JP2011088708A - Open-phase detecting device of power source for elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an open-phase detecting device of a power source for an elevator capable of surely detecting an open phase, even in the power source for the elevator using an inexpensive V-connection transformer and a voltage detecting device. <P>SOLUTION: The open-phase detecting device includes the voltage detecting device for detecting voltage of respective wiring between respective phases of the power source for the elevator and a motor for the elevator, a capacitor capacity control device for changing capacity of an inter-phase capacitor, and a controller for detecting the open phase of the power source for the elevator based on voltage detected by the voltage detecting device in a detection period, by setting the detection period, by temporarily changing the capacity of the inter-phase capacitor to a value set so that a resonance frequency of a partial pressure circuit formed of the inter-phase capacitor and the V-connection transformer, separates by a preset quantity from a frequency of the power source for the elevator, from a value set in the capacitor capacity control device for restraining normal mode noise. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a phase loss detection device for an elevator power supply.

  An inverter in a recent elevator is controlled by a PWM (Pulse Width Modulation) method. For this reason, downsizing, energy saving, and space saving of the inverter are progressing. However, on the other hand, the amount of noise generated from the elevator system increases. Therefore, there is a concern that the noise inside the building may be adversely affected by noise.

  Therefore, as a noise countermeasure, a noise filter is set at the input for taking in the building power. This noise filter is mainly composed of a common mode reactor and a capacitor. Capacitors are classified as interphase capacitors and grounded capacitors. The interphase capacitor is for suppressing normal mode noise. The grounding capacitor is for suppressing common mode noise.

  In an elevator, a transformer may be installed on a three-phase power line in order to generate an internal power source. As this transformer, a V-connection is often used from the viewpoint of cost and size.

  Here, the inverter and the converter of the elevator are designed on the assumption that the input power of the building is normal. For this reason, for example, when one of the three phases is not connected due to a mistake of an operator, a phase failure occurs, and a current exceeding the expected value flows to the device, causing damage to the device and deterioration of the life. Therefore, in the elevator, an open phase detection circuit is provided for the power source to detect the open phase.

  As this phase loss detection method, there are a current detection method and a voltage detection method. The current detection method generally requires an expensive current detector. Therefore, a voltage detection method is usually employed (see, for example, Patent Document 1).

JP 2006-42445 A

  However, if a phase failure occurs in the three-phase power supply line where the noise filter and V-connection transformer are installed, the phase is lost due to the correlation between the capacitance of the interphase capacitor of the noise filter and the inductance of the winding of the V-connection transformer. The voltage between the phase and the other phase may be different from the voltage assumed when the phase is normally lost. In this case, the power supply voltage detected by the voltage detection type phase loss detection circuit seems to hold a certain level of voltage and phase in any phase, and it is possible to detect which phase is in phase loss. There was a problem that I could not.

  The present invention has been made to solve the above-described problems, and its object is to reliably detect an open phase even in an elevator power source using an inexpensive V-connection transformer and a voltage detection device. It is an object of the present invention to provide a phase loss detection device for an elevator power supply.

  The phase loss detection device for an elevator power source according to the present invention includes an interphase capacitor connected to the elevator power source between each phase of the elevator power source and the elevator motor, and a V-connection transformer on the elevator motor side. In order to suppress normal mode noise, the voltage detection device that detects the voltage of each wiring connected to the capacitor, the capacitor capacitance control device that changes the capacitance of the interphase capacitor, and the capacitance control device, the capacitance of the interphase capacitor is reduced. From the value set to, the resonance frequency of the voltage dividing circuit formed by the interphase capacitor and the V-connection transformer is temporarily set to a value set so as to be separated from the frequency of the elevator power source by a preset amount. The detection period is set, and based on the voltage detected by the voltage detection device during the detection period. It is obtained and a controller for detecting the open phase of the power supply the elevator.

  In addition, the phase loss detection device for an elevator power source according to the present invention includes an interphase capacitor connected to the elevator power source between each phase of the elevator power source and the elevator motor, and V on the elevator motor side. A voltage detection device for detecting a voltage of each wiring connected to the wiring transformer, a connection device for connecting and disconnecting the wiring by the interphase capacitor, and a connection device between the wiring by the interphase capacitor; A controller for temporarily disconnecting the connection, setting a detection period, and detecting a phase failure of the elevator power supply based on a voltage detected by the voltage detection device during the detection period. It is.

