JP5396034B2 - Control device for compressor and control device for electric motor - Google Patents

Description

  The present invention relates to a control device for a compressor that compresses air or the like using a compression unit that is driven by an electric motor, and a control device for an electric motor. The present invention relates to the control of a compressor that supplies three-phase AC power to rotationally drive the electric motor. The present invention relates to a device and a control device for an electric motor.

  In general, compressors that drive a reciprocating type or scroll type compression unit using an electric motor are known. Here, the electric motor is rotationally driven by, for example, three-phase AC power supplied from an external power source. For this reason, if the wiring between the power source and the electric motor is wrong, the electric motor may rotate (reverse) in the reverse direction, and the compression unit may not operate normally. Specifically, when a reciprocating compression unit is used, the cooling fan reverses together with the electric motor, and the cooling effect decreases. Further, when a scroll-type compression unit is used, there arises a problem that the compression chamber between the two scrolls operates in an expanding direction and the compression operation cannot be performed.

  On the other hand, a configuration is known in which a control device is provided in an electric motor, and using the control device, it is determined whether or not three-phase AC power is reverse connection that reverses the electric motor (for example, see Patent Document 1). At this time, the control device generates a first pulse signal corresponding to the two-phase interphase voltage of the three-phase AC power, and the second pulse according to the other two-phase interphase voltage different from the two phases. A pulse generator for generating a signal is provided, and the two-phase AC power is determined to determine whether or not the three-phase AC power is in reverse-phase connection using two pulse signals from the pulse generator.

JP 2001-236128 A

  By the way, in the configuration in which the negative phase connection determination is performed using the pulse generator, the power supply voltage is unstable, such as when the power is turned on, the power supply voltage is low, or the three-phase voltage is unbalanced. In some cases, an accurate pulse signal cannot be obtained, and an erroneous determination may be made. For this reason, in Patent Document 1, a predetermined time from when the power is turned on until the power is stabilized is determined in advance, and the reverse phase determination is not performed until the predetermined time has elapsed, and the reverse phase determination is performed after the predetermined time has elapsed. A configuration is disclosed.

  However, the time until the power supply voltage is stabilized varies depending on the state of the power supply. For this reason, in the control apparatus of patent document 1, although the power supply is stable, there is a possibility that the reverse phase determination is not performed and the reverse phase determination is delayed. On the other hand, there is a problem in that the reverse phase determination is performed and the erroneous determination is performed even though the power source is unstable.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a compressor control device and an electric motor control device that can reliably detect a reverse-phase connection in accordance with a three-phase AC state. It is to provide.

In order to solve the above-described problems, the invention of claim 1 includes a compression unit that compresses a fluid, an electric motor that drives the compression unit, and a power supply circuit unit that supplies power to the electric motor from a three-phase AC power source. And a pulse generator for generating a pulse signal in accordance with a two-phase interphase voltage of the three-phase AC power supplied to the power supply circuit unit and another two-phase interphase voltage different from the two phases, A compressor comprising: a connection state determining means for determining whether or not the three-phase AC power is a reverse-phase connection that reverses the electric motor by using two pulse signals from the pulse generator; In the control device, the pulse generator is configured to change a duty ratio of each pulse signal in accordance with an amplitude of the three-phase AC power, and the connection state determining means is configured to change the duty ratio of each pulse signal by the pulse generator. There communicating Performing reverse phase connection determination if within a predetermined range over a plurality of cycles by reverse phase connected determine without, continuous duty ratio of each pulse signal when not within the predetermined range over a plurality of cycles by It is characterized by having a configuration including a determination permission unit.

  According to a second aspect of the present invention, the pulse generator includes a primary current supply unit that supplies a primary current corresponding to an interphase voltage, and whether or not the primary current from the primary current supply unit exceeds a threshold value. A photocoupler that determines a low level or a high level of the pulse signal according to the output and outputs the pulse signal, and a current limiting resistor that limits the primary current by the primary current supply unit and determines the threshold value It is composed by.

  According to a third aspect of the present invention, the determination permitting means reverses when the time measuring means for measuring the time of the low level section or the high level section of the pulse signal and when the time measured by the time measuring means is outside a predetermined range. It is constituted by time determination means for performing reverse phase connection determination when the phase connection determination is not performed and the measurement time is within a predetermined range.

  According to a fourth aspect of the present invention, the connection state determination means compares the times of the low level sections or the times of the high level sections of the two pulse signals, and does not perform the reverse phase connection determination when the comparison results are different. In addition, signal comparison means for performing a reverse phase connection determination when the comparison results are the same is provided.

  According to a fifth aspect of the present invention, the connection state determination unit is connected to an abnormality notification unit that notifies that the two phase voltages are different from each other when the comparison result is determined to be different by the signal comparison unit. It is configured to do.

Further, the invention of claim 6 is directed to an electric motor, a power supply circuit unit for supplying power to the electric motor from a three-phase AC power source, and a two-phase interphase voltage among the three-phase AC power supplied to the power supply circuit unit. The three-phase AC power is converted into an electric motor by using a pulse generator that generates a pulse signal in accordance with a voltage between the two phases different from the two phases and a pulse signal generated by the pulse generator. In the control apparatus for an electric motor configured by connection state determination means for performing reverse-phase connection determination as to whether or not the reverse-phase connection is reversed, the pulse generator is configured to change each of the three-phase AC power according to the amplitude of the three-phase AC power. The connection state determination means performs a reverse phase connection determination when the duty ratio of each pulse signal by the pulse generator is not continuously within a predetermined range over a plurality of cycles. Done It is characterized in that the arrangement comprises a determination permission means for performing reverse phase connection determination if within a predetermined range over a plurality of cycles duty ratio is continuously of each pulse signal.

  According to the first and sixth aspects of the invention, the pulse generator changes the duty ratio of each pulse signal according to the amplitude of the three-phase AC power. Thus, for example, when the amplitude of the three-phase AC power is large, the duty ratio of each pulse signal can be increased, and when the amplitude is small, the duty ratio of each pulse signal can be decreased.

Further, since the connection state determination means includes a determination permission means, the determination permission means determines whether the duty ratio of each pulse signal by the pulse generator is continuously within a predetermined range over a plurality of cycles . Decide whether or not to allow reverse-phase connection determination. As a result, the connection state determining means is configured such that when the duty ratio of at least one of the two pulse signals is not continuously within a predetermined range over a plurality of cycles , the three-phase AC power (voltage) is The reverse phase connection determination is not performed because it is unstable or unbalanced. On the other hand, the connection state determination means determines that the three-phase AC power is stable when both of the duty ratios of the two pulse signals are continuously within a predetermined range over a plurality of periods, and determines the reverse phase connection determination. Do. As a result, it is possible to grasp whether or not the three-phase alternating current is stable by using the determination permitting means, and it is possible to reliably detect the reverse phase connection according to the state of the three-phase alternating current.

