JP2011188592A - Higher harmonics countermeasure apparatus, refrigeration cycle device having the higher harmonics countermeasure apparatus, and method for detecting connection state of current detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a higher harmonics countermeasure apparatus capable of correctly determining (preventing an incorrect determination) whether or not the connection state of current detectors for detecting a current flowing from a power supply is normal. <P>SOLUTION: The higher harmonics countermeasure apparatus 3, which is for compensating higher harmonics related to a commercial power supply 1, includes a line-voltage zero-cross detection unit 11 which detects the zero-cross point of a line voltage of the commercial power supply 1 as a reference phase, a current unbalance state detection unit 12 which detects a coefficient related to a current unbalance state based on current detected values related to the detection of current detectors 4R, 4T that detect a current flowing from the power supply, a fundamental wave component calculation unit 17 which calculates a fundamental wave component of a current related to the detection of the current detectors 4R, 4T, and a phase angle determination unit 14 which determines the connection abnormality of the current detectors 4R, 4T based on the reference phase, the current unbalance state, and the fundamental wave component of the current. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a harmonic countermeasure device that compensates (suppresses) a harmonic current generated by driving an inverter device, for example. In particular, the present invention relates to abnormality detection such as a connection state of a current detector used to detect current flowing into an inverter device in a device (refrigeration cycle device) using a refrigeration cycle such as a refrigeration air conditioner.

  For example, in a refrigeration air conditioner that cools a target space and performs air conditioning, an inverter device is provided for variable speed control of an electric motor such as a compressor or a blower. When such an inverter device operates, harmonic current flows through the electric circuit. The influence of power supply voltage distortion caused by harmonic current may adversely affect other electrical equipment such as noise and heat generation. Therefore, a harmonic countermeasure device for compensating for the harmonic current generated by the inverter device is provided.

  The installation (equipment) of harmonic countermeasure devices to a refrigerated air conditioner is often performed locally. Here, at the time of mounting, the mounting position and orientation of the current detector necessary for controlling the harmonic countermeasure device may be wrong due to human error. If the refrigeration air conditioner (inverter device) is operated with the current detector installed incorrectly, the harmonic countermeasure device will not operate effectively, and harmonic current will flow through the power supply system (power system). Could adversely affect the equipment. In some cases, the harmonic countermeasure device itself may be damaged due to overcurrent or heat generation.

  Therefore, in the conventional harmonic countermeasure device, whether the current detector connection state is normal based on the output state of the zero-cross detection signal of the phase voltage in the harmonic countermeasure device and the current detection result of the current flowing into the inverter device. Whether or not is determined (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-91600 (pages 5-7, FIG. 1)

  In the conventional current detector connection state abnormality detection method, when there is an unbalance in the interphase voltage of the three-phase power supply, an unbalance also occurs in the input current, that is, the current flowing into the inverter device. For this reason, there is a problem that an intended current cannot be detected in a predetermined phase section and erroneously determined to be abnormal although the connection state of the current detector is normal.

  The present invention has been made in order to solve the above-described problems, and the connection state of the current detector for detecting the current flowing from the power supply is normal even when the interphase voltage of the power supply is unbalanced. Therefore, it is possible to obtain a harmonic countermeasure device or the like that can accurately determine (prevent erroneous determination). Moreover, the harmonic countermeasure apparatus etc. which can detect abnormality, such as the unbalanced state of the phase current of a three-phase power supply including the connection state of a current detector, are obtained.

  A harmonic countermeasure device according to the present invention is a harmonic countermeasure device for compensating harmonics related to a power source, and a line voltage zero cross detecting means for detecting a zero cross point of an interphase voltage of a power source as a reference phase, and a power source Current unbalanced state detecting means for detecting a coefficient related to the unbalanced state between the phases based on the current detection value related to the detection of the current flowing from the current detector, and the basics of the current related to the detection of the current detector A fundamental wave component calculating means for calculating a wave component, and a phase angle determining means for determining the presence or absence of connection abnormality of the current detector based on the reference phase, the coefficient relating to the unbalanced state, and the fundamental wave component of the current It is.

  In the harmonic countermeasure device according to the present invention, the phase angle determination means determines whether or not there is a connection abnormality in the current detector based on the reference phase, the coefficient relating to the current unbalanced state, and the fundamental wave component of the current. Therefore, it is possible to more accurately determine the connection state of the current detector in consideration of an unbalanced state such as a current of each phase in the power supply.

