JP2001139244A - Power supply device for ac elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device for an AC elevator capable of absorbing regenerative power properly while performing normal operation of the elevator based on a capacity meter and correcting an error of the capacity meter automatically and properly in a device compensating driving power. SOLUTION: In this power supply device which controls a motor of an elevator through an inverter 3 and controls an input voltage of the inverter to a fixed voltage based on electric power from commercial power supply 1, the power supply device consists of a battery E, charging circuits Tr1, Tr2 and discharging circuits D1, D2 of the battery, and a capacity meter Q. A means for preventing discharging into the battery and a means for preventing charging into the battery are provided under predetermined conditions to perform the operation at charging or discharging mode of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a power supply for an AC elevator.

[0002]

2. Description of the Related Art In recent years, with the advancement of power electronics elements and the technology for controlling the same, an inverter car is operated by supplying AC power of a variable voltage and a variable frequency to an induction motor to control the speed and operate an elevator car. Has been adopted.

That is, as shown in FIG. 2, an induction motor IM is supplied from a commercial power supply 1 through a converter 2 and an inverter 3.
The current is supplied to the ideal speed command 4
The inverter 3 is operated via the sine wave PWM control device 8 by a command from the variable frequency current command calculation unit 7 via the speed controller 6 by comparing the actual speed of the elevator car 5 from the pulse generator PG with the speed. Then, the speed of the elevator car 5 is appropriately controlled. here,
9 is a counterweight.

[0004] In the case of an elevator driven by an induction motor IM, when the elevator car 5 is full of passengers, or when nobody is on board and the car is operated as an empty car in response to a hall call, etc. Each time, the load fluctuates greatly. In particular, in the case of unloading operation, power must be regenerated, and it is generally consumed as heat by the resistor R. There were many.
In general, the power supply capacity is usually designed with a margin so that no inconvenience occurs even when the load is large. Therefore, a thick electric wire had to be used for the power supply line and the like.

For this reason, recently, the applicant has proposed an efficient power supply device which does not waste regenerative power as described below.

FIG. 3 is a circuit diagram of this power supply device, and FIG.
4 is a control block diagram of the circuit shown in FIG.

2, the same reference numerals as those in FIG. 2 denote the same parts, but reference numeral 10 denotes a power supply circuit, 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 a predetermined number of units according to the capacity of the elevator, for example, with eight cells as one unit. Q is a capacity meter for detecting the amount of charge of the battery E, L is a step-up coil, RT is a current detector, 11 is the battery E in an emergency such as a power outage.
Emergency power supply used as a control power supply for microcomputers, 12
Are emergency contacts for disconnecting the power supply circuit 10 in the event of a failure.

As shown in FIG. 4, the power supply circuit 10 controls the input voltage Vab of the inverter 3 at a constant voltage.
For a given voltage command, the input voltage Vab of the inverter 3 is negatively fed back to perform the matching control. The deviation signal e generates a current command through the transfer function G1 and the limiter circuit 20, matches the current command with the current feedback from the current detector RT, and inputs the current command to the comparator 21 through the transfer function G2.

In the comparator 21, for example, the triangular wave α from the triangular wave generator 22 is compared with the output signal from the transfer function G2 to control the control signal C for the transistors Tr1 and Tr2.
Has been created. Since the negation element 23 is connected in front of the transistor Tr2, the transistors Tr1 and Tr2 are not turned on at the same time.

If the commercial power supply 1 is assumed to be 200 V,
The voltage passed through the converter 2 is usually about 280V,
Here, if the voltage command of FIG. 4 is set to about 350 V,
The control system of the power supply circuit 10 is voltage-controlled to maintain the input voltage Vab of the inverter 3 at 350V.

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.

That is, since the comparator 21 outputs a control signal C for alternately bringing the transistors Tr1 and Tr2 to the ON state for the same time, the battery E alternately repeats charging and discharging for the same time, and the input voltage of the inverter 3 Vab to 350V
Try to keep on.