  The predetermined range of the duty ratio is set, for example, to a range of fluctuation that is allowable in a state where the amplitude of the three-phase AC power is stable. Specifically, with respect to the amplitude of the stable three-phase AC power, for example, a range that is wider than ± 5% and narrower than ± 30%, preferably a range of ± 10% that is allowed by rating as a fluctuation of the power supply Is set to

  According to the invention of claim 2, since the pulse generator includes the primary current supply unit and the photocoupler, the primary current supply unit supplies a primary current corresponding to the interphase voltage, and the photocoupler A low level or a high level of the pulse signal is determined depending on whether or not the current exceeds a threshold value. Since the pulse generator has a current limiting resistor that limits the primary current supplied by the primary current supply unit, the current limiting resistor is used to set the amplitude of the sinusoidal primary current with respect to a certain threshold value. can do.

  At this time, when the three-phase alternating current is in a stable state, the current limiting resistor is set so that the threshold of the photocoupler is, for example, 1/3 or more with respect to the maximum amplitude value of the primary current corresponding to the interphase voltage. Limit the primary current. Thereby, depending on whether or not the three-phase alternating current is in a stable state, the time during which the primary current exceeds the threshold value changes greatly, and the time ratio between the low level and the high level of the pulse signal changes greatly. As a result, since the duty ratio of the pulse signal can be changed greatly depending on whether the three-phase alternating current is in a stable state, the determination permitting means determines whether the duty ratio of the pulse signal is within a predetermined range. The state of three-phase alternating current can be easily determined.

  Although the duty ratio of the pulse signal varies up to 50%, the resistance value of the current limiting resistor is such that the duty ratio of the pulse signal varies by, for example, 5% or more between the upper limit value and the lower limit value of the predetermined range. It is preferable to set to.

  According to the invention of claim 3, since the determination permitting means is constituted by the time measuring means and the time determining means, the time measuring means measures the time of the low level section or the high level section of the pulse signal, and the time determining means Can determine whether or not to perform reverse phase connection determination according to whether or not the time measured by the time measuring means is within a predetermined range.

  According to the invention of claim 4, since the connection state determination means includes the signal comparison means for comparing the times of the low level sections or the times of the high level sections of the two pulse signals, the signal comparison means has a comparison result. It can be determined whether or not to perform the reverse phase connection determination according to whether or not they are the same. Here, when the times of the low level sections or the times of the high level sections of the two pulse signals are the same, the three-phase alternating current corresponds to an equilibrium state. On the other hand, when the times of the low level sections or the times of the high level sections of the two pulse signals are the same, the three-phase alternating current corresponds to an unbalanced state. For this reason, by using the signal comparison means, it is possible to detect whether or not the three-phase alternating current is in an equilibrium state, and erroneous reverse phase connection determination is not performed based on the unbalanced state.

  According to the invention of claim 5, the abnormality notifying means can notify that the two interphase voltages are different from each other when the comparison result is different by the signal comparing means. Thereby, it can be easily grasped that the three-phase alternating current is in an unbalanced state.

  Hereinafter, as a compressor control apparatus according to an embodiment of the present invention, a case where the present invention is applied to a scroll type air compressor will be described as an example and described in detail with reference to the accompanying drawings.

  First, FIG. 1 to FIG. 11 show a first embodiment. 1 and 2, reference numeral 1 denotes a compression unit that compresses air. The compression unit 1 includes a substantially cylindrical casing 2 that is open on one side in the axial direction, a fixed scroll 3, a turning scroll 9, and a drive shaft 19 described later. It is roughly composed of And the compression part 1 compresses external air, and discharges compressed air, when the turning scroll 9 rotationally moves to the fixed scroll 3 in the forward direction.

  Reference numeral 3 denotes a fixed scroll provided on the opening side of the casing 2, and the fixed scroll 3 includes an end plate 4 formed in a substantially disc shape with an axis OO as the center, and the end plate 4 as shown in FIG. A spiral wrap portion 5 erected in the axial direction on the tooth bottom surface, a cylindrical portion 6 that surrounds the wrap portion 5 and is provided on the outer diameter side of the end plate 4, and a rear surface of the end plate 4 The plurality of cooling fins 7 project from each other.

  Here, the wrap portion 5 has a spiral shape, for example, three turns before and after the outer diameter side from the inner diameter side to the outer diameter side when the outermost diameter end is the winding start end and the outermost diameter end is the winding end end, for example. It is wound. The tooth tip surface of the wrap portion 5 is separated from the tooth bottom surface of the end plate 10 of the orbiting scroll 9 as a counterpart by a certain axial dimension, and a tip seal 8 is provided on the tooth tip surface side.

  9 is a turning scroll provided in the casing 2 so as to be able to turn. The turning scroll 9 includes a substantially disc-shaped end plate 10 disposed opposite to the end plate 4 of the fixed scroll 3, and a surface of the end plate 10. A spiral wrap portion 11 erected on the bottom surface of the tooth, a plurality of cooling fins 12 projecting from the back surface of the end plate 10, and a back plate 13 positioned and fixed on the front end side of the cooling fins 12. It is roughly constituted by.

  Here, the wrap portion 11 has, for example, a spiral shape before and after the third winding, substantially the same as the wrap portion 5 of the fixed scroll 3. The tooth tip surface of the wrap portion 11 is separated from the tooth bottom surface of the end plate 4 of the fixed scroll 3 as a counterpart by a certain axial dimension, and a tip seal 14 is provided on the tooth tip surface side.

  A cylindrical boss portion 13A that is rotatably connected to a crank portion 19A of a drive shaft 19 to be described later is integrally formed on the center side of the back plate 13. Further, between the outer diameter side of the back plate 13 and the casing 2, for example, three auxiliary cranks 15 (only one is shown) that prevent the orbiting scroll 9 from rotating are provided.

  Reference numeral 16 denotes, for example, two suction ports provided on the outer diameter side of the fixed scroll 3. Each of the suction ports 16 opens from the outer diameter side of the end plate 4 to the cylindrical portion 6, and is an outer diameter side compression chamber described later. 18 communicates. The suction port 16 sucks fluid such as air into the outer compression chamber 18 through the suction filter 16A.

  Reference numeral 17 denotes a discharge port provided on the inner diameter side (center side) of the end plate 4 of the fixed scroll 3. The discharge port 17 communicates with the compression chamber 18 on the innermost diameter side, and the compressed air in the compression chamber 18 is transferred to the outside. Are discharged.

  Reference numeral 18 denotes a plurality of compression chambers provided between the fixed scroll 3 and the orbiting scroll 9, and these compression chambers 18 are located between the wrap portions 5 and 11 and are sequentially formed from the outer diameter side to the inner diameter side. These are kept airtight by the tip seals 8 and 14. Each compression chamber 18 is continuously reduced between the wrap portions 5 and 11 while moving from the outer diameter side toward the inner diameter side when the orbiting scroll 9 performs the orbiting motion in the forward direction. .

  As a result, of the compression chambers 18, outside air is sucked into the compression chamber 18 on the outermost diameter side from the suction port 16, and the compressed air is compressed until the air reaches the compression chamber 18 on the innermost diameter side. It becomes. The compressed air is discharged to the outside from the discharge port 17 and stored in a storage tank (not shown).

