JP2009219256A - Power factor improving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power factor improving device which continuously performs power factor control to cause a power factor to approach an ideal state 1 and allows a leading power factor to be adjustable as well. <P>SOLUTION: The power factor improving device comprises a rotary field type synchronous machine 12, an APFR device 13 which performs control for automatically keeping the power factor of the synchronous machine 12 at a set power factor by supplying a DC power to a rotary field of the synchronous machine 12, and a circuit breaker 14 which connects/disconnects the synchronous machine 12 and the APFR device 13 to/from a user load 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power factor correction apparatus.

  Generally, a phase advance capacitor having a series reactor is used in a load power factor correction apparatus in a consumer. As such a power factor improving device, a series reactor and a capacitor are set as one set, and a set corresponding to the maximum capacity is prepared, and a phase-advanced capacitor facility equipped with an automatic control device connected in parallel with a switch according to the load power factor. There are some (see, for example, Patent Document 1).

  Further, for example, a high-voltage capacitor used for improving the load power factor is well known and defined in Japanese Industrial Standards as a JIS C 4902 (1998) high-voltage and extra-high-voltage phase-advancing capacitor and accessory equipment. Similarly, a low voltage capacitor is known and defined in Japanese Industrial Standards as a JIS C 4901 (2000) low voltage phase advance capacitor.

  On the other hand, as a load power factor improvement device in a consumer, there are a rotary capacitor system in which a rotary field type synchronous machine is connected in parallel with a load and used as a phase adjuster, and a system in which a rotary capacitor and a static capacitor are combined.

  A rotary capacitor and a power factor improving device that combines a rotary capacitor and a static capacitor have characteristics such that no harmonics are generated, the power factor can be continuously variably controlled, and the delay power factor can be compensated from the advanced power factor.

  Conventionally, a rotary capacitor is used as a system voltage adjustment facility on the power supply side. Moreover, the hydroelectric generator is utilized as the same phase adjustment operation as a rotary capacitor (for example, refer patent document 2).

  On the other hand, a disturbance such as a lightning strike to the main system may cause a momentary drop (a momentary voltage drop) or a momentary interruption (a momentary power failure), and there are concerns about adverse effects on power and electronic equipment. In addition, it is considered that the case where the voltage drop is significant in the instantaneous drop corresponds to the instantaneous interruption, and the instantaneous drop described below includes the instantaneous interruption.

In addition, a voltage sag detection device for detecting the occurrence of voltage sag is already on the market as part of measures for voltage sag. The voltage sag detector detects the amount of power decrease in advance and a voltage sag that exceeds the voltage sag time, and outputs a signal such as an alarm at a high speed. Used for sequential power-on sequence.
Japanese Patent Laid-Open No. 11-046445 JP 05-038054 A

  However, in the phase-advanced capacitor equipment using the series reactor and the condenser described above, since the equipment is switched stepwise, continuous power factor adjustment cannot be performed.

  If the switching stage is made fine, switching control becomes complicated and the life of the switch for switching becomes short. On the other hand, if the switching stage is roughly set, there is a problem that the power factor cannot be made close to 1.

  In addition, the phase advance capacitor can be adjusted when the load side has a delayed power factor, but the advance power factor cannot be adjusted.

  On the other hand, stores, offices, factories, and the like that are trying to improve the power factor have greatly changed the load between night and daytime, and the load is low at night, especially from midnight to early morning. When the power factor is adjusted by the above-described rotary capacitor, the rotary capacitor is a rotating machine. Therefore, even when the load is low, an operating loss of the synchronous machine occurs and consumes active power.

  In this case, there is a problem that the loss due to the operation of the rotary capacitor is larger than the effect of the power factor improvement.

  On the other hand, when a power sag occurs in the main system due to a lightning strike or the like in the power factor correction apparatus described above, depending on the time of the power sag (several msec to several hundred msec) and the load situation of the customer at the time of the power sag, the power recovery There is a possibility that a phase shift occurs and the rotary capacitor is out of synchronization, an overcurrent flows through the equipment and the equipment is damaged.

  For example, when the voltage of the main system decreases (becomes 0) due to the occurrence of an instantaneous interruption, the consumer voltage also decreases, and the power supply to the connected rotary capacitor is cut off. However, since the rotary capacitor continues to rotate even after the power supply is cut off due to its inertial force, the rotary capacitor acts as a generator and supplies power to the system.