If the input voltage Vab becomes lower than 350 V, the output of the comparator 21 changes to the state shown in FIG. 6A, the time for turning on the transistor Tr1 is short, and the time for turning on the transistor Tr2 is turned on. The time to state becomes longer,
Eventually, the priority is given to the discharge from the battery E.

On the other hand, if the input voltage Vab is higher than 350 V, the output of the comparator 21 will be in the state shown in FIG. 6B, the time for turning on the transistor Tr2 is short, and the transistor Tr1 is turned on. The time for setting the state becomes longer, and the voltage is controlled to maintain the command voltage by giving priority to charging the battery E.

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, while the normal route for charging the battery E is the terminal a, Contact 12, transistor Tr1, coil L, current detector R
T, battery E, and terminal b. When the transistors Tr1 and Tr2 are turned off, the diode D2 or D1
The charging / discharging current of the battery E by the coil L flows through the coil L instantaneously.

Here, when the state of charge of the battery E detected by the capacity meter Q is, for example, 30% or less, 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 state of charge of the battery E is, for example, 80% or more, the limiter value on the charging side of the limiter circuit 20 is set to zero to perform only discharge, thereby preventing overcharge or complete discharge. Can extend the life of the battery.

By charging the battery from the commercial power supply when the elevator stops, the charged state detected by the capacity meter Q is set to, for example, about 60%, so that the charged state of the battery is maintained in the best state. Can be. (If the state exceeds 60%, the emergency power supply 11
It is sufficient to make an AC power supply from a battery and use it as a control power supply. Incidentally, the best state means a state in which the battery can be freely charged and discharged regardless of whether the next elevator operation is a regenerative operation or a drive operation.

The input voltage Vab of the inverter 3
Is too high, the transistor Tr3 is turned on so that the resistor R consumes regenerative power.

The operation of the limiter value of the limiter circuit 20 can be changed according to the operating state of the elevator as well as the state of charge of the battery E described above. The appropriate amount of charge of the battery E may be changed depending on weekdays, holidays, or time zones. That is, for example, when continuous powering operation such as when going to work in an office building is expected, the charge amount of the battery E is increased, and the use as an auxiliary power source is prioritized. Is expected, the charge amount of the battery E is suppressed to a low level, and the regenerative operation is prioritized. Then, in normal times, power running and regeneration are performed almost alternately, so that the charge amount of the battery E is set to about 60%.

[0020]

However, the capacity meter Q
Has a detection error in principle, and this error accumulates with the passage of time, and there is a problem that the function of the new power supply device cannot be sufficiently performed.

The present invention has been made in view of the above points, and has as its object to provide an apparatus which can appropriately correct even if a detection error occurs in a capacitance meter.

[0022]

According to the present invention, under predetermined conditions, charging is continued until the battery voltage is sufficiently high to reach the gas generation voltage, or discharging is continued until the battery voltage is sufficiently low, and the detection error of the capacity meter is detected. Is to be eliminated.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is intended to selectively operate a battery in a charging mode or a discharging mode under a predetermined condition.

[0024]

FIG. 1 is a control block diagram for instructing a charge mode according to an embodiment of the present invention. In FIG. 1, the same reference numerals as those in FIG. This is a limiter that commands a charge mode in which the limiter value (limit value) is set to zero.

In this device, if the limiter value on the discharge side is set to zero every predetermined time, for example, every hour, as in the limiter 20 ', the operation is completely switched to the operation of the elevator in the charging mode using the battery E during that time. become. It is also conceivable to set the charging mode by selecting that the elevator is stopped.

As a result, the battery E is thoroughly charged until the terminal voltage of the battery E becomes sufficiently high (for example, until a voltage at which gas generation starts inside the battery).

At this time, if the capacity meter Q is surely preset, the accumulation of detection errors can be eliminated.

In the above description, an example of the operation in the charging mode for the battery has been described. However, it is also possible to operate the battery in the discharging mode. That is, until the terminal voltage of the battery E becomes sufficiently low (for example, until the terminal voltage becomes about 1/3 or less of the rated voltage of the battery E), the limiter value on the charging side is set to zero, and the elevator continues to operate. A method of completely discharging the battery and resetting the capacity meter Q is also conceivable.