  Reference numeral 19 denotes a drive shaft that is rotatably provided on the casing 2 via a bearing or the like. The drive shaft 19 is driven by an electric motor 22 to be described later, thereby causing the orbiting scroll 9 to perform an orbiting motion.

  Here, on one end side of the drive shaft 19, a crank portion 19 </ b> A that is eccentric in the radial direction by a certain dimension with respect to the axis OO is provided. The back plate 13 of the back plate 13 is rotatably connected to the boss portion 13A. Further, a pulley 19B is provided outside the casing 2 on the other end side of the drive shaft 19, and this pulley 19B is connected to the output side of the electric motor 22 via a belt (not shown) or the like. ing.

  A cooling fan 20 is attached to the pulley 19 </ b> B using bolts or the like, and the cooling fan 20 generates cooling air in the fan casing 21. Thereby, the cooling fan 20 blows the cooling air along the duct in the fan casing 21 to the inside of the casing 2 and the back side of the scrolls 3, 9, and the casing 2, the fixed scroll 3, the orbiting scroll 9, etc. Cooling.

  Reference numeral 22 denotes an electric motor as a drive source, and the electric motor 22 is constituted by, for example, a three-phase induction motor. The electric motor 22 is connected to a three-phase AC power supply 24 via a power supply circuit unit 23 having an electromagnetic contactor 23A. The electric motor 22 is supplied with the three-phase AC power from the three-phase AC power source 24 by switching the electromagnetic contactor 23A from the OFF state to the ON state. Thereby, the electric motor 22 rotationally drives the drive shaft 19 and causes the orbiting scroll 9 to orbit.

  Reference numeral 25 denotes a power supply monitoring device (power supply monitoring means) connected to the power supply circuit unit 23. The power supply monitoring device 25 includes a power supply unit 26, a pulse generator 27, a control unit, which will be described later, as shown in FIGS. 32 or the like. Then, the power supply monitoring device 25 determines whether or not the R phase, S phase, and T phase of the three-phase AC power supply 24 are properly connected so that the electric motor 22 rotates forward, and whether or not the three-phase AC is in an equilibrium state. To monitor.

  A power supply unit 26 is connected to any two phases (for example, R phase and S phase) of the three-phase AC. The power supply unit 26 generates a DC voltage Vcc of, for example, +5 V from the AC voltage, and this DC voltage Vcc. Is supplied as a drive voltage for the pulse generator 27, the control unit 32, and the like.

  Reference numeral 27 denotes a pulse generator connected to the power supply circuit unit 23. The pulse generator 27 is a first generator corresponding to an interphase voltage Vrs of any two phases (for example, R phase and S phase) of the three-phase AC power. A first pulse generation circuit 28 for generating a pulse signal S1 and a second pulse generation circuit 29 for generating a second pulse signal S2 in accordance with the voltage Vst between the other two phases (for example, S phase and T phase). And is composed of.

  Here, the first pulse generation circuit 28 includes a primary current supply unit 28A that supplies a primary current I1 corresponding to the interphase voltage Vrs, and a primary current I1 generated by the primary current supply unit 28A is a threshold value It. And a photocoupler 28B that determines a low level (Low level) or a high level (High level) of the first pulse signal S1 in accordance with whether or not the signal exceeds the value and outputs the pulse signal S1.

  Further, a reverse voltage diode 28C is connected in parallel to the primary side input of the photocoupler 28B. Further, a DC voltage Vcc is applied to the output side of the photocoupler 28B via a pull-up resistor 28D. The output of the photocoupler 28B is connected to the interrupt terminal of the control unit 32. As a result, the photocoupler 28B becomes low level (0V) when the primary current I1 due to the interphase voltage Vrs increases above the threshold value It, and becomes high level (5V) when it decreases below the threshold value It. The first pulse signal S1 is output.

  On the other hand, the second pulse generation circuit 29 also includes a primary current supply unit 29A, a photocoupler 29B, a diode 29C, and a pull-up resistor 29D, almost the same as the first pulse generation circuit 28. The photocoupler 29B becomes low level (0V) when the primary current I2 due to the interphase voltage Vst increases above the threshold value It, and becomes high level (5V) when it decreases below the threshold value It. The second pulse signal S2 is output.

  Reference numerals 30 and 31 denote first and second current limiting resistors. The first and second current limiting resistors 30 and 31 together with the primary current supply units 28A and 29A, the photocouplers 28B and 29B, etc. Two pulse generation circuits 28 and 29 are configured. Here, the first current limiting resistor 30 is provided in the primary current supply unit 28 </ b> A of the first pulse generation circuit 28. The first current limiting resistor 30 limits the amplitude of the sinusoidal primary current I1 by the primary current supply unit 28A, and determines the magnitude of the threshold It with respect to the amplitude of the primary current I1. .

  The second current limiting resistor 30 is provided in the primary current supply unit 29A of the second pulse generating circuit 29, and limits the amplitude of the sinusoidal primary current I2 to reduce the amplitude of the primary current I2. The magnitude of the threshold value It is determined.

  At this time, the resistance values of the current limiting resistors 30 and 31 are, for example, the photocoupler 28B with respect to the maximum amplitude value of the primary currents I1 and I2 corresponding to the interphase voltage (200V) when the three-phase alternating current is in a stable state. 29B is set to such a value that the threshold value It becomes, for example, 1/3 or more. The resistance values of the current limiting resistors 30, 31 are such that the duty ratios of the first and second pulse signals S1, S2 change by 5% or more when the three-phase AC voltage fluctuates within a range of ± 10%. Is set to

  Reference numeral 32 denotes a control unit comprising a microcomputer or the like as a connection state determination means. A power supply unit 26 and a pulse generator 27 are connected to the input side of the control unit 32, and an alarm output unit 34 to be described later is connected to the output side. Has been. Further, a storage device 33 is connected to the control unit 32. The storage device 33 includes a connection state determination program for determining the connection state of the three-phase alternating current, and times Ta and Tb of the low level sections of the pulse signals S1 and S2. Are stored in advance.

  At this time, the lower limit value X and the upper limit value Y of the times Ta and Tb are determined by a predetermined range (allowable range) of the duty ratio when performing reverse phase connection determination. Here, the predetermined range of the duty ratio is set to, for example, a range of fluctuation width that is allowable in a state where the amplitude of the three-phase AC power is stable. Specifically, with respect to the amplitude of the stable three-phase AC power, for example, a range that is wider than ± 5% and narrower than ± 30%, preferably a range of ± 10% that is allowed by rating as a fluctuation of the power supply Set to. For this reason, the lower limit value X is set to a value corresponding to the duty ratio when the amplitude of the three-phase AC voltage is reduced by, for example, 10%. On the other hand, the upper limit value Y is set to a value corresponding to the duty ratio when the amplitude of the three-phase AC voltage rises by 10%, for example.

  Specifically, as shown in FIG. 11, the duty ratios of the pulse signals S1 and S2 change in accordance with the amplitude values of the interphase voltages Vrs and Vst. The magnitude of the change in the duty ratio changes according to the resistance values of the current limiting resistors 30 and 31. Therefore, in the present embodiment, the resistance values (for example, 250 kΩ) of the current limiting resistors 30 and 31 are set so that the change of the duty ratio becomes large in the vicinity of the three-phase AC voltage becoming stable.

