JP4463912B2 - AC elevator power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a power supply device for an AC elevator.
[0002]
[Prior art]
2. Description of the Related Art In recent years, power electronics elements and technologies for controlling them have been used to control the speed of inverter motors by supplying variable voltage / variable frequency AC power to induction motors to drive elevator cars. .
[0003]
That is, as shown in FIG. 2, a current is supplied from the commercial power source 1 to the induction motor IM through the converter 2 and the inverter 3, and this current is the ideal speed command 4 and the actual elevator car from the pulse generator PG. In response to a command from the variable frequency current command calculation unit 7 through the speed regulator 6 by matching with the speed 5, the inverter 3 is operated through the sine wave PWM control device 8, and the elevator car 5 is appropriately speed controlled. It is what is done. Here, 9 is a counterweight.
[0004]
[Problems to be solved by the invention]
By the way, in the case of an elevator driven by the induction motor IM, each time, for example, when there are full passengers in the elevator car 5, or when no one is on board and the car is driven as an empty car according to the hall call, etc. Although the load fluctuates greatly, the power must be regenerated especially in the case of a down load operation, and is usually consumed as heat by the resistance R, and the power is often wasted. Of course, it is usual to design the power supply capacity in advance so that no inconvenience occurs even when the load is large.
Therefore, it was necessary to use a thick electric wire for the power line.
[0005]
The present invention has been made in view of the above points, and an object thereof is to provide an efficient power supply apparatus that does not waste regenerative power.
[0006]
[Means for Solving the Problems]
The present invention relates to an AC elevator including a commercial power source, an inverter that operates with power from the commercial power source to generate AC power, and an electric motor that is driven by AC power generated by the inverter.
A battery capable of charging / discharging, a charging / discharging circuit for charging and discharging the battery, a charging control element for closing the charging circuit, and a discharging control element for closing the discharging circuit And by controlling the operation of the charging / discharging circuit by turning on / off the charging control element and the discharging control element, a voltage command having a value corresponding to a constant voltage higher than the full-wave rectified voltage of the commercial power supply is targeted. A control circuit that controls input power to the inverter as a value, and the control circuit alternately turns on and off the charge control element and the discharge control element, thereby regenerating the battery by regenerative power from the motor. which charges, after supplying the generated electric power of the battery to the inverter, in accordance with the operation state of the charging state or the elevator of the battery, and the charging circuit Is intended to provide means Ru determining superiority or inferiority between the serial discharge circuit.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes a power supply device that does not waste power.
[0008]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a circuit diagram of a power supply device showing an embodiment of the present invention, and FIG. 3 is a control block diagram of the circuit shown in FIG.
[0009]
In the figure, the same reference numerals as those in FIG. 2 denote the same elements, but 10 is a power supply circuit according to the present invention, Tr1 and Tr2 are transistors, D1 and D2 are diodes, and E is a battery such as a nickel metal hydride battery. The battery E selects, for example, a predetermined number of units according to the capacity of the elevator with 8 cells as one unit. Q is a capacity meter for detecting the amount of charge of the battery E, L is a coil for boosting, RT is a current detector, 11 is an emergency power source used as a control power source for the microcomputer, etc. from the battery E in the event of an emergency such as a power failure, Is an emergency contact for disconnecting the power supply circuit 10 if it fails.
[0010]
As shown in FIG. 3, the power supply circuit 10 performs constant voltage control of the input voltage Vab of the inverter 3, and performs matching control by negatively feeding back the input voltage Vab of the inverter 3 in response to a constant voltage command.
The deviation signal e creates a current command via the transfer function G1 and the limiter circuit 20, matches the current command from the current detector RT, and inputs it to the comparator 21 through the transfer function G2.
[0011]
In the comparator 21, for example, the control signal C of the transistors Tr1 and Tr2 is generated by comparing the triangular wave α from the triangular wave generator 22 with the output signal from the transfer function G2. Since the negative element 23 is connected to the previous stage of the transistor Tr2, the transistors Tr1 and Tr2 are not simultaneously turned on.