  According to the present invention, even in an elevator power source using an inexpensive V-connection transformer and a voltage detection device, it is possible to reliably detect an open phase.

1 is an overall configuration diagram of an elevator phase loss detection device according to Embodiment 1 of the present invention. It is a figure for demonstrating the method to change the capacity | capacitance of an interphase capacitor using the phase loss detection apparatus of the power supply for elevators in Embodiment 1 of this invention. It is a figure for demonstrating the connection state of the V connection transformer of the elevator in which the phase loss detection apparatus of the power supply for elevators in Embodiment 1 of this invention is utilized. It is a figure for demonstrating the case where the S phase of the power supply for elevators has lost the phase in FIG. It is a figure for demonstrating the case where the R phase of the power supply for elevators has a phase failure in FIG. It is a flowchart for demonstrating operation | movement of the phase loss detection apparatus of the power supply for elevators in Embodiment 1 of this invention. It is a whole block diagram of the phase loss detection apparatus of the power supply for elevators in Embodiment 2 of this invention.

  A mode for carrying out the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
1 is an overall configuration diagram of a phase loss detection apparatus for an elevator power supply according to Embodiment 1 of the present invention.
Reference numeral 1 denotes an elevator power source. The elevator power supply 1 is provided on the building side. The elevator power source 1 is a commercial three-phase AC power source. Reference numeral 2 denotes a converter. The converter 2 is connected to each phase of the elevator power supply 1 via wiring 3. The converter 2 has a function of generating a DC power source from the elevator power source 1. 4 is an inverter. The inverter 4 has a function of generating AC power from the DC power generated by the converter 2.

  Reference numeral 5 denotes an elevator motor. The elevator motor 5 is provided in an elevator hoisting machine. The elevator motor 5 is rotated by an AC power generated by the inverter 4 and has a function of driving the elevator. 6 is a V-connection transformer. The V-connection transformer 6 is selected from the viewpoint of low cost and space saving. The V-connection transformer 6 has a function of converting a voltage output from the elevator power supply 1 and generating a power supply in the elevator.

  Reference numeral 7 denotes an interphase capacitor. The interphase capacitor 7 is connected between the wires 3 in the elevator control panel on the elevator power supply 1 side. Specifically, the interphase capacitor 7 includes a plurality of variable capacitors. These variable capacitors can change the capacitance. One end of these variable capacitors is connected to each wiring 3. On the other hand, the other ends of these variable capacitors are connected to each other.

  Reference numeral 8 denotes a voltage detection type phase loss detection circuit. This voltage detection type phase loss detection circuit 8 is connected to the three-phase input portion of the elevator power supply 1 via each wiring 3. The voltage detection type phase loss detection circuit 8 functions as a voltage detection device that detects the voltage of each wiring 3. The voltage detection type phase loss detection circuit 8 has a function of detecting phase loss of the elevator power supply 1 based on the detected voltage of each wiring 3. Reference numeral 9 denotes a phase loss detection controller. The phase loss detection controller 9 functions as a capacitor capacity control device that changes the capacity of the interphase capacitor 7.

  Reference numeral 10 denotes an elevator controller. The elevator controller 10 has a function of setting the detection period by temporarily changing the capacitance of the interphase capacitor 7 in the phase loss detection controller 9. The elevator controller 10 has a function of quickly switching the operation of the elevator to the operation corresponding to the power supply abnormality when the voltage detection type phase loss detection circuit 8 detects the phase loss of the elevator power source 1 during the detection period. Prepare.

Next, a method for changing the capacitance of the interphase capacitor 7 will be described with reference to FIG.
FIG. 2 is a diagram for explaining a method of changing the capacitance of the interphase capacitor using the phase loss detector for the elevator power supply according to Embodiment 1 of the present invention.

  A schematic diagram of a variable capacitor constituting the interphase capacitor 7 is shown on the left side of FIG. A detailed view of the variable capacitor is shown on the right side of FIG. As shown on the right side of FIG. 2, the first series body 11 and the second series body 12 are connected in parallel. The first series body 11 includes a first capacitor 13 and a first switch 14. The capacity of the first capacitor 13 is selected to be a value set for suppressing normal mode noise.