  At this time, for example, if the allowable fluctuation range of the interphase voltages Vrs and Vst is ± 10% (for example, 254 to 310 V in peak value) with respect to a stable state (for example, 282 V in peak value), the characteristic line in FIG. Based on this, the lower limit duty ratio D1 (for example, D1 = 6%) and the upper limit duty ratio D2 (for example, D2 = 21%) can be determined. Thus, in the present embodiment, the lower limit value X and the upper limit value Y of the times Ta and Tb are set in correspondence with the lower and upper duty ratios D1 and D2. For example, in the case of 200 V three-phase AC at 50 Hz, the lower limit value X is about 1.2 ms, and the upper limit value Y is about 4.2 ms.

  Note that the duty ratio in FIG. 11 indicates the ratio between the time and period of the low level section of each pulse signal S1, S2.

  Then, the control unit 32 uses the two pulse signals S 1 and S 2 from the pulse generator 27 to make a reverse-phase connection determination as to whether or not the three-phase AC power is a reverse-phase connection that reverses the electric motor 22.

  Further, the control unit 32 determines whether or not to perform the reverse phase connection determination according to whether or not the duty ratio of the pulse signals S1 and S2 is within a predetermined range. In the present embodiment, the control unit 32 determines whether or not to perform the reverse phase connection determination using the times Ta and Tb of the low level sections of the pulse signals S1 and S2 instead of the duty ratio of the pulse signals S1 and S2. decide. Specifically, when the times Ta and Tb of the low level sections of the pulse signals S1 and S2 are outside a predetermined range (Ta, Tb ≦ X or Ta, Tb ≧ Y), the reverse phase connection determination is not performed and the time Ta , Tb is in the predetermined range (X <Ta <Y, X <Tb <Y), the reverse phase connection determination is performed.

  34 is an alarm output unit for notifying that an abnormality has occurred in the three-phase AC power supply 24 or the like. For example, when the alarm output unit 34 is in a reverse phase connection state, an abnormality has occurred in the interphase voltages Vrs and Vst. When the times Ta and Tb in the low level section of the pulse signals S1 and S2 cannot be measured, notification is made by displaying these abnormalities.

  Next, a connection state determination program by the control unit 32 will be described with reference to FIGS.

  First, FIG. 4 shows RS edge detection interrupt processing for detecting an edge portion (rising or falling) of the first pulse signal S1 and performing interrupt processing. This RS edge detection interrupt process measures the time Ta of the low level section of the pulse signal S1, and determines whether or not the interphase voltage Vrs is in a stable state, that is, whether or not a reverse phase connection determination is possible. .

  In the RS edge detection interrupt process, first, in step 1, it is determined whether or not the edge detected by the control unit 32 is the falling edge of the pulse signal S1. When it is determined as “YES” in Step 1, the control unit 32 detects the falling edge of the pulse signal S1. For this reason, the timer A for measuring the time Ta of the low level section of the pulse signal S1 is started in step 2, and the time difference between the falling edge of the pulse signal S1 and the falling edge of the pulse signal S2 is started in step 3. The timer C for measuring Tc is started.

  At this time, the time difference Tc becomes a value corresponding to the phase difference between the pulse signals S1 and S2. Timer A and timer C measure time in units of 100 μs, for example.

  Next, in step 4, in order to start the next RS edge detection interrupt process by detecting the rising edge of the pulse signal S1, the start condition of the RS edge detection interrupt process is changed to detection of the rising edge of the pulse signal S1. Then, after step 4 ends, the process proceeds to step 5 and returns.

  On the other hand, when it is determined as “NO” in Step 1, the control unit 32 detects the rising edge of the pulse signal S1. For this reason, in step 6, the current value of the timer A is taken into the time Ta (measurement time) of the low level section of the pulse signal S1, and the time Ta is measured. Thereafter, in step 7, the timer A is reset and stopped. In step 8, in order to start the next RS edge detection interrupt process by detecting the falling edge of the pulse signal S1, the start condition of the RS edge detection interrupt process is changed to detection of the falling edge of the pulse signal S1. .

  Next, in step 9, it is determined whether or not the time Ta is within a predetermined range (X <Ta <Y), that is, a value between the lower limit value X and the upper limit value Y. When it is determined as “YES” in step 9, it is considered that the time Ta is within a predetermined range and the interphase voltage Vrs is in a stable state (a state in which reverse phase connection determination is possible). For this reason, the process proceeds to step 10 where the value of the buffer Trs [n] for determining the state of the interphase voltage Vrs is set to 1.

  On the other hand, when “NO” is determined in Step 9, the time Ta is out of the predetermined range, and the interphase voltage Vrs is considered to be in an unstable state (a state in which the reverse phase connection determination is impossible). For this reason, the process proceeds to step 11 where the value of the buffer Trs [n] for determining the state of the interphase voltage Vrs is set to zero.

  The buffer Trs [n] is used for accurately grasping the state of the interphase voltage Vrs (pulse signal S1). That is, when the state of the interphase voltage Vrs is determined only by the time Ta for one cycle, it is easily affected by an error or the like. Therefore, in the present embodiment, the state of the interphase voltage Vrs is determined using, for example, a time Ta for five cycles. Accordingly, there are five buffers (Trs [0] to Trs [4]) in total.

  When Steps 10 and 11 are completed, the process goes to Step 12 to determine whether or not all of the five buffers Trs [0] to Trs [4] are 1. When it is determined as “YES” in step 12, the pulse signal S1 is within a predetermined range for five cycles, and the interphase voltage Vrs is in a stable state. For this reason, it moves to step 13 and sets permission flag A for permitting reverse phase connection judgment, and moves to step 17 and returns.

  On the other hand, when it is determined as “NO” in Step 12, the interphase voltage Vrs cannot be said to be sufficiently stable, and is considered to be in an unstable state. For this reason, in order to continue the determination with respect to the time Ta, the process proceeds to step 14 to determine whether or not the determination count n is less than 4 (n <4).

  If “YES” is determined in step 14, the process proceeds to step 15, the determination number n is increased by 1, and the process proceeds to step 17 and returns. On the other hand, if “NO” is determined in step 14, the process proceeds to step 16 to initialize the determination count n (n = 0), and then proceeds to step 17 and returns.

  Next, FIGS. 5 and 6 show ST edge detection interrupt processing for detecting and interrupting the edge portion (rising or falling) of the second pulse signal S2. This ST edge detection interrupt process measures the time Tb of the low level section of the pulse signal S2, and determines whether or not the interphase voltage Vst is in a stable state, that is, whether or not a reverse phase connection determination is possible. .

  In the ST edge detection interrupt process, first, in step 21, it is determined whether or not the edge detected by the control unit 32 is the falling edge of the pulse signal S2. When it is determined “YES” in step 21, the control unit 32 detects the falling edge of the pulse signal S2. For this reason, in step 22, the timer B starts to measure the time Tb of the low level section of the pulse signal S2. In step 23, the current timer C value is taken into the time difference Tc (measurement time difference) between the falling edges of the pulse signals S1 and S2, and the time difference Tc is measured. Thereafter, in step 24, the timer C is reset and stopped.