3 is a configuration diagram of a power supply system including a harmonic countermeasure device 3 according to Embodiment 1. FIG. 3 is a diagram illustrating an internal configuration of harmonic countermeasure device 3 according to Embodiment 1. FIG. It is a figure which shows the electric current, voltage waveform, etc. which are obtained by the process of each means. 4 is a flowchart showing processing of current unbalanced state detecting means 12. It is a figure which shows an example of the current waveform which flows into the inverter apparatus 2, and a definition area. It is a figure for demonstrating the peak value detection of an electric current. It is a figure which shows the waveform etc. which demonstrate the process of the determination phase angle correction | amendment means 13 grade | etc.,. FIG. 6 is a diagram for explaining a setting range of a determination phase angle setting unit 10. 3 is a flowchart showing processing of a phase angle determination unit 14. 6 is a diagram illustrating an internal configuration of harmonic countermeasure device 3 according to Embodiment 2. FIG. 4 is a flowchart showing processing of current detector connection state determination means 15. FIG. 10 is a configuration diagram of a power supply system including a harmonic countermeasure device 3 in a third embodiment. 6 is a diagram illustrating an internal configuration of a harmonic countermeasure device 3 according to Embodiment 3. FIG. 3 is a flowchart showing processing of current imbalance rate determination means 21. 4 is a flowchart showing processing of an abnormality determination unit 16. It is a block diagram of the frozen air conditioning apparatus which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a power supply system including a harmonic countermeasure device 3 according to Embodiment 1 of the present invention. In FIG. 1, an inverter device 2 converts the power of, for example, a three-phase commercial power source 1 that is an AC power source into power of a predetermined voltage and frequency, and supplies the motor to a load for driving. At this time, variable speed control of the electric motor is realized by arbitrarily changing the voltage and frequency to be converted by the control. Control relating to the voltage and frequency of the inverter device 2 is performed, for example, by a control device of a refrigeration air conditioner.

  The harmonic countermeasure device 3 is a device that compensates (suppresses) harmonics generated by the operation of the inverter device 2. The current detector 4R detects a current flowing into the inverter device 2 from the commercial power source 1 via the R phase (hereinafter referred to as R phase current, which is the same for the S phase and T phase). The current detector 4T detects a T-phase current. Here, the R-phase current and the T-phase current are detected, but a combination of detection of the R-phase current and the S-phase current, and the S-phase current and the T-phase current may be used.

  FIG. 2 is an internal configuration diagram of the harmonic countermeasure device 3 according to Embodiment 1 of the present invention. FIG. 2 particularly shows a configuration relating to means for determining the connection state of the current detector and the current unbalanced state. The determination phase angle setting means 10 has a lower limit value and an upper limit value of a reference phase angle (hereinafter referred to as a determination phase angle) for a current phase angle that is referred to when determining the connection state of the current detectors 4R and 4T. Are set (in this embodiment, the unit is degrees). The line voltage zero cross detecting means 11 detects a zero cross point of a reference voltage. The current unbalanced state detecting means 12 calculates an unbalance coefficient representing the degree of unbalanced state for each phase current, based on the current detection values relating to the detection of the current detector 4R and the current detector 4T. decide. Here, in the drawings and the like, the R-phase current is denoted as Ir, the S-phase current as Is, and the T-phase current as It.

  The determination phase angle correction unit 13 corrects the lower limit value and the upper limit value of the determination phase angle set by the determination phase angle setting unit 10 (the determination is performed using the corrected determination phase angle). The phase angle determination means 14 determines whether or not the current detectors 4R and 4T are normally connected by determining whether the phase angle related to the R-phase current and the T-phase current is normal or abnormal. . In this embodiment, the abnormality determination means 16 performs processing such as determination as to whether or not an abnormal state is present based on the determination result of the phase angle determination means 14.

  The fundamental wave component calculation means 17 calculates the fundamental wave component of the current based on the current detection values of the current detectors 4R and 4T. Then, the zero cross phase detection storage unit 18 detects a zero cross point (zero cross phase) from negative to positive in the fundamental wave component, and stores it in the storage unit 22.

  The storage means 22 is a means for temporarily or long-term storing the values and determination results detected and calculated by the respective calculation means, detection means and determination means in the harmonic countermeasure device 3 as data.

  FIG. 3 is a diagram illustrating a current, a voltage waveform, and the like related to processing of each unit of the harmonic countermeasure device 3. FIG. 3 mainly shows current and voltage waveforms related to the R phase. Next, the operation of each means will be described. The line voltage zero cross detection means 11 detects a zero cross point (phase 0 degree) in the voltage between the R phase and the S phase as a reference phase.

