurred in the active filter device 2, and the controller 25 monitors the status of the current source 23 and the like, and sequentially outputs the above signal from the controller 25.

[0062] The fault detection unit 4 detects the presence of a fault based on the input signal, and outputs a fault / stop signal indicating the detection result (ie, whether the active filter device 2 has a fault) to the controller 37 of the power conversion device 3 .

[0063] 〈Regarding Operational Work Restriction Control〉

[0064] The active filter device 2 has a higher power factor value related to the power voltage and power current of the AC power source 1. In this way, in the first embodiment, the reactive power is reduced compared to the case where the active filter device 2 is not present, so the input power (i.e., power supply power) to the air conditioner 70 is reduced, and the input current (i.e., power supply current) to the air conditioner 70 is reduced.

[0065] However, when the active filter device 2 fails, and the active filter device 2 stops operating due to the failure, the power factor of the AC power source 1 decreases compared to the case where the active filter device 2 operates normally. Therefore, when the active filter device 2 fails, the power current (input current) Is when the load of the air conditioner 70 is the maximum load becomes larger than when the active filter device 2 operates normally, and there is a possibility that it exceeds the capacity of the AC power source 1, the capacity of the wiring 11, etc.

[0066] Therefore, the controller 37 of the power conversion device 3 according to the first embodiment performs operation restriction control to restrict the operation of the compressor by restricting the drive of the compressor motor 31 driven by the power conversion device 3 when the active filter device 2 fails.

[0067] Specifically, when the active filter device 2 is in a state of failure or stops working due to a failure, a failure state signal indicating this is output from the controller 25 of the active filter device 2 to the fault detection unit 4. The fault detection unit 4 detects that the active filter device 2 has failed or stopped working due to a failure based on the failure state signal. The fault detection unit 4 generates a failure / stop signal indicating the detection result and outputs it to the controller 37 of the power conversion device 3.

[0068] The controller 37 to which the fault / stop signal is input controls the operation of the power conversion device 3 so that the power current Is (i.e., the power current Is when the active filter device 2 fails) is less than the maximum value of the power current Is when the active filter device 2 is not faulty and is in the working state, thereby limiting the operation of the compressor motor 31. Alternatively, the controller 37 controls the operation of the power conversion device 3 so that the power (i.e., the power when the active filter device 2 fails) is less than the maximum value of the power when the active filter device 2 is not faulty and is in the working state, thereby limiting the operation of the compressor motor 31. As an example of these cases, it can be cited that the controller 37 reduces the rotation speed of the compressor motor 31 by reducing the frequency of the AC power output from the power conversion device 3 to the compressor motor 31, or stops the compressor motor 31 from rotating by stopping the output of the AC power from the power conversion device 3.

[0069] That is, the controller 37 limits the operation of the power conversion device 3 so that the power supply current Is or the power supply power does not exceed the respective maximum values ​​when the active filter device 2 fails. In this way, the power supply power can be reduced from exceeding the capacity of the AC power source 1, the capacity of the wiring 11, and the like.

[0070] It should be noted that, when the active filter device 2 is operating normally, a fault status signal indicating the condition may be output from the controller 25 to the fault detection unit 4. In this case, the fault detection unit 4 may not output a fault / stop signal to the controller 37 of the power conversion device 3, or may output a fault / stop signal indicating that the active filter device 2 is operating normally to the controller 37. In the above case, the controller 37 of the power conversion device 3 does not perform the operation restriction control.

[0071] <Effect>

[0072] In the first embodiment, through the operation limit control, the power supply power etc. when the active filter device 2 fails will not exceed the maximum value of the power supply power etc. when the active filter device 2 is normal. Therefore, it is possible to suppress the power supply power etc. when the active filter device 2 fails from exceeding the capacity of the power receiving device (specifically, the AC power supply 1, the wiring 11, and the circuit breaker). Therefore, when the active filter device 2 fails, the damage and burning of the power receiving device can be reduced.

[0073] Second Implementation Method

[0074] In the second embodiment, an example is given in which the power quality improving unit is the PWM converter 5 that promotes improvement of power harmonics, and the harmonic generating unit is the inverter 6 .

[0075] 〈Structure of air conditioning unit〉

[0076] Figure 2 1 is a block diagram showing the structure of an air conditioner 70 according to the second embodiment. The air conditioner 70 is connected to an AC power supply 1, and includes, in addition to the same fault detection unit 4 as the first embodiment, an inverter device 6 as a higher harmonic generation unit, a controller 37 included in the inverter device 6 and functioning as an operation restriction unit, a PWM conversion device 5 as a power quality improvement unit, and a refrigerant circuit (not shown) having a compressor, etc.

[0077] The inverter device 6 is configured by removing the rectifier circuit 32 from the power conversion device 3 of the first embodiment. Figure 2 In the figure, each main structure included in the inverter device 6 is marked with Figure 1 Same symbols.

[0078] The PWM converter 5 is built into the air conditioner 70, that is, assembled into the air conditioner 70. The PWM converter 5 is a device that suppresses power supply harmonics and improves power supply power factor by turning on and off the switching elements 51a to 51f at high speed, so that the waveform of the power supply current Is as the input current is substantially sinusoidal. Therefore, like the active filter device 2 involved in the first embodiment, the PWM converter 5 has the function of improving the quality of the AC power supply 1.

[0079] Such a PWM conversion device 5 is connected in parallel with the inverter device 6 relative to the AC power supply 1. Specifically, the PWM conversion device 5 has: a conversion circuit 53 composed of six switching elements 51a to 51f and six freewheeling diodes 52a to 52f, a current sensor 54, and a controller 55 composed of a CPU and the like for controlling the on and off of each switching element 51a to 51f.

