JPH0617196B2 - Elevator control equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an elevator control device, and more particularly, to a passenger by automatically and promptly landing a car on the nearest floor when a power failure occurs. The present invention relates to a control device for an elevator that is suitable for use in driving to evacuate a vehicle.

[Prior Art] Elevator control by conventional technology to evacuate passengers in the event of a power outage is performed by disconnecting the AC power supply of the power converter that supplies power to the drive motor and connecting the emergency battery to operate during a power outage. Is to do.

As a conventional technique relating to the elevator control device as described above, for example, the techniques described in Japanese Patent Laid-Open Nos. 61-12072 and 63-174586 are known.

[Problems to be Solved by the Invention] The above-described conventional technology does not consider the voltage level difference between the AC power source connected to the input side of the power converter and the battery, and particularly, the input side of the power converter. No consideration was given to the level difference between the voltage due to the electric charge remaining in the overvoltage absorption capacitor connected to the battery and the voltage of the battery. This overvoltage absorption capacitor holds a high voltage at the time of power failure, and a high voltage in the opposite direction to the power source of the battery depending on the phase of the AC power source.

Therefore, in the conventional technique, when the AC power supply is disconnected and the battery is connected in the event of a power failure, a large current may flow in the peripheral circuit, which may overload the battery and the peripheral circuit and destroy them. I have a problem.

The object of the present invention is to solve the above-mentioned problems of the prior art, to disconnect the AC power supply at the time of a power failure, and to connect a battery, do not apply an excessive load to the battery and peripheral circuits, and perform stable elevator emergency operation. It is to provide a control device for an elevator that enables the operation.

[Means for Solving the Problems] According to the present invention, the object is to disconnect the AC power supply and switch to a second power supply such as a battery to discharge the electric charge possessed by the capacitor, the voltage of the capacitor, and the battery. Second
This is achieved by minimizing the voltage difference from the voltage of the power source and then switching the power source. Also,
The purpose is to cut off the AC power supply and switch to a second power supply such as a battery by inserting a current limiting element between the capacitor and the second power supply for a predetermined time, thereby causing a current caused by electric charge held in the capacitor. It is achieved by suppressing.

[Operation] The electric charge of the capacitor can be discharged by creating an electric circuit connecting both ends of the capacitor. A first means of the present invention is to create an electric circuit connecting both ends of the capacitor by using a control method of a power converter.

That is, the control device for driving an ordinary elevator is
Power converter, a second power converter, and a DC reactor that connects them, and is controlled so that a DC current always flows. , When these power converters are made to perform power conversion operation, a power path of capacitor ⇒ first power converter ⇒ DC reactor ⇒ second power converter is created, and this second power converter is formed.
A current path in the opposite direction to that described above is created through the electric motor of the second power converter or the electric motor that is the load of the second power converter, whereby the charge of the capacitor can be discharged.

A second means of the present invention is to discharge the electric charge of the capacitor by once connecting a conductor or a resistor to both ends of the high voltage prevention capacitor after disconnecting the AC power supply.

The present invention discharges the electric charge of the capacitor held at the time of power failure by the above-mentioned first or second means, thereby reducing the voltage difference between the voltage of the battery and the voltage of the capacitor, It is possible to prevent an excessive load on the peripheral circuit.

On the other hand, the maximum value of the current that flows when the capacitor and battery are connected is determined by the difference between the voltage held by the capacitor and the voltage of the battery. The maximum value of the current can be suppressed by connecting the element.

Therefore, the third means of the present invention is to insert a current limiting element into the current path after disconnecting the AC power source, whereby the battery and the peripheral circuits are discharged without discharging the charge of the capacitor. Excessive load can be prevented.