  On the other hand, the second series body 12 includes a second capacitor 15 and a second switch 16. The capacity of the second capacitor 15 is selected to be a value set so that the resonance frequency obtained from the inductance of the V-connection transformer 6 and the capacity of the interphase capacitor 7 is separated from the frequency of the elevator power supply 1 by a predetermined amount. .

  In the variable capacitor having such a configuration, the first switch 14 is normally closed and the second switch 16 is open. Thereby, normally, the variable capacitor has a capacity corresponding to the first capacitor 13. On the other hand, when the switching signal is received from the phase loss detection controller 9, the first switch 14 is opened and the second switch 16 is closed. As a result, the variable capacitor becomes the capacity of the second capacitor 15.

Next, a method for setting the capacitance of the second capacitor 15 will be described with reference to FIGS.
FIG. 3 is a diagram for explaining the connection state of the V-connection transformer of the elevator in which the phase loss detection device for the elevator power source according to Embodiment 1 of the present invention is used. FIG. 4 is a diagram for explaining a case where the S phase of the elevator power supply is lost in FIG. FIG. 5 is a diagram for explaining a case where the R phase of the elevator power supply is lost in FIG.

FIG. 3 shows an equivalent circuit of the elevator power supply 1, the V-connection transformer 6, and the interphase capacitor 17 having a fixed capacity. In FIG. 3, the capacitance of each capacitor constituting the interphase capacitor 17 is C (F). Further, in the V-connection transformer 6, the inductance between the connection point with the R phase and the connection point with the S phase of the elevator power supply 1 is L _RS (H). Further, the inductance between the connection point with the S phase and the connection point with the T phase of the elevator power supply 1 is L _ST (H).

  As shown in FIG. 3, when the V-connection transformer 6 is connected, the impedance from the S phase to the R phase and the T phase is balanced. On the other hand, the impedance from the R phase to the S phase and the T phase and the impedance of the S phase and the R phase viewed from the T phase are not balanced. When the phase failure of the elevator power supply 1 occurs, a voltage obtained by dividing the voltage of the connected phase by the impedance of the connected device appears from the phase that has been lost to another phase.

For example, when the S phase of the elevator power source 1 is lost, as can be seen from the circuit of FIG. A common current flows from the connection point to the T-phase connection point. For this reason, the inductances L _RS (H) and L _ST (H) of the V-connection transformer 6 are equal. The capacities of the capacitors of the interphase capacitor 17 are also equal. For this reason, the circuit of FIG. 4 appears to be balanced.

  In this case, the voltage between the R phase and the S phase of the elevator power supply 1 and the voltage between the S phase and the T phase of the elevator power supply 1 are between the R phase and the T phase of the elevator power supply 1. The voltage is half of the voltage. The voltage phase between the R phase and the S phase of the elevator power supply 1 and the voltage phase between the S phase and the T phase of the elevator power supply 1 are the same as the R phase and the T phase of the elevator power supply 1. The voltage phase is 180 degrees out of phase. That is, it does not appear that any phase of the elevator power supply 1 holds a certain voltage and phase. Therefore, it is easy to detect the phase loss of the elevator power supply 1 regardless of the size of each capacitor of the interphase capacitor 17.

  On the other hand, when the R phase of the elevator power supply 1 is lost, the transformer between the connection point with the R phase and the connection point with the S phase of the elevator power supply 1 is energized, as can be seen from the circuit of FIG. There is no. On the other hand, the transformer between the connection point with the S phase and the connection point with the T phase of the elevator power supply 1 is energized. For this reason, the impedances of these transformers are completely different from each other. Therefore, the impedance to the S phase and the T phase viewed from the R phase of the elevator power supply 1 is not balanced.

  In general, impedance has frequency dependency. Therefore, the voltage dividing ratio of the voltage dividing circuit formed by the inductance of the V-connection transformer 6 and the capacitance of the interphase capacitor 17 is determined by the frequency of the elevator power supply 1. When the resonance frequency of the voltage dividing circuit approaches the frequency of the elevator power supply 1, the impedance between the R phase and the other phase of the elevator power supply 1 increases. Thereby, the voltage of each phase of the elevator power supply 1 is distorted or shifted in phase due to the current flowing on the secondary side of the V-connection transformer 6. In this case, it may appear that any phase of the elevator power supply 1 holds some voltage and phase.