[0080] 〈Regarding Operational Work Restriction Control〉

[0081] In the PWM converter 5, even if the switching elements 51a to 51f or the current sensor 54 fails, if the flyback diodes 52a to 52f do not fail, the current can flow to the inverter 6 via the flyback diodes 52a to 52f. Therefore, even if the PWM converter 5 fails, the inverter 6 can drive the compressor motor 31 to continue the operation of the compressor, so the air conditioner 70 can continue to operate.

[0082] As an example, if only the current sensor 54 fails, the PWM converter 5 cannot perform the switching operation of the switch elements 51a to 51f according to the detection result of the current sensor 54, so the power factor of the power supply cannot be improved. However, if the switch elements 51a to 51f and the freewheeling diodes 52a to 52f are normal, the PWM converter 5 itself can work.

[0083] However, as described above, when the PWM converter 5 fails and the operation of the PWM converter 5 itself stops due to the failure, the power factor of the power supply is reduced compared to when the PWM converter 5 operates normally. Therefore, compared to the case where the PWM converter 5 does not fail, the input current when the load of the air conditioner 70 is the maximum load, that is, the power supply current Is becomes larger, and there is a possibility that it exceeds the capacity of the AC power supply 1 and the capacity of the wiring 11.

[0084] Therefore, in the second embodiment, when the PWM converter 5 fails or stops working due to a failure, a fault status signal indicating this is output from the controller 55 of the PWM converter 5 to the fault detection unit 4. If the fault detection unit 4 detects that the PWM converter 5 fails or stops working due to a failure based on the fault status signal, it generates a fault / stop signal indicating the detection result and outputs it to the controller 37 of the inverter 6.

[0085] The controller 37 to which the fault / stop signal is input controls the operation of the inverter device 6 so that the power supply current Is is less than the maximum value of the power supply current Is when the PWM converter device 5 is in operation without a fault, thereby limiting the operation of the compressor motor 31. Alternatively, the controller 37 controls the operation of the inverter device 6 so that the power supply power is less than the maximum value of the power supply power when the PWM converter device 5 is in operation without a fault, thereby limiting the operation of the compressor motor 31.

[0086] As an example of these situations, it can be cited that the controller 37 reduces the rotation speed of the compressor motor 31 by reducing the frequency of the AC power output by the inverter device 6 to the compressor motor 31, or stops the compressor motor 31 from rotating by stopping the output of AC power from the inverter device 6.

[0087] That is, the controller 37 limits the operation of the inverter device 6 so that the power supply current Is or the power supply power does not exceed the respective maximum values ​​when the PWM converter device 5 fails. In this way, the input power (i.e., power supply power) of the air conditioner 70 as the load of the AC power supply 1 can be reduced to exceed the capacity of the AC power supply 1, the capacity of the wiring 11, etc.

[0088] It should be noted that, when the PWM converter 5 is operating normally, a fault status signal indicating the condition may be output from the controller 55 of the PWM converter 5 to the fault detection unit 4. In this case, the fault detection unit 4 may not output a fault / stop signal to the controller 37 of the inverter 6, or may output a fault / stop signal indicating that the PWM converter 5 is operating normally to the controller 37 of the inverter 6. In the above case, the controller 37 of the inverter 6 does not perform the operation restriction control.

[0089] <Effect>

[0090] In the second embodiment, the power quality improving unit is a PWM converter 5, and the same effects as those of the first embodiment are obtained.

[0091] 《Third Implementation Mode》

[0092] In the third embodiment, a power quality management system 100 is exemplified, which includes a plurality of air conditioners 70A and 70B as load devices of an AC power source 1, and an active filter device 2 as a power quality improvement unit. The air conditioners 70A and 70B do not include a power quality improvement unit such as an active filter device and a PWM converter.

[0093] 〈Structure of Power Quality Management System〉

[0094] Figure 3 2 is a block diagram showing the structure of a power quality management system 100 according to the third embodiment.

[0095] The power quality management system 100 includes a plurality of (here, two) air conditioners 70A and 70B, an active filter device 2 as a power quality improvement unit, a fault detection unit 4, and controllers 37A and 37B functioning as an operation restriction unit.

[0096] The plurality of air conditioners 70A and 70B and the active filter device 2 are connected to the AC power source 1 via a wiring 11 in parallel with respect to the AC power source 1 .

[0097] Each of the air conditioners 70A and 70B performs air conditioning operation by receiving power from the AC power supply 1. The air conditioners 70A and 70B each have a configuration in which the active filter device 2 and the fault detection unit 4 are removed from the air conditioner 70 of the first embodiment. Specifically, the air conditioners 70A and 70B each include a refrigerant circuit (not shown) having a compressor and the like, and a power conversion device 3A and 3B as a harmonic generation load (equivalent to a harmonic generation unit). Similar to the power conversion device 3 of the first embodiment, each of the power conversion devices 3A and 3B includes a rectifier circuit 32, a smoothing capacitor 33, an inverter circuit 34 as a harmonic generation unit that generates power source harmonics, and controllers 37A and 37B composed of a CPU and the like. Since the rectifier circuit 32, the smoothing capacitor 33, and the inverter circuit 34 are the same as those of the first embodiment, the same symbols as those of the first embodiment are given.

[0098] The active filter device 2 is connected to the AC power source 1 and improves the quality of the AC power source 1. The active filter device 2 is not built into the air conditioner 70 but is pre-installed in the building, etc., and its structure is the same as the active filter device 2 of the first embodiment. Therefore, the components of the active filter device 2 are respectively marked with the same symbols as those of the first embodiment.

[0099] The fault detection unit 4 is the same as the fault detection unit 4 involved in the first embodiment. That is, the fault detection unit 4 is connected to the controller 25 of the active filter device 2 and the controllers 37A and 37B of the power conversion devices 3A and 3B, and detects whether the active filter device 2 has a fault based on the fault state signal from the controller 25.