[Embodiment] An embodiment of an elevator control apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing the configuration of the first embodiment of the present invention, and FIG. 2 is a timing chart showing the waveform of each part for explaining the operation thereof. In FIG. 1, 1 is an AC power supply, 2 is an overvoltage absorption capacitor, 3 is a first power converter, 4 is a DC reactor, 5 is a second power converter, 6 is a filter capacitor, 7 is an electric motor, and 8 is Speed reducer, 9 sheave, 10 counterweight, 11 car, 12 rope, 13 power failure detector, 14 and 15 electromagnetic contactor, 16 battery, 17 resistance, 18 speed control circuit, Reference numeral 19 is a power converter control circuit, 20 and 23 are signal generation circuits, 21 and 24 are drive circuits, 22 is a current detector, and 25 is a speed detector.

In the elevator control apparatus of one embodiment of the present invention shown in FIG. 1, the main circuit thereof is an AC power supply 1 and self-extinguishing elements G _{1 to} G ₆ for converting the AC power of the AC power supply 1 into DC.
And a first power converter 3 configured to absorb the overvoltage generated when the self-extinguishing elements G _{1 to} G ₆ are ignited.
Second power converter composed of an overvoltage absorbing capacitor 2 connected to the input side of the power converter 3, a DC reactor 4 for smoothing a DC current, and a self-extinguishing element for converting to a DC voltage AC power. 5 and a filter capacitor 6 for reducing harmonic components contained in the AC power output from the second power converter 5.

Then, the electric motor 7 receives the supply of the AC power from the second power converter 5, generates a driving force, and transmits the driving force to the sheave 9 via the speed reducer 8. Car 1 for sheave 9
The rope 12 connecting the 1 and the counterweight 10 is covered, and the operation of the car 11 is controlled by the rotation of the sheave 9.

The control circuit that controls the above-described control circuit is a signal that controls the ignition of the speed control circuit 18, the power converter control circuit 19, and the self-extinguishing elements G _{1 to} G ₆ that form the first power converter. Signal generation circuit 20 and drive circuit 21 for generating P _{1 to} P ₆
A current detector 22, a signal generating circuit 23 and a drive circuit 24 for generating a signal for controlling the ignition of the self-extinguishing element forming the second power converter, and a speed for detecting the rotation speed of the electric motor 7. And a detector 25.

The speed control circuit 18 receives the power supply establishment signal S _P from the power failure detector 13, the speed feedback signal S _V from the speed detector 15, and other command signals not shown, and receives the speed command S _C1 and pulse switching. The command S _B and the conversion suppression signal S _S for stopping the power conversion are output. Further, the power converter control circuit 19 uses the speed command S from the speed control circuit 18.
_C1 and the pulse switching command S _B , the speed feedback signal S _V from the speed detector 15, and the current detection output S _I from the current detector 22 are received, and the control signal S _C2 for the signal generating circuits 20 and 23, Output S _C3 .

The signal generation circuit 20 creates pulse signals P _{1 to} P ₆ corresponding to the control signal S _C2 while synchronizing with the AC power supply 1 based on the power supply synchronization signal S ₀ from the power failure detection circuit 13. Drive circuit 22 receives the pulse signal P ₁ to P _6, in response to the pulse signal P ₁ to P _6, the self-turn-off devices G ₁
Let G ₆ perform the switching operation.

As a result, the AC power from the AC power supply 1 is converted into DC power by the first power converter 3 and the DC reactor 4
To the second power converter 5.

The second power converter 5 is a control signal S for instructing conversion from the power converter control circuit 19 into alternating current of an arbitrary frequency.
_{With the} signal generation circuit 23 and the drive circuit 24 that receive _C3 ,
The self-extinguishing element is subjected to switching control in substantially the same manner as described above, and converts the DC power from the first power converter 3 into three-phase AC power of variable frequency.

The details of the operation according to the present invention of the first embodiment of the present invention which performs the basic operation as described above will be described with reference to the timing chart shown in FIG.