  Note that the timer B measures time in units of, for example, 100 μs, similarly to the timer A and the timer C.

  Next, in step 25, it is determined whether or not the time difference Tc is less than the determination value T0 (Tc <T0) in order to determine whether or not the reverse phase connection state is established using the time difference Tc. At this time, the determination value T0 is set to an intermediate value (Tc1 <T0 <Tc2) between the time difference Tc1 in the normal phase connection state and the time difference Tc2 in the reverse phase connection state. For example, in the case of 50 Hz three-phase alternating current, the time difference Tc1 (phase difference 120 °) in the normal phase connection state is about 6.7 ms, and the time difference Tc2 (phase difference 60 °) in the reverse phase connection state is about 13.3 ms. is there. Therefore, the determination value T0 is set to, for example, 10 ms as an intermediate value between the two time differences Tc1 and Tc2.

  And when it determines with "YES" at step 25, it is thought that the time difference Tc is less than the determination value T0, and it is a normal phase connection state. Therefore, the process proceeds to step 26, and the value of the buffer Trev [m] for performing the reverse phase connection determination is set to 1.

  On the other hand, when it is determined as “NO” in step 25, it is considered that the time difference Tc is equal to or larger than the determination value T0 and the reverse phase connection state is established. Therefore, the process proceeds to step 27, and the value of the buffer Trev [m] for performing the reverse phase connection determination is set to zero.

  Note that the buffer Trev [m] is used to accurately perform the reverse phase connection determination. For this reason, in this Embodiment, a negative phase connection determination is performed using the time difference Tc for 5 cycles, for example. Accordingly, there are a total of five buffers Trev [m] (Trev [0] to Trev [4]).

  When Steps 26 and 27 are completed, the process proceeds to Step 28 to determine whether or not the determination number m is less than 4 (m <4). If “YES” is determined in the step 28, the process shifts to a step 29 to increase the determination count m by 1. On the other hand, if “NO” is determined in the step 28, the process proceeds to a step 30 to initialize the determination count m (m = 0).

  When Steps 29 and 30 are completed, the process proceeds to Step 31 to start the next ST edge detection interrupt process by detecting the rising edge of the pulse signal S2, and set the start condition of the ST edge detection interrupt process to the pulse signal S2. Change to detection of rising edge. Thereafter, the process proceeds to step 32 and returns.

  On the other hand, when it is determined as “NO” in Step 21, the control unit 32 detects the rising edge of the pulse signal S2. For this reason, in step 33, the current value of the timer B is taken into the time Tb (measurement time) of the low level section of the pulse signal S2, and the time Tb is measured. Thereafter, in step 34, the timer B is reset and stopped. In step 35, in order to start the next ST edge detection interrupt processing by detecting the falling edge of the pulse signal S2, the start condition of the ST edge detection interrupt processing is changed to detection of the falling edge of the pulse signal S2. .

  Next, in step 36, it is determined whether or not the time Tb is within a predetermined range (X <Tb <Y), that is, a value between the lower limit value X and the upper limit value Y. When it is determined as “YES” in step 36, it is considered that the time Tb is within the predetermined range and the interphase voltage Vst is in a stable state (a state in which a reverse phase connection determination is possible). Therefore, the process proceeds to step 37, and the value of the buffer Tst [n] for determining the state of the interphase voltage Vst is set to 1.

  On the other hand, when it is determined “NO” in step 36, the time Tb is out of the predetermined range, and the interphase voltage Vst is considered to be unstable (a state in which the reverse phase connection determination is impossible). Therefore, the process proceeds to step 38, and the value of the buffer Tst [n] for determining the state of the interphase voltage Vst is set to zero.

  The buffer Tst [n] is used for accurately grasping the state of the interphase voltage Vst (pulse signal S2). For this reason, in this embodiment, for example, the state of the interphase voltage Vst is determined using a time Tb for five cycles. Therefore, there are five buffers Tst [n] (Tst [0] to Tst [4]) in total.

  When Steps 37 and 38 are completed, the process goes to Step 39 to determine whether or not all of the five buffers Tst [0] to Tst [4] are 1. When it is determined as “YES” in step 39, the pulse signal S2 is within a predetermined range for five cycles, and the interphase voltage Vst is in a stable state. For this reason, it moves to step 40, sets permission flag B for permitting reverse phase connection determination, moves to step 44, and returns.

  On the other hand, if “NO” is determined in step 39, it cannot be said that the interphase voltage Vst is sufficiently stable, and is considered to be in an unstable state. For this reason, in order to continue the determination with respect to the time Tb, the process proceeds to step 41 to determine whether or not the determination count n is less than 4 (n <4).

  If “YES” is determined in step 41, the process proceeds to step 42, the determination count n is increased by 1, and the process proceeds to step 44 and returns. On the other hand, if “NO” is determined in step 41, the process proceeds to step 43, the determination count n is initialized (n = 0), and the process proceeds to step 44 and returns.

  Next, FIG. 7 shows a reverse phase connection determination process for determining whether the three-phase alternating current is a normal phase connection or a reverse phase connection.

  When the magnetic contactor 23A is turned on, the power supply monitoring device 25 is activated, and the reverse phase connection determination process is started. In the reverse phase connection determination process, in step 51, it is determined whether 1 minute has elapsed since the start. And when it determines with "YES" at step 51, even if 1 minute passes since starting of the power supply monitoring apparatus 25, the reverse phase connection determination process is not complete | finished and it is still continuing. Therefore, it is determined that a time-out error has occurred, an error output process described later is performed in step 52, and the process ends in step 53.

  On the other hand, when it is determined as “NO” in step 51, it is considered that only one minute has elapsed since the activation of the power supply monitoring device 25, and the reverse phase connection determination is in progress. For this reason, the process proceeds to step 54 to determine whether or not the permission flags A and B are both set.

  If “YES” is determined in step 54, the interphase voltages Vrs and Vst are both in a stable state. Therefore, the process proceeds to step 55 and the five buffers Trev [0 for performing the reverse phase connection determination. ] To Trev [4] are all determined to be 1. If “YES” is determined in step 55, the process proceeds to step 56, where it is determined that the three-phase alternating current is a forward rotation connection state in which the electric motor 22 is normally rotated, and the process proceeds to step 57 and the process ends.

  On the other hand, if “NO” is determined in step 55, the process proceeds to step 58 to determine whether or not all the five buffers Trev [0] to Trev [4] for performing the reverse phase connection determination are 0. If “YES” is determined in the step 58, the process shifts to a step 59 to determine that the three-phase alternating current is a reverse connection state in which the electric motor 22 is reversely rotated. Thereafter, an error output process described later is performed in step 60, and the process ends in step 61.

  When it is determined “NO” in step 58, the interphase voltages Vrs and Vst are both in a stable state, but the five buffers Trev [0] to Trev [4] do not match. Therefore, in order to acquire the values of the buffers Trev [0] to Trev [4] again, the process proceeds to step 62 where both the permission flags A and B are reset (cancelled), and the process returns at step 63.