[0100] The controllers 37A and 37B of the power conversion devices 3A and 3B can perform operation restriction control to restrict the operation of the compressor by restricting the driving of the compressor motors 31A and 31B driven by the power conversion devices 3A and 3B when the active filter device 2 fails.

[0101] It should be noted that in Figure 3 In the example, the number of the air conditioners 70A and 70B is two and the number of the active filter device 2 is one. However, the number of the air conditioners 70A and 70B and the number of the active filter device 2 is not limited to Figure 3 The number of air conditioners 70A and 70B may be two or more, and the number of active filter devices 2 may be one or more.

[0102] 〈Regarding Operational Work Restriction Control〉

[0103] Next, the operation restriction control according to the third embodiment will be described in detail.

[0104] When the active filter device 2 is in a state of failure or stops operating due to a failure, a failure state signal indicating this is output from the controller 25 of the active filter device 2 to the fault detection unit 4. The fault detection unit 4 detects that the active filter device 2 has failed or stopped operating due to a failure based on the failure state signal. When a failure / stop signal indicating the detection result is generated, the fault detection unit 4 outputs the signal to any one of the controllers 37A and 37B of the power conversion devices 3A and 3B included in each of the air conditioners 70A and 70B.

[0105] Here, as an example, it is assumed that the fault / stop signal is input only to the controller 37A. The controller 37A limits the operation of the air conditioner 70A so that the power current supplied from the AC power supply 1 to all load devices of the power supply 1 is less than the maximum value of the power current when the active filter device 2 is in an operating state without a fault. Alternatively, the controller 37A controls the operation of the air conditioner 70A so that the power supply power supplied from the AC power supply 1 to all load devices of the power supply 1 is less than the maximum value of the power supply power when the active filter device 2 is in an operating state without a fault.

[0106] As an example of these situations, it can be cited that the controller 37A reduces the rotation speed of the compressor motor 31A by reducing the frequency of the AC power output by the power conversion device 3A to the compressor motor 31A, or stops the rotation of the compressor motor 31A by stopping the output of AC power from the power conversion device 3.

[0107] That is, the operation of the air conditioner 70A is restricted, while the operation of the air conditioner 70B continues without restriction. Therefore, even if the active filter device 2 fails, the compressor motor 31B is continuously driven. That is, in the third embodiment, by restricting the operation of only one air conditioner 70A, the total value of the power of the power quality management system 100 can be reduced from exceeding the capacity of the AC power source 1, the capacity of the wiring 11, and the like.

[0108] It should be noted that, when the active filter device 2 operates normally, a fault status signal indicating this may be output from the controller 25 of the active filter device 2 to the fault detection unit 4. At this time, since the fault detection unit 4 does not output a fault / stop signal to the controllers 37A and 37B of the power conversion devices 3A and 3B, the controllers 37A and 37B do not perform the operation restriction control.

[0109] <Effect>

[0110] In the third embodiment, the operation limit control is performed so that the power supply power etc. when the active filter device 2 fails does not exceed the maximum value of the power supply power etc. when the active filter device 2 is normal. Therefore, it is possible to prevent the power supply power etc. when the active filter device 2 fails from exceeding the capacity of the power receiving device (specifically, the AC power supply 1, the wiring 11, and the circuit breaker). Therefore, when the active filter device 2 fails, damage and burning of the power receiving device can be reduced.

[0111] 《Fourth Implementation Mode》

[0112] In the fourth embodiment, a power quality management system 100 is exemplified when a combination of one air conditioner 70 and lighting equipment 7 is used as a load device of an AC power source 1 .

[0113] 〈Structure of Power Quality Management System〉

[0114] Figure 4 2 is a block diagram showing the structure of a power quality management system 100 according to a fourth embodiment.

[0115] The power quality management system 100 includes an air conditioner 70 and a lighting device 7 as load devices, an active filter device 2 as a power quality improvement unit, a fault detection unit 4, and controllers 37 and 75 functioning as an operation restriction unit.

[0116] The air conditioner 70 , the lighting device 7 , and the active filter device 2 are connected to the AC power source 1 via a wiring 11 in parallel with respect to the AC power source 1 .

[0117] The air conditioner 70 and the lighting device 7 are operated by being supplied with power from the AC power source 1 .

[0118] The air conditioner 70 is configured by removing the active filter device 2 and the fault detection unit 4 from the air conditioner 70 involved in the first embodiment, that is, the same as the air conditioners 70A and 70B of the third embodiment. Specifically, the air conditioner 70 includes a refrigerant circuit (not shown) having a compressor and the like, and a power conversion device 3 as a harmonic generation load (equivalent to a harmonic generation unit). The power conversion device 3 is the same as the power conversion device 3 involved in the first embodiment, and includes a rectifier circuit 32 composed of six diodes 32a to 32f, a smoothing capacitor 33, an inverter circuit 34 composed of switching elements 35a to 35f and freewheeling diodes 36a to 36f, and a controller 37 composed of a CPU and the like and controlling the on and off of each switching element 35a to 35f.

[0119] The lighting device 7 is a single-phase device and is installed on the ceiling of a building, etc. The lighting device 7 is composed of an LED (not shown) and a controller 75. The controller 75 is a microcomputer composed of a CPU, etc., and controls the illumination of the LED (not shown).

[0120] The active filter device 2 is connected to the AC power source 1 and improves the quality of the AC power source 1. The active filter device 2 is not built into the air conditioner 70, but is pre-installed in the building, etc., and its structure is the same as the active filter device 2 of the first and third embodiments. Therefore, the components of the active filter device 2 are respectively marked with the same symbols as those of the first embodiment.