  Further, since the rotary capacitor is rotated by inertial force, the rotational speed thereof decreases with time with respect to the rated rotational speed. As a result, the generated power decreases with the passage of voltage and frequency, and becomes out-of-rated power out of phase.

  At this time, the electric power is restored after the lapse of the lapse of time, but it is considered that a phase shift occurs between the electric power generated by the rotary capacitor and the rotary capacitor is out of synchronization.

  For example, when the instantaneous interruption time is short (about several milliseconds to several tens of milliseconds), the voltage drop and the phase shift during the instantaneous interruption time are not so large. As a result, when the electric power returns after the lapse of the lapse of time, the rotary capacitor absorbs the phase shift by the APFR device and recovers the synchronization, so that the voltage returns to the rated voltage. In addition, the waveform of the current is distorted after recovery, but this also gradually stabilizes.

  However, when the instantaneous interruption time is long (about several hundreds msec), the voltage greatly decreases during the instantaneous interruption time, and the phase is also greatly shifted. As a result, the APFR device cannot follow and cannot synchronize even after returning after the momentary interruption time has elapsed, and the rotary capacitor is out of synchronization and abnormal vibration occurs. The voltage gradually returns to the rated voltage, but the current continues to be disturbed without being stabilized.

  Note that whether or not a synchronization loss occurs is determined by the instantaneous drop time, the amount of reduction, and the load state of the customer, that is, the load state as a power factor improving device of the rotary capacitor. When the load of the consumer is large and the load of the rotary capacitor is large, the synchronization is likely to be lost.

  The present invention has been made in consideration of the above-described circumstances, and provides a power factor correction apparatus that performs power factor control continuously, brings the power factor closer to the ideal state of 1, and can also adjust the advance power factor. With the goal.

  Another object of the present invention is to provide a power factor correction apparatus that employs a control system that automatically stops the synchronous machine when the load is low and automatically operates the synchronous machine when the load increases.

  Furthermore, another object of the present invention is to provide a power factor correction apparatus that prevents the synchronous machine from being out of synchronization after the voltage sag recovery and prevents damage to equipment due to overcurrent.

  In order to solve the above-described problems, a power factor correction apparatus according to the present invention supplies a rotating field type synchronous machine and DC power to the rotating field of the synchronous machine as described in claim 1. By doing so, it has an APFR device that performs control to automatically keep the power factor of the synchronous machine at a set power factor, and a circuit breaker that cuts the synchronous machine and the APFR device into a consumer load.

  Further, in order to solve the above-described problem, as described in claim 2, an excitation transformer is provided for gradually decreasing the supply voltage to the APFR device from the received voltage.

  Furthermore, in order to solve the above-mentioned problem, as described in claim 3, a phase advance capacitor combining a series reactor and a capacitor, a switch for turning on and off the phase advance capacitor, and a switch for the phase advance capacitor An APFR device having a control signal for turning on and off the machine, and a circuit breaker for turning the synchronous machine, the APFR device and the phase advance capacitor into and out of the consumer load.

  And in order to solve the subject mentioned above, as described in Claim 4, it has a flywheel directly connected with the rotating shaft of the said synchronous machine.

  And in order to solve the subject mentioned above, as described in Claim 5, it has a clutch apparatus with the function which can control coupling force between the said synchronous machine and the said flywheel.

  Further, in order to solve the above-mentioned problem, as described in claim 6, the current detection means of the power factor improving circuit and the control circuit for automatically starting and stopping the rotary field type synchronous machine by the current detection means It is what has.

  Furthermore, in order to solve the above-mentioned problem, as described in claim 7, the flow detection means is provided with a time-limiting characteristic.

  In order to solve the above-described problem, as described in claim 8, the current detection means is provided with a hysteresis characteristic.

  And in order to solve the subject mentioned above, as described in Claim 9, the control circuit which provided the programmable timer which sets an operation time zone, and starts and stops the above-mentioned rotary field type synchronous machine automatically with this programmable timer It is what has.

  Further, in order to solve the above-described problem, as described in claim 10, when an instantaneous voltage drop is detected, this is detected and power supply to the rotary field type synchronous machine is stopped, and the rotation is performed. The field type synchronous machine is configured to be stopped.

  Further, in order to solve the above-described problem, as described in claim 11, when the instantaneous voltage drop occurs, this is detected and the rotary field type synchronous machine is restarted. It is.