  FIG. 4 is a flowchart showing the processing of the current imbalance state detection means 12. For example, an apparatus such as a refrigeration air conditioner has characteristics that load (mainly compressor) fluctuation during operation is small and an input current waveform is stable. Utilizing this feature, the current unbalanced state detecting means 12 captures the current unbalanced state and obtains it as an unbalance coefficient. Here, the description will focus on the processing related to the R-phase current, but the same processing is performed for the T-phase current.

  FIG. 5 is a diagram illustrating an example of a current waveform flowing into the inverter device 2 and a definition section. In step S100, the current unbalanced state detection means 12 obtains the R phase voltage phase from the reference phase related to the detection by the line voltage zero-cross detection means 11. Based on the phase voltage phase, six sections are defined for the R-phase current (waveform) as shown in FIG. Here, the A section is a section in which the phase voltage phase is 0 to 30 degrees, the B section is a section from 60 to 90 degrees, the C section is a section from 120 to 150 degrees, the D section is a section from 180 degrees to 210 degrees, and E The section is a section of 240 to 270 degrees, and the F section is a section of 300 to 330 degrees.

  FIG. 6 is a diagram for explaining current peak value detection in the current imbalance state detection means 12. In step S101, the current peak value in the current detection value is detected for each predetermined section (sections B and C in this case) among the sections defined in step S100, and stored in the storage means 22 as data. Here, since the phase of the T-phase current is different from that of the R-phase current, the section for detecting the peak value is also different.

  In step S102, it is determined whether data for one cycle of current has been stored, and the processing in step S101 is repeated until data for one cycle of current is stored. Here, data for one cycle is stored, but data for a plurality of cycles may be averaged, for example.

  After storing the data of the predetermined section, in step S103, it is determined whether or not the current peak value BP in the B section is zero (0). A predetermined threshold is determined in advance as to whether or not it is zero, and if it is equal to or smaller than the threshold, it is determined to be zero, and if it is larger than the threshold, it is determined not to be zero. Here, as shown in FIG. 5, the peak value of the R-phase current is usually not zero in the B section. If it is determined that it is zero, the process of step S104 is performed, and if it is determined that it is not zero, the process of step S105 is performed.

  In step S104, it is determined whether or not the current peak value (CP) in section C is zero. The determination is performed based on a predetermined threshold as in step S104. As shown in FIG. 5, normally, the peak value of the R-phase current is not zero even in the C section. If it is determined that it is zero, the process proceeds to step S106, and the unbalance coefficient = 0 is determined. If it is determined that it is not zero, the process proceeds to step S107, and the unbalance coefficient = 1 is determined. Also in step S105, it is determined whether or not the current peak value CP in section C is zero. If it is determined that the value is zero, the process proceeds to step S108, and the unbalance coefficient = −1 is determined. If it is determined that it is not zero, the process of step S109 is performed.

In step S108, BP and CP, which are current peak values in the B section and the C section, are compared. If it is determined that BP> CP, the process proceeds to step S110, and the unbalance coefficient K is calculated and determined based on the following equation (1).
K = (CP / BP) −1 (1)

On the other hand, if it is determined that the peak value in the B section is not greater than the peak value in the C section, the process proceeds to step S111, and the unbalance coefficient K is calculated and determined based on the following equation (2).
K = 1- (BP / CP) (2)

  The above processing is performed to determine the unbalance coefficient K related to the R-phase current and the T-phase current, respectively.

FIG. 7 is a diagram showing current, voltage waveforms and the like for explaining the processing of the determination phase angle correction means 13 and the like. FIG. 7 mainly shows current and voltage waveforms in the R phase. Next, processing operations of the determination phase angle setting unit 10 and the determination phase angle correction unit 13 will be described. First, based on the reference phase related to the detection of the line voltage zero-cross detection means 11, the determination phase angle setting means 10 is a fundamental wave of (virtual) current in the R-phase current and T-phase current when there is no current imbalance. For the component, the phase angle at the zero cross point from negative to positive is obtained. Then, the pre-correction determination phase angle upper limit value and the pre-correction determination phase angle lower limit value are calculated from the obtained phase angle and the detection error coefficient in the detection circuit based on the following equations (3) and (4).
Pre-correction judgment phase angle upper limit value = phase angle × maximum detection error coefficient (3)
Pre-correction determination phase angle lower limit value = phase angle × minimum detection error coefficient (4)