[0121] The fault detection unit 4 is the same as the fault detection unit 4 involved in the first embodiment. The fault detection unit 4 is connected to the controller 25 of the active filter device 2, the controller 37 of the power conversion device 3, and the controller 75 of the lighting device 7, and detects the presence of a fault based on the fault state signal input from the controller 25.

[0122] The controller 37 of the power conversion device 3 can perform operation restriction control to restrict the operation of the compressor by restricting the driving of the compressor motor 31 using the power conversion device 3 as a driving source when the active filter device 2 fails.

[0123] The controller 75 of the lighting device 7 can perform operation restriction control to restrict the operation of the lighting device 7 (specifically, the LED included in the lighting device 7 ) when the active filter device 2 fails.

[0124] 〈Regarding Operational Work Restriction Control〉

[0125] Next, the operation restriction control according to the fourth embodiment will be described in detail.

[0126] When the active filter device 2 is in a state of failure or stops working due to a failure, a failure state signal indicating this is output from the controller 25 of the active filter device 2 to the fault detection unit 4. The fault detection unit 4 detects that the active filter device 2 has failed or stopped working due to a failure based on the failure state signal. When a failure / stop signal indicating the detection result is generated, the fault detection unit 4 outputs the signal to at least one of the controller 37 of the power conversion device 3 included in the air conditioning device 70 and the controller 75 of the lighting device 7.

[0127] The controller 37 of the power conversion device 3 to which the fault / stop signal is input controls the operation of the air conditioning device 70 so that the power supply current is less than the maximum value of the power supply current when the active filter device 2 is in operation without fault. Alternatively, the controller 37 controls the operation of the air conditioning device 70 so that the power supply power is less than the maximum value of the power supply power when the active filter device 2 is in operation without fault. As an example of these cases, it can be cited that the controller 37 reduces the rotation speed of the compressor motor 31 by reducing the frequency of the AC power output by the power conversion device 3.

[0128] The controller 75 of the lighting device 7 to which the fault / stop signal is input performs control to reduce the illumination of the lighting device 7 so that the power supply current is less than the maximum value of the power supply current when the active filter device 2 is in a working state without fault. Alternatively, the controller 75 performs control to reduce the illumination of the lighting device 7 so that the power supply power is less than the maximum value of the power supply power when the active filter device 2 is in a working state without fault.

[0129] By the above control, the occurrence of a phenomenon in which the total value of the input power to the load devices 70 and 7, that is, the power supply power exceeds the capacity of the AC power supply 1 and the capacity of the wiring 11, etc. is reduced.

[0130] It should be noted that, when the active filter device 2 is operating normally, a fault status signal indicating the condition may be output from the controller 25 of the active filter device 2 to the fault detection unit 4. In this case, the fault detection unit 4 may not output a fault / stop signal to each controller 37, 75, or may output a fault / stop signal indicating that the active filter device 2 is operating normally to each controller 37, 75. In the above case, the operation restriction control is not performed.

[0131] <Effect>

[0132] In the fourth embodiment, the load devices are the air conditioner 70 and the lighting device 7, and the same effects as those of the third embodiment are obtained.

[0133] 《Fifth Implementation Mode》

[0134] In the fifth embodiment, a power quality management system 100 is exemplified when the power quality improving unit is a phase adjustment device 8 and the load devices of the AC power supply 1 are two elevators 9A and 9B. In the fifth embodiment, a case where a failure of the phase adjustment device 8 is determined instead of detected is exemplified.

[0135] 〈Structure of Power Quality Management System〉

[0136] Figure 51 is a block diagram showing the structure of a power quality management system 100 according to the fifth embodiment.

[0137] The power quality management system 100 includes two elevators 9A and 9B as load devices, a phase adjustment device 8 as a power quality improvement unit, a fault determination unit 41, and controllers 95A and 95B functioning as operation restriction units.

[0138] The phase adjustment device 8 is connected to the AC power source 1 via the wiring 11, and is a device for improving the quality of the AC power source 1. The elevators 9A and 9B are connected in parallel with the AC power source 1, and are supplied with power from the AC power source 1 to operate.

[0139] Each elevator 9A, 9B has a harmonic generation load 91A, 91B that generates harmonics, and a controller 95A, 95B. The harmonic generation load 91A, 91B is a power conversion device of an inverter circuit that can supply power to a motor (not shown) that is a driving source of the elevator 9A, 9B.

[0140] The phase modulator 8 includes a phase modulator 82 capable of absorbing no-load power of 20 kVar, a phase modulator 81 capable of absorbing no-load power of 50 kVar, a phase modulator controller 83, and a power supply measuring device 86. The phase modulator 82 is composed of phase-advancing capacitors Ca, Cb, Cc and phase-advancing reactors La, Lb, Lc. The phase modulator 81 is composed of phase-advancing capacitors Ca, Cb, Cc, phase-advancing reactors La, Lb, Lc, and a switch 811. The switch 811 turns on and off the phase modulator 81 according to the on / off switching signal output by the phase modulator controller 83. The power supply measuring device 86 is composed of current detectors 84a, 84b for detecting power supply currents Irs, Its from the AC power supply 1, and a voltage detector 85 for detecting line voltages Vrs, Vst, Vtr of the power supply voltage. That is, the power supply measurement device 86 detects the power supply currents Irs and Its and the line voltages Vrs, Vst and Vtr as information used for calculating reactive power or power factor.

[0141] The power supply currents Irs, Its and the line voltages Vrs, Vst, Vtr detected by the power supply measuring device 86 are input to the phase modulation device controller 83. The phase modulation device controller 83 uses the input power supply currents Irs, Its and the line voltages Vrs, Vst, Vtr to calculate the active power Pα and the reactive power Pβ using the following equations (1) to (4).