  According to the power factor correction apparatus of the present invention, the power at the power receiving end can be controlled to an ideal state with a power factor of 1. Also, continuous power factor control is possible. Furthermore, even if an instantaneous voltage drop occurs on the system side, it is possible to prevent an instantaneous drop in the load voltage.

  Further, it is possible to avoid an unstartable state due to an excessive start current and step-out. Furthermore, power loss can be prevented and power factor improvement can be performed efficiently. Furthermore, it is possible to control the current change in the vicinity of the detection current without excessively turning the synchronous machine on and off. Then, it is possible to prevent the synchronous machine from being out of synchronization when power is restored after a voltage sag, and it is possible to prevent equipment damage due to overcurrent and abnormal vibration of the synchronous machine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a basic system diagram showing a first embodiment of a power factor correction apparatus according to the present invention. As shown in FIG. 1, a consumer 2 having a plurality of loads 1 (load ₁ to load _n ) inside is provided with a power receiving end 3 that receives power supply from an external power source (not shown). A main power supply line 4 extends into the customer 2. A main circuit breaker 4 a is provided in the middle of the main power supply line 4, and the main power supply line 4 is branched into a plurality of sub power supply lines 5 downstream of the main circuit breaker 4 a and connected to each load 1. Further, a sub circuit breaker 5 a is provided on the upstream side of each load 1 of the sub power supply line 5. One of the plurality of sub power supply lines 5 is led out of the customer 2 and connected to the power factor correction device 11.

  The power factor correction device 11 is a rotary field type synchronous machine 12 (hereinafter abbreviated as a synchronous machine) such as a rotary capacitor (RC), and the rotary field of the synchronous machine 12 is supplied with DC power to An APFR (power factor control) device 13 that performs control to automatically maintain the power factor at the set power factor, and a circuit breaker 14 (electromagnetic contactor) that cuts the synchronous machine 12 and the APFR device 13 into the consumer load 1 are configured. Is done.

  The auxiliary power supply line 5 led to the outside of the customer 2 is connected to the synchronous machine 12 and a circuit breaker 14 is provided on the upstream side of the synchronous machine 12. Further, an APFR device 13 is connected between the circuit breaker 14 and the synchronous machine 12.

In the power factor correction apparatus 11 (first embodiment) having the above configuration, the customer 2 uses the load ₁ from the load ₁ to the load _n , and as a result, the load power factor is delayed from the ideal load power factor. In the state, when the circuit breaker 14 of the power factor correction apparatus 11 according to the present invention is turned on, the synchronous machine 12 starts as a no-load synchronous motor and reaches the synchronous speed.

  At the same time when the circuit breaker 14 is turned on, the APFR device 13 applies DC excitation to the field of the synchronous machine 12. The amount of excitation at this time is controlled so as to become the set power factor by performing feedback control with the power factor of the actual load on the power factor set in the APFR device 13.

  In this way, the power factor of the current flowing through the synchronous machine 12 can be controlled by connecting the unloaded synchronous machine 12 to the system and increasing or decreasing the field current. That is, if the power factor of the customer load 1 is in a delayed state, the power flowing through the synchronous machine 12 is set to the advanced state, whereby the power at the power receiving end 3 can be controlled to an ideal state with a power factor of 1.

  Further, even when the load 1 changes due to work like a motor load in a factory, and as a result, the power factor of the power receiving end 3 is changed, according to this method, feedback control of the APFR device 13 is performed. Follows real time, and continuous power factor control that cannot be obtained by step control becomes possible.

  Furthermore, even when a large power load stops like a nighttime condition in a factory, the load of an electronic device having a capacitor is mainly used, and even if the power factor advances and the power factor decreases in the opposite direction, the synchronous machine can be adjusted by adjusting the excitation. 12, the power at the power receiving end 3 can be controlled to an ideal state with a power factor of 1.

  FIG. 2 is a system diagram showing a second embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 11 shown in 1st embodiment, and the overlapping description is abbreviate | omitted.