  FIG. 8 is a diagram for explaining a setting range of the determination phase angle setting means 10. As shown in FIG. 8, the determination phase angle setting means 10 sets the pre-correction determination phase angle upper limit value and the pre-correction determination phase angle lower limit value so as to be smaller than ± 30 degrees from the obtained phase angle. For example, when the current detector is miswired in another phase (when the R-phase current detector 4R is attached to the S-phase and the T-phase in the opposite direction), at least the zero cross phase of the current is shifted by ± 60 degrees. The reason why the angle is smaller than ± 30 degrees is to be within ± 30 degrees that is an intermediate value in order to distinguish from the phase related to the other two-phase currents.

  Next, the determination phase angle correction unit 13 determines the predetermined value X or Y related to the unbalance coefficient K and the phase angle correction amount determined by the current unbalance state detection unit 12 based on the following equations (5) to (8). To correct the pre-correction determination phase angle lower limit value and the pre-correction determination phase angle upper limit value, and calculate the determination phase angle lower limit value and the determination phase angle upper limit value. Here, the predetermined value X as a reference amount of the phase angle correction amount is a value of the zero cross phase angle when the unbalance coefficient K is -1. The predetermined value Y is the value of the zero cross phase angle when the unbalance coefficient K is 1. Then, a range between the calculated determination phase angle upper limit value and determination phase angle lower limit value is set as a phase determination range. Here, the predetermined value X and the predetermined value Y may be the same. If the unbalance coefficient K is zero, no correction is necessary.

When unbalance coefficient K is negative Judgment phase angle lower limit value = pre-correction judgment phase angle lower limit value + X × K (5)
Determination phase angle upper limit value = pre-correction determination phase angle upper limit value + X × K (6)
When unbalance coefficient K is positive Determination phase angle lower limit value = pre-correction determination phase angle lower limit value + Y × K (7)
Determination phase angle upper limit value = pre-correction determination phase angle upper limit value + Y × K (8)

For example, if the pre-correction determination phase angle lower limit value = 0, the pre-correction determination phase angle upper limit value = 30, the predetermined value X = 25, and the unbalance coefficient K = −0.5, the determination phase angle lower limit value and the determination phase angle upper limit value The values are as follows:
Judgment phase angle lower limit = 0−25 × 0.5 = −12.5
Determination phase angle lower limit = 30−25 × 0.5 = 17.5

  On the other hand, the fundamental wave component calculation means 17 performs Fourier analysis on the current values detected by the current detectors 4R and 4T, and calculates the fundamental wave component of the current. The zero cross phase detection storage means 18 obtains the zero cross phase angle at the zero cross point from negative to positive with respect to the fundamental wave component of the current related to the calculation by the fundamental wave component calculation means 17 and stores it in the storage means 22.

  FIG. 9 is a flowchart showing the processing of the phase angle determination means 14. In step S200, it is determined whether the zero-cross phase angle is within the phase determination range related to the correction by the determination phase angle correction unit 13. In step S201, it is determined that the phase angle is normal by determining that it is within the phase determination range. At this time, it is determined that the connection state of the current detector is normal. In step S202, it is determined that the phase angle is abnormal by determining that the phase is out of the phase determination range. At this time, it is determined that the connection state of the current detector is not normal (abnormal).

  When the phase angle determination unit 14 determines that the phase angle is normal, the abnormality determination unit 16 determines that there is no abnormality and starts the harmonic suppression operation by the harmonic countermeasure device 3. When the phase angle determination means 14 determines that the phase angle is not normal, it is determined that the phase angle is abnormal, the abnormal stop state is set, and the harmonic suppression device 3 stops without starting the harmonic suppression operation.

  As described above, according to the harmonic countermeasure device 3 of the first embodiment, the current unbalanced state detection unit 12 unbalances the current unbalanced state based on the detected current value related to the detection of the current detectors 4R and 4T. The phase angle is determined as a coefficient, and the phase determination range determined by correction by the determination phase angle correction unit 13 based on the coefficient and the zero cross phase of the fundamental wave component calculated from the current detection values of the current detectors 4R and 4T Since the determination means 14 compares and determines whether or not the connection state of the current detector is normal, it is possible to more accurately determine the connection state of the current detectors 4R and 4T even in the unbalanced state. Can do.