[0142] [Formula 1]

[0143]

[0144] [Formula 2]

[0145]

[0146] [Formula 3]

[0147] Pα=Vα×iα+Vβ×iβ···(3)

[0148] [Formula 4]

[0149] Pβ=Vα×iβ-Vβ×iα···(4)

[0150] Next, the phase modulation device controller 83 calculates the power factor θαβ by substituting the calculated active power Pα and reactive power Pβ into the following equation (5).

[0151] [Formula 5]

[0152]

[0153] The above formula (5) shows that the larger the reactive power Pβ is, the lower the power factor θαβ is. On the contrary, the smaller the reactive power Pβ is, the higher (improved) the power factor θαβ is. Therefore, the phase modulation device controller 83 can also use the reactive power Pβ as the on / off switching signal of the phase modulators 81 and 82. However, the case where the power factor θαβ is used as the on / off switching signal of the phase modulators 81 and 82 is exemplified here.

[0154] Furthermore, the phase adjustment device controller 83 outputs the calculated power factor θαβ to the fault determination unit 41 .

[0155] The fault judgment unit 41 is connected to the phase adjustment device controller 83 of the phase adjustment device 8 and the controllers 95A and 95B of each elevator 9A and 9B. The fault judgment unit 41 judges whether the phase adjustment device 8 has a fault based on the power factor θαβ input from the phase adjustment device controller 83. Specifically, the fault judgment unit 41 compares the power factor θαβ with a preset power factor setting value (equivalent to the first specified value). When the power factor θαβ is lower than the power factor setting value, the fault judgment unit 41 judges that the phase adjustment device 8 has a fault. When the power factor θαβ is not lower than the power factor setting value, the fault judgment unit 41 judges that the phase adjustment device 8 has not failed and is in a normal state.

[0156] It should be noted that the power factor setting value is preferably appropriately set in consideration of the specifications of the power quality management system 100 , power supply conditions, and the like.

[0157] Controllers 95A and 95B of elevators 9A and 9B perform operation restriction control to restrict the operation of elevators 9A and 9B (specifically, harmonic generating loads 91A and 91B included in elevators 9A and 9B) when phase adjustment device 8 fails.

[0158] 〈Regarding Operational Work Restriction Control〉

[0159] Next, the operation restriction control according to the fifth embodiment will be described in detail.

[0160] For example, when the switch 811 fails and cannot perform the switching operation of connecting the phase modulators 81 and 82, the power factor θαβ remains in a decreased state. Therefore, when the power factor θαβ is lower than the power factor setting value, the fault determination unit 41 determines that the phase modulator 8 has failed. The fault / stop signal indicating the judgment result is output from the fault determination unit 41 to the controllers 95A and 95B of the elevators 9A and 9B.

[0161] Each controller 95A, 95B to which the fault / stop signal is input controls the operation of the elevators 9A, 9B so that the power supply current is less than the maximum value of the power supply current when the phase adjustment device 8 is in operation without fault. Alternatively, the controllers 95A, 95B controls the operation of the elevators 9A, 9B so that the power supply power is less than the maximum value of the power supply power when the phase adjustment device 8 is in operation without fault. As an example of these cases, it can be cited that the controllers 95A, 95B stop the operation of either elevator 9A, 9B, or operate the two elevators 9A, 9B alternately when both are operated.

[0162] By such control, it is possible to reduce the occurrence of a phenomenon in which the total value of the input power to each elevator 9A, 9B, that is, the power supply power exceeds the capacity of the AC power supply 1 or the capacity of the wiring 11.

[0163] It should be noted that, when the phase adjustment device 8 is normal, each controller 95A, 95B does not perform the above-mentioned operation restriction control.

[0164] <Effect>

[0165] In the fifth embodiment, the load devices are elevators 9A and 9B, the power quality improvement unit is a phase adjustment device 8, and the same effects as those of the third embodiment are obtained.

[0166] In particular, the fault determination unit 41 of the fifth embodiment determines that the phase adjustment device 8 has a fault based on the power factor θαβ being lower than the power factor setting value. When, for example, the switching operation of connecting the phase adjusters 81 and 82 cannot be performed due to the fault of the phase adjustment device 8, the power factor θαβ decreases. In other words, the fault of the phase adjustment device 8 affects the power factor θαβ. Therefore, it is relatively easy to grasp whether the phase adjustment device 8 has a fault based on the power factor θαβ.

[0167] 《Sixth Implementation Method》

[0168] In the sixth embodiment, an example is given. Figure 1 In the air conditioning device 70 , the signal output from the active filter device 2 is not used to determine whether the active filter device 2 has failed.

[0169] 〈Structure of air conditioning unit〉

[0170] Figure 6 It is a block diagram showing the structure of an air conditioning device 70 according to the sixth embodiment.

[0171] The air conditioning device 70 according to the sixth embodiment includes a failure determination unit 42 instead of Figure 1 The other structures of the air conditioner 70 involved in the sixth embodiment are the same as those of the first embodiment. Figure 6 In the example, the components other than the fault determination unit 42 are marked with Figure 1 Same symbols.

[0172] Next, the failure determination unit 42 will be described.

[0173] - Fault diagnosis department -

[0174] The failure determination unit 42 includes a power supply measurement device 43, a power factor calculation unit 45 formed of a CPU or the like, a storage unit 46 formed of a semiconductor memory or the like, and a comparator 47 formed of a semiconductor chip or the like.

[0175] The power supply measuring device 43 is composed of current detectors 44a and 44b for detecting two-phase power supply currents Is and It from the AC power supply 1, and a voltage detector 44c for detecting line voltages Vrs, Vst and Vtr of the power supply voltage. That is, the power supply measuring device 43 detects the power supply currents Is and It and the line voltages Vrs, Vst and Vtr as information used for calculating reactive power or power factor.