Here, when the inductance of the V-connection transformer 6 is simplified to L (H) and the frequency of the elevator power supply 1 is F (Hz), the frequency of the elevator power supply 1 is equal to the resonance frequency of the voltage dividing circuit. Is represented by the following equation (1).

In order not to be affected by this resonance, the resonance frequency of the voltage dividing circuit needs to be 1 / 10F or less, or 10F or more. Therefore, in the present embodiment, the capacity of the second capacitor 15 is set so that the interphase capacitor 17 at the time of phase loss detection of the elevator power supply 1 satisfies the following expression (2) or (3).

Next, the phase loss detection method of the elevator power supply 1 will be described with reference to FIG.
FIG. 6 is a flowchart for explaining the operation of the phase loss detector for the elevator power supply according to Embodiment 1 of the present invention.
When the elevator is operating normally, the first switch 14 is closed and the second switch 16 is open. As a result, the interphase capacitor 7 has a function of suppressing normal mode noise.

  In step S1, it is determined whether or not the elevator is normally stopped. If the elevator is stopped, the process proceeds to step S2. In step S <b> 2, the elevator controller 10 transmits a switching signal to the phase loss detection controller 9. As a result, the phase loss detection controller 9 switches the interphase capacitor 7 by opening the first switch 14 and closing the second switch 16. That is, the interphase capacitor 7 is switched to a value that does not resonate with the elevator power supply 1 and the detection period is set. Note that normal mode noise hardly occurs while the elevator is stopped. For this reason, there is no problem even if the value of the interphase capacitor 7 changes.

  Thereafter, the process proceeds to step S3, where it is determined whether or not the voltage detection type phase loss detection circuit 8 has detected phase loss of the elevator power supply 1. When the phase failure of the elevator power supply 1 is not detected, the process returns to step S1. On the other hand, when the phase failure of the elevator power supply 1 is detected, the process proceeds to step S4. In step S4, the elevator controller 10 shifts the operation of the elevator to the power supply abnormality handling mode.

  If the elevator is not stopped at step S1, the process proceeds to step S5. In step S5, it is determined whether any abnormality has occurred during the traveling of the elevator. If no abnormality has occurred, the process returns to step S1. On the other hand, if an abnormality has occurred, the process proceeds to step S6. In step S6, the elevator is urgently stopped and the process proceeds to step S7.

  In step S <b> 7, the elevator controller 10 transmits a switching signal to the phase loss detection controller 9. As a result, the phase loss detection controller 9 switches the interphase capacitor 7 by opening the first switch 14 and closing the second switch 16. As a result, the interphase capacitor 7 is switched to a value that does not resonate with the elevator power supply 1, and the detection period is set.

  Thereafter, the process proceeds to step S8, where it is determined whether or not the voltage detection type phase loss detection circuit 8 has detected a phase loss of the elevator power supply 1. If no phase failure of the elevator power supply 1 is detected, the process proceeds to step S9. In step S9, the elevator controller 10 shifts the operation of the elevator to an operation mode corresponding to the error content. On the other hand, when the phase failure of the elevator power supply 1 is detected in step S8, the process proceeds to step S4, and the elevator controller 10 shifts the operation of the elevator to the power supply abnormality handling mode.

  According to the first embodiment described above, the elevator controller 10 determines that the capacity of the interphase capacitor 7 is equal to the resonance frequency of the voltage dividing circuit formed by the V-connection transformer 6 and the interphase capacitor 7. The detection period is set by temporarily changing the value to a value set so as to be separated by a preset amount. The elevator controller 10 detects the phase loss of the elevator power supply 1 based on the voltage detected by the voltage detection type phase loss detection circuit 8 during the detection period. For this reason, even in the elevator power source 1 using the inexpensive V-connection transformer 6 and the voltage detection device, it is possible to reliably detect the phase loss without being affected by the surrounding impedance.