Embodiment 2. FIG.
FIG. 10 is an internal configuration diagram of the harmonic countermeasure device 3 according to Embodiment 2 of the present invention. In FIG. 10, the same processing is performed for the means having the same reference numerals as in FIG. 2 and the like. In the present embodiment, the current detector connection state determination means 15 determines whether or not the current detectors 4R and 4T are normally connected based on the current detection values of the current detectors 4R and 4T. It is determined from a point different from 14.

  Next, processing of the current detector connection state determination unit 15 will be described. For example, even if the above-mentioned zero cross phase angle is properly mounted depending on the unbalanced state, the above-described zero cross phase angle cannot be distinguished from the case where the current detector is mistakenly attached to a different phase in the opposite direction. The value may be close. For this reason, as described above, even when the pre-correction determination phase angle upper limit value and the pre-correction determination phase angle lower limit value are determined and correction is performed, erroneous determination may occur. Therefore, the current detector connection state determination means 15 determines the connection state in the current detectors 4R and 4T from the point different from the phase angle.

  FIG. 11 is a flowchart showing the processing of the current detector connection state determination means 15. Here, determination of the connection state in the current detector 4R will be described. If the current detector 4R is normally connected, the current detection value related to the detection of the current detector 4R is zero in the A section and the D section. However, when the current detector 4R is connected to another phase, the current detection value The detected value is not zero. Therefore, in the present embodiment, the determination is made based on the current detection values in the A section and the D section. Also in the connection state determination of the current detector 4T, the procedure is the same except that the section related to the determination is different.

  In step S300, it is determined whether or not the current detection value in section A is zero. If it is determined to be zero, the process proceeds to step S301, and if it is not zero, the process proceeds to step S304. Here, in determining whether or not it is zero, a predetermined threshold value is set, and if it is equal to or smaller than the threshold value, it is determined to be zero, and if it is larger than the threshold value, it is determined to be not zero (the same applies to the following determination). In step S301, it is determined whether or not the current detection value in section D is zero. If it is determined to be zero, the process proceeds to step S303, and if it is not zero, the process proceeds to step S304. In step S303, it is determined that the connection state is normal. On the other hand, in step S304, it is determined that the connection state is abnormal.

  As described above, according to the harmonic countermeasure device 3 of the second embodiment, whether the current detector connection state determination unit 15 determines that the connection state of the current detector is normal based on the peak value of the current in a predetermined section. By determining whether or not, the determination of the connection state of the current detectors 4R and 4T can be performed more accurately by processing from another point.

Embodiment 3 FIG.
FIG. 12 is a configuration diagram of a power supply system including the harmonic countermeasure device 3 according to Embodiment 3 of the present invention. In FIG. 12, the same reference numerals as those in FIG. In the present embodiment, the display unit 5 is a unit that displays, for example, the determination result of the abnormality determination unit 16. The transmission unit 6 is a unit that performs transmission processing (communication processing) of a signal including data such as a determination result of the abnormality determination unit 16 to other devices and apparatuses. In the present embodiment, a signal is transmitted to the inverter device 2 via the communication signal line 7.

  FIG. 13 is an internal configuration diagram of the harmonic countermeasure device 3 according to the third embodiment. In FIG. 13, the same processing is performed for the means and the like having the same reference numerals as in FIGS. 2 and 10. In the present embodiment, the effective current value calculation means 19 calculates an effective current value in each phase. The current imbalance rate calculation unit 20 calculates the current imbalance rate based on the effective current value of each phase calculated by the effective current value calculation unit 19. Based on the current imbalance rate calculated by the current imbalance rate calculating means 20, the current imbalance rate determining means 21 is not balanced in the current flowing in each phase, and is in an abnormal state (current unbalanced state). Determine if it exists.

  The effective current value calculation means 19 calculates an effective current value for three phases based on the following equation (9) with respect to the current detection values related to the detection of the current detectors 4R and 4T. The S phase current can be obtained by calculation from the R phase current and the T phase current.

The current unbalance rate calculating means 20 calculates the current unbalance rate by the following equation (10) based on the maximum current effective value and the minimum current effective value among the effective current values for the three phases.
Current imbalance ratio = maximum current effective value / minimum current effective value (10)

  FIG. 14 is a flowchart showing the processing of the current imbalance rate determination means 21. In step S400, the current unbalance rate calculated by the current unbalance rate calculation means 20 is compared with a predetermined value to determine whether or not the current unbalance rate is greater than the predetermined value. If it is determined that the current imbalance rate is greater than the predetermined value, the process proceeds to step S401. If it is determined that the current imbalance rate is equal to or less than the predetermined value, the process proceeds to step S402. In step S401, it is determined that the current flowing through each phase is in an unbalanced state. On the other hand, in step S402, it is determined that the state is not unbalanced (the state is balanced).