  In 2nd embodiment, the case where the power factor improvement apparatus 21 is connected to a high voltage | pressure or a special high voltage | pressure is shown. The power factor improving device 21 automatically applies DC power to the synchronous machine 12 such as a rotary capacitor (RC) and the rotating field of the synchronous machine 12 to automatically keep the power factor of the synchronous machine 12 at a set power factor. APFR device 13 that performs control, circuit breaker 14 (electromagnetic contactor) that cuts off synchronous machine 12 and APFR device 13 into customer load 1, and excitation transformer 22 that gradually reduces high voltage or extra high voltage to a predetermined voltage; The excitation transformer 22 is provided on the upstream side of the APFR device 13 connected between the circuit breaker 14 and the synchronous machine 12. Further, another excitation transformer 23 is also provided in the sub power supply line 5 on the upstream side of each load 1. However, the sub power supply line 5 that branches toward the power factor correction device 21 branches on the upstream side of the other excitation transformer 23.

In the power factor correction apparatus 21 (second embodiment) having the above configuration, the customer 2 uses the load ₁ from the load ₁ to the load _n , and as a result, the load power factor is delayed from the ideal load power factor. In the state, when the circuit breaker 14 of the power factor correction device 21 according to the present invention is turned on, the synchronous machine 12 is activated as a no-load synchronous motor and reaches the synchronous speed.

  At the same time when the circuit breaker 14 is turned on, the APFR device 13 applies DC excitation to the field of the synchronous machine 12. The amount of excitation at this time is controlled so as to become the set power factor by performing feedback control with the power factor of the actual load on the power factor set in the APFR device 13. Further, the excitation transformer 22 reduces the high voltage or extra high voltage to a voltage necessary for excitation.

  Thus, the power factor of the current flowing through the synchronous machine 12 can be controlled by connecting the synchronous machine 12 in a no-load state to the system and increasing or decreasing the field current. This power factor improving apparatus 21 is also the first embodiment. The same effect as the power factor improving apparatus 11 shown in FIG.

  FIG. 3 is a system diagram showing a third embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 11 shown in 1st embodiment, and the overlapping description is abbreviate | omitted.

  In the third embodiment, the power factor improving apparatus 31 applies a DC power to the synchronous machine 12 such as a rotary capacitor (RC) and the rotating field of the synchronous machine 12 to set the power factor of the synchronous machine 12. APFR device 13 having a control signal of switch 33 that performs control to automatically maintain the rate and switches on / off phase-advancing capacitor 32 that is a combination of a series reactor and a capacitor, and synchronous machine 12 and APFR device 13 are connected to consumer load. It is composed of a circuit breaker 14 (electromagnetic contactor) that enters and exits one. The capacity of the phase advance capacitor 32 is the same as the phase advance capacity of the synchronous machine 12.

In the power factor correction apparatus 31 (third embodiment) having the above configuration, the customer 2 uses the load ₁ from the load ₁ to the load _n , and as a result, the load power factor is delayed from the ideal load power factor. In the state, when the circuit breaker 14 of the power factor correction apparatus 31 according to the present invention is turned on, the synchronous machine 12 is activated as a no-load synchronous motor and reaches the synchronous speed.

  At the same time when the circuit breaker 14 is turned on, the APFR device 13 applies DC excitation to the field of the synchronous machine 12. The amount of excitation at this time is controlled so as to become the set power factor by performing feedback control with the power factor of the actual load on the power factor set in the APFR device 13. Further, when the phase advance power capacity is insufficient for adjusting the power factor, the phase advance capacitor 32 switch 33 is turned on to increase the phase advance capacity. When the current of the synchronous machine 12 becomes delayed due to the change of the load 1 after the phase advance capacitor 32 is turned on, the switch 33 for the phase advance capacitor 32 is opened and the phase advance power is supplied only by the synchronous machine 12.

  In this way, the power factor of the current flowing through the synchronous machine 12 can be controlled by connecting the unloaded synchronous machine 12 to the system and increasing or decreasing the field current. That is, if the power factor of the customer load 1 is in a delayed state, the current flowing through the synchronous machine 12 is set to the advanced state, whereby the power at the power receiving end 3 can be controlled to an ideal state with a power factor of 1.

  Further, even when the load 1 changes due to work like a motor load in a factory, and as a result, the power factor of the power receiving end 3 is changed, according to this method, feedback control of the APFR device 13 is performed. Follows real time, and continuous power factor control that cannot be obtained by step control becomes possible.

  Furthermore, even when a large power load stops like a nighttime condition in a factory, the load of an electronic device having a capacitor is mainly used, and even if the power factor advances and the power factor decreases in the opposite direction, the synchronous machine can be adjusted by adjusting the excitation. 12, the power at the power receiving end 3 can be controlled to an ideal state with a power factor of 1.