  Further, the elevator controller 10 sets the detection period when the elevator driven by the elevator power supply 1 is normally stopped during normal operation. For this reason, the phase failure of the elevator power supply 1 can be detected at a timing at which there is no adverse effect on the equipment inside the building due to noise.

  Furthermore, the elevator controller 10 sets a detection period when the elevator driven by the elevator power supply 1 is abnormal and makes an emergency stop. For this reason, even when the phase failure of the elevator power source 1 occurs during the traveling of the elevator and an abnormality is detected before the elevator stops, the phase failure of the elevator power source 1 can be reliably confirmed. Thereby, the operation | movement of the elevator according to the abnormality which has generate | occur | produced can be performed reliably.

Embodiment 2. FIG.
FIG. 7 is an overall configuration diagram of a phase loss detection device for an elevator power source according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to Embodiment 1 and an equivalent part, and description is abbreviate | omitted.
In the first embodiment, the capacitance of the interphase capacitor 7 is changed when phase loss is detected. On the other hand, the second embodiment has a configuration in which the connection of each wiring 3 by the interphase capacitor 7 is disconnected when the phase loss is detected.

  Specifically, a cutoff switch 18 is provided between the interphase capacitors 7 provided corresponding to each phase of the elevator power supply 1. That is, the cutoff switch 18 functions as a connection device that connects and disconnects the wires 3 by the interphase capacitor 7.

  In the phase loss detection device having such a configuration, the elevator controller 10 causes the cutoff switch 18 to temporarily disconnect the connection between the wires 3 by the interphase capacitor 7 via the phase loss detection controller 9 while the elevator is stopped. To set the detection period. The voltage detection type phase loss detection circuit 8 detects the phase loss of the elevator power source 1 based on the voltage of each wiring 3 during the detection period. Note that normal mode noise hardly occurs while the elevator is stopped. For this reason, there is no problem even if the interphase capacitor 7 is disconnected.

  According to the second embodiment described above, it is possible to reliably detect the phase failure of the elevator power supply 1 without grasping the inductance of the V-connection transformer 6. Therefore, even if it replaces with the V connection transformer 6 from which inductance differs, the phase loss of the power supply 1 for elevators can be detected easily.

1 power supply for elevator, 2 converter, 3 wiring, 4 inverter,
5 Elevator motor, 6 V connection transformer, 7-phase capacitor,
8 Voltage detection type phase loss detection circuit, 9 Phase loss detection controller,
10 elevator controller, 11 first series body, 12 second series body,
13 first capacitor, 14 first switch, 15 second capacitor,
16 Second switch, 17 Interphase capacitor, 18 Shut-off switch

Claims (4)

A voltage detecting device for detecting a voltage of each wiring in which an interphase capacitor is connected to the elevator power supply side and a V-connection transformer is connected to the elevator motor side between each phase of the elevator power supply and the elevator motor. When,
A capacitor capacity control device for changing the capacity of the interphase capacitor;
The resonance frequency of the voltage dividing circuit formed by the interphase capacitor and the V-connection transformer is determined from the value set for suppressing the normal mode noise from the value set in the capacitor capacity control device for suppressing the normal mode noise. Set the detection period by temporarily changing to a value set to be away from the frequency of the power supply by a preset amount,
A controller for detecting an open phase of the elevator power supply based on the voltage detected by the voltage detection device during the detection period;
A phase loss detection device for an elevator power supply, comprising: A voltage detecting device for detecting a voltage of each wiring in which an interphase capacitor is connected to the elevator power supply side and a V-connection transformer is connected to the elevator motor side between each phase of the elevator power supply and the elevator motor. When,
A connection device for connecting and disconnecting the wires by the interphase capacitor;
In the connection device, temporarily disconnect the connection between the wires by the interphase capacitor, set the detection period,
A controller for detecting an open phase of the elevator power supply based on the voltage detected by the voltage detection device during the detection period;
A phase loss detection device for an elevator power supply, comprising:   The lack of the elevator power supply according to claim 1 or 2, wherein the controller sets the detection period when an elevator driven by the elevator power supply is normally stopped during normal operation. Phase detector.   4. The elevator power supply according to claim 1, wherein the controller sets the detection period when an elevator driven by the elevator power supply is abnormal and makes an emergency stop. 5. Phase loss detection device.

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