  FIG. 15 is a flowchart showing the processing of the abnormality determination means 16. The abnormality determination unit 16 of the present embodiment includes a determination result related to the phase angle in the phase angle determination unit 14, a determination result related to the current detector connection state in the current detector connection state determination unit 15, and a current imbalance rate determination unit. Based on the current imbalance determination result at 21, the presence / absence of abnormality is generally determined.

  In step S500, it is determined whether or not the phase angle determination unit 14 determines that the phase angle is normal. If it is determined that it is normal, the process proceeds to step S501. If it is determined that it is not normal (abnormal), the process proceeds to step S504.

  In step S501, it is further determined whether or not the current detector connection state determination means 15 determines that the connection state of the current detectors 4R and 4T is normal. If it is determined that it is normal, the process proceeds to step S502. If it is determined that it is not normal (abnormal), the process proceeds to step S504.

  In step S502, it is determined that there is no abnormality in the connection state of the phase angle and the current detectors 4R and 4T. And the operation | movement of the harmonic suppression by the harmonic countermeasure apparatus 3 is started.

  In step S503, the process branches depending on the state determined by the current imbalance rate determination unit 21. If it is determined that the current is in a balanced state, the process ends. If it is determined that the current is in an unbalanced state, the process proceeds to step S506.

  In step S504, it is determined that there is an abnormality in the connection state of the phase angle or the current detectors 4R and 4T. In step S505, an abnormal stop state is set, and the harmonic suppression operation by the harmonic countermeasure device 3 is stopped (not started). Further, in step S506, the display means 5 is displayed as being abnormal. Further, for example, the transmission means 6 is caused to transmit a signal indicating an abnormality to the heat source side unit having the inverter device 2 and the like via the communication signal line 7. At this time, in addition to the abnormal state, for example, data such as an effective current value and a current imbalance rate related to the calculation may be transmitted.

  And in the heat source side unit which has the inverter apparatus 2, based on the signal transmitted from the transmission means 6, for example, information on abnormality of the harmonic countermeasure device 3, current imbalance, etc. The information is displayed on the display means of the controller (operation means). Here, you may make it display on the display means of the centralized management apparatus which manages not only a heat source side unit but a heat source side unit, a load side unit, etc. .

  As described above, according to the harmonic countermeasure device 3 of the third embodiment, the effective current value calculating unit 19 calculates the effective current value of each phase from the detected current value related to the detection of the current detectors 4R and 4T, Also, a transmission means for causing the current unbalance rate calculating means 20 to calculate the current unbalance ratio, causing the current unbalance rate determining means 21 to determine the current unbalanced state, and causing the display means 5 to display the determination result. 6 is notified by performing transmission to the inverter device 2 via the communication signal line 7, for example, not only the harmonic countermeasure device 3 but also the unbalanced state of each phase in the commercial power source 1, for example. It can be determined and further notified. Moreover, the state of the power supply environment by the commercial power supply 1 etc. can be confirmed at the time of trial operation. For this reason, the malfunction resulting from a power supply environment can be prevented in advance. Further, it can be effectively used to determine whether or not a failure has occurred due to the power supply environment even during service such as when the inverter device 2 actually starts operating.

Embodiment 4 FIG.
FIG. 16 is a configuration diagram of a refrigeration air conditioning apparatus according to Embodiment 4 of the present invention. In the present embodiment, a refrigeration air conditioner will be described as an example of a refrigeration cycle apparatus provided with the harmonic countermeasure device 3. The refrigeration air conditioning apparatus of FIG. 16 includes a heat source side unit (outdoor unit) 100 and a load side unit (indoor unit) 200, which are connected by a refrigerant pipe and are referred to as a main refrigerant circuit (hereinafter referred to as a main refrigerant circuit). ) To circulate the refrigerant. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300, and a pipe through which a liquid refrigerant (liquid refrigerant, which may be a gas-liquid two-phase refrigerant) flows is referred to as a liquid pipe 400.

  In the present embodiment, the heat source side unit 100 includes a compressor 101, an oil separator 102, a four-way valve 103, a heat source side heat exchanger 104, a heat source side fan 105, an accumulator (gas-liquid separator) 106, and a heat source side throttle. The apparatus (expansion valve) 107, the inter-refrigerant heat exchanger 108, the bypass expansion device 109, and the heat source side control device 110 are configured (units).