In FIG. 2, up to time t ₁ , the AC power supply 1 is normal, and the first power converter 3 converts this AC power into DC. Therefore, the power supply voltages V _UV , V _VW , and V _WU between the respective phases of the AC power supply 1 are changed in a sine wave shape. Pulse signal P ₀ output from the signal generation circuit 20
P ₆ is synchronized with the power supply, and its pulse width is distributed in a sine wave shape. Then, a DC voltage self-turn-off devices G ₁ ~G ₆ which is switching-this pulse signal P ₀ to P ₆ outputs is a pulse shape as shown as V _d in Figure 2, by the DC voltage The current flowing through the second power converter 5 has a continuous waveform as shown by I _{d in} FIG. 2 due to the action of the DC reactor 4.

At the time of power failure, the power source is from AC power source 1 to second power source, battery 1
The circuit for switching to 6 comprises a power failure detector 13, electromagnetic contactors 14 and 15, a battery 16 and a resistor 17, and the power failure detector 13 is a power supply establishment signal which becomes “L” level at the time of power failure. It outputs S _P and the power supply synchronization signal S ₀ .

Now, when a power failure occurs at time t ₁ , the power failure detector 13
Sets the power supply establishment signal _SP to "L" level to notify the speed control circuit 18 of the occurrence of a power failure. As a result, the speed control circuit 18 sets the control signal S ₁ to the electromagnetic contactor 14 to the “L” level, releases the electromagnetic contactor 14, and disconnects the first power converter 3 and the AC power supply 1.

At the same time, the speed control circuit 18 prevents the first and second power converters 3 and 5 from performing the power conversion operation in the abnormal state of power failure.
The conversion suppression signal S _S for 1 and 24 is set to the “L” level to stop the power conversion operation. As a result, the overvoltage absorption capacitor 2 connected to the input side of the first power converter 3 retains a high voltage.

Therefore, the speed control circuit 18 sets the conversion inhibition signal S _S to the “H” level at time t ₂ to cause the first and second power converters 3 and 5 to temporarily perform the power conversion operation. As a result, the residual charge of the capacitor 2 is discharged.

After that, the speed control circuit 18 again drops the conversion inhibition signal S _S to the “L” level at time t ₃ , but at this time, the electric charge of the capacitor 2 is completely discharged.

Next, the speed control circuit 18 sets the pulse switching signal S _B to the “H” level at a time t ₄ when a sufficient time has elapsed from the discharging process of the capacitor 2 described above. This pulse switching signal S _B is sent to the signal S _BB via the power converter control circuit 19.
Is transmitted to the signal generating circuit 20, and the pulse signal P ₁
Switch the to P ₆ from AC power to DC power supply. Further, the speed control circuit 18 turns on the electromagnetic contactor 15 by setting the control signal S ₂ for the electromagnetic contactor 15 to “H” level at time t ₅ when the switching of the pulse signals P _{1 to} P ₆ is completed. As a result, the battery 16 and the resistor 17 are connected to the first power converter 3. After that, the speed control circuit 18
At time t ₆ , the conversion inhibit signal S _{S is set} to the “H” level, and the first
And the second power converters 3 and 5 are caused to start the power conversion operation.

According to the first embodiment of the present invention, by the above operation, it is possible to supply the DC power to the second power converter 5 even during a power failure, operate the elevator, and move the car 11 to the evacuation floor 2
6 can be landed.

According to the above-described first embodiment of the present invention, the first and second
It is possible to completely discharge the electric charge of the capacitor 2 at the time of switching the power supply without changing the configuration of the control device by only operating the timing of the control signal to the power converters 3 and 5 of FIG. Also, the power supply can be switched at the time of power failure without applying an excessive load to the peripheral circuits.

FIG. 3 is a circuit diagram showing the configuration of the second embodiment of the present invention, and FIG. 4 is a timing chart showing the waveforms of control signals for explaining the operation thereof. In FIG. 3, 28 is a discharge resistor, 29 is an electromagnetic contactor, and other reference numerals are the same as those in FIG.

The second embodiment of the present invention shown in FIG. 3 is to discharge the residual charge of the capacitor 2 using the discharge resistor 28 at the time of switching the power supply during a power failure. The electromagnetic contactor 29 differs from the first embodiment of the present invention in that the electromagnetic contactor 29 is controlled to be closed and released by the control signal S ₃ from the speed control circuit 18, and is otherwise different. , Are similarly configured.