[0029]

As described above, according to the present invention, the new power supply device absorbs the regenerative electric power as appropriate while performing the normal operation of the elevator based on the capacity meter.
In the device that supplements the driving power, the error of the capacity meter can be automatically corrected as appropriate, so that the effects of the new power supply device can be fully exhibited.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a power supply device according to 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 circuit diagram of a new power supply device.

FIG. 4 is a control block diagram of the circuit shown in FIG. 3;

FIG. 5 is a diagram showing signals of respective units in FIG. 4;

FIG. 6 is a diagram illustrating signals of respective units in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply 3 Inverter 10 Power supply device E Battery Q Capacity meter Tr1, Tr2 Transistor 20, 20 'Limiter circuit 21 Comparator 1 Triangular wave generator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Shiode 1-28-10 Sho, Ibaraki-shi Inside Fujitec Co., Ltd. (72) Inventor Kazunori Hasegawa 23-6 Tsuruwakucho, Jobanshita-cho, Iwaki Furukawa Battery Inside the Iwaki Works Co., Ltd. (72) Shinichi Murakami, inventor 23-6 Tsukuwashi Funao-cho, Iwaki City Furukawa Battery Co., Ltd. Inside the Iwaki Works (72) Inventor Shigeru Nagashima 23, Tsukiwashi Funaocho, Iwaki-shi 6 F-term in Furukawa Battery Co., Ltd. Iwaki Plant 3F002 EA05 EA08 EA09 GA03 GA07 5H007 AA12 BB01 BB06 CA01 CC01 DA05 DB01 DB09 DC02 DC05 EA02

Claims (14)

[Claims] An electric motor of an elevator is controlled by an electric power from a commercial power supply via an inverter. The electric power supply includes a power supply for controlling the input voltage of the inverter to be constant. A power supply device for an AC elevator, comprising: a charging circuit, a discharging circuit, and a capacity meter, wherein means for preventing discharge to the battery under predetermined conditions is provided. 2. An apparatus in which an electric motor of an elevator is controlled by an electric power from a commercial power supply via an inverter and includes a power supply device for controlling an input voltage of the inverter to be constant, wherein the power supply device includes a battery and the battery. A power supply device for an AC elevator, comprising: a charging circuit, a discharging circuit, and a capacity meter, and a means for preventing charging of the battery under predetermined conditions. 3. The power supply device for an AC elevator according to claim 1, wherein the battery is a nickel metal hydride battery. 4. The power supply apparatus for an AC elevator according to claim 1, wherein the battery selects a predetermined number of units according to the capacity of the elevator. 5. The AC elevator power supply device according to claim 1, wherein the predetermined condition is every predetermined time. 6. The power supply device for an AC elevator according to claim 1, wherein the predetermined condition is during a predetermined time. 7. The predetermined condition is a specific day of the week or a specific time zone.
A power supply device for an AC elevator according to claim 1. 8. The power supply apparatus for an AC elevator according to claim 1, wherein the predetermined condition is that the elevator is stopped. 9. The AC elevator according to claim 1, wherein the power supply device includes a current command circuit having a limiter having a function of instructing charging or discharging of a battery. Power supply. 10. The power supply apparatus for an AC elevator according to claim 9, further comprising a charge or discharge prevention means for setting a limiter value on a charge side or a discharge side to zero. 11. The power supply device for an AC elevator according to claim 1, wherein the capacity meter is preset when charging of the battery is completed. 12. The power supply device for an AC elevator according to claim 2, wherein the capacity meter is reset when the discharging of the battery is completed. 13. The power supply device for an AC elevator according to claim 11, wherein the time when the charging of the battery is completed is a time when the voltage of the battery reaches a voltage at which gas is generated. 14. The power supply device for an AC elevator according to claim 12, wherein the time when the discharge of the battery is completed is a time when the battery voltage becomes about 1/3 or less of the rated voltage of the battery.