  Furthermore, by using the phase advance capacitor 32 in a hybrid manner, the equipment capacity of the synchronous machine 12 can be reduced, and the equipment cost is superior to the case of installing the synchronous machine 12 alone.

  By the way, in 3rd embodiment mentioned above, although the case where the number of phase-advance capacitor | condensers 32 was one set was shown, when a plurality of sets are installed, for example, when n sets are installed, the capacity | capacitance machine 12 capacity | capacitance is 1 / (n + 1) Further, it is advantageous in terms of equipment costs. In addition, since the switching control becomes complicated and frequent when the number of phase-advancing capacitors 32 is increased, 5 sets or less are desirable.

  Further, in the third embodiment, it is possible to provide equipment (high voltage or extra high voltage) as in the second embodiment, and the connection point voltage of the power factor correction device 31 may be low voltage, high voltage or extra high voltage.

  FIG. 4 is a system diagram showing a fourth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 11 shown in 1st embodiment, and the overlapping description is abbreviate | omitted.

  In the fourth embodiment, the power factor improving device 41 is configured to apply a DC power to the synchronous machine 12 such as a rotary capacitor (RC) and the rotating field of the synchronous machine 12 to set the power factor of the synchronous machine 12. APFR device 13 that performs control to automatically maintain the rate, circuit breaker 14 (electromagnetic contactor) that cuts synchronous machine 12 and APFR device 13 into customer load 1, and fly attached to rotating shaft 42 of synchronous machine 12 And a wheel 43.

  In the power factor correction apparatus 41 (fourth embodiment) having the above-described configuration, the action relating to the phase adjustment of the power factor is the same as that shown in the first embodiment. However, the flywheel 43 attached to the rotating shaft 42 of the synchronous machine 12 is always rotating at the synchronous speed.

  When the flywheel 43 is mounted on the rotary shaft 42 of the synchronous machine 12, when a large load is suddenly applied on the load 1 side, or when an instantaneous voltage drop due to lightning strikes on the system side, the flywheel The instantaneous power is supplied to the load 1 side by the effect of 43, and the instantaneous decrease in the load voltage can be prevented as a whole.

  This instantaneous voltage drop compensation operation can prevent the loss of memory (not shown) of the electronic device or the stoppage of operation as a load that has increased rapidly in recent years.

  FIG. 5 is a system diagram showing a fifth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 41 shown in 4th embodiment, and the overlapping description is abbreviate | omitted.

  In the fifth embodiment, the power factor improving device 51 is provided with a clutch device 52 such as a powder clutch that can adjust the coupling force between the synchronous machine 12 and the flywheel 43 of the power factor improving device 41 shown in the fourth embodiment. It is a thing.

  In the power factor correction apparatus 51 (fifth embodiment) having the above-described configuration, the action relating to the phase adjustment of the power factor is the same as that shown in the first embodiment. Further, when the circuit breaker 14 is turned on and started, the clutch device 52 is in a released state, and the synchronous machine 12 is started with no load.

  After the synchronous machine 12 reaches the synchronous speed, the coupling force of the clutch device 52 is gradually increased, and the flywheel 43 is connected to the synchronous machine 12 so that the synchronous machine 12 does not step out. When the flywheel 43 reaches the synchronous speed, it is completely connected.

  In the power factor correction apparatus 51 (fifth embodiment) configured as described above, the effects relating to the phase adjustment of the power factor and the instantaneous voltage drop are the same as those shown in the fourth embodiment. Moreover, since the flywheel 43 is excluded at the time of start-up and the start-up is performed with no load, it is possible to avoid an unstartable state due to an excessive start-up current and step-out.

  FIGS. 6A and 6B are a system diagram and a control circuit diagram which are a sixth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 11 shown in 1st embodiment, and the overlapping description is abbreviate | omitted.

  The power factor improving device 61 in the sixth embodiment is configured to set the power factor of the synchronous machine 12 by applying DC power to the synchronous machine 12 such as a rotary capacitor (RC) and the rotating field of the synchronous machine 12. APFR device 13 that performs control to be automatically maintained, and circuit breaker 14 (electromagnetic contactor) that allows synchronous machine 12 and APFR device 13 to enter and exit customer load 1. Also, there is a current detection means of the power factor improving circuit which operates when the current of the feeder for improving the power factor exceeds a set value between the main circuit breaker 4a downstream of the main power supply line 4 and the APFR device 13. A current detection relay 62 is provided.