  On the other hand, when “NO” is determined in step 54, at least one of the interphase voltages Vrs and Vst is in an unstable state. Therefore, the process proceeds to step 64 to determine whether or not the permission flag A is set.

  If “YES” is determined in step 64, the process proceeds to step 65 to determine whether or not the buffers Tst [0] to Tst [4] for determining the state of the interphase voltage Vst are all zero.

  If “YES” is determined in step 65, it is determined in step 66 that the three-phase alternating current is in an open phase state in which the interphase voltage Vst is not output. Thereafter, an error output process, which will be described later, is performed in step 67, and the process ends in step 68.

  On the other hand, when “NO” is determined in step 65, it is considered that the value of the buffer Tst [n] is being acquired. For this reason, the process proceeds to step 69 to perform standby display, and returns to step 63.

  Further, when “NO” is determined in the step 64, the process moves to a step 69 to perform standby display, and returns in a step 63.

  Next, FIG. 8 shows an error output process for notifying when an incorrect connection or a missing phase occurs in the three-phase alternating current.

  In step 71, it is determined whether or not the buffers Trs [0] to Trs [4] for determining the state of the interphase voltage Vrs are all one. When it is determined “NO” in step 71, it is considered that an abnormality has occurred in the interphase voltage Vrs, such as disconnection of the R phase or S phase. For this reason, the process proceeds to step 72 where the alarm output unit 34 is used to notify the abnormal state of the interphase voltage Vrs by display or voice.

  On the other hand, if “YES” is determined in step 71, the process proceeds to step 73 to determine whether or not the buffers Tst [0] to Tst [4] for determining the state of the interphase voltage Vst are all 1.

  When it is determined “NO” in step 73, it is considered that an abnormality has occurred in the interphase voltage Vst, such as disconnection of the S phase or the T phase. For this reason, the abnormal state of the interphase voltage Vst is displayed using the alarm output unit 34 in step 77, and the process ends in step 78.

  On the other hand, if “YES” is determined in step 73, the process proceeds to step 74 to determine whether or not the buffers Trev [0] to Trev [4] for performing the reverse phase connection determination are all zero. And when it determines with "YES" at step 74, it is thought that three-phase alternating current is a reverse phase connection state. Therefore, in step 75, the alarm output unit 34 is used to display the reverse phase connection state, and the process ends in step 78.

  If “NO” is determined in step 74, the alarm output unit 34 is used in step 76 to display a time-out error indicating that one minute has elapsed since the start-up, and the process ends in step 78.

  The compressor control apparatus according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, when the electric motor 22 operates, the rotation is transmitted to the drive shaft 19 via the pulley 19B and the like, and the drive shaft 19 rotates about the axis line OO. At this time, the orbiting scroll 9 connected to the crank portion 19A of the drive shaft 19 performs an orbiting motion with a constant orbiting radius about the axis OO in a state where the orbiting scroll 9 is prevented from rotating by the auxiliary crank 15.

  Thereby, each compression chamber 18 defined between the wrap part 5 of the fixed scroll 3 and the wrap part 11 of the orbiting scroll 9 is continuously reduced while moving from the outer diameter side toward the inner diameter side. . For this reason, outside air is sucked into the compression chamber 18 on the outer diameter side from the suction port 16 of the fixed scroll 3, and this air becomes compressed air by being compressed in each compression chamber 18. The compressed air is discharged to the outside through the discharge port 17 from the compression chamber 18 on the inner diameter side.

  Further, the pulse generator 27 is a pulse that becomes a low level when the primary currents I1 and I2 due to the interphase voltages Vrs and Vst rise above the threshold value It, and becomes a high level when it falls below the threshold value It. Signals S1 and S2 are output. At this time, as shown in FIGS. 9 and 10, when the three-phase AC voltage approaches the stable state, the pulse generator 27 greatly changes the time during which the primary currents I1 and I2 exceed the threshold value It. For this reason, the pulse generator 27 outputs pulse signals S1 and S2 whose duty ratio changes according to the amplitude of the three-phase AC voltage.

  The control unit 32 measures the times Ta and Tb of the low level sections of the pulse signals S1 and S2 that change according to the duty ratio, and whether the times Ta and Tb are between the lower limit value X and the upper limit value Y. Determine whether or not. Thus, the control unit 32 determines whether or not the three-phase AC voltage is in a stable state, and when it is in a stable state, the control unit 32 quickly determines the reverse phase connection using the phase difference (time difference Tc) between the pulse signals S1 and S2. Do. On the other hand, when the three-phase AC voltage is in an unstable state, the negative phase connection determination is not performed, and the fact that the interphase voltages Vrs and Vst are in an abnormal state is notified by disconnection or the like.

  Thus, in the present embodiment, the pulse generator 27 changes the duty ratio of each pulse signal S1, S2 according to the amplitude of the three-phase AC power. Thus, for example, when the amplitude of the three-phase AC power is large, the duty ratio of each pulse signal S1, S2 can be increased, and when the amplitude is small, the duty ratio of each pulse signal S1, S2 can be decreased. .

  Further, the control unit 32 determines whether or not to permit the reverse phase connection determination depending on whether or not the duty ratio of each of the pulse signals S1 and S2 by the pulse generator 27 is within a predetermined range. As a result, the control unit 32 causes the three-phase AC power (voltage) to be unstable or unbalanced when the duty ratio of at least one of the two pulse signals S1 and S2 is outside the predetermined range. Assuming there is no reverse-phase connection determination. For this reason, erroneous determination is not caused when the three-phase AC power is unstable or unbalanced.

  On the other hand, when both of the duty ratios of the two pulse signals S1 and S2 are within a predetermined range, the control unit 32 determines that the three-phase AC power is stable and performs the reverse phase connection determination. For this reason, it can be grasped | ascertained whether the three-phase alternating current is stable using the control unit 32, and a reverse phase connection can be detected reliably according to the state of a three-phase alternating current.

  Therefore, when the compressor is started, the reverse-phase connection state can be quickly detected when the three-phase AC voltage is stabilized without waiting for the elapse of a fixed time as in the prior art. Thereby, even if it is a reverse connection state, since the compression part 1 is not driven in a reverse rotation state for a long time, the cooling shortage accompanying the reverse rotation of the cooling fan 20 and the heating of the compression part 1 are prevented. be able to.

  In particular, in this embodiment, since the present invention is applied to the scroll-type compression unit 1, damage to the wrap portions 5 and 11 of the scrolls 3 and 9 can be prevented. That is, when the electric motor 22 rotates in the reverse direction, the compression chamber 18 tends to have a negative pressure, so that the pressure in the compression chamber 18 acts in a direction in which the scrolls 3 and 9 approach each other. For this reason, when the electric motor 22 rotates reversely for a long time, the tips of the wrap portions 5 and 11 of the scrolls 3 and 9 may come into contact with the end plates 10 and 4 to cause galling or the like. On the other hand, in the present embodiment, since the reverse connection state can be detected promptly even when the compressor is started, the scrolls 3 and 9 can be prevented from being damaged.