[0012]
If the commercial power source 1 is 200V, the voltage passed through the converter 2 is normally about 280V. Here, if the voltage command of FIG. The voltage is controlled to maintain the input voltage Vab at 350V.
[0013]
That is, when the input voltage Vab is 350 V, the deviation signal e is zero, the current command i through the limiter circuit 20 is also zero, and the output of the comparator 21 has the waveform shown in FIG.
[0014]
That is, since the comparator 21 outputs a control signal C that alternately turns the transistors Tr1 and Tr2 into the ON state for the same time, the battery E repeats charging and discharging alternately for the same time, and the input voltage Vab of the inverter 3 is set to 350V. Try to keep on.
[0015]
If the input voltage Vab becomes lower than 350 V, the output of the comparator 21 is in the state shown in FIG. 5A, the time for turning on the transistor Tr1 is short, and the transistor Tr2 is turned on. The time becomes longer, and eventually discharge from the battery E is prioritized.
[0016]
On the other hand, if the input voltage Vab becomes higher than 350 V, the output of the comparator 21 will be in the state shown in FIG. 5B, the time for turning on the transistor Tr2 is short, and the transistor Tr1 is turned on. The time is long, and voltage control is performed to maintain the command voltage by giving priority to the charging of the battery E.
[0017]
Incidentally, the normal route for discharging the battery E is the battery E, the current detector RT, the coil L, the transistor Tr2, and the battery E. On the other hand, the normal route for charging the battery E is the terminal a, the contact 12, The transistor Tr1, the coil L, the current detector RT, the battery E, and the terminal b. When the transistors Tr1 and Tr2 are OFF, the charging / discharging current of the battery E by the coil L flows instantaneously through the diode D2 or D1.
[0018]
Here, when the charge state of the battery E detected by the capacity meter Q is, for example, 30% or less of the rated capacity, the limiter value on the discharge side of the limiter circuit 20 is set to zero, and the control system performs only charging. In addition, when the charge state of the battery E is, for example, 80% or more of the rated capacity, if the limiter value on the charge side of the limiter circuit 20 is set to zero and only discharge is performed, overcharge or complete discharge By preventing this, it is possible to extend the battery life.
[0019]
By charging the battery from the commercial power source when the elevator stops, the charge state detected by the capacity meter Q can be maintained at, for example, about 60% of the rated capacity, so that the battery is kept in the best state. Can do. (If it exceeds 60%, an AC power source may be made from a battery like the emergency power source 11 and used as a control power source.)
Incidentally, the best state means a state where the battery can be freely charged / discharged regardless of whether the next elevator operation is a regenerative operation or a driving operation.
[0020]
In particular, if another elevator control inverter 3 'is connected in parallel, the power running / regenerative operation of each elevator can be canceled well, and further an energy saving effect can be exhibited.
[0021]
If the input voltage Vab of the inverter 3 becomes too high, the transistor Tr3 is turned on and the regenerative power is consumed by the resistor R.
[0022]
The operation of the limiter value of the limiter circuit 20 can be changed according to not only the above-described charging state of the battery E but also the operating state of the elevator.
An appropriate amount of the charge amount of the battery E may be changed according to weekdays, holidays, or time zones. That is, for example, when power running is expected to continue during office work, for example, the amount of charge of the battery E is increased and priority is given to use as an auxiliary power source. When continuous operation is expected, the regenerative operation is prioritized by keeping the charge amount of the battery E low. In normal times, power running and regeneration are performed almost alternately, so the charge amount of the battery E is set to about 60% of the rated capacity.
[0023]
In addition, even if power running / regeneration continues, the limit value of the limiter on the discharge side is maintained so that the amount of charge of the battery E does not change so much, for example, about 30% of the motor rated power can be supplied. Thus, the remaining 70% of the power to be supplied from the commercial power source can be used even when the elevator is loaded, and as a result, the capacity of the power supply facility can be considerably reduced.