In the control method (sixth embodiment) of the power factor correction apparatus 61 having the above-described configuration, the power factor correction apparatus is activated when a manual switch is turned on and the total current from load ₁ to load _n, which is a power factor improvement target, is detected. When the set value of the relay 62 is exceeded, the contact 62a of the current detection relay 62 operates and the synchronous machine 12 starts rotating.

  Further, when the load current such as at night falls and the current detection relay 62 is restored, the contact 62a of the current detection relay 62 is restored, and the synchronous machine 12 is stopped.

  Thus, by adopting a control method in which the load current is detected and the synchronous machine 12 is automatically stopped when the load current is small, power loss can be prevented and efficient power factor improvement can be performed.

  FIGS. 7A and 7B are a system diagram and a control circuit diagram showing a seventh embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 61 shown in 6th embodiment, and the overlapping description is abbreviate | omitted.

  The power factor improving apparatus 71 in the seventh embodiment is configured to set the power factor of the synchronous machine 12 by applying DC power to the synchronous machine 12 such as a rotary capacitor (RC) and the rotating field of the synchronous machine 12. APFR device 13 that performs control to be automatically maintained, and circuit breaker 14 (electromagnetic contactor) that allows synchronous machine 12 and APFR device 13 to enter and exit customer load 1. In addition, a current detection relay 62 is provided between the main circuit breaker 4a downstream of the main power supply line 4 and the APFR device 13 and operates when the current of the feeder for improving the power factor exceeds a set value. A control circuit for operating the circuit breaker 14 is constituted by the auxiliary relay 72, the time limit operation relay 73, and the time limit return operation relay 74 that operate under the conditions of the start and stop switches.

In the control method (seventh embodiment) of the power factor correction apparatus 71 having the above-described configuration, the power factor correction apparatus is activated when a manual switch is turned on and the total current from load ₁ to load _n, which is the power factor improvement target, is detected as a current. When the value exceeds the set value of the relay 62, the contact 62a of the current detection relay 62 operates to excite the time limit operation relay 73 and the time limit return operation relay 74 simultaneously.

  Although the contact 62a of the time-return relay operates instantaneously, it is connected in series with the contact of the time-operation relay 73 and drives the circuit breaker 14, so that the synchronous machine 12 starts rotating after the set time has elapsed.

  Further, when the load current decreases at night and the current detection relay 62 is restored, the synchronous machine 12 is stopped after the set time elapses by the time-return relay.

  Thus, by adopting a control method in which the load current is detected and the synchronous machine 12 is automatically stopped when the load current is small, power loss can be prevented and efficient power factor improvement can be performed.

  Further, by giving a time-limited characteristic to the operation and return of the current detection relay 62 as in this embodiment, it is possible to control the current change in the vicinity of the detection current without excessively turning the synchronous machine 12 on and off. it can.

  FIGS. 8A and 8B are a system diagram and a control circuit diagram showing an eighth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 61 shown in 6th embodiment, and the overlapping description is abbreviate | omitted.

  The power factor correction apparatus 81 in the eighth embodiment has basically the same configuration as the power factor improvement apparatus 61 shown in the sixth embodiment, but the power factor improvement apparatus 61 in the sixth embodiment is one current detection relay. On the other hand, the power factor correction apparatus 81 of the eighth embodiment includes two current detection relays 82 and 83 having different set values. The set value of the current detection relay 82 arranged on the upstream side is set larger than the set value of the current detection relay 83 arranged on the downstream side.

In the control method (eighth embodiment) of the power factor correction apparatus 81 having the above-described configuration, the power factor correction apparatus 81 is activated by turning on the manual switch and the total current from the load ₁ to the load _n that is the power factor improvement target is downstream. When the set value of the side current detection relay 83 becomes equal to or greater than the set value, the contact 83a of the downstream side current detection relay 83 operates. At this time, the contact 82a of the upstream current detection relay 82 is already operating, and the synchronous machine 12 starts rotating.

  Further, when the load 1 current at night or the like decreases and the downstream current detection relay 83 is restored, the contact 82a of the upstream current detection relay 82 has already been restored, and the synchronous machine 12 stops.