  Since the pulse generator 27 includes primary current supply units 28A and 29A and photocouplers 28B and 29B, the primary current supply units 28A and 29A provide primary currents I1 and I2 corresponding to the interphase voltages Vrs and Vst. The photocouplers 28B and 29B determine the low level or the high level of the pulse signals S1 and S2 depending on whether or not the primary currents I1 and I2 exceed the threshold value It. Further, since the current limiting resistors 30 and 31 of the pulse generator 27 limit the primary currents I1 and I2 by the primary current supply units 28A and 29A, the current limiting resistors 30 and 31 are used to set a predetermined constant value. The amplitude of the sinusoidal primary currents I1 and I2 can be set with respect to the threshold value It.

  Thereby, depending on whether or not the three-phase alternating current is in a stable state, the time during which the primary currents I1 and I2 exceed the threshold It changes greatly, and the time ratio between the low level and the high level of the pulse signals S1 and S2 Changes significantly. As a result, the duty ratio of the pulse signals S1, S2 can be changed greatly depending on whether the three-phase alternating current is in a stable state, so that the control unit 32 has a duty ratio of the pulse signals S1, S2 within a predetermined range. The state of the three-phase alternating current can be easily determined depending on whether or not there is.

  Since the pulse generator 27 is composed of the primary current supply units 28A and 29A and the photocouplers 28B and 29B, the voltage signal of the three-phase AC power supply 24 is insulated by the photocouplers 28B and 29B, and then the pulse signal S1, It can be detected as a change in the duty ratio of S2.

  Further, the control unit 32 measures the times Ta and Tb in the low level section of the pulse signals S1 and S2. At this time, since the times Ta and Tb change according to the duty ratio of the pulse signals S1 and S2, whether or not the reverse phase connection determination is performed depending on whether or not the measurement times Ta and Tb are within a predetermined range. Can be determined. As a result, without directly calculating the duty ratio of the pulse signals S1 and S2, it is possible to determine whether or not to perform the reverse phase connection determination indirectly according to the duty ratio, thereby simplifying the calculation process. it can.

  Next, FIG. 12 to FIG. 14 show a second embodiment. The feature of this embodiment is that the control unit compares the times of the low level sections of two pulse signals and the comparison result is the same. The present invention is configured to determine whether or not to perform the reverse phase connection determination according to whether or not. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Reference numeral 41 denotes a control unit as connection state determination means according to the second embodiment. The control unit 41 is substantially the same as the control unit 32 according to the first embodiment. The generator 27 is connected, and an alarm output unit 42 described later is connected to the output side. Further, a storage device 33 is connected to the control unit 32. The storage device 33 includes a connection state determination program for determining the connection state of the three-phase alternating current, and times Ta and Tb of the low level sections of the pulse signals S1 and S2. Are stored in advance. In addition, the storage device 33 stores a prescribed value Z for determining whether or not the times Ta and Tb of the low level sections of the two pulse signals S1 and S2 are the same.

  At this time, the specified value Z is a value determined according to, for example, an allowable range of errors of the times Ta and Tb. For example, if the error of the time Ta and Tb is allowable up to 5%, the specified value Z is 1 ms in the case of 50 Hz three-phase alternating current. In addition, the allowable range of the error of the times Ta and Tb is appropriately determined between about 2 to 15%, for example, according to the stability of the three-phase AC power supply 24. For this reason, the value of the prescribed value Z is also set as appropriate according to this allowable range.

  Then, as with the control unit 32 according to the first embodiment, the control unit 41 determines whether to perform the reverse phase connection determination according to the duty ratios of the pulse signals S1, S2 (time Ta, Tb in the low level section). And determining the reverse phase connection using the pulse signals S1 and S2.

  Further, the control unit 41 determines whether or not the times Ta and Tb of the low level sections of the pulse signals S1 and S2 are the same using the specified value Z, and at the same time, determines that the three-phase AC power is in an equilibrium state. To check the reverse phase connection. On the other hand, when the times Ta and Tb are different, it is determined that the three-phase AC power is in an unbalanced state, and the reversed-phase connection determination is not performed and a notification that the state is in an unbalanced state is given.

  Reference numeral 42 denotes an alarm output unit that notifies that an abnormality has occurred in the three-phase AC power supply 24 and the like. The alarm output unit 42 is, for example, in a reverse phase connection state, similar to the alarm output unit according to the first embodiment. In this case, when an abnormality occurs in the interphase voltages Vrs and Vst, and when the times Ta and Tb in the low level sections of the pulse signals S1 and S2 cannot be measured, the abnormality is notified by displaying them. Further, the alarm output unit 42 constitutes an abnormality notification means, and notifies when the two interphase voltages Vrs and Vst are different from each other by displaying an unbalanced state.

  Next, ST edge detection interrupt processing according to the present embodiment will be described with reference to FIG.

  The ST edge detection interrupt process according to the present embodiment also performs substantially the same process as the ST edge detection interrupt process according to the first embodiment shown in FIGS. However, in the present embodiment, step 81 is provided between step 39 and step 40, and it is determined in this step 81 whether or not the times Ta and Tb of the low level sections of the pulse signals S1 and S2 are the same. Is different.

  That is, if “YES” is determined in step 39 and all the five buffers Tst [0] to Tst [4] are 1, the process proceeds to step 81, where the absolute value of the difference between the times Ta and Tb is the specified value. It is determined whether it is smaller than Z (| Ta−Tb | <Z). When it is determined “YES” in step 81, it is considered that the interphase voltages Vrs and Vst are in the same equilibrium state. For this reason, it moves to step 40, sets permission flag B for permitting reverse phase connection determination, moves to step 44, and returns.

  On the other hand, when “NO” is determined in step 81, for example, disconnection or the like occurs in any of the R phase, the S phase, and the T phase, and the interphase voltages Vrs and Vst are considered to be in an unbalanced state. Therefore, the process proceeds to step 82, the unbalance flag is set, and the process proceeds to step 44 and returns.

  Next, error output processing according to the present embodiment will be described with reference to FIG.

  The error output process according to the present embodiment also performs substantially the same process as the error output process according to the first embodiment shown in FIG. However, the present embodiment is different in that a step 91 is provided before the step 71, and it is determined in this step 91 whether or not the interphase voltages Vrs and Vst are in an unbalanced state.

  That is, in step 91, it is determined whether or not an unbalance flag is set. And when it determines with "YES" at step 91, it is thought that three-phase alternating current is in an unbalanced state. For this reason, the alarm output unit 42 is used in step 92 to display an unbalanced state, and the process ends in step 93. On the other hand, when it is determined “NO” in step 91, it is considered that the three-phase alternating current is in an equilibrium state, and therefore, the processing after step 71 is performed as in the first embodiment.

  Thus, the second embodiment can provide the same effects as those of the first embodiment. In particular, in the second embodiment, the control unit 41 compares the times Ta and Tb in the low level sections of the two pulse signals S1 and S2, and makes a reverse phase connection determination according to whether the comparison results are the same. It is determined whether or not. As a result, it is possible to detect whether or not the three-phase alternating current is in an equilibrium state, and erroneous reverse-phase connection determination is not performed based on the unbalanced state.