[0176] The power supply current Is, It and the line voltages Vrs, Vst, Vtr detected by the power supply measuring device 43 are input to the power factor calculation unit 45. The power factor calculation unit 45 uses the input power supply current Is, It and the line voltages Vrs, Vst, Vtr to calculate the active power Pα and the reactive power Pβ using the following equations (6) to (9).

[0177] [Formula 6]

[0178]

[0179] [Formula 7]

[0180]

[0181] [Formula 8]

[0182] Pα=Vα×iα+Vβ×iβ···(8)

[0183] [Formula 9]

[0184] Pβ=Vα×iβ-Vβ×iα···(9)

[0185] Next, the power factor calculation unit 45 calculates the power factor θαβ by substituting the calculated active power Pα and reactive power Pβ into the following equation (10).

[0186] [Formula 10]

[0187]

[0188] The power factor calculation unit 45 outputs the calculated power factor θαβ to the comparator 47 .

[0189] A preset power factor setting value (corresponding to a third predetermined value) is stored in the storage unit 46. The power factor setting value is preferably appropriately set in consideration of the specifications of the air conditioner 70, power supply conditions, and the like.

[0190] In addition to the calculated power factor θαβ, the power factor setting value stored in the storage unit 46 is also input to the comparator 47. The comparator 47 compares the power factor θαβ with the power factor setting value. When the power factor θαβ is lower than the power factor setting value, the comparator 47 outputs a fault / stop signal indicating that the active filter device 2 has failed to the controller 37 of the power conversion device 3. When the power factor θαβ is not lower than the power factor setting value, the comparator 47 may output a fault / stop signal indicating that the active filter device 2 is normal, or may not output a fault / stop signal.

[0191] 〈Regarding Operational Work Restriction Control〉

[0192] When a fault / stop signal indicating that a fault has occurred in the active filter device 2 is input, the controller 37 of the power conversion device 3 performs an operation restriction control for restricting the operation of the power conversion device 3 .

[0193] Specifically, the controller 37 controls the operation of the power conversion device 3 so that the power supply current is less than the maximum value of the power supply current when the active filter device 2 is in a working state without failure, thereby limiting the operation of the compressor motor 31. Alternatively, the controller 37 controls the operation of the power conversion device 3 so that the power supply power is less than the maximum value of the power supply power when the active filter device 2 is in a working state without failure, thereby limiting the operation of the compressor motor 31. As an example of the above situation, it can be cited that the controller 37 reduces the rotation speed of the compressor motor 31 by reducing the frequency of the AC power output by the power conversion device 3, or stops the compressor motor 3 from rotating by stopping the output of the AC power from the power conversion device 3.

[0194] By such control, the occurrence of a phenomenon in which the power of the power source exceeds the capacity of the AC power source 1 or the capacity of the wiring 11 is reduced.

[0195] <Effect>

[0196] The sixth embodiment achieves the same effects as those of the first embodiment.

[0197] In particular, the fault determination unit 42 of the sixth embodiment determines that the active filter device 2 has a fault based on the fact that the power factor θαβ is lower than the power factor setting value. When, for example, the switch elements 21a to 21f in the active filter device 2 cannot perform switching operations due to the fault of the active filter device 2, the power factor θαβ decreases. In other words, the fault of the active filter device 2 affects the power factor θαβ. Therefore, even if the fault determination unit 42 is not directly connected to the active filter device 2, it is possible to easily grasp whether the active filter device 2 has a fault based on the power factor θαβ.

[0198] Seventh Implementation Method

[0199] In the seventh embodiment, the same method as that in the sixth embodiment is exemplified. Figure 6 The structure of the fault judgment unit is different.

[0200] 〈Structure of air conditioning unit〉

[0201] Figure 7 It is a block diagram showing the structure of an air conditioning device 70 according to the seventh embodiment.

[0202] The air conditioning device 70 according to the seventh embodiment has the same structure as that of the sixth embodiment except for the failure determination unit 48. Figure 7 In the figure, the components other than the fault determination unit 48 are marked with Figure 6 Same symbols.

[0203] Next, the failure determination unit 48 will be described.

[0204] - Fault diagnosis department -

[0205] The failure determination unit 48 includes a current detector 43 a , a harmonic calculation unit 49 formed of a CPU or the like, a storage unit 46 formed of a semiconductor memory or the like, and a comparator 47 formed of a semiconductor chip or the like.

[0206] The current detector 43 a detects a one-phase power supply current Is from the AC power supply 1 .

[0207] The power supply current Is detected by the current detector 43a is input to the harmonics calculation unit 49. The harmonics calculation unit 49 performs frequency analysis on the input power supply current Is to extract harmonic components. The harmonics calculation unit 49 outputs the extracted harmonic components to the comparator 47.

[0208] A preset harmonic setting value (corresponding to a fourth predetermined value) is stored in the storage unit 46. The harmonic setting value is preferably appropriately set in consideration of the specifications of the air conditioner 70, power supply conditions, and the like.

[0209] In addition to the extracted higher harmonic components, the higher harmonic setting values ​​stored in the storage unit 46 are also input to the comparator 47. The comparator 47 compares the magnitude of the higher harmonic components with the higher harmonic setting values. When the higher harmonic components exceed the higher harmonic setting values, a fault / stop signal indicating that the active filter device 2 is faulty (abnormal) is output from the comparator 47 to the controller 37 of the power conversion device 3. When the higher harmonic components do not exceed the higher harmonic setting values, a fault / stop signal indicating that the active filter device 2 is normal may be output from the comparator 47, or no fault / stop signal may be output.