  Thus, by adopting a control method in which the load current is detected and the synchronous machine 12 is automatically stopped when the load current is small, power loss can be prevented and efficient power factor improvement can be performed.

  Further, by giving hysteresis characteristics to the operation and recovery of the current detection relays 82 and 83 as in this embodiment, the synchronous machine 12 is not excessively turned on and off by chattering with respect to a current change in the vicinity of the detection current. Can be controlled.

  FIGS. 9A and 9B are a system diagram and a control circuit diagram which are a ninth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 61 shown in 6th embodiment, and the overlapping description is abbreviate | omitted.

  The power factor correction apparatus 91 in the ninth embodiment basically has the same configuration as the power factor improvement apparatus 61 shown in the sixth embodiment, but the power factor improvement apparatus 61 in the sixth embodiment replaces the current detection relay 62. In contrast, the power factor correction device 91 of the ninth embodiment includes a programmable timer 92 that sets a time for operating the synchronous machine 12 in the main circuit.

  This programmable timer 92 is called a daily timer or a weekly timer, and the operation time zone of the synchronous machine 12 is set in accordance with the time of the factory equipment or the like where the increase or decrease of the load 1 is determined by the time.

In the control method (9th embodiment) of the power factor correction apparatus 91 having the above-described configuration, the power factor correction apparatus is activated when the load ₁ of the load ₁ to the load _n that is the power factor improvement target is increased after the manual switch is turned on. Then, the operation is started, and the operation of the synchronous machine 12 is stopped at night when the load 1 decreases.

  Thus, the operation is performed by setting the time zone in which the load 1 increases, and the synchronous machine 12 is automatically stopped in the time zone in which the load 1 is small, so that loss of power can be prevented and efficient power factor improvement can be performed. it can.

  In addition, as an application example of the load current detection method applied to the sixth to eighth embodiments described above, the present invention can be a load power detection method, and also includes digitization and software control. It is. Further, the present invention includes a combination of the actual current detection method for the load 1 applied to the sixth to eighth embodiments and the timer for setting the operation time zone applied to the ninth embodiment.

  FIG. 10 is a system diagram showing a tenth embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 11 shown in 1st embodiment, and the overlapping description is abbreviate | omitted.

  The power factor correction apparatus 101 in the tenth embodiment basically has the same configuration as the power factor improvement apparatus 11 shown in the first embodiment, but for the power factor correction apparatus installed on the upstream side of the synchronous machine 12. An instantaneous voltage drop (instantaneous voltage drop) detection device 102 is installed upstream of the switch 33, and the voltage drop detection device 102 opens the power factor correction device switch 33 by a control signal when the voltage drop is detected. It is configured. It should be noted that the installation position of the voltage sag detector 102 is not limited to the present embodiment as long as it can detect a voltage sag in the main system.

  In the power factor improving device 101 according to the tenth embodiment, when a voltage sag occurs on the main system side of the power receiving end 3, the voltage sag detecting device 102 detects this voltage sag. The power factor improving device switch 33 is quickly opened by a control signal when the amount of voltage drop or the like is exceeded, and the power supply to the synchronous machine 12 is stopped.

  In this way, by quickly stopping the power supply to the synchronous machine 12 when a voltage sag occurs and stopping the synchronous machine 12, the synchronization of the synchronous machine 12 can be prevented from being lost when power is restored after the voltage sag. It is possible to prevent equipment damage due to overcurrent and abnormal vibration of the synchronous machine 12.

  FIG. 11 is a system diagram showing an eleventh embodiment of the power factor correction apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the structure same as the power factor improvement apparatus 101 shown in 10th Embodiment, and the overlapping description is abbreviate | omitted.

  The power factor correction apparatus 111 in the eleventh embodiment has basically the same configuration as the power factor improvement apparatus 101 shown in the tenth embodiment, but for the power factor correction apparatus installed on the upstream side of the synchronous machine 12. The voltage sag detection device 102 installed upstream of the switch 33 of the switch issues a restart command to the APFR device 13 by a control signal when a voltage sag is detected, and the APFR device 13 restarts the synchronous machine 12. It is configured. It should be noted that the installation position of the voltage sag detector 102 is not limited to the present embodiment as long as it can detect a voltage sag in the main system.