  The compressor 101 compresses and discharges the sucked refrigerant. Here, the compressor 101 includes the inverter device 2 according to the first embodiment, and the capacity of the compressor 101 (the amount of refrigerant sent out per unit time) is finely changed by arbitrarily changing the operation frequency. Shall be able to. Further, the harmonic countermeasure device 3 according to the first embodiment is attached between the commercial power source 1 that supplies power for driving the compressor 101 and the inverter device 2.

  The oil separator 102 separates the lubricating oil discharged from the compressor 101 mixed with the refrigerant. The separated lubricating oil is returned to the compressor 101. The four-way valve 103 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from the heat source side control device 110. The heat source side heat exchanger 104 performs heat exchange between the refrigerant and air (outdoor air). For example, during the heating operation, it functions as an evaporator, performs heat exchange between the low-pressure refrigerant that has flowed in through the heat source side expansion device 107 and air, and evaporates and vaporizes the refrigerant. Further, during the cooling operation, it functions as a condenser and performs heat exchange between the refrigerant compressed in the compressor 101 flowing in from the four-way valve 103 side and air, thereby condensing and liquefying the refrigerant. The heat source side heat exchanger 104 is provided with a heat source side fan 105 in order to efficiently exchange heat between the refrigerant and the air. The heat source side fan 105 may also include the inverter device 2 described in the first embodiment and arbitrarily change the fan motor operating frequency to finely change the rotational speed of the fan.

  The inter-refrigerant heat exchanger 108 exchanges heat between the refrigerant flowing in the main flow path of the refrigerant circuit and the refrigerant branched from the flow path and adjusted in flow rate by the bypass expansion device 109 (expansion valve). . In particular, when it is necessary to supercool the refrigerant during the cooling operation, the refrigerant is supercooled and supplied to the load side unit 200. The liquid flowing through the bypass throttle device 109 is returned to the accumulator 106 via the bypass pipe 107. The accumulator 106 is means for storing, for example, liquid excess refrigerant. The heat source side control device 110 is composed of, for example, a microcomputer. It is possible to perform wired or wireless communication with the load-side control device 204. For example, based on data relating to detection by various detection means (sensors) in the refrigeration air conditioner, operation frequency control of the compressor 101 by inverter circuit control, etc. Then, the respective units related to the refrigeration air conditioner are controlled to control the operation of the entire refrigeration air conditioner.

  On the other hand, the load side unit 200 includes a load side heat exchanger 201, a load side expansion device (expansion valve) 202, a load side fan 203, and a load side control device 204. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the gas pipe 300 and air, condenses and liquefies the refrigerant (or gas-liquid two-phase), and moves to the liquid pipe 400 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 202, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the piping 300 side. In addition, the load side unit 200 is provided with a load side fan 203 for adjusting the flow of air for heat exchange. The operating speed of the load-side fan 203 is determined by, for example, user settings. The load side expansion device 202 is provided to adjust the pressure of the refrigerant in the load side heat exchanger 201 by changing the opening degree.

  Further, the load side control device 204 is also composed of a microcomputer or the like, and can communicate with the heat source side control device 110 by wire or wireless, for example. Based on an instruction from the heat source side control device 110 and an instruction from a resident or the like, for example, each device (means) of the load side unit 200 is controlled such that the room has a predetermined temperature. Further, a signal including data related to detection by the detection means provided in the load side unit 200 is transmitted.

  As described above, in the refrigeration air conditioner of the fourth embodiment, since the harmonic countermeasure device 3 provided in the refrigeration air conditioner is used to determine the unbalanced state particularly in the commercial power source 1, for example, the inverter device 2 By limiting the upper limit capacity (upper limit of the refrigerant discharge amount) in the compressor 101, it is possible to extend the service life while suppressing excessive stress on the electrolytic capacitor, the rectifier diode, etc., and to continue the air conditioning capability. Can be obtained.

  In the above-described embodiment, since the load fluctuation during operation is small, it is easy to grasp the current imbalance state and the determination can be easily performed. Therefore, the case where the harmonic countermeasure device of the present invention is applied to the refrigeration air conditioner has been described. . As described above, the harmonic countermeasure device and the determination method thereof according to the present invention are most suitable for the refrigeration cycle apparatus (refrigerated air conditioner), but the apparatus to be applied is not particularly limited. It can also be used for conveying equipment such as an elevator.