[0210] 〈Regarding Operational Work Restriction Control〉

[0211] When receiving a fault / stop signal indicating that the active filter device 2 has failed (abnormal), the controller 37 of the power conversion device 3 performs the operation restriction control for restricting the operation of the power conversion device 3 similar to the sixth embodiment.

[0212] That is, the controller 37 limits the operation of the power conversion device 3 so that the power supply current or power supply power does not exceed the respective maximum values ​​when the active filter device 2 fails. In this way, the power supply power can be reduced from exceeding the capacity of the AC power source 1, the capacity of the wiring 11, and the like.

[0213] <Effect>

[0214] The seventh embodiment achieves the same effects as those of the first embodiment.

[0215] In particular, the fault determination unit 48 of the seventh embodiment determines that the active filter device 2 has a fault based on the higher harmonic component of the power supply current Is exceeding the higher harmonic setting value. When the switch elements 21a to 21f in the active filter device 2 cannot perform switching operations due to the fault of the active filter device 2, for example, the higher harmonic component increases. In this way, the fault of the active filter device 2 affects the higher harmonic component. Therefore, even if the fault determination unit 48 is not directly connected to the active filter device 2, it is possible to easily grasp whether the active filter device 2 has a fault based on the higher harmonic component.

[0216] 《Eighth Implementation Mode》

[0217] In the eighth embodiment, the Figure 7 The structure of the fault determination unit 48 in the air conditioning device 70 is different.

[0218] 〈Structure of air conditioning unit〉

[0219] Figure 8 It is a block diagram showing the structure of an air conditioning device 70 according to the eighth embodiment.

[0220] The air conditioning device 70 according to the eighth embodiment has the same structure as that of the sixth and seventh embodiments except for the failure determination unit 48a. Figure 8 In the figure, the components other than the fault determination unit 48a are marked with Figure 6 , Figure 7 Same symbols.

[0221] Next, the failure determination unit 48a will be described.

[0222] - Fault diagnosis department -

[0223] The failure determination unit 48 a includes a current detector 43 a , a storage unit 46 formed of a semiconductor memory or the like, and a comparator 47 formed of a semiconductor chip or the like.

[0224] The current detector 43a detects a one-phase power supply current Is from the AC power supply 1. The detected power supply current Is is input to the comparator 47 in sequence.

[0225] The storage unit 46 stores the waveform of the power supply current Is when the active filter device 2 is in a normal state without any failure. It should be noted that, preferably, the waveform is detected by the current detector 43a and stored in the storage unit 46 when the active filter device 2 is in a normal state.

[0226] In addition to the power supply current Is detected by the current detector 43a, the waveform of the power supply current Is when the active filter device 2 is normal and stored in the storage unit 46 is input to the comparator 47. The comparator 47 compares the waveform of the power supply current Is detected by the current detector 43a with the waveform of the power supply current Is when the active filter device 2 is normal. When the waveform of the power supply current Is detected by the current detector 43a is different from the waveform of the power supply current Is when the active filter device 2 is normal, the comparator 47 outputs a fault / stop signal indicating that a fault (abnormality) has occurred in the active filter device 2 to the controller 37 of the power conversion device 3. When the waveform of the power supply current Is detected by the current detector 43a is consistent with the waveform of the power supply current Is when the active filter device 2 is normal, the comparator 47 may output a fault / stop signal indicating that the active filter device 2 is normal, or may not output a fault / stop signal.

[0227] It should be noted that the fault determination unit 48a may determine whether the waveforms of the power supply current Is detected by the current detector 43a and the waveform of the power supply current Is when the active filter device 2 is normal are consistent based on whether the consistency between these waveforms is less than a predetermined amount.

[0228] 〈Regarding Operational Work Restriction Control〉

[0229] When receiving a fault / stop signal indicating that the active filter device 2 has failed (abnormal), the controller 37 of the power conversion device 3 performs operation restriction control for restricting the operation of the power conversion device 3 similar to the sixth and seventh embodiments.

[0230] That is, the controller 37 limits the operation of the power conversion device 3 so that the power supply current or power supply power does not exceed the respective maximum values ​​when the active filter device 2 fails. In this way, the power supply power can be reduced from exceeding the capacity of the AC power source 1, the capacity of the wiring 11, and the like.

[0231] <Effect>

[0232] The eighth embodiment achieves the same effects as those of the first embodiment.

[0233] In particular, when the active filter device 2 fails, the power factor of the power supply will decrease. The decrease in the power factor of the power supply will cause the waveform of the power supply current Is output from the AC power supply 1 to be distorted. Therefore, the fault determination unit 48a involved in the eighth embodiment determines that the active filter device 2 has failed when the waveform of the power supply current Is is different from the waveform of the power supply current Is when the active filter device 2 is normal. In this way, even if the fault determination unit 48a is not directly connected to the active filter device 2, the fault of the active filter device 2 can be easily determined.

[0234] 《Other Implementation Methods》

[0235] In the third to eighth embodiments described above, the power quality improving unit may also be a PWM conversion device to replace the active filter device 2 and the phase modulation device 8 .

[0236] In the fifth and sixth embodiments described above, the reactive power Pβ and the power factor θαβ are obtained by calculation, but the reactive power Pβ and the power factor θαβ may be directly measured.

[0237] In the fifth embodiment, the case where the power quality improvement unit (specifically, the phase adjustment device 8) is judged to have a fault based on the power factor θαβ is exemplified. However, as a method for judging whether there is a fault, the method shown in the seventh and eighth embodiments may be used, that is, a method of comparing the power harmonics with the harmonic setting value, and a method of comparing the waveform of the power current with the waveform in normal state.