Furthermore, various methods such as allowing only the charging mode to be performed while the elevator car is stopped are conceivable.
[0024]
In such a circuit, even if a power failure occurs during operation of the elevator, if the brake of the electric motor IM is not dropped, the elevator can be promptly stopped at the target floor without stopping at the time of a power failure. Can do. In particular, instantaneous power failure countermeasures will be taken naturally.
[0025]
In this embodiment, a system is described in which the elevator is driven in a sliding manner by an electric motor. For example, a system in which a battery is loaded on a counterweight and a sheave (not shown) on the counterweight side is directly driven is adopted. It is also possible.
[0026]
【The invention's effect】
As described above, according to the present invention, even if a load such as an elevator fluctuates significantly only by newly adding a power supply device according to the present invention, the power supply device is appropriately changed through normal operation of the elevator. Since the regenerative power can be absorbed and the driving power can be supplemented, it is not necessary to provide a large power supply facility in advance. Power supply facilities can be kept low. In addition, energy can be saved by absorbing regenerative power.
Furthermore, since charging / discharging operation of the battery used in the power supply device is appropriately performed, there is no problem even if a power failure occurs.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a power supply device showing an embodiment of the present invention.
FIG. 2 is a schematic diagram showing an example of a conventional AC elevator control device.
FIG. 3 is a control block diagram of the circuit shown in FIG. 1;
4 is a diagram showing signals at various parts in FIG. 3. FIG.
FIG. 5 is a diagram showing signals at various parts in FIG. 3;
[Explanation of symbols]
1 Commercial power supply 3 Inverter 10 Power supply E Battery Q Capacity meter
Tr1, Tr2 Transistor 20 Limiter circuit 1 Comparator 2 Triangular wave generator

Claims (7)

In an AC elevator comprising a commercial power source, an inverter that operates with power from the commercial power source to generate AC power, and an electric motor that is driven by AC power generated by the inverter,
A battery capable of charging / discharging, a charging / discharging circuit for charging and discharging the battery, a charging control element for closing the charging circuit, and a discharging control element for closing the discharging circuit And by controlling the operation of the charging / discharging circuit by turning on / off the charging control element and the discharging control element, a voltage command having a value corresponding to a constant voltage higher than the full-wave rectified voltage of the commercial power supply is targeted. A control circuit that controls input power to the inverter as a value, and the control circuit alternately turns on and off the charge control element and the discharge control element, thereby regenerating the battery by regenerative power from the motor. which charges, after supplying the generated electric power of the battery to the inverter, in accordance with the operation state of the charging state or the elevator of the battery, and the charging circuit Power supply AC elevator, characterized in that it comprises means for determining the relative merits of the serial discharge circuit. The power supply apparatus for an AC elevator according to claim 1, wherein the control circuit is a control circuit that performs negative feedback control of an input voltage to the inverter with a predetermined voltage command as a target value. 3. The AC elevator power supply apparatus according to claim 1, wherein the battery selects a predetermined number of units according to an elevator capacity. 4. The AC elevator power supply apparatus according to any one of claims 1 to 3, wherein a plurality of elevators are installed, inverters are provided for each elevator control, and the inverters are connected in parallel. The said power supply device includes a current command circuit having a limiter has a function of instructing the charging or discharging of the battery, to claim 1, characterized in that the limiter values of the limiter to the variable under certain conditions The power supply apparatus of the AC elevator as described. 6. The AC elevator power supply apparatus according to claim 5 , wherein when the state of charge of the battery reaches 80% or more of the rated capacity, the charge side limiter value for the battery is set to zero. 6. The AC elevator power supply apparatus according to claim 5 , wherein when the state of charge of the battery becomes 30% or less of the rated capacity, the limit value on the discharge side of the battery is set to zero.

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