  DESCRIPTION OF SYMBOLS 1 Commercial power supply, 2 Inverter apparatus, 3 Harmonic countermeasure apparatus, 4R, 4T Current detector, 5 Display means, 6 Transmission means, 7 Communication signal line, 10 Judgment phase angle setting means, 11 Line voltage zero cross detection means, 12 Current imbalance state detection means, 13 determination phase angle correction means, 14 phase angle determination means, 15 current detector connection state determination means, 16 abnormality determination means, 17 fundamental wave component calculation means, 18 zero cross phase detection storage means, 19 effective Current value calculation means, 20 Current imbalance rate calculation means, 21 Current imbalance rate determination means, 22 Storage means, 100 Heat source side unit, 101 Compressor, 102 Oil separator, 103 Four way valve, 104 Heat source side heat exchanger, 105 heat source side fan, 106 accumulator, 107 heat source side expansion device, 108 heat exchanger between refrigerants, 10 9 Bypass throttle device, 110 Heat source side control device, 200 Load side unit, 201 Load side heat exchanger, 202 Load side throttle device, 203 Load side fan, 204 Load side control device, 300 Gas piping, 400 Liquid piping

Claims (10)

A harmonic countermeasure device for compensating for harmonics related to a power supply,
A line voltage zero-cross detection means for detecting a zero-cross point of the inter-phase voltage of the power supply as a reference phase;
Current unbalanced state detecting means for detecting a coefficient related to an unbalanced state between the phases based on a current detection value related to detection of a current detector for detecting current flowing from the power source;
Fundamental wave component calculation means for calculating a fundamental wave component of a current related to detection by the current detector;
Harmonic countermeasure device comprising phase angle determination means for determining the presence or absence of connection abnormality of the current detector based on the reference phase, the coefficient related to the unbalanced state, and the fundamental wave component of the current .   The current unbalanced state detecting means detects a coefficient related to the unbalanced state based on a peak value of the detected current value in a predetermined section among currents for one cycle defined based on the reference phase. The harmonic countermeasure apparatus of Claim 1 characterized by the above-mentioned. Zero-cross phase detection means for detecting a zero-cross phase angle from the fundamental wave component of the current calculated by the fundamental wave component calculation means;
Based on the reference phase detected by the line voltage zero-cross detection means, a determination phase angle setting means for setting a range of phase angles that can be taken by the zero-cross phase angle;
A determination phase angle correction unit that corrects the range of the phase angle set by the determination phase angle setting unit based on a coefficient related to the unbalanced state detected by the current unbalanced state detection unit;
The phase angle determination means determines whether the zero cross phase angle detected by the zero cross phase detection means is within a range of the phase angle corrected by the determination phase angle correction means, and connects the current detector The harmonic countermeasure device according to claim 1, wherein presence / absence of abnormality is determined.   A current detector for determining whether or not there is a connection abnormality of the current detector based on the current detection value in a section different from the predetermined section of the current for one cycle defined by the current unbalanced state detecting means The harmonic countermeasure device according to claim 2, further comprising a connection state determination unit. Based on the effective current value of each phase calculated from the detected current value, current unbalance rate calculating means for calculating the degree of unbalance between the phases numerically;
5. The current unbalance rate determining means for determining whether each phase of the power source is unbalanced based on the numerical value calculated by the current imbalance rate calculating means. Harmonic countermeasure device described in any of the above.   The harmonic countermeasure device according to any one of claims 1 to 5, further comprising display means for displaying a determination result.   The harmonic countermeasure device according to any one of claims 1 to 5, further comprising transmission means for transmitting the determination result.   A refrigeration cycle apparatus, wherein the harmonic countermeasure device according to any one of claims 1 to 7 is provided between an inverter device for variable speed control of a compressor that compresses a refrigerant and the power source.   The refrigeration cycle apparatus according to claim 8, wherein when the harmonic countermeasure device determines that the current is unbalanced, the operation of the compressor is limited. A method for detecting a connection state of a current detector for detecting a current flowing between a power source and an inverter device,
Detecting a zero cross point of the interphase voltage of the power source as a reference phase;
Detecting a coefficient relating to an unbalanced state between the phases based on a current detection value relating to detection by the current detector;
Calculating a fundamental component of a current related to detection by the current detector;
Detecting a connection state of the current detector based on the reference phase, a coefficient related to the unbalanced state, and a fundamental wave component of the current, and determining whether or not there is a connection abnormality of the current detector. Method.

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