  Further, when the alarm output unit 42 determines that the comparison results of the times Ta and Tb are different, the alarm output unit 42 can notify that the two interphase voltages Vrs and Vst are different from each other. Thereby, it can be easily grasped that the three-phase alternating current is in an unbalanced state.

  In each of the above embodiments, Steps 1 to 15 in FIG. 4, Steps 21 to 43 in FIG. 5, FIG. 6, FIG. 13 and Step 54 in FIG. Steps 1, 2, 4 to 8 in FIG. 4, Steps 21, 22, 31 to 35 in FIG. 5 and FIG. 6 show specific examples of time measuring means, and Steps 9 to 13, FIG. 6, FIG. Steps 36 to 43 in Fig. 13 show specific examples of the time determination means. In the second embodiment, steps 81 and 82 in FIG. 13 show a specific example of the signal comparison means.

  In each of the above embodiments, the states Ta and Tb of the low level sections of the pulse signals S1 and S2 are used to determine the state of the interphase voltages Vrs and Vst to determine whether or not to perform the reverse phase connection determination. The configuration. However, the present invention is not limited to this. For example, as shown in FIG. 9, the states of the interphase voltages Vrs and Vst may be determined using the times Ta ′ and Tb ′ of the high level sections of the pulse signals S1 and S2. Good.

  Further, in each of the above-described embodiments, the reverse phase connection determination is performed using the time Tc between the falling edges of the pulse signals S1 and S2, but for example, as shown in FIG. 9, the pulse signals S1 and S2 A configuration may be adopted in which reverse phase connection determination is performed using time Tc ′ between rising edges.

  In each of the above embodiments, the states of the phase voltages Vrs and Vst are determined using the times Ta and Tb in the low level sections of the pulse signals S1 and S2, but the duty ratios of the pulse signals S1 and S2 are determined. It is good also as a structure which calculates and determines the state of the phase voltage Vrs and Vst using this duty ratio.

  In each of the above embodiments, the interphase voltage Vrs between the R phase and the S phase among the R phase, S phase, and T phase of the three-phase alternating current and the interphase voltage Vst between the S phase and the T phase are calculated. However, instead of any one of the interphase voltages Vrs and Vst, an interphase voltage between the T phase and the R phase may be used.

  Further, in each of the above embodiments, the scroll type air compressor has been described as an example, but the present invention can be applied to, for example, a scroll type vacuum pump, a refrigerant compressor, and the like. Further, the present invention is not limited to the scroll type, and can be widely applied to various compressors such as a reciprocating compressor, and can also be applied to a control device for an electric motor that does not include a compression unit.

It is a block diagram which shows the control apparatus of the compressor by 1st Embodiment. It is a longitudinal cross-sectional view which shows the compression part in FIG. It is a block diagram which shows the pulse generator in FIG. It is a flowchart which shows the RS edge detection interruption process of a control unit. It is a flowchart which shows the ST edge detection interruption process of a control unit. It is a flowchart following FIG. It is a flowchart which shows the reverse phase connection determination process of a control unit. It is a flowchart which shows the error output process of a control unit. It is a characteristic diagram which shows the time change of an interphase voltage, a primary current, and a pulse signal when a three-phase alternating current will be in a stable state. It is a characteristic diagram which shows the time change of an interphase voltage, a primary current, and a pulse signal when a three-phase alternating current becomes an unstable state with a small amplitude. It is a characteristic diagram which shows the relationship between an interphase voltage and a duty ratio. It is a block diagram which shows the control apparatus of the compressor by 2nd Embodiment. FIG. 7 is a flowchart similar to FIG. 6 illustrating part of the ST edge detection interrupt processing according to the second embodiment. It is a flowchart which shows the error output process by 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compression part 22 Electric motor 23 Power supply circuit part 24 Three-phase alternating current power supply 27 Pulse generator 28A, 29A Primary current supply part 28B, 29B Photocoupler 30, 31 Current limiting resistance 32, 41 Control unit (connection state determination means)
34, 42 Alarm output section (Abnormality notification means)

Claims (6)

A compression section for compressing the fluid;
An electric motor for driving the compression unit;
A power supply circuit section for supplying power to the electric motor from a three-phase AC power supply;
A pulse generator that generates a pulse signal in accordance with an interphase voltage of two phases of the three-phase AC power supplied to the power supply circuit unit and an interphase voltage of another two phases different from the two phases,
A compressor comprising: a connection state determining means for determining whether or not the three-phase AC power is a reverse-phase connection that reverses the electric motor by using two pulse signals from the pulse generator; In the control device,
The pulse generator is configured to change the duty ratio of each pulse signal according to the amplitude of the three-phase AC power,
The connection state determination means does not perform reverse phase connection determination when the duty ratio of each pulse signal by the pulse generator is not continuously within a predetermined range for a plurality of cycles, and the duty ratio of each pulse signal is continuous. And the control apparatus of the compressor characterized by having the structure which comprises the determination permission means which performs a reverse phase connection determination when it exists in a predetermined range over multiple periods .   The pulse generator includes a primary current supply unit that supplies a primary current corresponding to an interphase voltage, and the pulse signal based on whether or not the primary current from the primary current supply unit exceeds a threshold value. 2. A photocoupler that determines a low level or a high level and outputs the pulse signal, and a current limiting resistor that limits a primary current by the primary current supply unit and determines the threshold value. The control apparatus of the compressor of 1.   The determination permitting means is a time measuring means for measuring the time of the low level section or the high level section of the pulse signal, and does not perform the reverse phase connection determination when the measurement time by the time measuring means is outside a predetermined range, The compressor control device according to claim 2, comprising a time determination unit that performs reverse-phase connection determination when the measurement time is within a predetermined range.   The connection state determination means compares the time of the low level section or the time of the high level section of the two pulse signals, does not perform the reverse phase connection determination when the comparison results are different, and when the comparison results are the same 4. The compressor control device according to claim 3, further comprising signal comparison means for performing a reverse phase connection determination.   5. The connection state determining means is provided with an abnormality notifying means for notifying that the two phase voltages are different from each other when the comparison result is determined to be different by the signal comparing means. The compressor control device described. An electric motor;
A power supply circuit section for supplying power to the electric motor from a three-phase AC power supply;
A pulse generator that generates a pulse signal in accordance with an interphase voltage of two phases of the three-phase AC power supplied to the power supply circuit unit and an interphase voltage of another two phases different from the two phases,
An electric motor comprising: a connection state determining means for determining whether or not the three-phase AC power is a reverse-phase connection that reverses the electric motor by using two pulse signals from the pulse generator. In the control device,
The pulse generator is configured to change the duty ratio of each pulse signal according to the amplitude of the three-phase AC power,
The connection state determination means does not perform reverse phase connection determination when the duty ratio of each pulse signal by the pulse generator is not continuously within a predetermined range for a plurality of cycles, and the duty ratio of each pulse signal is continuous. And the control apparatus of the electric motor characterized by having the structure which comprises the determination permission means which performs a reverse phase connection determination when it exists in a predetermined range over multiple periods .

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