[0238] In the third to fifth embodiments described above, the power quality improving units 2 and 8 may be incorporated into the load devices 70A, 70B, 70 , 7 , 9A, and 9B.

[0239] In the sixth to eighth embodiments described above, the power quality improving unit is not limited to the active filter device 2, but may also be a PWM converter.

[0240] In the first to eighth embodiments described above, other load devices not shown may be connected to the AC power supply 1. In this case, the operation restriction control may be performed on the other load devices.

[0241] In the first to fourth embodiments and the sixth to eighth embodiments described above, the case where the object driven by the power conversion device 3 , 3A, 3B and the inverter device 6 is the compressor motor 31 is exemplified, but the object to be driven is not limited to this.

[0242] The above embodiments and modifications are described, but it is understood that various changes can be made to the scheme and specific circumstances without departing from the spirit and scope of the claims. As long as the functions of the objects of the present disclosure are not affected, the above embodiments and modifications can also be appropriately combined and replaced.

[0243] - Industrial Applicability -

[0244] In summary, the present disclosure is useful as a power quality management system and a power conversion device.

[0245] - Explanation of symbols -

[0246] 1 AC power supply (power supply)

[0247] 2 Active filter device (power quality improvement unit)

[0248] 3, 3A, 3B Power conversion device (higher harmonic generation unit)

[0249] 4 Fault detection unit (fault judgment unit)

[0250] 5 PWM conversion device (power quality improvement unit)

[0251] 6 Inverter (Harmonic Generator)

[0252] 7 Lighting equipment (load device)

[0253] 37, 37A, 37B, 75 Controller (Work limiter)

[0254] 41, 42, 48, 48a Fault diagnosis unit

[0255] 70, 70A, 70B Air conditioning device (load device)

[0256] 100 Power Quality Management System

Claims

1. A power quality management system, characterized in that: The power quality management system comprises: A load device (70A, 70B, 7, 70, 9A, 9B) which is supplied with power from a power source (1) to operate; A power quality improvement unit (2, 8) connected to the power source (1) and improving the quality of the power source (1); a fault judging unit (4, 41) for judging whether the power quality improving unit (2, 8) has a fault; and An operation limiting unit (37A, 37B, 37, 75, 95A, 95B) which, when the fault judgment unit (4, 41) judges that the power quality improvement unit (2, 8) has failed, causes the operation of the load device (70A, 70B, 7, 70, 9A, 9B) to continue in a restricted state compared to when the power quality improvement unit (2, 8) has not failed, so that any one of the power supply power, the power supply current and the power supply harmonics is less than the respective maximum values ​​of the power supply power, the power supply current and the power supply harmonics when the power quality improvement unit (2, 8) has not failed.

2. The power quality management system according to claim 1, characterized in that: The power quality improvement unit (2, 8) is any one of a PWM conversion device, an active filter device (2) and a phase modulation device (8).

3. The power quality management system according to claim 1 or 2, characterized in that: The load device (70A, 70B, 7, 70, 9A, 9B) is any one of an air conditioning device (70A, 70B, 70), an elevator (9A, 9B) and a lighting device (7).

4. The power quality management system according to any one of claims 1 to 3, characterized in that: The fault judgment unit (41) judges that the power quality improvement unit (8) has a fault based on the power factor of the power supply (1) being lower than a first specified value.

5. The power quality management system according to any one of claims 1 to 3, characterized in that: The failure judgment unit (4, 41) judges that a failure has occurred in the power quality improvement unit (2) based on the fact that the power supply harmonic exceeds a second predetermined value.

6. The power quality management system according to any one of claims 1 to 3, characterized in that: The fault judgment unit (4, 41) judges that the power quality improvement unit (2) has a fault when the waveform of the power supply current (Is) from the power supply (1) is different from the waveform of the power supply current (Is) when the power quality improvement unit (2) is not faulty.

7. The power quality management system according to claim 1, characterized in that: The power quality improving unit (2) is incorporated in the load device (70A, 70B, 7, 70, 9A, 9B).

8. An air conditioning device, characterized in that: The air conditioning device comprises: A higher harmonics generating unit (3, 6) connected to the power source (1) and supplied with power from the power source (1), and serving as a source of generating power source higher harmonics; A power quality improvement unit (2, 5) connected in parallel with the higher harmonic generation unit (3, 6) relative to the power supply (1) and improving the quality of the power supply (1); a fault judging unit (4, 42, 48, 48a) for judging whether the power quality improving unit (2, 5) has a fault; and An operation limiting unit (37) which, when the fault judgment unit (4, 42, 48, 48a) judges that the power quality improvement unit (2, 5) has a fault, continues the operation of the harmonic generation unit (3, 6) in a restricted state compared to when the power quality improvement unit (2, 8) has not failed, so that any one of the power supply power, the power supply current and the power supply harmonics is less than the respective maximum values ​​of the power supply power, the power supply current and the power supply harmonics when the power quality improvement unit (2, 5) has not failed.

9. The air conditioning device according to claim 8, characterized in that: The power quality improvement unit (2, 5) is any one of an active filter (2) and a PWM converter (5).

10. The air conditioning device according to claim 8 or 9, characterized in that: The failure judgment unit (42) judges that the power quality improvement unit (2) has failed based on the power factor of the power supply (1) being lower than a third specified value.

11. The air conditioning device according to claim 8 or 9, characterized in that: The failure determination unit (48) determines that a failure has occurred in the power quality improvement unit (2) based on the fact that the power supply harmonics exceed a fourth predetermined value.

12. The air conditioning device according to claim 8 or 9, characterized in that: The fault judgment unit (48a) judges that the power quality improvement unit (2) has a fault when the waveform of the power supply current (Is) from the power supply (1) is different from the waveform of the power supply current (Is) when the power quality improvement unit (2) is not faulty.

Images