Next, the operation of the second embodiment of the present invention will be described with reference to FIG.

Now, when a power failure occurs at time t ₁ , the power failure detector 13 sets the power supply establishment signal _SP to the “L” level to notify the speed control circuit 18 of the power failure, as described above.
As a result, the speed control circuit 18 sets the control signal S ₁ to the electromagnetic contactor 14 to the “L” level, and the electromagnetic contactor 1
4 is released, and the power conversion operation is stopped by setting the conversion suppression signal S _S “L” level.

Next, the speed control circuit 18 during the time t ₂ ~t _3, the control signal S ₃ as "H" level, and charged electromagnetic contactor 29, to discharge the capacitor 2, then the time t ₄
Then, the pulse switching signals S _B and S _BB are set to the “H” level to switch the power conversion operation from the AC power supply to the DC power supply. Then, the speed control circuit 18 further determines that the time t
_{At 5} the control signal S _{2 is set} to “H” level and the battery 16 is connected. At time t ₆ , the conversion suppression signal S _{S is set} to “H” level to cause the power conversion operation at the time of power failure to control the operation of the elevator. .

According to the second embodiment of the present invention as described above, the same effect as that of the first embodiment can be obtained.

FIG. 5 is a circuit diagram showing the configuration of the third embodiment of the present invention, and FIG. 6 is a timing chart showing the waveform of a control signal for explaining the operation thereof. In FIG. 5, 31 is a current limiting resistor, 32 and 33 are electromagnetic contactors, 34 is a DC motor, 3
Reference numeral 5 is a field control circuit, and other symbols are the same as those in FIG.

The third embodiment of the present invention shown in FIG. 5 is one in which the present invention is applied to an elevator control device using a DC motor 34 as an electric motor for driving an elevator, and a second power converter is provided. Without the first power converter 3
Is connected to the DC motor 34. Then, the field of the DC motor 34 is controlled by the power converter control circuit 19
It is controlled by the field control circuit 35 which controls the current of the field coil based on the control signal S _C4 from

In the third embodiment of the present invention, a current limiting resistor 31 and electromagnetic contactors 32, 33 are provided in the main circuit thereof in order to limit the discharge current due to the capacitor charge when the battery is connected. ing.

The operation of the third embodiment of the present invention will be described with reference to FIG.

Now, when a power failure occurs at time t ₁ , the power failure detector 13 sets the power supply establishment signal _SP to the “L” level to notify the speed control circuit 18 of the power failure, as described above. As a result, the speed control circuit 18 sets the control signal S ₁ to the electromagnetic contactor 14 to the “L” level, and the electromagnetic contactor 14
AC power source 1 is disconnected, and the power conversion operation is stopped by setting the conversion suppression signal S _S “L” level,
At the same time, the control signal S ₅ for the electromagnetic contactor 33 is set to the “L” level, and the electromagnetic contactor 33 is released.

Next, the speed control circuit 13 outputs the control signal S _{6 at} time t ′ _2.
Is set to the “H” level, the electromagnetic contactor 32 is turned on, the current limiting resistor 31 is inserted into the circuit, and then, at time t ′ ₃ , the pulse switching signals S _B and S _BB are set to the “H” level,
The power conversion operation is switched from AC power supply to DC power supply. Further, the speed control circuit 18 sets the control signal S ₂ to the “H” level at time t ′ ₄ to connect the battery 16, and
₅ , the electromagnetic contactor 32 is released, the electromagnetic contactor 33 is turned on, the current limiting resistor 31 is disconnected, and the conversion suppression signal S _{S is set} to “H” level at time t ₆ to perform the power conversion operation at the time of power failure. Control the operation of the elevator.

According to the third embodiment of the present invention described above, by adding a simple circuit and performing simple timing control together, it is possible to suppress the inrush current at the time of switching the current,
It is possible to prevent an excessive load from being applied to the battery and peripheral circuits.