  Then, in the power factor improving device 111 according to the eleventh embodiment, when a sag is corrected on the main system side of the power receiving end 3, the sag detecting device 102 detects the sag and the sag is set in advance. The APFR device 13 restarts the synchronous machine 12 by the control signal when the time or the voltage decrease amount is exceeded. At this time, the APFR device 13 that has received the restart command from the voltage sag detector 102 stops the excitation of the field of the synchronous machine 12.

  When the power returns after the sag time, the synchronous machine 12 starts as a no-load induction motor in the same way as at the start, and after reaching the synchronous speed and the rated rotational speed, the synchronous machine 12 is energized with a direct current. The synchronous machine 12 is restored.

  As described above, when the APFR device 13 promptly restarts the synchronous machine 12 when a voltage sag occurs, in a situation where a phase shift occurs when the voltage sag is restored, the synchronous machine 12 can be turned off by turning off the excitation. As an induction motor, it is possible to start up without being affected by a phase shift and reach a synchronous speed. The synchronous machine 12 can be restored in the same manner as at the start by applying excitation after reaching the synchronous speed.

  As described above, the synchronous machine 12 can be recovered without causing a loss of synchronization as in the start-up when the instantaneous drop is restored.

The basic system figure which shows 1st embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 2nd embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 3rd embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 4th embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 5th embodiment of the power factor improvement apparatus which concerns on this invention. (A) And (b) is the systematic diagram and control circuit diagram which respectively show 6th embodiment of the power factor improvement apparatus which concerns on this invention. (A) And (b) is the systematic diagram and control circuit diagram which respectively show 7th embodiment of the power factor improvement apparatus which concerns on this invention. (A) And (b) is the systematic diagram and control circuit diagram which respectively show 8th embodiment of the power factor improvement apparatus which concerns on this invention. (A) And (b) is the systematic diagram and control circuit diagram which respectively show 9th embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 10th Embodiment of the power factor improvement apparatus which concerns on this invention. The systematic diagram which shows 11th Embodiment of the power factor improvement apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load 2 Customer 11, 21, 32, 41, 51, 61, 71, 81, 91, 101, 111 Power factor improvement apparatus 12 Rotating field type synchronous machine 13 APFR apparatus 14 Breaker 22 Excitation transformer 32 Advance phase Capacitor 33 Switch 43 Flywheel 52 Clutch devices 62, 82, 83 Current detection relay (current detection means for power factor improvement circuit)
92 Programmable timer 102 Instantaneous voltage drop detection device

Claims (11)

A rotary field type synchronous machine, an APFR device that performs control to automatically maintain a power factor of the synchronous machine at a set power factor by supplying DC power to the rotary field of the synchronous machine, and the synchronous machine And a circuit breaker that cuts the APFR device into a consumer load. The power factor correction apparatus according to claim 1, further comprising an excitation transformer that gradually decreases a supply voltage to the APFR apparatus from a reception voltage. A phase advance capacitor combining a series reactor and a capacitor, a switch for turning on and off the phase advance capacitor, an APFR device having a control signal for turning on and off the phase advance capacitor switch, the synchronous machine, the APFR device, and The power factor improving apparatus according to claim 1, further comprising a circuit breaker that cuts the phase advance capacitor into the customer load. 4. The power factor correction apparatus according to claim 1, further comprising a flywheel directly connected to a rotating shaft of the synchronous machine. 5. The power factor correction apparatus according to claim 4, further comprising a clutch device having a function of controlling a coupling force between the synchronous machine and the flywheel. 6. The power factor improving apparatus according to claim 1, further comprising: a current detecting unit of the power factor improving circuit; and a control circuit for automatically starting and stopping the rotary field type synchronous machine by the current detecting unit. 7. A power factor correction apparatus according to claim 6, wherein said current detection means has a time-limiting characteristic. The power factor correction apparatus according to claim 6 or 7, wherein the current detecting means has a hysteresis characteristic. 9. The power factor correction apparatus according to claim 8, further comprising a control circuit that includes a programmable timer for setting an operation time zone, and that automatically starts and stops the rotating field type synchronous machine with the programmable timer. The system according to any one of claims 1 to 9, wherein when a momentary voltage drop occurs, this is detected, power supply to the rotary field type synchronous machine is stopped, and the rotary field type synchronous machine is stopped. Power factor correction device as described in 1. 10. The power factor correction apparatus according to any one of 1 to 9, which is configured to detect when an instantaneous voltage drop occurs and restart the rotary field type synchronous machine.

Images