The method of the third embodiment of the present invention described above can also be applied to a control device for an elevator including a second power converter as in the first and second embodiments of the present invention,
Further, conversely, the methods of the first and second embodiments of the present invention are applied to the elevator control device configured by connecting the DC motor to the first power converter as in the third embodiment. can do.

Further, in the above-described embodiment of the present invention, the battery is used as the second power source, but the second power source may be another emergency AC power source.

[Effects of the Invention] As described above, according to the present invention, an excessive load is not applied to the second power supply such as a battery and its peripheral circuits at the time of switching the power supply during a power failure in the elevator control device. Therefore, it is possible to eliminate the need to set large capacitances of elements, contactors, and the like that form the peripheral circuit. Further, according to the present invention, the capacity of the overvoltage absorption capacitor connected to the input side of the first power converter can be set to the capacity in normal times, and when this capacitor is operated by an AC power supply, It can be shared with the case of operating with a second power source such as a battery.

Furthermore, according to the present invention, it is possible to provide a highly reliable control device for the elevator while avoiding the increase in size of the device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a first embodiment of the present invention, FIG. 2 is a timing chart showing waveforms of respective parts for explaining its operation, and FIG. 3 is a configuration of a second embodiment of the present invention. FIG. 4 is a timing chart showing the waveform of a control signal for explaining the operation, FIG. 5 is a circuit diagram showing the configuration of the third embodiment of the present invention, and FIG. 6 is for explaining the operation. 3 is a timing chart showing a waveform of a control signal for controlling. 1 is an AC power supply, 2 is an overvoltage absorption capacitor, 3 is a first power converter, 4 is a DC reactor, 5 is a second power converter, 6 is a filter capacitor, 7 is an electric motor, 8 is a speed reducer, 9 is Sheave, 10 is a counterweight, 11 is a basket,
12 is a rope, 13 is a power failure detector, 14, 15, 29, 3
2, 33 are electromagnetic contactors, 16 are batteries, 17 are resistors, 18
Is a speed control circuit, 19 is a power converter control circuit, 20, 2
3 is a signal generation circuit, 21 and 24 are drive circuits, 22 is a current detector, 25 is a speed detector, 28 is a discharge resistor, 31 is a current limiting resistor, 34 is a DC motor, and 35 is a field control circuit.

Claims (6)

[Claims] 1. A first power converter for converting AC power from a power source into DC power, and a second power converter for converting DC power supplied from the first power converter via a DC reactor into AC power. A power converter, an AC motor driven by AC power from the second power converter, a capacitor connected to the input side of the first power converter, and the AC power disappearing, In an elevator control device comprising a power supply switching means for switching to a second power supply, the power supply switching means, when the AC power disappears, disconnects the AC power, and then discharges the electric charge remaining in the capacitor, After that, the elevator control device is characterized by switching to the second power source. 2. A first power converter for converting AC power from a power supply into DC power, and a DC motor driven by DC power supplied from the first power converter via a DC reactor. In an elevator control device comprising a capacitor connected to an input side of the first power converter and a power source switching unit that switches to a second power source when the AC power disappears, the power source switching unit may include: When the AC power disappears, the AC power is cut off, the electric charge remaining in the capacitor is discharged, and then the electric power is switched to the second power supply. 3. The electric power conversion operation of the first and second power converters for discharging the electric charge remaining in the capacitor by the power supply switching means. Elevator control device. 4. The elevator according to claim 2, wherein the electric power remaining in the capacitor is discharged by the power supply switching means by a power conversion operation of the first power converter. Control device. 5. The discharge of the electric charge remaining in the capacitor by the power supply switching means is performed by connecting a resistor to the capacitor for a predetermined time required for discharging the electric charge. The elevator control device according to item 1 or 2. 6. The power supply switching means inserts a current limiting element between the second power supply and the capacitor for a predetermined time after disconnecting the AC power when the AC power disappears. After that, the control device for the elevator according to claim 1 or 2, wherein the control device is switched to the second power source.